Revision as of 06:24, 25 June 2008 view sourceSenator Palpatine (talk | contribs)4,929 editsm Undid revision 221599649 by 85.224.131.98 (talk)← Previous edit | Latest revision as of 08:57, 23 January 2025 view source Polyamorph (talk | contribs)Extended confirmed users, Page movers, Pending changes reviewers, Rollbackers29,989 edits →See also: MOS:NOTSEEALSO links are already present in the articleTag: Manual revert | ||
Line 1: | Line 1: | ||
{{ |
{{Short description|Transparent non-crystalline solid material}} | ||
{{About|the material}} | |||
], a natural glass formed by ] impact, from ], ]]] | |||
{{Pp-vandalism|small=yes}} | |||
{{Good article}} | |||
{{Use dmy dates|date=March 2020}} | |||
{{Use British English|date=March 2020}} | |||
] | |||
'''Glass''' is an ] (]) solid. Because it is often ] and chemically inert, glass has found widespread practical, technological, and decorative use in ] panes, ], and ]. Some common objects made of glass are named after the material, e.g., a ] for drinking, "]" for vision correction, and a "]". | |||
]]] | |||
Glass is most often formed by rapid cooling (]) of the ] form. Some glasses such as ] are naturally occurring, and ] has been used to make arrowheads and knives since the ]. Archaeological evidence suggests glassmaking dates back to at least 3600 BC in ], ], or ]. The earliest known glass objects were ], perhaps created accidentally during ] or the production of ], which is a form of pottery using lead glazes. | |||
'''Glass''' in the ''common'' sense refers to a ], ], ] ], such as that used for ]s, many ], or ], including ], ], ], ], ] (Muscovy-glass), or ]. | |||
Due to its ease of ] into any shape, glass has been traditionally used for vessels, such as ], ]s, ]s, jars and drinking glasses. ], containing around 70% ], accounts for around 90% of modern manufactured glass. Glass can be coloured by adding metal salts or painted and printed with ]s, leading to its use in ] windows and other ] objects. | |||
In the ''technical'' sense, glass is an inorganic product of fusion which has been cooled to a rigid condition without crystallizing.<ref>] definition of glass from 1945; also: ] 1259, Glas - Begriffe für Glasarten und Glasgruppen, September 1986</ref><ref name=Zallen83>Zallen, ''The Physics of Amorphous Solids'', John Wiley, New York, (1983).</ref><ref>''The physics of structurally disordered matter: an introduction'', Adam Hilger in association with the University of Sussex press (1987)</ref><ref name=Elliot84>Elliot, ''Physics of amorphous materials'', Longman group ltd (1984)</ref><ref>Horst Scholze: "Glass - Nature, Structure, and Properties"; Springer, 1991, ISBN 0-387-97396-6</ref> Many glasses contain ] as their main component and ''glass former''.<ref name=vogel>Werner Vogel: "Glass Chemistry"; Springer-Verlag Berlin and Heidelberg GmbH & Co. K; 2nd revised edition (November 1994), ISBN 3540575723</ref> | |||
The ], ] and ] properties of glass make glass suitable for manufacturing ], ]s, and ] materials. Extruded ] have applications as ] in communications networks, thermal insulating material when matted as ] to trap air, or in glass-fibre reinforced plastic (]). | |||
In the ''scientific'' sense the term glass is often extended to all ]s (and melts that easily form amorphous solids), including ]s, ]s, or other silica-free amorphous solids. In addition, besides traditional ] techniques, any other means of preparation are considered, such as ], and the ] method.<ref name=vogel/> However, '']'' commonly includes only ] amorphous solids, while plastics and similar organics are covered by ], ] and further scientific disciplines. | |||
== Microscopic structure == | |||
The optical and physical properties of glass make it suitable for applications such as ], ], ] and ] material, ], thermal insulator (]), reinforcement fiber (], ]), and ]. | |||
] in two dimensions. No long-range order is present, although there is local ordering to the ] arrangement of oxygen (O) atoms around the silicon (Si) atoms.|alt=A graphic showing the lack of periodic arrangement in the microscopic structure of glass]] | |||
] has atoms in a near-perfect ] arrangement; a ] is composed of many microscopic crystals; and an ] solid such as glass has no periodic arrangement even microscopically.|alt=A graphic visually showing the difference between the microscopic arrangement of single crystals, polycrystals, and amorphous solids, as explained in the caption]] | |||
{{Main|Structure of liquids and glasses}} | |||
The standard definition of a ''glass'' (or vitreous solid) is a non-crystalline solid formed by rapid melt ].<ref>] definition of glass from 1945</ref><ref name="Zallen83">{{cite book |last=Zallen |first=R. |title=The Physics of Amorphous Solids |publisher=John Wiley |place=New York |year=1983 |pages=1–32|isbn=978-0-471-01968-8}}</ref><ref name="Cusack87">{{Cite book |last=Cusack |first=N.E. |title=The physics of structurally disordered matter: an introduction |publisher=Adam Hilger in association with the University of Sussex press |year=1987 |page=13 |isbn=978-0-85274-829-9}}</ref><ref name="Horst Scholze 1991">{{Cite book |last=Scholze |first=Horst |title=Glass – Nature, Structure, and Properties |publisher=Springer |year=1991 |pages=3–5 |isbn=978-0-387-97396-8}}</ref> However, the term "glass" is often defined in a broader sense, to describe any non-crystalline (]) solid that exhibits a ] when heated towards the liquid state.<ref name="Horst Scholze 1991" /><ref name="Elliot84">{{Cite book |last=Elliot |first=S.R. |title=Physics of Amorphous Materials |publisher=Longman group ltd |year=1984 |pages=1–52 |isbn=0-582-44636-8}}</ref> | |||
Glass is an ]. Although the atomic-scale structure of glass shares characteristics of the structure of a ], glass exhibits all the mechanical properties of a solid.<ref>{{cite web|last=Neumann |first=Florin |url=http://dwb.unl.edu/Teacher/NSF/C01/C01Links/www.ualberta.ca/~bderksen/florin.html |title=Glass: Liquid or Solid – Science vs. an Urban Legend |access-date=8 April 2007 |url-status=dead |archive-url=https://web.archive.org/web/20070409022023/http://dwb.unl.edu/Teacher/NSF/C01/C01Links/www.ualberta.ca/~bderksen/florin.html |archive-date=9 April 2007}}</ref><ref name="Gibbs">{{cite web |last=Gibbs |first=Philip |url=http://math.ucr.edu/home/baez/physics/General/Glass/glass.html |title=Is glass liquid or solid? |access-date=21 March 2007 |url-status=live |archive-url=https://web.archive.org/web/20070329154027/http://math.ucr.edu/home/baez/physics/General/Glass/glass.html |archive-date=29 March 2007}}</ref><ref>"Philip Gibbs" ''Glass Worldwide'', (May/June 2007), pp. 14–18</ref> As in other ]s, the atomic structure of a glass lacks the long-range periodicity observed in ]. Due to ] constraints, glasses do possess a high degree of short-range order with respect to local atomic ].<ref>{{cite journal |last=Salmon |first=P.S. |title=Order within disorder |doi=10.1038/nmat737 |journal=Nature Materials |pmid=12618817 |volume=1 |issue=2 |year=2002 |pages=87–8|s2cid=39062607 |issn = 1476-1122 }}</ref> The notion that glass flows to an appreciable extent over extended periods well below the glass transition temperature is not supported by empirical research or theoretical analysis (see ]). Though atomic motion at glass surfaces can be observed,<ref>{{cite journal |last1=Ashtekar |first1=Sumit |last2=Scott |first2=Gregory |last3=Lyding |first3=Joseph |last4=Gruebele |first4=Martin |year=2010 |title=Direct Visualization of Two-State Dynamics on Metallic Glass Surfaces Well Below Tg |journal=J. Phys. Chem. Lett. |volume=1 |issue=13 |pages=1941–1945 |doi=10.1021/jz100633d |arxiv=1006.1684 |s2cid=93171134 }}</ref> and viscosity on the order of 10<sup>17</sup>–10<sup>18</sup> Pa s can be measured in glass, such a high value reinforces the fact that glass would not change shape appreciably over even large periods of time.<ref name=Elliot84 /><ref>{{cite journal |last1=Vannoni |first1=M. |last2=Sordini |first2=A. |last3=Molesini |first3=G. |year=2011 |title=Relaxation time and viscosity of fused silica glass at room temperature |journal=Eur. Phys. J. E |volume=34 |issue=9 |pages=9–14 |doi=10.1140/epje/i2011-11092-9|pmid=21947892 |s2cid=2246471 }}</ref> | |||
== General properties, uses, occurrence == | |||
] made from ] (])]] | |||
=== Formation from a supercooled liquid === | |||
], using thin sheets of special ]-free<ref>See article: ], TFT-LCD Glass substrates</ref> glass]] | |||
{{Main|Glass transition|Glass formation}} | |||
{{Unsolved |physics |What is the nature of the ] between a fluid or regular solid and a glassy phase? | |||
"The deepest and most interesting unsolved problem in solid state theory is probably the theory of the nature of glass and the glass transition." —]<ref>{{cite journal |last=Anderson |first=P.W. |journal=Science |volume=267 |year=1995 |doi=10.1126/science.267.5204.1615-e |pmid=17808155 |issue=5204 |pages=1615–16 |title=Through the Glass Lightly|s2cid=28052338 }}</ref> }} | |||
For melt quenching, if the cooling is sufficiently rapid (relative to the characteristic ] time) then crystallization is prevented and instead, the disordered atomic configuration of the ] liquid is frozen into the solid state at T<sub>g</sub>. The tendency for a material to form a glass while quenched is called glass-forming ability. This ability can be predicted by the ].<ref name="phillips1979">{{cite journal |last=Phillips |first=J.C. |title=Topology of covalent non-crystalline solids I: Short-range order in chalcogenide alloys |journal=Journal of Non-Crystalline Solids |year=1979 |volume=34 |issue=2 |page=153 |doi=10.1016/0022-3093(79)90033-4 |bibcode=1979JNCS...34..153P }}</ref> Generally, a glass exists in a structurally ] state with respect to its ] form, although in certain circumstances, for example in ] polymers, there is no crystalline analogue of the amorphous phase.<ref name="Folmer">{{cite journal |last1=Folmer |first1=J.C.W. |last2=Franzen |first2=Stefan |title=Study of polymer glasses by modulated differential scanning calorimetry in the undergraduate physical chemistry laboratory |journal=Journal of Chemical Education |year=2003 |volume=80 |issue=7 |page=813 |doi=10.1021/ed080p813 |bibcode=2003JChEd..80..813F}}</ref> | |||
Glass is sometimes considered to be a liquid due to its lack of a first-order ]<ref name=Gibbs /><ref>{{cite web|last=Loy |first=Jim |url=http://www.jimloy.com/physics/glass.htm |title=Glass Is A Liquid? |access-date=21 March 2007 |url-status=dead |archive-url=https://web.archive.org/web/20070314004114/http://www.jimloy.com/physics/glass.htm |archive-date=14 March 2007}}</ref> | |||
Ordinary glass is prevalent due to its transparency to ]. This transparency is due to an absence of electronic ]s in the range of visible light. The ] of the glass on length scales greater than the ] of visible light also contributes to its transparency as heterogeneities would cause light to be ], breaking up any coherent image transmission. Many household objects are made of glass. ], ] and ] are often made of glass, as are ]s, ]s, ], ], computer ]s, and ]s. | |||
where certain ] ] such as ], ] and ] are discontinuous through the glass transition range. The ] may be described as analogous to a second-order phase transition where the intensive thermodynamic variables such as the ] and ] are discontinuous.<ref name=Zallen83 /> However, the equilibrium theory of phase transformations does not hold for glass, and hence the glass transition cannot be classed as one of the classical equilibrium phase transformations in solids.<ref name="Horst Scholze 1991" /><ref name="Elliot84" /> | |||
== Occurrence in nature == | |||
In research ], ], ]s, and other ] are often made of ] for its low ], giving greater resistance to ] and greater accuracy in measurements. For high-temperature applications, ] is used, although it is very difficult to work. Most ] is ], but large laboratories also keep a ] on staff for preparing custom made glass equipment. | |||
{{Main|Volcanic glass|Impactite|Fulgurite}} | |||
Glass can form naturally from volcanic magma. ] is a common volcanic glass with high silica (SiO<sub>2</sub>) content formed when felsic lava extruded from a volcano cools rapidly.<ref>{{cite web|url=https://geology.com/rocks/obsidian.shtml|title=Obsidian: Igneous Rock – Pictures, Uses, Properties|website=geology.com}}</ref> ] is a form of glass formed by the impact of a ], where ] (found in central and eastern Europe), and ] (found in areas in the eastern ], the ] and ]) are notable examples.<ref>{{cite web|url=https://geology.com/meteorites/impactites.shtml|title=Impactites: Impact Breccia, Tektites, Moldavites, Shattercones|website=geology.com}}</ref> ] of ] can also occur when ] strikes ], forming hollow, ] structures called ]s.<ref>{{Cite book|url=https://books.google.com/books?id=cxEEAAAAQAAJ&pg=PA363|title=Land, sea and sky; or, Wonders of life and nature, tr. from the Germ. of H.J. Klein and dr. Thomé, by J. Minshull|last=Klein|first=Hermann Joseph|date=1881-01-01}}</ref> ] is a glassy residue formed from the desert floor sand at the ] ] site.<ref>{{Cite news|url=http://www.atlasobscura.com/articles/trinitite-trinity-test-mineral-cultural-jewelry|title=The Long, Weird Half-Life of Trinitite|last=Giaimo|first=Cara|date=2017-06-30|work=Atlas Obscura|access-date=2017-07-08|language=en|df=mdy-all}}</ref> ], found in ], is proposed to originate from ] grassland fires, ] strikes, or ] by one or several ]s or ]s.<ref>{{cite journal|last1=Roperch |first1=Pierrick |last2=Gattacceca |first2=Jérôme |last3=Valenzuela |first3=Millarca |last4=Devouard |first4=Bertrand |last5=Lorand |first5=Jean-Pierre |last6=Arriagada |first6=Cesar |last7=Rochette |first7=Pierre |last8=Latorre |first8=Claudio |last9=Beck |first9=Pierre |title=Surface vitrification caused by natural fires in Late Pleistocene wetlands of the Atacama Desert|journal=Earth and Planetary Science Letters |volume=469 |issue=1 July 2017 |pages=15–26 |date=2017 |doi=10.1016/j.epsl.2017.04.009|bibcode=2017E&PSL.469...15R |s2cid=55581133 |url=https://hal.archives-ouvertes.fr/hal-02889687 }}</ref> | |||
Sometimes, glass is created naturally from volcanic ], ] strikes, or ] impacts (e.g., ], ], ], ], ]). If the lava is ] this glass is called ], and is usually black with impurities. Obsidian is a raw material for ]s, who have used it to make extremely sharp ] since the ]. | |||
<gallery mode="nolines"> | |||
Glass sometimes occurs in nature resulting from human activity, for example ] (from nuclear testing) and ]. | |||
File:Lipari-Obsidienne (5).jpg|A piece of volcanic ] glass | |||
===Glass in buildings=== | |||
File:Moldavite Besednice.jpg|], a natural glass formed by ] impact, from ], ] | |||
{{main|Architectural Glass|Glazing in architecture|Window}} | |||
File:Fulgurites-algeria.jpg|Tube ] | |||
File:Trinitite from Trinity Site.jpg|], a glass made by the ] | |||
File:Libyan Desert Glass.jpg|] | |||
</gallery> | |||
== History == | |||
] sheets in apartments in ], ].]] | |||
{{Main|History of glass}} | |||
] from the 4th century|alt=Refer to caption]] | |||
Naturally occurring ] glass was used by ] societies as it fractures along very sharp edges, making it ideal for cutting tools and weapons.<ref name="Harvey09">{{Cite book|url=https://books.google.com/books?id=7ig5XnOx4RMC&pg=PA83|pages=83–90|title=Fundamental Building Materials|last=Ward-Harvey|first=K.|date=2009|publisher=Universal-Publishers|isbn=978-1-59942-954-0}}</ref><ref>{{cite web |url=https://www.nationalgeographic.com/news/2015/04/150413-Paleolithic-obsidian-weapons-arteni-armenia-archaeology/ |archive-url=https://web.archive.org/web/20191003025824/https://www.nationalgeographic.com/news/2015/04/150413-Paleolithic-obsidian-weapons-arteni-armenia-archaeology/ |url-status=dead |archive-date=3 October 2019 |title=Digs Reveal Stone-Age Weapons Industry With Staggering Output |date=13 April 2015 |website=National Geographic News}}</ref> | |||
Glassmaking dates back at least 6000 years, long before humans had discovered how to ] iron.<ref name="Harvey09" /> Archaeological evidence suggests that the first true synthetic glass was made in ] and the coastal north ], ] or ].<ref name="Henderson_ancient_glass">{{cite book |author=Julian Henderson |title=Ancient Glass |year=2013 |publisher=Cambridge University Press |doi=10.1017/CBO9781139021883.006 |pages=127–157}}</ref><ref>{{cite web |url=http://www.glassonline.com/infoserv/history.html |title=Glass Online: The History of Glass |access-date=29 October 2007 |url-status=dead |archive-url=https://web.archive.org/web/20111024000436/http://www.glassonline.com/infoserv/history.html |archive-date=24 October 2011 }}</ref> The earliest known glass objects, of the mid-third millennium BC, were ], perhaps initially created as accidental by-products of ] (]s) or during the production of ], a pre-glass ] material made by a process similar to ].<ref>{{cite web |url=https://www.cmog.org/article/life-string-35-centuries-glass-bead |title=All About Glass | Corning Museum of Glass |website=www.cmog.org}}</ref> | |||
Glass is commonly used in buildings as transparent windows, internal glazed partitions, and as architectural features. It is also possible to use glass as a structural material, for example, in beams and columns, as well as in the form of "fins" for wind reinforcement, which are visible in many glass frontages like large shop windows. Safe load capacity is, however, limited; although glass has a high theoretical yield stress, it is very susceptible to brittle (sudden) failure, and has a tendency to shatter upon localized impact. This particularly limits its use in columns, as there is a risk of vehicles or other heavy objects colliding with and shattering the structural element. One well-known example of a structure made entirely from glass is the northern entrance to ] in ]. | |||
Early glass was rarely transparent and often contained impurities and imperfections,<ref name="Harvey09" /> and is technically faience rather than true glass, which did not appear until the 15th century BC.<ref>{{Cite journal|last=Karklins|first=Karlis|title=Simon Kwan – Early Chinese Faience and Glass Beads and Pendants|url=https://www.academia.edu/38201095|journal=BEADS: Journal of the Society of Bead Researchers|date=January 2013|language=en}}</ref> However, red-orange glass beads excavated from the ] dated before 1700 BC (possibly as early as 1900 BC) predate sustained glass production, which appeared around 1600 BC in Mesopotamia and 1500 BC in Egypt.<ref>{{Cite book|last=Kenoyer|first=J.M|url=https://www.harappa.com/sites/default/files/pdf/BeadTechnologiesSummary.pdf |archive-url=https://web.archive.org/web/20190708064827/https://www.harappa.com/sites/default/files/pdf/BeadTechnologiesSummary.pdf |archive-date=2019-07-08 |url-status=live|title=South Asian Archaeology|year=2001|location=Paris|pages=157–170|chapter=Bead Technologies at Harappa, 3300–1900 BC: A Comparative Summary}}</ref><ref>{{Cite book|last=McIntosh|first=Jane|url=https://books.google.com/books?id=1AJO2A-CbccC&q=indus+valley+civilization|title=The Ancient Indus Valley: New Perspectives|date=2008|publisher=ABC-CLIO|isbn=978-1-57607-907-2|pages=99|language=en}}</ref> | |||
Glass in buildings can be of a safety type, including wired, heat strengthened (tempered) and laminated glass. Glass fibre insulation is common in roofs and walls. Foamed glass, made from waste glass, can be used as lightweight, closed-cell insulation. As insulation, glass (e.g., ]) is also used. In the form of long, fluffy-looking sheets, it is commonly found in homes. Fiberglass insulation is used particularly in attics, and is given an R-rating, denoting the insulating ability. | |||
During the ], there was a rapid growth in ] technology in ] and ].<ref name="Henderson_ancient_glass" /> Archaeological finds from this period include coloured glass ], vessels, and beads.<ref name="Henderson_ancient_glass" /><ref>{{cite web |url=https://dailyhistory.org/How_did_Manufactured_Glass_Develop_in_the_Bronze_Age? |title=How did Manufactured Glass Develop in the Bronze Age? - DailyHistory.org |website=dailyhistory.org}}</ref> | |||
===Technological applications=== | |||
]s to large sized ] doped glass ] and glass fibres]] | |||
Much early glass production relied on grinding techniques borrowed from ], such as grinding and carving glass in a cold state.<ref>Wilde, H. "Technologische Innovationen im 2. Jahrtausend v. Chr. Zur Verwendung und Verbreitung neuer Werkstoffe im ostmediterranen Raum". GOF IV, Bd 44, Wiesbaden 2003, 25–26.</ref> | |||
] orbiting above earth, containing ]s]] | |||
The term ''glass'' has its origins in the late ], in the ] making centre at ] (located in current-day Germany) where the ] term ''glesum'' originated, likely from a ] word for a ], ] substance.<ref name="douglas">{{cite book |last=Douglas |first=R.W. |title=A history of glassmaking |publisher=G T Foulis & Co Ltd |place=Henley-on-Thames |year=1972 |isbn=978-0-85429-117-5 |pages=5}}</ref> Glass objects have been recovered across the Roman Empire<ref>{{Cite book |url=https://books.google.com/books?id=bBBkBJN_lJMC&pg=PA45|title=Roman Glass in the Corning Museum of Glass, Volume 3 |last=Whitehouse |first=David |year=2003 |publisher=Hudson Hills |isbn=978-0-87290-155-1 |page=45}}</ref> in domestic, ],<ref>{{Cite book |url=https://books.google.com/books?id=UO5MAQAAMAAJ&pg=PA365|title=The Art Journal |date=1888 |publisher=Virtue and Company |page=365}}</ref> and industrial contexts,<ref>{{Cite journal |url=https://books.google.com/books?id=ouIkAQAAMAAJ&pg=PA259|title=The Manufacture of Glass Milk Bottles |last=Brown |first=A.L. |journal=The Glass Industry |volume=2 |issue=11 |date=November 1921 |publisher=Ashlee Publishing Company |page=259}}</ref> as well as trade items in marketplaces in distant provinces.<ref>Aton, Francesca, '''', Art News, January 25, 2022</ref><ref>McGreevy, Nora, '''', National Geographic, January 28, 2022</ref> Examples of ] have been found outside of the former ] in ],<ref>{{Cite book |url=https://books.google.com/books?id=0zp6iMZoqt0C&pg=PA290|title=Six Dynasties Civilization |last=Dien |first=Albert E. |year=2007 |publisher=Yale University Press |isbn=978-0-300-07404-8 |page=290}}</ref> the ], the ], and ].<ref>{{Cite book |url=https://books.google.com/books?id=xeJMAgAAQBAJ&pg=RA2-PA29|title=The Oxford Companion to Archaeology |last1=Silberman |first1=Neil Asher |last2=Bauer |first2=Alexander A. |year=2012 |publisher=Oxford University Press |isbn=978-0-19-973578-5 |page=29}}</ref> The Romans perfected ], produced by ] and carving through fused layers of different colours to produce a design in relief on the glass object.<ref name="britannica-glass">{{Cite web|url=https://www.britannica.com/technology/glass|title=glass | Definition, Composition, & Facts|website=Encyclopedia Britannica|date=2 October 2023 }}</ref> | |||
Pure ] (the same chemical compound as ], or, in its ] form, ]) does not absorb ] ] and is used for applications that require transparency in this region. '''Large natural single crystals of quartz''' are pure silicon dioxide, and upon crushing are used for high quality specialty glasses. Synthetic amorphous silica, an almost 100 % pure form of quartz, is the raw material for the most expensive specialty glasses, such as ] core. ] have sections doped with ], which ] transmitted signals by ] emission from within the glass itself. Amorphous SiO<sub>2</sub> is also used as a ] material in ]s due to the smooth and electrically neutral interface it forms with ]. | |||
], one of the earliest uses of extensive areas of glass (early 13th-century architecture with restored glass of the 19th century)|alt=Elaborate stained glass windows in the choir of the Basilica of Saint Denis]] | |||
]s such as ], ]s, ], ], and ] are based on glass ], ]s, and ]. The glasses used for making these instruments are categorized using a six-digit ], or alternatively a letter-number code from the ] catalogue. For example, ''BK7'' is a low-] ] ], and ''SF10'' is a high-dispersion dense ]. The glasses are arranged by composition, refractive index, and ]. | |||
In ] West Africa, ] was a manufacturer of glass and glass beads.<ref>Oliver, Roland, and Fagan, Brian M. ''Africa in the Iron Age, c500 B.C. to A.D. 1400''. New York: Cambridge University Press, p. 187. {{ISBN|0-521-20598-0}}.</ref> | |||
Glass ] is a technique that can be used to incorporate additives that modify the properties of glass that would otherwise be destroyed during high temperature preparation. ] is an example of glass polymerization and enables embedding of organic and bioactive molecules, to add a new level of functionality to glass.<ref></ref> | |||
Glass was used extensively in Europe during the ]. ] has been found across England during archaeological excavations of both settlement and cemetery sites.<ref>{{Cite book |url=https://books.google.com/books?id=idAVBAAAQBAJ&pg=PP1 |title=Neighbours and Successors of Rome: Traditions of Glass Production and use in Europe and the Middle East in the Later 1st Millennium AD |last1=Keller |first1=Daniel |last2=Price |first2=Jennifer |last3=Jackson |first3=Caroline |year=2014 |publisher=Oxbow Books |isbn=978-1-78297-398-0 |pages=1–41}}</ref> From the 10th century onwards, glass was employed in ] of churches and ]s, with famous examples at ] and the ]. By the 14th century, architects were designing buildings with walls of ] such as ], Paris, (1203–1248) and the East end of ]. With the change in architectural style during the ] period in Europe, the use of large stained glass windows became much less prevalent,<ref>{{Cite book |url=https://archive.org/details/discoveringstain0000tuta |url-access=registration |title=Discovering Stained Glass in Detroit |last1=Tutag |first1=Nola Huse |last2=Hamilton |first2=Lucy |date=1987 |publisher=Wayne State University Press |isbn=978-0-8143-1875-1 |pages=}}</ref> although stained glass had a major revival with ] in the 19th century.<ref>{{Cite book |url=https://archive.org/details/encyclopediaofam00hunt |url-access=registration |title=Encyclopedia of American architecture |last1=Packard |first1=Robert T. |last2=Korab |first2=Balthazar |last3=Hunt |first3=William Dudley |date=1980 |publisher=McGraw-Hill |isbn=978-0-07-048010-0 |pages=}}</ref> | |||
During the 13th century, the island of ], ], became a centre for glass making, building on medieval techniques to produce colourful ornamental pieces in large quantities.<ref name=britannica-glass /> ] makers developed the exceptionally clear colourless glass ], so called for its resemblance to natural crystal, which was extensively used for windows, mirrors, ships' lanterns, and lenses.<ref name="Harvey09" /> In the 13th, 14th, and 15th centuries, enamelling and ] on glass vessels were perfected in Egypt and Syria.<ref name="EB1911-incorp" /> Towards the end of the 17th century, ] became an important region for glass production, remaining so until the start of the 20th century. By the 17th century, glass in the Venetian tradition was also being produced in ]. In about 1675, ] invented ] glass, with ] becoming fashionable in the 18th century.<ref name=britannica-glass /> Ornamental glass objects became an important art medium during the ] period in the late 19th century.<ref name="britannica-glass" /> | |||
==Glass production== | |||
{{main|Glass production|Float glass}} | |||
Throughout the 20th century, new ] techniques led to the widespread availability of glass in much larger amounts, making it practical as a building material and enabling new applications of glass.<ref>{{Cite book |url=https://books.google.com/books?id=jm9hGqECbXcC&pg=PA705 |title=Global Roadmap for Ceramic and Glass Technology |last=Freiman |first=Stephen |year=2007 |publisher=John Wiley & Sons |isbn=978-0-470-10491-0 |pages=705}}</ref> In the 1920s a ]-etch process was developed, in which art was etched directly into the mould so that each cast piece emerged from the mould with the image already on the surface of the glass. This reduced manufacturing costs and, combined with a wider use of coloured glass, led to cheap glassware in the 1930s, which later became known as ].<ref>{{cite web |title=Depression Glass |url=http://www.glassonweb.com/articles/article/201/ |access-date=2007-10-19 |archive-date=2 December 2014 |archive-url=https://web.archive.org/web/20141202110304/http://www.glassonweb.com/articles/article/201/ |url-status=dead }}</ref> In the 1950s, ], ], developed the ] process, producing high-quality distortion-free flat sheets of glass by floating on molten ].<ref name="Harvey09" /> Modern multi-story buildings are frequently constructed with ] made almost entirely of glass.<ref>{{Cite book |url=https://books.google.com/books?id=b_PmZAzJecYC&pg=PT187 |title=Sustainable Renovation: Strategies for Commercial Building Systems and Envelope |last1=Gelfand |first1=Lisa |last2=Duncan |first2=Chris |year=2011 |publisher=John Wiley & Sons |pages=187 |isbn=978-1-118-10217-6}}</ref> ] has been widely applied to vehicles for windscreens.<ref>{{Cite book |url=https://books.google.com/books?id=g-YCKEPYMpYC&pg=PA274 |title=Photodermatology |last1=Lim |first1=Henry W. |last2=Honigsmann |first2=Herbert |last3=Hawk |first3=John L.M. |year=2007 |publisher=CRC Press |pages=274 |isbn=978-1-4200-1996-4}}</ref> Optical glass for spectacles has been used since the Middle Ages.<ref>{{cite book|title=The Properties of Optical Glass|first1=Hans|last1=Bach|first2=Norbert|last2=Neuroth|publisher=Springer|year=2012|url=https://books.google.com/books?id=y3nnCAAAQBAJ&pg=PA267|isbn=978-3-642-57769-7|pages=267}}</ref> The production of lenses has become increasingly proficient, aiding ]s<ref>{{cite book |first1=Ian S. |last1=McLean |title=Electronic Imaging in Astronomy: Detectors and Instrumentation |url=https://books.google.com/books?id=FGHhZf-k8SkC&pg=PA78 |publisher=Springer Science & Business Media |year=2008 |pages=78 |isbn=978-3-540-76582-0}}</ref> as well as having other applications in medicine and science.<ref name="glassalliance">{{cite web|url=https://www.glassallianceeurope.eu/en/applications |title=Glass Applications – Glass Alliance Europe |publisher=Glassallianceeurope.eu |access-date=2020-03-01}}</ref> Glass is also employed as the aperture cover in many ] collectors.<ref>{{Cite book |url=https://books.google.com/books?id=QNTKBQAAQBAJ&pg=PA122 |title=Solar Energy Sciences and Engineering Applications |last1=Enteria |first1=Napoleon |last2=Akbarzadeh |first2=Aliakbar |pages=122 |year=2013 |publisher=CRC Press |isbn=978-0-203-76205-9}}</ref> | |||
] from ], ], Sweden. In the middle the mark from the ] pipe]] | |||
===Glass production history=== | |||
In the 21st century, glass manufacturers have developed different brands of ] for widespread application in ]s for ]s, ]s, and many other types of ]s. These include ], developed and manufactured by ], ]'s ] and ]'s Xensation.<ref>{{cite web |url=http://www.physnews.com/materials-news/cluster251747226/ |title=Gorilla Glass maker unveils ultra-thin and flexible Willow Glass |work=Physics News |access-date=2013-11-01 |url-status=dead |archive-url=https://web.archive.org/web/20131106075448/http://www.physnews.com/materials-news/cluster251747226/ |archive-date=6 November 2013 }}</ref><ref>{{cite web |url=http://www.schott.com/xensation/english/index.html |title=Xensation |publisher=] |access-date=2013-11-01 |url-status=live |archive-url=https://web.archive.org/web/20131103224742/http://www.schott.com/xensation/english/index.html |archive-date=2013-11-03 }}</ref><ref name="gensix">{{cite web |url=https://www.engadget.com/2018/07/18/corning-unveils-gorilla-glass-6/ |title=Gorilla Glass 6 gives phones a better shot at surviving multiple drops |publisher=Engadget |date=19 July 2018 |first=Jon |last=Fingas }}</ref> | |||
Glass melting technology has passed through several stages:<ref name=ullmann>B. H. W. S. de Jong, "Glass"; in "Ullmann's Encyclopedia of Industrial Chemistry"; 5th edition, vol. A12, VCH Publishers, Weinheim, Germany, 1989, ISBN 3-527-20112-5, p 365-432.</ref> | |||
== Physical properties == | |||
* Glass was manufactured in open pits, ca. 3000 B.C. until the invention of the blowpipe in ca. 250 B.C. | |||
=== Optical === | |||
{{Main|Optical glass}} | |||
Glass is in widespread use in optical systems due to its ability to refract, reflect, and transmit light following ]. The most common and oldest applications of glass in optics are as ], ]s, ]s, and ]s.<ref name="Bach12">{{cite book |title=The Properties of Optical Glass |first1=Hans |last1=Bach |first2=Norbert |last2=Neuroth |publisher=Springer |year=2012|url=https://books.google.com/books?id=y3nnCAAAQBAJ&pg=PA1 |pages=1–11 |isbn=978-3-642-57769-7}}</ref> The key optical properties ], ], and ], of glass are strongly dependent on chemical composition and, to a lesser degree, its thermal history.<ref name=Bach12 /> Optical glass typically has a refractive index of 1.4 to 2.4, and an ] (which characterises dispersion) of 15 to 100.<ref name=Bach12 /> The refractive index may be modified by high-density (refractive index increases) or low-density (refractive index decreases) additives.<ref>{{Cite book |url=https://books.google.com/books?id=-0DOBQAAQBAJ&pg=PA70 |title=Physical Properties of Materials, Second Edition |last=White |first=Mary Anne |authorlink1=Mary Anne White |year=2011 |pages=70 |publisher=CRC Press|isbn=978-1-4398-9532-0}}</ref> | |||
Glass transparency results from the absence of ] which ] in polycrystalline materials.<ref name="Carter-Norton">{{Cite book |url=https://books.google.com/books?id=aE_VQ8I24OoC&pg=PA583 |title=Ceramic Materials: Science and Engineering |last1=Carter |first1=C. Barry |first2=M. Grant |last2= Norton |year=2007| publisher=Springer Science & Business Media| pages=583|isbn=978-0-387-46271-4 }}</ref> Semi-opacity due to crystallization may be induced in many glasses by maintaining them for a long period at a temperature just insufficient to cause fusion. In this way, the crystalline, devitrified material, known as Réaumur's glass ] is produced.<ref name="EB1911-incorp">{{EB1911|inline=1 |wstitle=Glass |volume=12 |page=86}}</ref><ref name="Mysen05">{{cite book|last1=Mysen|first1=Bjorn O.|last2=Richet|first2=Pascal|title=Silicate Glasses and Melts: Properties and Structure|publisher=Elsevier|year=2005|pages=10}}</ref> Although generally transparent to visible light, glasses may be ] to other ]. While silicate glasses are generally opaque to ] wavelengths with a transmission cut-off at 4 μm, heavy-metal ] and ] glasses are transparent to infrared wavelengths of 7 to 18 μm.<ref name=brittanica-industrial /> The addition of metallic oxides results in different coloured glasses as the metallic ions will absorb wavelengths of light corresponding to specific colours.<ref name=brittanica-industrial /> | |||
* The mobile wood-fired melting pot furnace was used until around the 17th century by traveling glass manufacturers. | |||
=== Other === | |||
* Around 1688, a process for ] glass was developed, which led to glass becoming a much more commonly used material.{{Fact|date=December 2007}} | |||
{{See also|List of physical properties of glass|Corrosion#Corrosion of glass|Strength of glass}} | |||
] | |||
In the manufacturing process, glasses can be poured, formed, extruded and moulded into forms ranging from flat sheets to highly intricate shapes.<ref>{{Cite book |url=https://books.google.com/books?id=BZUtFQNuNgMC&pg=PA60 |title=Handbook of Physical Vapor Deposition (PVD) Processing |last=Mattox |first=D.M. |year=2014 |page=60 |publisher=Cambridge University Press |isbn=978-0-08-094658-0}}</ref> The finished product is brittle but can be ] or ] to enhance durability.<ref>{{Cite book|url=https://books.google.com/books?id=D7Z8ywb3QggC&pg=PA361|title=Glasses and the Vitreous State|last=Zarzycki|first=Jerzy|year=1991|publisher=Cambridge University Press|isbn=978-0-521-35582-7|pages=361}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=CL8Z38FaPsAC&pg=PA365|title=Collision Repair and Refinishing: A Foundation Course for Technicians|last1=Thomas|first1=Alfred|last2=Jund|first2=Michael|year=2013|pages=365|publisher=Cengage Learning |isbn=978-1-133-60187-6}}</ref> Glass is typically inert, resistant to chemical attack, and can mostly withstand the action of water, making it an ideal material for the manufacture of containers for foodstuffs and most chemicals.<ref name="Harvey09" /><ref name="Gardner-1949">{{Cite book|url=https://books.google.com/books?id=yYQ3BMs9Ql0C&pg=PA13|title=Research and Development in Applied Optics and Optical Glass at the National Bureau of Standards: A Review and Bibliography|last1=Gardner|first1=Irvine Clifton|last2=Hahner|first2=Clarence H.|date=1949|publisher=U.S. Government Printing Office|page=13|isbn=9780598682413}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=rJTBCQAAQBAJ&pg=PA550|title=Food Safety in the 21st Century: Public Health Perspective|last1=Dudeja|first1=Puja|last2=Gupta|first2=Rajul K.| page=550 |last3=Minhas|first3=Amarjeet Singh|year=2016|publisher=Academic Press|isbn=978-0-12-801846-0}}</ref> Nevertheless, although usually highly resistant to chemical attack, glass will corrode or dissolve under some conditions.<ref name="Gardner-1949" /><ref name="Bengisu 2013">{{Cite book|url=https://books.google.com/books?id=PXD8CAAAQBAJ&pg=PA360|title=Engineering Ceramics|last=Bengisu|first=M.|year=2013|publisher=Springer Science & Business Media|isbn=978-3-662-04350-9|page=360}}</ref> The materials that make up a particular glass composition affect how quickly the glass corrodes. Glasses containing a high proportion of ] or ] elements are more susceptible to corrosion than other glass compositions.<ref>{{Cite book|url=https://books.google.com/books?id=IVe7CgAAQBAJ&pg=PA141|title=Materials Degradation and Its Control by Surface Engineering|last1=Batchelor|first1=Andrew W.|last2=Loh|first2=Nee Lam|last3=Chandrasekaran|first3=Margam|year=2011|publisher=World Scientific|page=141|isbn=978-1-908978-14-1}}</ref><ref name="Chawla93">{{Cite book|url=https://books.google.com/books?id=_NXYRgHnnqkC&pg=PA328|pages=327–328|title=Materials Selection for Corrosion Control|last=Chawla|first=Sohan L.|date=1993|publisher=ASM International|isbn=978-1-61503-728-5}}</ref> | |||
The density of glass varies with chemical composition with values ranging from {{convert|2.2|g/cm3|kg/m3}} for ] to {{convert|7.2|g/cm3|kg/m3}} for dense flint glass.<ref>{{cite Q|Q87511351}}<!--"Density of Glass" in The Physics Factbook--></ref> Glass is stronger than most metals, with a theoretical ] for pure, flawless glass estimated at {{convert|14|to|35|GPa|psi}} due to its ability to undergo reversible compression without fracture. However, the presence of scratches, bubbles, and other microscopic flaws lead to a typical range of {{convert|14|to|175|MPa|psi}} in most commercial glasses.<ref name="brittanica-industrial">{{Cite web|url=https://www.britannica.com/topic/glass-properties-composition-and-industrial-production-234890|title=Industrial glass – Properties of glass|website=Encyclopedia Britannica}}</ref> Several processes such as ] can increase the strength of glass.<ref>{{cite web|url=https://www.pilkington.com/en-gb/uk/architects/glass-information/functions-of-glass/mechanicalfunctionsofglass/glass-strength|title=Glass Strength|website=www.pilkington.com|access-date=2017-11-24|url-status=live|archive-url=https://web.archive.org/web/20170726123604/http://www.pilkington.com/en-gb/uk/architects/glass-information/functions-of-glass/mechanicalfunctionsofglass/glass-strength|archive-date=26 July 2017}}</ref> Carefully drawn flawless ]s can be produced with a strength of up to {{convert|11.5|GPa|psi}}.<ref name=brittanica-industrial /> | |||
* The local pot furnace, fired by wood and coal was used between 1600 and 1850. | |||
{{Further|topic=the tiny glass flakes formed during glass vial manufacturing |Spicule (glass manufacture)|label1=Spicule}} | |||
=== Reputed flow === | |||
* The ] of creating ] was used in the ] for the first time in the 1820s. It was used to commercially produce windows.{{Fact|date=December 2007}} | |||
The observation that old windows are sometimes found to be thicker at the bottom than at the top is often offered as supporting evidence for the view that glass flows over a timescale of centuries, the assumption being that the glass has exhibited the liquid property of flowing from one shape to another.<ref>{{cite news|url=https://www.nytimes.com/2008/07/29/science/29glass.html?ex=1375070400&en=048ade4011756b24&ei=5124&partner=permalink&exprod=permalink|title=The Nature of Glass Remains Anything but Clear|work=The New York Times|access-date=29 July 2008|date=29 July 2008|author=Kenneth Chang|url-status=live|archive-url=https://web.archive.org/web/20090424094929/http://www.nytimes.com/2008/07/29/science/29glass.html?ex=1375070400&en=048ade4011756b24&ei=5124&partner=permalink&exprod=permalink|archive-date=24 April 2009}}</ref> This assumption is incorrect, as once solidified, glass stops flowing. The sags and ripples observed in old glass were already there the day it was made; manufacturing processes used in the past produced sheets with imperfect surfaces and non-uniform thickness (the near-perfect ] used today only became widespread in the 1960s).<ref name=Gibbs /> | |||
A 2017 study computed the rate of flow of the medieval glass used in ] from the year 1268. The study found that the room temperature viscosity of this glass was roughly 10<sup>24</sup>{{nbsp}}]·] which is about 10<sup>16</sup> times less viscous than a previous estimate made in 1998, which focused on soda-lime silicate glass. Even with this lower viscosity, the study authors calculated that the maximum flow rate of medieval glass is 1 ] per billion years, making it impossible to observe in a human timescale.<ref>{{cite journal | last1=Gulbiten | first1=Ozgur | last2=Mauro | first2=John C. | last3=Guo | first3=Xiaoju | last4=Boratav | first4=Olus N. | title=Viscous flow of medieval cathedral glass | journal=Journal of the American Ceramic Society| volume=101 | issue=1 | date=3 August 2017 | issn=0002-7820 | doi=10.1111/jace.15092 | pages=5–11}}</ref><ref>{{Cite web |title=Glass viscosity calculations definitively debunk the myth of observable flow in medieval windows |last=Gocha |first=April |work=The American Ceramic Society |date=3 August 2017 |url= https://ceramics.org/ceramic-tech-today/glass-viscosity-calculations-definitively-debunk-the-myth-of-observable-flow-in-medieval-windows}}</ref> | |||
* The invention of the glass pressing machine in 1827 allowed the mass production of inexpensive glass products<ref>http://www.redsofts.com/articles/read/151/61135/Cut_Glass_And_Glass_Blowing_History_And_Development.html</ref>. | |||
== Types == | |||
* The gas-heated melting pot and tank furnaces dating from 1860, followed by the electric furnace of 1910. | |||
=== Silicate glasses === | |||
] (silica) is the main raw material in commercial glass production|alt=Close-up photograph of sand]] | |||
] (SiO<sub>2</sub>) is a common fundamental constituent of glass. ] is a glass made from chemically pure silica.<ref name="Chawla93" /> It has very low thermal expansion and excellent resistance to ], being able to survive immersion in water while red hot, resists high temperatures (1000–1500 °C) and chemical weathering, and is very hard. It is also transparent to a wider spectral range than ordinary glass, extending from the visible further into both the ] and ] ranges, and is sometimes used where transparency to these wavelengths is necessary. Fused quartz is used for high-temperature applications such as furnace tubes, lighting tubes, melting crucibles, etc.<ref name="Seafriends-1994">{{cite web|url=http://www.seafriends.org.nz/oceano/seasand.htm|title=Mining the sea sand|url-status=live|archive-url=https://web.archive.org/web/20120229061512/http://www.seafriends.org.nz/oceano/seasand.htm|archive-date=29 February 2012|website=Seafriends|date=1994-02-08|access-date=2012-05-15}}</ref> However, its high melting temperature (1723 °C) and viscosity make it difficult to work with. Therefore, normally, other substances (fluxes) are added to lower the melting temperature and simplify glass processing.<ref name="Chemistry-explained">{{cite web|url=http://www.chemistryexplained.com/Ge-Hy/Glass.html|access-date=1 April 2015|title=Glass – Chemistry Encyclopedia|url-status=live|archive-url=https://web.archive.org/web/20150402113454/http://www.chemistryexplained.com/Ge-Hy/Glass.html|archive-date=2 April 2015}}</ref> | |||
==== Soda–lime glass ==== | |||
* Hand-blown ] was replaced in the 20th century by rolled plate glass.{{Fact|date=December 2007}} | |||
{{Main|Soda–lime glass}} | |||
] (Na<sub>2</sub>CO<sub>3</sub>, "soda") is a common additive and acts to lower the glass-transition temperature. However, ] is ], so ] (CaO, ], generally obtained from ]), along with ] (MgO), and ] (Al<sub>2</sub>O<sub>3</sub>), are commonly added to improve chemical durability. Soda–lime glasses (Na<sub>2</sub>O) + lime (CaO) + magnesia (MgO) + alumina (Al<sub>2</sub>O<sub>3</sub>) account for over 75% of manufactured glass, containing about 70 to 74% silica by weight.<ref name="Chawla93" /><ref name="ullmann">B.H.W.S. de Jong, "Glass"; in "Ullmann's Encyclopedia of Industrial Chemistry"; 5th edition, vol. A12, VCH Publishers, Weinheim, Germany, 1989, {{ISBN|978-3-527-20112-9}}, pp. 365–432.</ref> Soda–lime–silicate glass is transparent, easily formed, and most suitable for window glass and tableware.<ref name="Spence-2016">{{Cite book|url=https://books.google.com/books?id=KX5TCwAAQBAJ&pg=PA509|title=Construction Materials, Methods and Techniques|last1=Spence|first1=William P.|last2=Kultermann|first2=Eva|year=2016|publisher=Cengage Learning|isbn=978-1-305-08627-2|pages=510–526}}</ref> However, it has a high thermal expansion and poor resistance to heat.<ref name="Spence-2016" /> Soda–lime glass is typically used for ]s, ]s, ]s, and ]s.<ref name="Chemistry-explained" /> | |||
==== Borosilicate glass ==== | |||
* The ] process was invented in the 1950s. | |||
] ] ] |alt=Refer to caption]] | |||
]es (e.g. ], ]) typically contain 5–13% ] (B<sub>2</sub>O<sub>3</sub>).<ref name="Chemistry-explained" /> Borosilicate glasses have fairly low ] (7740 Pyrex CTE is 3.25{{e|-6}}/°C<ref>{{cite web|url=http://www.quartz.com/pxprop.pdf|title=Properties of PYREX®, PYREXPLUS® and Low Actinic PYREX Code 7740 Glasses|publisher=Corning, Inc.|url-status=live|archive-url=https://web.archive.org/web/20120113050839/http://www.quartz.com/pxprop.pdf|archive-date=13 January 2012|access-date=2012-05-15}}</ref> as compared to about 9{{e|-6}}/°C for a typical soda–lime glass<ref>{{cite web|url=http://www.us.schott.com/tubing/media/selector/datasheets/english/schott-tubing_datasheet_ar-glas_english.pdf|title=AR-GLAS® Technical Data|url-status=live|archive-url=https://web.archive.org/web/20120612224929/http://www.us.schott.com/tubing/media/selector/datasheets/english/schott-tubing_datasheet_ar-glas_english.pdf|archive-date=12 June 2012|publisher=Schott, Inc.}}</ref>). They are, therefore, less subject to ] caused by ] and thus less vulnerable to ] from ]. They are commonly used for e.g. ], ], and sealed beam car ]s.<ref name="Chemistry-explained" /> | |||
=== |
==== Lead glass ==== | ||
{{Main|Lead glass}}{{See also|Lead poisoning}} | |||
] (silica) as main raw material for commercial glass production]] | |||
The addition of ] into silicate glass lowers the melting point and ] of the melt.<ref>{{Cite book |url=https://books.google.com/books?id=ZeF_QLW6-xsC&pg=PA125 |title=Introduction to Glass Science and Technology |last=Shelby |first=J.E. |year=2017 |page=125 |publisher=Royal Society of Chemistry |isbn=978-0-85404-639-3}}</ref> The high density of lead glass (silica + lead oxide (PbO) + potassium oxide (K<sub>2</sub>O) + soda (Na<sub>2</sub>O) + zinc oxide (ZnO) + alumina) results in a high electron density, and hence high refractive index, making the look of glassware more brilliant and causing noticeably more ] and increased ].<ref name="Chawla93" /><ref name="Schwartz-2002">{{Cite book |url=https://books.google.com/books?id=0ETMBQAAQBAJ&pg=PA352 |title=Encyclopedia of Materials, Parts and Finishes |edition=Second |last=Schwartz |first=Mel |year=2002 |page =352 |publisher=CRC Press |isbn=978-1-4200-1716-8}}</ref> Lead glass has a high elasticity, making the glassware more workable and giving rise to a clear "ring" sound when struck. However, lead glass cannot withstand high temperatures well.<ref name="Seafriends-1994" /> Lead oxide also facilitates the solubility of other metal oxides and is used in coloured glass. The viscosity decrease of lead glass melt is very significant (roughly 100 times in comparison with soda glass); this allows easier removal of bubbles and working at lower temperatures, hence its frequent use as an additive in ]s and ]s. The high ] of the Pb<sup>2+</sup> ion renders it highly immobile and hinders the movement of other ions; lead glasses therefore have high electrical resistance, about two orders of magnitude higher than soda–lime glass (10<sup>8.5</sup> vs 10<sup>6.5</sup> Ω⋅cm, ] at 250 °C).<ref>{{Cite book|url=https://books.google.com/books?id=ASIYuNCp81YC&pg=PA158|title=Ceramic and Glass Materials: Structure, Properties and Processing|last1=Shackelford|first1=James F.|last2=Doremus|first2=Robert H.|date=2008-04-12|publisher=Springer Science & Business Media|isbn=978-0-387-73362-3 |page=158}}</ref> | |||
==== Aluminosilicate glass ==== | |||
Pure ] (SiO<sub>2</sub>) has a "glass melting point"— at a ] of 10 ] (100 ])— of over 2300 ] (4200 ]). While pure silica can be made into glass for special applications (see ]), other substances are added to common glass to simplify processing. One is ] (Na<sub>2</sub>CO<sub>3</sub>), which lowers the melting point to about 1500 °C (2700 °F) in ]; "]" refers to the original source of sodium carbonate in the ] obtained from certain plants. However, the soda makes the glass water soluble, which is usually undesirable, so ] (] (CaO), generally obtained from ]), some magnesium oxide (MgO) and aluminium oxide are added to provide for a better chemical durability. The resulting glass contains about 70 to 74 percent silica by weight and is called a ].<ref name=ullmann/> Soda-lime glasses account for about 90 percent of manufactured glass. | |||
Aluminosilicate glass typically contains 5–10% ] (Al<sub>2</sub>O<sub>3</sub>). Aluminosilicate glass tends to be more difficult to melt and shape compared to borosilicate compositions but has excellent thermal resistance and durability.<ref name="Chemistry-explained" /> Aluminosilicate glass is extensively used for ],<ref name="Askeland-2008">{{Cite book|url=https://books.google.com/books?id=TL4j-jDXsk0C&pg=PA485|title=Essentials of Materials Science & Engineering|last1=Askeland|first1=Donald R.|last2=Fulay|first2=Pradeep P.|year=2008|page=485|publisher=Cengage Learning|isbn=978-0-495-24446-2}}</ref> used for making glass-reinforced plastics (boats, fishing rods, etc.), top-of-stove cookware, and halogen bulb glass.<ref name="Seafriends-1994" /><ref name="Chemistry-explained" /> | |||
==== Other oxide additives ==== | |||
As well as soda and lime, most common glass has other ingredients added to change its properties. ] glass, such as ] or ], is more 'brilliant' because the increased ] causes noticeably more "sparkles", while ] may be added to change the thermal and electrical properties, as in ]. Adding ] also increases the refractive index. ] gives glass a high refractive index and low dispersion, and was formerly used in producing high-quality lenses, but due to its ] has been replaced by ] in modern glasses. Large amounts of ] are used in glass that absorbs ] energy, such as heat absorbing filters for movie projectors, while ] can be used for glass that absorbs ] wavelengths (biologically damaging ionizing radiation). | |||
The addition of ] also increases the refractive index. ] gives glass a high refractive index and low dispersion and was formerly used in producing high-quality lenses, but due to its ] has been replaced by ] in modern eyeglasses.<ref>{{cite web|url=http://www.historyofglass.com/glass-making-process/glass-ingredients/|title=Glass Ingredients – What is Glass Made Of?|website=www.historyofglass.com|access-date=2017-04-23|url-status=live|archive-url=https://web.archive.org/web/20170423155431/http://www.historyofglass.com/glass-making-process/glass-ingredients/|archive-date=23 April 2017}}</ref> Iron can be incorporated into glass to absorb ] radiation, for example in heat-absorbing filters for movie projectors, while ] can be used for glass that absorbs ] wavelengths.<ref>{{cite book |last=Pfaender |first=Heinz G. |title=Schott guide to glass |url=https://books.google.com/books?id=v5q4Hje3iFgC&pg=PA135 |access-date=8 February 2011 |year=1996 |publisher=Springer |isbn=978-0-412-62060-7 |pages=135, 186 |url-status=live |archive-url=https://web.archive.org/web/20130525185349/http://books.google.com/books?id=v5q4Hje3iFgC&pg=PA135 |archive-date=25 May 2013}}</ref> ] lowers the ] of glass. Fluorine is highly ] and lowers the polarizability of the material. Fluoride silicate glasses are used in the manufacture of ]s as an insulator.<ref>{{cite book |last1=Doering |first1=Robert |last2=Nishi |first2=Yoshio |url=https://books.google.com/books?id=PsVVKz_hjBgC&pg=SA12-PA3 |title=Handbook of semiconductor manufacturing technology |pages=12–13 |publisher=CRC Press |year=2007 |isbn=978-1-57444-675-3}}</ref> | |||
==== Glass-ceramics ==== | |||
Besides the chemicals mentioned, in some furnaces recycled glass ("cullet") is added, originating from the same factory or other sources. Cullet leads to savings not only in the raw materials, but also in the energy consumption of the glass furnace. However, impurities in the cullet may lead to product and equipment failure. Fining agents such as ], ], or ] are added to reduce the bubble content in the glass.<ref name=ullmann/> | |||
{{Main|Glass-ceramic}} | |||
] with negligible ] |alt=A cooktop with two of its eyes turned on]] | |||
] materials contain both non-crystalline glass and ] ] phases. They are formed by controlled nucleation and partial crystallisation of a base glass by heat treatment.<ref name="Holand-glass-ceramics">{{cite book |url=https://books.google.com/books?id=Bw_Yz52jdFQC&pg=PA1 |title=Glass Ceramic Technology |last1=Holand |first1=Wolfram |last2=Beall |first2=George H. |year=2012 |pages=1–38 |publisher=John Wiley & Sons |isbn=978-1-118-26592-5}}</ref> Crystalline grains are often embedded within a non-crystalline intergranular phase of ]. Glass-ceramics exhibit advantageous thermal, chemical, biological, and dielectric properties as compared to metals or organic polymers.<ref name=Holand-glass-ceramics /> | |||
The most commercially important property of glass-ceramics is their imperviousness to thermal shock. Thus, glass-ceramics have become extremely useful for countertop cooking and industrial processes. The negative ] coefficient (CTE) of the crystalline ceramic phase can be balanced with the positive CTE of the glassy phase. At a certain point (~70% crystalline) the glass-ceramic has a net CTE near zero. This type of ] exhibits excellent mechanical properties and can sustain repeated and quick temperature changes up to 1000 °C.<ref name="MOD">{{cite book |last=Richerson |first=David W. |title=Modern ceramic engineering : properties, processing and use in design |year=1992 |publisher=Dekker |pages=577–578 |location=New York |isbn=978-0-8247-8634-2 |edition=2nd}}</ref><ref name=Holand-glass-ceramics /> | |||
A further raw material used in the production of soda-lime and fiber glass is calumite, which is a glassy granular by-product of the iron making industry, containing mainly silica, calcium oxide, alumina, magnesium oxide (and traces of iron oxide).<ref></ref> | |||
==== Fibreglass ==== | |||
For obtaining the desired glass composition, the correct raw material mixture (batch) must be determined by ]. | |||
{{Main|Fiberglass|Glass wool}} | |||
] (also called glass fibre reinforced plastic, GRP) is a ] made by reinforcing a plastic ] with ]s. It is made by melting glass and stretching the glass into fibres. These fibres are woven together into a cloth and left to set in a plastic resin.<ref name="Parkyn">{{cite book |url=https://books.google.com/books?id=gfEkBQAAQBAJ&pg=PA3 |title=Glass Reinforced Plastics |last=Parkyn |first=Brian |publisher=Elsevier |year=2013 |pages=3–41|isbn=978-1-4831-0298-6 }}</ref><ref>{{cite book |last= Mayer |first= Rayner M. |title= Design with reinforced plastics |page= 7 |publisher= Springer |year= 1993 |url= https://books.google.com/books?id=XQFJego9nGUC&pg=PA7 |isbn= 978-0-85072-294-9}}</ref><ref name="propertiesofmatter">{{cite web|url=http://www.propertiesofmatter.si.edu/teamwork.html|title=Properties of Matter Reading Selection: Perfect Teamwork|website=www.propertiesofmatter.si.edu|access-date=2017-04-25|url-status=dead|archive-url=https://web.archive.org/web/20160512174222/http://www.propertiesofmatter.si.edu/teamwork.html|archive-date=12 May 2016}}</ref> | |||
Fibreglass has the properties of being lightweight and corrosion resistant and is a good ] enabling its use as ] and for electronic housing for consumer products. Fibreglass was originally used in the United Kingdom and United States during ] to manufacture ]s. Uses of fibreglass include building and construction materials, boat hulls, car body parts, and aerospace composite materials.<ref name="brittanica-fibreglass">{{Cite web|url=https://www.britannica.com/technology/fiberglass|title=Fibreglass | glass|website=Encyclopedia Britannica|date=28 August 2024 }}</ref><ref name=Parkyn /><ref name=propertiesofmatter /> | |||
] is an excellent ] and ] insulation material, commonly used in buildings (e.g. ] and ]), and plumbing (e.g. ]), and ].<ref name=brittanica-fibreglass /> It is produced by forcing molten glass through a fine mesh by ] and breaking the extruded glass fibres into short lengths using a stream of high-velocity air. The fibres are bonded with an adhesive spray and the resulting wool mat is cut and packed in rolls or panels.<ref name=brittanica-industrial /> | |||
===Contemporary glass production=== | |||
=== Non-silicate glasses === | |||
Following the ] preparation and mixing the raw materials are transported to the furnace. ] for mass production is melted in ]. Smaller scale furnaces for specialty glasses include electric melters, pot furnaces and day tanks.<ref name=ullmann/> | |||
] (CD). ] forms the basis of rewritable CD and DVD solid-state memory technology.<ref name="Greer05">{{cite journal |last1=Greer |first1=A. Lindsay |doi=10.1038/4371246a |journal=Nature |volume=437 |pages=1246–1247 |year=2005 |title=Materials science: Changing Face of the Chameleon |pmid=16251941 |last2=Mathur |first2=N |issue=7063 |bibcode=2005Natur.437.1246G|s2cid=6972351 |doi-access=free }}</ref>|alt=A CD]] | |||
Besides common silica-based glasses many other ] and ] materials may also form glasses, including ], ]s, ]s, ]s, ], ]s, germanates (glasses based on ]), tellurites (glasses based on TeO<sub>2</sub>), antimonates (glasses based on Sb<sub>2</sub>O<sub>3</sub>), arsenates (glasses based on As<sub>2</sub>O<sub>3</sub>), titanates (glasses based on TiO<sub>2</sub>), tantalates (glasses based on Ta<sub>2</sub>O<sub>5</sub>), ]s, ]s, ], ], and many other substances.<ref name="Elliot84" /> Some of these glasses (e.g. ] (GeO<sub>2</sub>, Germania), in many respects a structural analogue of silica, ], ], ], ], and ] glasses) have physicochemical properties useful for their application in ] ]s in communication networks and other specialised technological applications.<ref>{{Cite book|url=https://books.google.com/books?id=gL-RDgAAQBAJ&pg=PA214|title=Technological Advances in Tellurite Glasses: Properties, Processing, and Applications|last1=Rivera|first1=V. A. G.|last2=Manzani|first2=Danilo|date=2017-03-30|publisher=Springer|isbn=978-3-319-53038-3|page=214|language=en}}</ref><ref>{{Cite journal | |||
|last1=Jiang|first1=Xin|last2=Lousteau|first2=Joris|last3=Richards|first3=Billy|last4=Jha|first4=Animesh|date=2009-09-01 | |||
|title=Investigation on germanium oxide-based glasses for infrared optical fibre development | |||
|journal=Optical Materials|volume=31|issue=11|pages=1701–1706|doi=10.1016/j.optmat.2009.04.011 |bibcode=2009OptMa..31.1701J | |||
}}</ref> | |||
Silica-free glasses may often have poor glass-forming tendencies. Novel techniques, including containerless processing by ] (cooling the melt whilst it floats on a gas stream) or ] (pressing the melt between two metal anvils or rollers), may be used to increase the cooling rate or to reduce crystal nucleation triggers.<ref>{{cite journal|author1=J. W. E. Drewitt|author2=S. Jahn|author3=L. Hennet|title=Configurational constraints on glass formation in the liquid calcium aluminate system|journal=Journal of Statistical Mechanics: Theory and Experiment|year=2019|volume=2019|issue=10|page=104012|doi=10.1088/1742-5468/ab47fc|arxiv=1909.07645|bibcode=2019JSMTE..10.4012D|s2cid=202583753}}</ref><ref>{{cite journal|author1=C. J. Benmore |author2=J. K. R. Weber|year=2017|title=Aerodynamic levitation, supercooled liquids and glass formation|journal=Advances in Physics: X|volume=2|issue=3|pages=717–736|doi= 10.1080/23746149.2017.1357498|bibcode=2017AdPhX...2..717B|doi-access=free}}</ref><ref>{{cite journal|last=Davies|first=H. A.|author2=Hull J. B. |title=The formation, structure and crystallization of non-crystalline nickel produced by splat-quenching|journal=Journal of Materials Science|year=1976|volume=11|issue=2|pages=707–717|doi=10.1007/BF00551430|bibcode=1976JMatS..11..215D|s2cid=137403190}}</ref> | |||
After melting, homogenization and refining (removal of bubbles) the glass is ]. Flat glass for windows and similar applications is formed by the ] process, developed between 1953 and 1957 by Sir ] and Kenneth Bickerstaff of the UK's Pilkington Brothers, which created a continuous ribbon of glass using a molten tin bath on which the molten glass flows unhindered under the influence of gravity. | |||
Container glass for common bottles and jars is formed by ] methods. Further glass forming techniques are summarized in the table ]. | |||
==== Amorphous metals ==== | |||
Once the desired form is obtained, glass is usually ] for the removal of stresses. | |||
{{Main|Amorphous metal}} | |||
] | |||
In the past, small batches of ]s with high surface area configurations (ribbons, wires, films, etc.) have been produced through the implementation of extremely rapid rates of cooling. Amorphous metal wires have been produced by sputtering molten metal onto a spinning metal disk.<ref name=klement60>{{cite journal | last1=Klement | first1=W. Jr. |last2=Willens |first2=R.H. |last3=Duwez |first3=Pol |doi=10.1038/187869b0 |title=Non-crystalline Structure in Solidified Gold-Silicon Alloys |year=1960 |journal=Nature |volume=187 |issue=4740 |page=869| bibcode=1960Natur.187..869K |s2cid=4203025 }}</ref><ref name=lieb76>{{cite journal |last1=Liebermann |first1=H. |last2=Graham |first2=C. |doi=10.1109/TMAG.1976.1059201 |title=Production of Amorphous Alloy Ribbons and Effects of Apparatus Parameters on Ribbon Dimensions |journal=IEEE Transactions on Magnetics |year=1976 |volume=12 |issue=6 |page=921 |bibcode=1976ITM....12..921L}}</ref> | |||
Several alloys have been produced in layers with thicknesses exceeding 1 millimetre. These are known as bulk metallic glasses (BMG). ] sells several ]-based BMGs. | |||
Various surface treatment techniques, coatings, or ] may follow to improve the chemical durability (], ]), strength (], ], ]s), or optical properties (], ]). | |||
Batches of amorphous steel have also been produced that demonstrate mechanical properties far exceeding those found in conventional steel alloys.<ref name=ponn04>{{cite journal |last1=Ponnambalam |first1=V. |last2=Poon |first2=S. Joseph |last3=Shiflet |first3=Gary J. |title=Fe-based bulk metallic glasses with diameter thickness larger than one centimeter |journal=Journal of Materials Research |year=2004 |volume=19 |issue=5 |page=1320 |doi=10.1557/JMR.2004.0176 |bibcode=2004JMatR..19.1320P|s2cid=138846816 }}</ref> | |||
===Glassmaking in the laboratory=== | |||
Experimental evidence indicates that the system Al-Fe-Si may undergo a ''first-order transition'' to an amorphous form (dubbed "q-glass") on rapid cooling from the melt. ] (TEM) images indicate that q-glass nucleates from the melt as discrete particles with uniform spherical growth in all directions. While ] reveals the isotropic nature of q-glass, a ] barrier exists implying an interfacial discontinuity (or internal surface) between the glass and melt phases.<ref>{{cite web|url=http://www.metallurgy.nist.gov/techactv2004/TechnicalHighlights.html#glass|title=Metallurgy Division Publications|work=NIST Interagency Report 7127|url-status=live|archive-url=https://web.archive.org/web/20080916063500/http://www.metallurgy.nist.gov/techactv2004/TechnicalHighlights.html#glass|archive-date=16 September 2008}}</ref><ref>{{cite journal |last1=Mendelev |first1=M.I. |last2=Schmalian |first2=J. |last3=Wang |first3=C.Z. |last4=Morris |first4=J.R. |author5=K.M. Ho |doi=10.1103/PhysRevB.74.104206 |bibcode=2006PhRvB..74j4206M |title=Interface Mobility and the Liquid-Glass Transition in a One-Component System |year=2006 |journal=Physical Review B |volume=74 |issue=10|page=104206 |url=https://zenodo.org/record/1233751 }}</ref> | |||
] disposal at ].]] | |||
==== Polymers ==== | |||
].]] | |||
Important ] glasses include amorphous and glassy pharmaceutical compounds. These are useful because the solubility of the compound is greatly increased when it is amorphous compared to the same crystalline composition. Many emerging pharmaceuticals are practically insoluble in their crystalline forms.<ref>{{cite web|url=http://www-ics.u-strasbg.fr/etsp//research/glass/field.php|archive-url=https://web.archive.org/web/20160525003628/http://www-ics.u-strasbg.fr/etsp/research/glass/field.php|url-status=dead|title=A main research field: Polymer glasses|archive-date=25 May 2016|website=www-ics.u-strasbg.fr}}</ref> Many polymer ]s familiar to everyday use are glasses. For many applications, like ] or ], polymer glasses (], ] or ]) are a lighter alternative to traditional glass.<ref name="Carraher-polymer">{{cite book|url=https://books.google.com/books?id=_izOBgAAQBAJ&q=polymer%20glass%20lighter%20alternative&pg=PA274|title=Introduction to Polymer Chemistry|first=Charles E. Jr.|last=Carraher|year=2012|pages=274|publisher=CRC Press|isbn=978-1-4665-5495-5}}</ref> | |||
=== Molecular liquids and molten salts === | |||
New chemical glass compositions or new treatment techniques can be initially investigated in small-scale ] experiments. The raw materials for laboratory-scale glass melts are often different from those used in mass production because the cost factor has a low priority. In the laboratory mostly pure ] are used. Care must be taken that the raw materials have not reacted with moisture or other chemicals in the environment (such as ] oxides and hydroxides, ] oxides and hydroxides, or ]), or that the impurities are quantified (loss on ignition).<ref name=pnnl></ref> Evaporation losses during glass melting should be considered during the selection of the raw materials, e.g., sodium selenite may be preferred over easily evaporating ]. Also, more readily reacting raw materials may be preferred over relatively ] ones, such as ] over ]. Usually, the melts are carried out in platinum crucibles to reduce contamination from the crucible material. Glass ] is achieved by homogenizing the raw materials mixture (]), by stirring the melt, and by crushing and re-melting the first melt. The obtained glass is usually ] to prevent breakage during processing.<ref name=pnnl/><ref></ref> | |||
Molecular liquids, ]s, ]s, and ]s are mixtures of different ] or ]s that do not form a covalent network but interact only through weak ]s or transient ]s. In a mixture of three or more ionic species of dissimilar size and shape, crystallization can be so difficult that the liquid can easily be supercooled into a glass.<ref>{{Cite book|page=21|chapter-url=https://books.google.com/books?id=-ajaBwAAQBAJ&pg=PA21|chapter=Crystals, Supercooled Liquids, and Glasses in Frozen Aqueous Solutions|first1=S.L.|last1=Ruby|first2=I.|last2=Pelah|title=Mössbauer Effect Methodology: Volume 6 Proceedings of the Sixth Symposium on Mössbauer Effect Methodology New York City, January 25, 1970|editor-last=Gruverman|editor-first=Irwin J.|year=2013|publisher=Springer Science & Business Media|isbn=978-1-4684-3159-9}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=om31BwAAQBAJ&pg=PA226|title=Water Relationships in Foods: Advances in the 1980s and Trends for the 1990s|last1=Levine|first1=Harry|last2=Slade|first2=Louise|author-link2=Louise Slade|year=2013|publisher=Springer Science & Business Media|isbn=978-1-4899-0664-9|page=226}}</ref> Examples include LiCl:''R''H<sub>2</sub>O (a solution of ] salt and water molecules) in the composition range 4<''R''<8.<ref>{{Cite journal|vauthors=Dupuy J, Jal J, Prével B, Aouizerat-Elarby A, Chieux P, Dianoux AJ, Legrand J|s2cid=39468740|date=October 1992|title=Vibrational dynamics and structural relaxation in aqueous electrolyte solutions in the liquid, undercooled liquid and glassy states|journal=Journal de Physique IV |volume=2|issue=C2|pages=C2-179–C2-184|doi=10.1051/jp4:1992225|bibcode=1992JPhy4...2C.179D|url=https://hal.archives-ouvertes.fr/jpa-00251296/file/ajp-jp4199202C225.pdf |archive-url=https://web.archive.org/web/20200509082002/https://hal.archives-ouvertes.fr/jpa-00251296/file/ajp-jp4199202C225.pdf |archive-date=2020-05-09 |url-status=live}} European Workshop on Glasses and Gels.</ref> ],<ref>{{Cite book|url=https://books.google.com/books?id=uk66BAAAQBAJ&pg=PA38|title=Candy Bites: The Science of Sweets|last1=Hartel|first1=Richard W.|last2=Hartel|first2=AnnaKate|year=2014|page=38|publisher=Springer Science & Business Media|isbn=978-1-4614-9383-9}}</ref> or Ca<sub>0.4</sub>K<sub>0.6</sub>(NO<sub>3</sub>)<sub>1.4</sub>.<ref>{{cite journal|author=Charbel Tengroth|title=Structure of Ca0.4K0.6(NO3)1.4 from the glass to the liquid state|journal=Phys. Rev. B|volume=64|page=224207|year=2001|issue=22|doi=10.1103/PhysRevB.64.224207|bibcode=2001PhRvB..64v4207T}}</ref> Glass electrolytes in the form of Ba-doped Li-glass and Ba-doped Na-glass have been proposed as solutions to problems identified with organic liquid electrolytes used in modern lithium-ion battery cells.<ref>{{cite web|url=http://fortune.com/2017/03/05/lithium-ion-battery-goodenough/|title=Lithium-Ion Pioneer Introduces New Battery That's Three Times Better|website=Fortune|access-date=2017-05-06|url-status=live|archive-url=https://web.archive.org/web/20170409193506/http://fortune.com/2017/03/05/lithium-ion-battery-goodenough/|archive-date=9 April 2017}}</ref> | |||
== Production == | |||
See also: ], ] | |||
{{Main|Glass production|Float glass|Glassblowing}} | |||
] | |||
] | |||
Following the ] preparation and mixing, the raw materials are transported to the furnace. ] for ] is melted in ]s. Smaller-scale furnaces for speciality glasses include electric melters, pot furnaces, and day tanks.<ref name=ullmann /> | |||
After melting, homogenization and ] (removal of bubbles), the glass is ]. This may be achieved manually by ], which involves gathering a mass of hot semi-molten glass, inflating it into a bubble using a hollow blowpipe, and forming it into the required shape by blowing, swinging, rolling, or moulding. While hot, the glass can be worked using hand tools, cut with shears, and additional parts such as handles or feet attached by welding.<ref name="Brittanica-glass-blowing">{{Britannica|235045|Glassblowing}}</ref> | |||
] for windows and similar applications is formed by the ] process, developed between 1953 and 1957 by Sir ] and Kenneth Bickerstaff of the UK's Pilkington Brothers, who created a continuous ribbon of glass using a molten tin bath on which the molten glass flows unhindered under the influence of gravity. The top surface of the glass is subjected to nitrogen under pressure to obtain a polished finish.<ref>{{cite web|url=http://www.pfg.co.za/about%20glass.htm |title=PFG Glass |publisher=Pfg.co.za |access-date=24 October 2009 |url-status=dead |archive-url=https://web.archive.org/web/20091106210357/http://www.pfg.co.za/about%20glass.htm |archive-date=6 November 2009}}</ref> ] for common bottles and jars is formed by ] methods.<ref>{{Cite book|url=https://books.google.com/books?id=Kbxv0oPJPK4C&pg=PA449|title=Code of Federal Regulations, Title 40,: Protection of Environment, Part 60 (Sections 60.1-end), Revised As of July 1, 2011|date=October 2011|publisher=Government Printing Office|isbn=978-0-16-088907-3}}</ref> This glass is often slightly modified chemically (with more alumina and calcium oxide) for greater water resistance.<ref>{{Cite book|url=https://books.google.com/books?id=Pwvtj9jJd6wC&pg=PA552|title=Leachables and Extractables Handbook: Safety Evaluation, Qualification, and Best Practices Applied to Inhalation Drug Products|last1=Ball|first1=Douglas J.|last2=Norwood|first2=Daniel L.|last3=Stults|first3=Cheryl L. M.|last4=Nagao|first4=Lee M.|date=2012-01-24|publisher=John Wiley & Sons|isbn=978-0-470-17365-7|page=552|language=en}}</ref> | |||
Once the desired form is obtained, glass is usually ] for the removal of stresses and to increase the glass's hardness and durability.<ref name="EB1911">{{Cite EB1911|wstitle=Glass|volume=12|pages=87–105}}</ref> Surface treatments, coatings or ] may follow to improve the chemical durability (], ]), strength (], ], ]s<ref>{{cite web|url= https://www.autoglassguru.com/blog/windshields-how-theyre-made/ |title= windshields how they are made|publisher=autoglassguru |access-date=2018-02-09}}</ref>), or optical properties (], ]).<ref>{{cite web|url=https://www.lehigh.edu/imi/teched/GlassProcess/Lectures/Lecture10_Pantano_Surface_Treatments.pdf |archive-url=https://web.archive.org/web/20150909081808/http://www.lehigh.edu/imi/teched/GlassProcess/Lectures/Lecture10_Pantano_Surface_Treatments.pdf |archive-date=2015-09-09 |url-status=live|title=Glass Surface Treatments: Commercial Processes Used in Glass Manufacture|last=Pantano|first=Carlo}}</ref> | |||
==Silica-free glasses== | |||
Besides common ]-based glasses, many other ] and ] materials may also form glasses, including ] (e.g., ]), ], ], carbon dioxide (see below), ]s, ]s, ], ]s, germanates (glasses based on ]), tellurites (glasses based on TeO<sub>2</sub>), antimonates (glasses based on Sb<sub>2</sub>O<sub>3</sub>), arsenates (glasses based on As<sub>2</sub>O<sub>3</sub>), titanates (glasses based on TiO<sub>2</sub>), tantalates (glasses based on Ta<sub>2</sub>O<sub>5</sub>), ]s, ]s and many other substances.<ref name=vogel/> | |||
New chemical glass compositions or new treatment techniques can be initially investigated in small-scale laboratory experiments. The raw materials for laboratory-scale glass melts are often different from those used in mass production because the cost factor has a low priority. In the laboratory mostly pure ]s are used. Care must be taken that the raw materials have not reacted with moisture or other chemicals in the environment (such as ] or ] oxides and hydroxides, or ]), or that the impurities are quantified (loss on ignition).<ref name="pnnl">{{cite web|url=http://depts.washington.edu/mti/1999/labs/glass_ceramics/mst_glass.html |title=Glass melting, Pacific Northwest National Laboratory |publisher=Depts.washington.edu |access-date=24 October 2009 |url-status=dead |archive-url=https://web.archive.org/web/20100505144629/http://depts.washington.edu/mti/1999/labs/glass_ceramics/mst_glass.html |archive-date=5 May 2010}}</ref> Evaporation losses during glass melting should be considered during the selection of the raw materials, e.g., ] may be preferred over easily evaporating ] (SeO<sub>2</sub>). Also, more readily reacting raw materials may be preferred over relatively ] ones, such as ] (Al(OH)<sub>3</sub>) over ] (Al<sub>2</sub>O<sub>3</sub>). Usually, the melts are carried out in platinum crucibles to reduce contamination from the crucible material. Glass ] is achieved by homogenizing the raw materials mixture (]), stirring the melt, and crushing and re-melting the first melt. The obtained glass is usually ] to prevent breakage during processing.<ref name=pnnl /><ref>{{cite web |last=Fluegel |first=Alexander |url=http://glassproperties.com/melting/ |title=Glass melting in the laboratory |publisher=Glassproperties.com |access-date=24 October 2009 |url-status=live |archive-url=https://web.archive.org/web/20090213120553/http://glassproperties.com/melting/ |archive-date=13 February 2009}}</ref> | |||
Some glasses that do not include silica as a major constituent may have physico-chemical properties useful for their application in ] and other specialized technical applications. These include fluorozirconate, fluoroaluminate, ], ] and ]es. | |||
=== Colour === | |||
Under extremes of pressure and temperature solids may exhibit large structural and physical changes which can lead to ] phase transitions.<ref>McMillan, P.F. Journal of Materials Chemistry, '''14''', 1506-1512 (2004)</ref> In 2006 Italian scientists created an amorphous phase of ] using extreme pressure. The substance was named ](a-CO<sub>2</sub>) and exhibits an atomic structure resembling that of Silica.<ref> 15 June 2006, www.newscientisttech.com. Retrieved 3 August 2006</ref> | |||
{{Main|Glass coloring and color marking}} | |||
Colour in glass may be obtained by addition of homogenously distributed electrically charged ions (or ]). While ordinary ] appears colourless in thin section, ] (FeO) impurities produce a green tint in thick sections.<ref name="Mukherjee13">{{cite book|last=Mukherjee|first=Swapna|title=The Science of Clays: Applications in Industry, Engineering, and Environment|publisher=Springer Science & Business Media|year=2013|pages=142|url=https://books.google.com/books?id=wALFBAAAQBAJ&pg=PA142|isbn=978-9-4007-6683-9}}</ref> ] (MnO<sub>2</sub>), which gives glass a purple colour, may be added to remove the green tint given by FeO.<ref>{{Cite book|title=CRC Handbook of Metal Etchants|last1=Walker|first1=Perrin|last2=Tarn|first2=William H.|publisher=CRC press|year=1990|page=798|isbn=978-1-4398-2253-1|url=https://books.google.com/books?id=-2ObmTZTq2QC&pg=PA798}}</ref> FeO and ] (Cr<sub>2</sub>O<sub>3</sub>) additives are used in the production of green bottles.<ref name="Mukherjee13" /> ], on the other-hand, produces yellow or yellow-brown glass.<ref name="Langhamer03">{{cite book|url=https://books.google.com/books?id=UwLCa_h3hTEC&pg=PA273|title=The Legend of Bohemian Glass: A Thousand Years of Glassmaking in the Heart of Europe|first=Antonín|last=Langhamer|pages=273|year=2003|publisher=Tigris|isbn=978-8-0860-6211-2}}</ref> Low concentrations (0.025 to 0.1%) of ] (CoO) produce rich, deep blue ].<ref>{{cite journal |title=3. Glass, Colour and the Source of Cobalt |url=https://intarch.ac.uk/journal/issue52/3/3.html |website=Internet Archaeology |doi=10.11141/ia.52.3}}</ref> ] is a very powerful colouring agent, yielding dark green.<ref> {{Webarchive|url=https://web.archive.org/web/20170815033017/http://www.speclab.com/elements/chromium.htm |date=2017-08-15 }} www.speclab.com.</ref> | |||
==The physics of glass== | |||
] combined with ] and iron salts produces amber glass ranging from yellowish to almost black.<ref>David M Issitt. 1st.glassman.com.</ref> A glass melt can also acquire an amber colour from a reducing combustion atmosphere.<ref>{{Cite book|url=https://books.google.com/books?id=-mwoDwAAQBAJ&pg=PA211|title=Introduction to Glass Science and Technology|last=Shelby|first=James E.|year=2007|page=211|publisher=Royal Society of Chemistry|isbn=978-1-84755-116-0}}</ref> ] produces imperial ], and combined with selenium can produce shades of yellow, orange, and red.<ref name="Mukherjee13" /><ref name="Langhamer03" /> Addition of ] (CuO) produces a ] colour in glass, in contrast to ] (Cu<sub>2</sub>O) which gives a dull red-brown colour.<ref name="Nicholson00">{{cite book|url=https://books.google.com/books?id=Vj7A9jJrZP0C&pg=PA208|title=Ancient Egyptian Materials and Technology|first1=Paul T.|last1=Nicholson|first2=Ian|last2=Shaw|publisher=Cambridge University Press|year=2000|pages=208|isbn=978-0-521-45257-1}}</ref> | |||
] arrangement of Oxygen (O) atoms around the Silicon (Si) atoms.]] | |||
<!-- WORKING ON FINDING MORE SUITABLE REFERENCES FOR THIS | |||
The standard definition of a glass (or ] solid) requires the solid phase to be formed by rapid melt quenching.<ref name=Zallen83/><ref name=Cusack87>Cusack, ''The physics of structurally disordered matter: an introduction'', Adam Hilger in association with the University of Sussex press (1987)</ref><ref name=Elliot84/> Glass is therefore formed via a ] liquid and cooled sufficiently rapidly (relative to the characteristic ] time) from its molten state through its ], T<sub>g</sub>, that the supercooled disordered atomic configuration at T<sub>g</sub>, is frozen into the solid state. Generally, the structure of a glass exists in a ] state with respect to its ] form, although in certain circumstances, for example in ] polymers, there is no crystalline analogue of the amorphous phase <ref name=Folmer>"Folmer, J. C. W.; Franzen, Stefan." Study of polymer glasses by modulated differential scanning calorimetry in the undergraduate physical chemistry laboratory. Journal of Chemical Education (2003), 80(7), 813-818. CODEN: JCEDA8 ISSN:0021-9584. </ref>. By definition as an ], the atomic structure of a glass lacks any long range ]. However, by virtue of the local ] constraints glasses do possess a high degree of short-range order with respect to local atomic ]<ref>Salmon, P.S., ''Order within disorder'', Nature Materials, '''1'''(87), (2002)</ref>. It is deemed that the bonding structure of glasses, although disordered, has the same symmetry signature (]) as for crystalline materials<ref>M.I. Ojovan, W.E. Lee. Topologically disordered systems at the glass transition. ''J. Phys.: Condensed Matter'', '''18''', 11507-11520 (2006)</ref>. | |||
* ], depending on the concentration, produces blue, or ], or even ] glass. ] with added nickel acquires purplish colour. Nickel together with a small amount of cobalt was used for decolourizing of ]. --> | |||
<gallery mode="nolines"> | |||
File:Bottle, wine (AM 1997.80.28-1).jpg|alt=A green glass bottle|] and ] additives are often used in the production of green bottles.<ref name="Mukherjee13" /> | |||
File:Bristol.blue.glass.arp.750pix.jpg|alt=Several examples of deep blue glass|] produces rich, ], such as ]. | |||
File:Colour Eclipse, Danny Lane.jpg|alt=Three glass disks, with one coloured turquoise, another purple, and a third coloured red|Different oxide additives produce the different colours in glass: ] (]),<ref name="Nicholson00" /> purple (]),<ref name="Mukherjee13" /> and red (]).<ref name="Mukherjee13" /> | |||
File:Chinese snuff bottle, Qing dynasty, glass bottle with amber stopper, Honolulu Museum of Art.JPG|Red glass bottle with yellow glass overlay | |||
File:Glass ornaments.JPG|Amber-coloured glass | |||
File:Glass garland bowl MET DP122006.jpg|Four-colour Roman glass bowl, manufactured {{Circa|1st century B.C.}} | |||
</gallery> | |||
== Uses == | |||
===Glass versus a supercooled liquid=== | |||
=== Architecture and windows === | |||
{{Main|Architectural glass|Window}} | |||
Soda–lime ] is typically used as a transparent ] material, typically as ]s in external walls of buildings. Float or rolled sheet glass products are cut to size either by ] and snapping the material, ], ], or ]d saw. The glass may be thermally or chemically ] (strengthened) for ] and bent or curved during heating. Surface coatings may be added for specific functions such as scratch resistance, blocking specific wavelengths of light (e.g. ] or ]), dirt-repellence (e.g. ]), or switchable ] coatings.<ref name="Weller12">{{cite book|url=https://books.google.com/books?id=NXXTAAAAQBAJ&q=glass%20in%20buildings&pg=PA1|title=Glass in Building: Principles, Applications, Examples|last1=Weller|first1=Bernhard|last2=Unnewehr|first2=Stefan|last3=Tasche|first3=Silke|last4=Härth|first4=Kristina|year=2012|pages=1–19|publisher=Walter de Gruyter|isbn=978-3-0346-1571-6}}</ref> | |||
Structural glazing systems represent one of the most significant architectural innovations of modern times, where glass buildings now often dominate the ]s of many modern ].<ref name="glass-times">{{cite web|url=https://glasstimes.co.uk/featured-articles/the-rise-of-glass-buildings/ |title=The rise of glass buildings |work=Glass Times|date=9 January 2017 |access-date=2020-03-01}}</ref> These systems use stainless steel fittings countersunk into recesses in the corners of the glass panels allowing strengthened panes to appear unsupported creating a flush exterior.<ref name="glass-times" /> Structural glazing systems have their roots in iron and ] of the nineteenth century<ref name="Patterson">{{cite book|title=Structural Glass Facades and Enclosures|last=Patterson|first=Mic|url=https://books.google.com/books?id=qsqi2jdH7ecC&pg=PT29|publisher=Jon Wiley & Sons|year=2011|pages=29|isbn=978-0-470-93185-1}}</ref> | |||
Glass is generally treated as an ] rather than a liquid, though both views can be justified.<ref name=Gibbs>{{cite web| url = http://math.ucr.edu/home/baez/physics/General/Glass/glass.html| title = Is glass liquid or solid? | accessdate = 2007-03-21| author = Philip Gibbs}}</ref> However, the notion that glass flows to an appreciable extent over extended periods of time is not supported by empirical research or theoretical analysis (see ]). From a more commonsense point of view, glass should be considered a solid since it is rigid according to everyday experience.<ref>"Philip Gibbs" ''Glass Worldwide'', (may/june 2007), pp 14-18</ref> | |||
=== Tableware === | |||
Some people consider glass to be a liquid due to its lack of a first-order ] <ref name=Gibbs/><ref>{{cite web| url = http://www.jimloy.com/physics/glass.htm| title = Glass Is A Liquid? | accessdate = 2007-03-21| author = Jim Loy}}</ref> where certain ] ] such as ], ] and ] are continuous through the glass transition temperature. However, the glass transition temperature may be described as analogous to a second-order phase transition where the intensive thermodynamic variables such as the ] and ] are discontinuous. Despite this, thermodynamic phase transition theory does not entirely hold for glass, and hence the glass transition cannot be classed as a genuine thermodynamic phase transition.<ref name=Elliot84/> | |||
{{Main|Tableware|List of glassware}} | |||
Glass is an essential component of tableware and is typically used for water, ] and ] drinking glasses.<ref name="glassalliance" /> Wine glasses are typically ], i.e. goblets formed from a bowl, stem, and foot. Crystal or ] glass may be cut and polished to produce decorative drinking glasses with gleaming facets.<ref>{{cite journal|title=Lead, glass and the environment |first1=Michael|last1=Hynes|first2=Bo|last2=Jonson|year=1997|journal=Chemical Society Reviews|volume=26|issue=2|page=145|doi=10.1039/CS9972600133}}</ref><ref>{{Cite web|url=https://www.britannica.com/art/cut-glass|title=Cut glass | decorative arts|website=Encyclopedia Britannica}}</ref> Other uses of glass in tableware include ], ]s, ], and ]s.<ref name="glassalliance" /> | |||
<gallery mode="nolines"> | |||
File:Jubilee Campus MMB «62 Melton Hall Christmas Dinner.jpg|Wine glasses and other glass tableware | |||
Although the ]ic structure of glass shares characteristics of the structure in a ], glass is generally classed as solid below its glass transition temperature.<ref>{{cite web| url = http://dwb.unl.edu/Teacher/NSF/C01/C01Links/www.ualberta.ca/~bderksen/florin.html| title = Glass: Liquid or Solid -- Science vs. an Urban Legend | accessdate = 2007-04-08| author = Florin Neumann}}</ref> There is also the problem that a supercooled liquid is still a liquid and not a solid but it is below the freezing point of the material and will crystallize almost instantly if a crystal is added as a ]. The change in ] at a ] and a ] of comparable materials are typically of the same order of magnitude indicating that the change in active ] is comparable as well. Both in a glass and in a crystal it is mostly only the ]al degrees of freedom that remain active, whereas ] and ] motion becomes impossible explaining why glasses and crystalline materials are hard. | |||
File:British dimpled glass pint jug with ale.jpg|Dimpled glass beer pint jug | |||
File:Crystal glass.jpg|] | |||
File:Decanter and Stopper LACMA 56.35.29a-b.jpg|A glass ] and ] | |||
</gallery> | |||
=== |
=== Packaging === | ||
{{Main|Container glass}} | |||
The inert and impermeable nature of glass makes it a stable and widely used material for food and drink packaging as ]s and ]s. Most ] is ], produced by ] techniques. Container glass has a lower ] and ] content than flat glass, and a higher ], ], and ] content.<ref name=seward>"High temperature glass melt property database for process modeling"; Eds.: Thomas P. Seward III and Terese Vascott; The American Ceramic Society, Westerville, Ohio, 2005, {{ISBN|1-57498-225-7}}</ref> Its higher content of water-insoluble oxides imparts slightly higher ] against water, which is advantageous for storing beverages and food. Glass packaging is sustainable, readily recycled, reusable and refillable.<ref>{{Cite web|url=https://feve.org/about-glass/|title=Why choose Glass?|website=FEVE}}</ref> | |||
For electronics applications, glass can be used as a substrate in the manufacture of ], ]s, and as a ]ing material in device packaging,<ref>{{cite book |last1=Sun |first1=P. |last2=et |first2=al. |title=2018 19th International Conference on Electronic Packaging Technology (ICEPT) |chapter=Design and Fabrication of Glass-based Integrated Passive Devices |doi=10.1109/ICEPT.2018.8480458 |year=2018 |pages=59–63 |isbn=978-1-5386-6386-8 |s2cid=52935909 }}</ref><ref>{{cite book |last1=Letz |first1=M. |last2=et |first2=al. |title=2018 IEEE 68th Electronic Components and Technology Conference (ECTC) |chapter=Glass in Electronic Packaging and Integration: High Q Inductances for 2.35 GHZ Impedance Matching in 0.05 mm Thin Glass Substrates |doi=10.1109/ECTC.2018.00167 |year=2018 |pages=1089–1096 |isbn=978-1-5386-4999-2 |s2cid=51972637 }}</ref> including very thin solely glass based encapsulation of integrated circuits and other semiconductors in high manufacturing volumes.<ref>{{cite book |last1=Lundén |first1=H. |last2=et |first2=al. |title=Proceedings of the 5th Electronics System-integration Technology Conference (ESTC) |chapter=Novel glass welding technique for hermetic encapsulation |year=2014 |doi=10.1109/ESTC.2014.6962719 |pages=1–4 |isbn=978-1-4799-4026-4 |s2cid=9980556 }}</ref> | |||
The observation that old windows are often thicker at the bottom than at the top is often offered as supporting evidence for the view that glass flows over a matter of centuries. It is then assumed that the glass was once uniform, but has flowed to its new shape, which is a property of liquid. The likely source of this unfounded belief is that when panes of glass were commonly made by ], the technique used was to spin molten glass so as to create a round, mostly flat and even plate (the ] process, described above). This plate was then cut to fit a window. The pieces were not, however, absolutely flat; the edges of the disk would be thicker because of ] relaxation. When actually installed in a window frame, the glass would be placed thicker side down for the sake of stability and visual sparkle.<ref></ref> Occasionally such glass has been found thinner side down or on either side of the window's edge, as would be caused by carelessness at the time of installation. | |||
=== Laboratories === | |||
Mass production of glass window panes in the early twentieth century caused a similar effect. In glass factories, molten glass was poured onto a large cooling table and allowed to spread. The resulting glass is thicker at the location of the pour, located at the center of the large sheet. These sheets were cut into smaller window panes with nonuniform thickness. Modern glass intended for windows is produced as ] and is very uniform in thickness. | |||
{{Main|Laboratory glassware}} | |||
Glass is an important material in scientific laboratories for the manufacture of experimental apparatus because it is relatively cheap, readily formed into required shapes for experiment, easy to keep clean, can withstand heat and cold treatment, is generally non-reactive with many ]s, and its transparency allows for the observation of chemical reactions and processes.<ref name="Zumdahl">{{cite book|url=https://books.google.com/books?id=5qgZBQAAQBAJ&q=laboratory%20glassware&pg=PT10|last=Zumdahl|first=Steven|year=2013|publisher=Cengage Learning|title=Lab Manual|pages=ix–xv|isbn=978-1-285-69235-7}}</ref><ref>{{Cite web|url=https://americanhistory.si.edu/science-under-glass|title=Science Under Glass|date=29 July 2015|website=National Museum of American History|access-date=4 March 2020|archive-date=10 March 2020|archive-url=https://web.archive.org/web/20200310090831/https://americanhistory.si.edu/science-under-glass|url-status=dead}}</ref> ] applications include ], ]es, ]s, ]s, ]s, glass-lined metallic containers for chemical processing, ]s, glass pipes, ]s, ], and ]s.<ref name="BASUDEB">{{cite book|url=https://books.google.com/books?id=T838DAAAQBAJ&q=uses%20of%20glass&pg=PA5|title=Functional Glasses and Glass-Ceramics: Processing, Properties and Applications|pages=3–5|year=2017|last=Basudeb|first=Karmakar|publisher=Butterworth-Heinemann|isbn=978-0-12-805207-5}}</ref><ref name="Zumdahl" /> Although most standard laboratory glassware has been mass-produced since the 1920s, scientists still employ skilled ]s to manufacture bespoke glass apparatus for their experimental requirements.<ref>{{cite web |url=https://americanhistory.si.edu/science-under-glass/scientific-glassblowing |title=Scientific Glassblowing | National Museum of American History |publisher=Americanhistory.si.edu |date=2012-12-17 |access-date=2020-03-04 |archive-date=11 March 2020 |archive-url=https://web.archive.org/web/20200311145518/https://americanhistory.si.edu/science-under-glass/scientific-glassblowing |url-status=dead }}</ref> | |||
<gallery mode="nolines"> | |||
File:Vigreux column lab.jpg|A Vigreux ] in a laboratory setup | |||
Several other points exemplify the misconception of the 'cathedral glass' theory: | |||
File:Double vac line front view.jpg|A ] with four ports | |||
File:Different types of graduated cylinder- 10ml, 25ml, 50ml and 100 ml graduated cylinder.jpg|]s | |||
File:250 mL Erlenmeyer flask.jpg|Erlenmeyer ] | |||
</gallery> | |||
=== Optics === | |||
* Writing in the ],<ref>"Do Cathedral Glasses Flow?" ''Am. J. Phys.'', '''66''' (May 1998), pp 392–396</ref> physicist ] states "...the predicted ] for GeO<sub>2</sub> at room temperature is 10<sup>32</sup> years. Hence, the relaxation period (characteristic flow time) of cathedral glasses would be even longer". | |||
Glass is a ubiquitous material in ] because of its ability to ], ], and ] light. These and other optical properties can be controlled by varying chemical compositions, thermal treatment, and manufacturing techniques. The many applications of glass in optics include ] for eyesight correction, imaging optics (e.g. ]es and ]s in ]s, ]s, and ]s), ] in ] technology, and ]. ]es and ] (where the ] is non-uniform) find application in e.g. reading ]s, ]s, ]s, and ]s.<ref name=Bach12 /> | |||
* If medieval glass has flowed perceptibly, then ancient Roman and Egyptian objects should have flowed proportionately more — but this is not observed. Similarly, prehistoric ] blades should have lost their edge; this is not observed either (although obsidian may have a different viscosity from window glass).<ref name=Gibbs/> | |||
* If glass flows at a rate that allows changes to be seen with the naked eye after centuries, then the effect should be noticeable in antique telescopes. Any slight deformation in the antique telescopic lenses would lead to a dramatic decrease in optical performance, a phenomenon that is not observed.<ref name=Gibbs/> | |||
* There are many examples of centuries-old glass shelving which has not bent, even though it is under much higher stress from gravitational loads than vertical window glass. | |||
=== Modern Art === | |||
Some glasses have a glass transition temperature close to or below room temperature. The behaviour of a material that has a glass transition close to room temperature depends upon the timescale during which the material is manipulated. If the material is hit it may break like a solid glass, however if the material is left on a table for a week it may flow like a liquid. This simply means that for the fast timescale its transition temperature is above room temperature, but for the slow one it is below. The shift in temperature with timescale is not very large however as indicated by the transition of polypropylene glycol of -72 °C and -71 °C over different timescales. <ref name=Folmer/> To observe window glass flowing as liquid at room temperature we would have to wait a much longer time than the universe exists. Therefore it is safe to consider a glass a solid far enough below its transition temperature: Cathedral glass does not flow because its glass transition temperature is many hundreds of degrees above room temperature. Close to this temperature there are interesting time-dependent properties. One of these is known as aging. Many polymers that we use in daily life such as ], ] and ] are in a glassy state but they are not too far below their glass transition temperature. Their mechanical properties may well change over time and this is serious concern when applying these materials in construction. | |||
{{Main|Studio glass|Art glass|Glass art}} | |||
The 19th century saw a revival in ancient glassmaking techniques including ], achieved for the first time since the Roman Empire, initially mostly for pieces in a ] style. The ] movement made great use of glass, with ], ], and ] in the first French wave of the movement, producing coloured vases and similar pieces, often in cameo glass or ] techniques.<ref>{{cite book |title=The Art of Glass: Art Nouveau to Art Deco |last=Arwas |first=Victor |year=1996 |pages=1–54 |publisher=Papadakis Publisher |url=https://books.google.com/books?id=bZsuJ90UAtIC&pg=PP1 |isbn=978-1-901092-00-4}}</ref> | |||
] in America specialised in ], both secular and religious, in panels and his famous lamps. The early 20th century saw the large-scale factory production of glass art by firms such as ] and ]. Small studios may hand-produce glass artworks. Techniques for producing glass art include ], kiln-casting, fusing, slumping, ], flame-working, hot-sculpting and cold-working. Cold work includes traditional stained glass work and other methods of shaping glass at room temperature. Objects made out of glass include vessels, ], ], ]s, sculptures and ].<ref name="V&A A-Z">{{cite web |title=A-Z of glass |url=https://www.vam.ac.uk/articles/a-z-of-glass |publisher=Victoria and Albert Museum |access-date=9 March 2020}}</ref> | |||
===Physical properties=== | |||
<gallery mode="nolines"> | |||
The following table lists some physical properties of common glasses. Unless otherwise stated, the technical glass compositions and many experimentally determined properties are taken from one large study.<ref name=seward>"High temperature glass melt property database for process modeling"; Eds.: Thomas P. Seward III and Terese Vascott; The American Ceramic Society, Westerville, Ohio, 2005, ISBN 1-57498-225-7</ref> Unless stated otherwise, the properties of ] (quartz glass) and ] glass are derived from the SciGlass ] by forming the ] of all the experimental values from different authors (in general more than 10 independent sources for quartz glass and Tg of germanium oxide glass). Those values marked in ''italic'' font have been interpolated from similar glass compositions (see ]) due to the lack of experimental data. | |||
Image:Portland Vase BM Gem4036 n5.jpg|The ], Roman ], about 5–25 AD | |||
File:Medallion St Demetrios Louvre OA6457.jpg|Byzantine ] plaque of ], c. 1100, using the ''senkschmelz'' or "sunk" technique | |||
{| class="wikitable" | |||
File:Gallé, nancy, vaso clematis, 1890-1900.JPG|], Marquetry glass vase with clematis flowers (1890–1900) | |||
|- | |||
File:Vase (Perruches) by René Jules Lalique, 1922, blown four mold glass - Cincinnati Art Museum - DSC04355.JPG|Glass vase by ] artist ] | |||
! Properties | |||
File:Clara driscoll per tiffany studios, lampada laburnum, 1910 ca. 02.jpg|] ], ] pattern, c. 1910 | |||
! ] (for ])<ref>Soda-lime glass for containers is slightly different from soda-lime glass for windows (also called flat glass or ]). Float glass has a higher ] content as compared to container glass, and a lower silica and ] content. For further details see main article ].</ref> | |||
File:Glass.sculpture.kewgardens.london.arp.jpg|A glass sculpture by ], ''The Sun'', at the "Gardens of Glass" exhibition in Kew Gardens, London | |||
! ] (low expansion, similar to ], ]) | |||
File:GlassFlowers1HMNH.jpg|The ] by ], exhibited at the ] | |||
! Glass wool (for ]) | |||
</gallery> | |||
! Special ] glass (similar to<br>]) | |||
! ] | |||
! ] glass | |||
! Germanium selenide glass | |||
|- | |||
| Chemical<br>composition,<br>wt% | |||
| 74 ], 13 ], 10.5 ], 1.3 ], 0.3 ], 0.2 ], 0.2 ], 0.01 ], 0.04 ] | |||
| 81 SiO<sub>2</sub>, 12.5 ], 4 Na<sub>2</sub>O, 2.2 Al<sub>2</sub>O<sub>3</sub>, 0.02 CaO, 0.06 K<sub>2</sub>O | |||
| 63 SiO<sub>2</sub>, 16 Na<sub>2</sub>O, 8 CaO, 3.3 B<sub>2</sub>O<sub>3</sub>, 5 Al<sub>2</sub>O<sub>3</sub>, 3.5 MgO, 0.8 K<sub>2</sub>O, 0.3 Fe<sub>2</sub>O<sub>3</sub>, 0.2 SO<sub>3</sub> | |||
| 41.2 SiO<sub>2</sub>, 34.1 ], 12.4 ], 6.3 ], 3.0 K<sub>2</sub>O, 2.5 CaO, 0.35 ], 0.2 ] | |||
| SiO<sub>2</sub> | |||
| GeO<sub>2</sub> | |||
| GeSe<sub>2</sub> | |||
|- | |||
| ]<br>log(η, Pa·s) = A +<br>B / (T in °C - T<sub>o</sub>) | |||
| 550-1450°C:<br>A = -2.309<br>B = 3922<br>T<sub>o</sub> = 291 | |||
| 550-1450°C:<br>A = -2.834<br>B = 6668<br>T<sub>o</sub> = 108 | |||
| 550-1400°C:<br>A = -2.323<br>B = 3232<br>T<sub>o</sub> = 318 | |||
| 500-690°C:<br>A = -35.59<br>B = 60930<br>T<sub>o</sub> = -741 | |||
| 1140-2320°C:<br>A = -7.766<br>B = 27913<br>T<sub>o</sub> = -271.7 | |||
| 515-1540°C:<br>A = -11.044<br>B = 30979<br>T<sub>o</sub> = -837 | |||
|- | |||
| ]<br>], T<sub>g</sub>, °C | |||
| 573 | |||
| 536 | |||
| 551 | |||
| ~540 | |||
| 1140 | |||
| 526 ± 27<ref>Leadbetter et al, Journal of non-crystalline solids, 7:37-52 (1972)</ref><ref>Micoulaut et al, Physical Review E, 73:031504 (2006)</ref><ref>35 T<sub>g</sub> data for GeO<sub>2</sub> from ] 6.7</ref> | |||
| 395 <ref name=Kotkata94>Kotkata et al., J. Phys. D: Appl. Phys. '''27''' pp 623-627 (1994)</ref> | |||
|- | |||
| ]<br>],<br>ppm/K, ~100-300°C | |||
| 9 | |||
| 3.5 | |||
| 10 | |||
| 7 | |||
| 0.55 | |||
| 7.3 | |||
| | |||
|- | |||
| ]<br>at 20°C, g/cm<sup>3</sup> | |||
| 2.52 | |||
| 2.235 | |||
| 2.550 | |||
| 3.86 | |||
| 2.203 | |||
| 3.65 <ref>Salmon et al, Physical Review Letters, '''96''', 235502 (2006)</ref> | |||
| 4.16 <ref name=Kotkata94/> | |||
|- | |||
| ] n<sub>D</sub><ref name=refind>The subscript ''D'' indicates that the refractive index ''n'' was measured at a wavelength λ of 589.29 nm, ''F'' and ''C'' indicate 486.13 nm (blue) and 656.27 nm (red) respectively (see article ])</ref> at 20°C | |||
| ''1.518'' | |||
| 1.473 | |||
| 1.531 | |||
| 1.650 | |||
| 1.459 | |||
| 1.608 | |||
| 1.7 | |||
|- | |||
| ] at 20°C,<br>10<sup>4</sup>×(n<sub>F</sub>-n<sub>C</sub>)<ref name=refind/> | |||
| ''86.7'' | |||
| ''72.3'' | |||
| ''89.5'' | |||
| 169 | |||
| 67.8 | |||
| 146 | |||
| | |||
|- | |||
| ]<br>at 20°C, GPa | |||
| ''72'' | |||
| ''65'' | |||
| ''75'' | |||
| 67 | |||
| 72 | |||
| 43.3 <ref>Hwa et al, Materials Chemistry and Physics, '''94''', 1, 37-41 (2005)</ref> | |||
| | |||
|- | |||
| ]<br>at 20°C, GPa | |||
| ''29.8'' | |||
| ''28.2'' | |||
| | |||
| 26.8 | |||
| 31.3 | |||
| | |||
| | |||
|- | |||
| ]<br>], °C | |||
| ''1040'' | |||
| 1070<ref>Valid for glass composition, wt%: 80.7 SiO<sub>2</sub>, 13.1 B<sub>2</sub>O<sub>3</sub>, 4.1 Na<sub>2</sub>O, 2.1 Al<sub>2</sub>O<sub>3</sub>; Reference: Baak N. T. E. A. and Rapp C. F., GB Patent No. 1132885 Cl C 03 C 3/04, Abridg. Specif., 1968; Assignee: Owens-Illinois, Inc. (US).</ref> | |||
| | |||
| | |||
| 1715 | |||
| 1115 | |||
| | |||
|- | |||
| ]<br>] at 20°C,<br>J/(mol·K) | |||
| ''49'' | |||
| ''50'' | |||
| ''50'' | |||
| 51 | |||
| 44 | |||
| 52 | |||
| | |||
|- | |||
| ],<br>at ~1300°C, mJ/m<sup>2</sup> | |||
| 315 | |||
| 370 | |||
| 290 | |||
| | |||
| | |||
| | |||
| | |||
|- | |||
| ],<br>],<br>after ISO 719<ref></ref> | |||
| ''3'' | |||
| ''1'' | |||
| ''3'' | |||
| | |||
| | |||
| | |||
| | |||
|} | |||
====Color==== | |||
] appears green in thick sections because of Fe<sup>2+</sup> impurities.]] | |||
{{main|Glass_production#Colors}} | |||
]s in glass may be obtained by addition of coloring ions that are homogeneously distributed and by precipitation of finely dispersed particles (such as in ]).<ref name=vogel/> Ordinary ] appears colorless to the naked eye when it is thin, although ] (FeO) impurities of up to 0.1 wt%<ref name=seward/> produce a ] tint which can be viewed in thick pieces or with the aid of scientific instruments. Further FeO and ] additions may be used for the production of green bottles. ], together with ] and iron salts, is used to form iron polysulfides and produce amber glass ranging from yellowish to almost black.<ref> 1st.glassman.com (David M Issitt). Retrieved 3 August 2006</ref> ] can be added in small amounts to remove the green tint given by iron(II) oxide. | |||
== History == | |||
] from the 4th century A.D.]] | |||
] | |||
:''see also category ]'' | |||
Naturally occurring glass, especially ], has been used by many Stone Age societies across the globe for the production of sharp cutting tools and, due to its limited source areas, was extensively traded. According to ], ] traders were the first to stumble upon glass manufacturing techniques at the site of the ]. Agricola, '']'', reported a traditional serendipitous "discovery" tale of familiar type: | |||
<blockquote>"The tradition is that a merchant ship laden with ] being moored at this place, the merchants were preparing their meal on the beach, and not having stones to prop up their pots, they used lumps of nitrum from the ship, which fused and mixed with the sands of the shore, and there flowed streams of a new translucent liquid, and thus was the origin of glass."<ref name=Agricola>], Georgius, '']'', translated by Herbert Clark Hoover and Lou Henry Hoover, Dover Publishing. Retrieved = 12 September 2007 </ref></blockquote> | |||
This account is more a reflection of Roman experience of glass production, however, as white silica sand from this area was used in the production of Roman glass due to its low impurity levels. But in general archaeological evidence suggests that the first true glass was made in coastal north Syria, ] or ].<ref>{{cite web| url = http://www.glassonline.com/infoserv/history.html| title = Glass Online: The History of Glass| accessdate = 2007-10-29}}</ref> Due to Egypt's favourable environment for preservation, the majority of well-studied early glass is found in Egypt, although some of this is likely to have been imported. The earliest known glass objects, of the mid third millennium BC, were beads, perhaps initially created as accidental by-products of metal-working ]s or during the production of ], a pre-glass ] material made by a process similar to glazing.<ref>True glazing over a ceramic body was not used until many centuries after the production of the first glass.</ref> | |||
During the ] in ] and ] there was an explosion in glass-making technology. Archaeological finds from this period include coloured glass ], vessels (often coloured and shaped in imitation of highly prized wares of semi-precious stones) and the ubiquitous beads. The alkali of Syrian and Egyptian glass was ], sodium carbonate, which can be extracted from the ashes of many plants, notably ] seashore plants: (see ]). The earliest vessels were 'core-wound', produced by winding a ductile rope of metal round a shaped core of sand and clay over a metal rod, then fusing it with repeated reheatings. Threads of thin glass of different colours made with admixtures of oxides were subsequently wound around these to create patterns, which could be drawn into festoons with a metal raking tools. The vessel would then be rolled flat ('marvered') on a slab in order to press the decorative threads into its body. Handles and feet were applied separately. The rod was subsequently allowed to cool as the glass slowly ] and was eventually removed from the centre of the vessel, after which the core material was scraped out. Glass shapes for ]s were also often created in moulds. Much early glass production, however, relied on grinding techniques borrowed from stone working. This meant that the glass was ground and carved in a cold state. | |||
By the 15th century BC extensive glass production was occurring in ] and ]. It is thought the techniques and recipes required for the initial fusing of glass from raw materials was a closely guarded technological secret reserved for the large palace industries of powerful states. Glass workers in other areas therefore relied on imports of pre-formed glass, often in the form of cast ingots such as those found on the ] shipwreck off the coast of Turkey. | |||
Glass remained a luxury material, and the disasters that overtook Late Bronze Age civilisations seem to have brought glass-making to a halt. It picked up again in its former sites, in Syria and Cyprus, in the ninth century BC, when the techniques for making colourless glass were discovered. In Egypt glass-making did not revive until it was reintroduced in ]. Core-formed vessels and beads were still widely produced, but other techniques came to the fore with experimentation and technological advancements. During the ] period many new techniques of glass production were introduced and glass began to be used to make larger pieces, notably table wares. Techniques developed during this period include 'slumping' ] (but not fully molten) glass over a mould in order to form a dish and ']' (meaning 'thousand flowers') technique, where canes of multi-coloured glass were sliced and the slices arranged together and fused in a mould to create a mosaic-like effect. It was also during this period that colourless or decoloured glass began to be prized and methods for achieving this effect were investigated more fully. | |||
During the first century BC ] was discovered on the Syro-Palestinian coast, revolutionising the industry and laying the way for the explosion of glass production that occurred throughout the Roman world. Over the next 1000 years glass making and working continued and spread through southern Europe and beyond. | |||
===South Asia=== | |||
Indigenous development of glass technology in ] may have begun in 1730 BCE.<ref name=Gowlett>Gowlett 1997, page 276-277</ref> Evidence of this culture includes a red-brown glass bead along with a hoard of beads dating to 1730 BCE, making it the earliest attested glass from the ] locations.<ref name=Gowlett/> Glass discovered from later sites dating from 600-300 BCE displays common color.<ref name=Gowlett/> | |||
] evidence of glass has been found in ], ].<ref name=Ghosh>Ghosh 1990, page 219</ref> | |||
Some of the texts which mention glass in India are the '']'' and '']''.<ref name=Ghosh/> However, the first unmistakable evidence in large quantities, dating from the 3rd century BCE, has been uncovered from the archaeological site in ], ].<ref name=Ghosh/> | |||
By the beginning of the ], glass was being used for ornaments and casing in South Asia.<ref name=Ghosh/> Contact with the ] added newer techniques, and Indians artisans mastered several techniques of glass molding, decorating and coloring by the early centuries of the Common Era.<ref name=Ghosh/> ] period of India further reveals short cylinders of composite glass, including those displaying a lemon yellow matrix covered with green glass.<ref name=Ghosh2>"Ornaments, Gems etc." (Ch. 10) in Ghosh 1990</ref> | |||
===Romans=== | |||
A full discussion of Roman glass making and working can be found on the ] page. | |||
===Anglo-Saxon world=== | |||
Evidence for glass making, working and use in the 5th to 8th centuries in England is discussed in the ] page. | |||
===Islamic world=== | |||
In the ], the first clear, colourless, high-purity glasses were produced by ], ] and ] in the 9th century. Examples include ] and colourless high-purity glass invented by ] (810-887), who was the first to produce glass from ] and ].<ref name=White-100>] (Spring, 1961). "Eilmer of Malmesbury, an Eleventh Century Aviator: A Case Study of Technological Innovation, Its Context and Tradition", ''Technology and Culture'' '''2''' (2), pp. 97-111 . | |||
{{quote|"Ibn Firnas was a ]: a ], a rather bad ], the first to make glass from ], a student of ], and inventor of some sort of ]."}}</ref> The ] al-] (820-897) described the clarity of such glass, | |||
"Its colour hides the glass as if it is standing in it without a container."<ref name=Glass>], , ''History of Science and Technology in Islam''.</ref> | |||
] was also first produced by ] in ] using coloured glass rather than stone. In the 8th century, the ] chemist ] (Geber) scientifically described 46 original recipes for producing coloured glass in ''Kitab al-Durra al-Maknuna'' (''The Book of the Hidden Pearl''), in addition to 12 recipes inserted by al-Marrakishi in a later edition of the book.<ref>], , ''History of Science and Technology in Islam''.</ref> | |||
The ] was first described by ] in his ''On the Burning Instruments'' in the 10th century, and later described again in ]'s ''On Burning Mirrors'' and '']'' (1021).<ref>Roshdi Rashed (1990), "A Pioneer in Anaclastics: Ibn Sahl on Burning Mirrors and Lenses", '']'' '''81''' (3), p. 464-491 .</ref> By the 11th century, clear glass ]s were being produced in ]. The first glass ] were also built by Muslim craftsmen in the Islamic world. The first glass factories in ] Europe were later built in the 11th century by Muslim ]ian craftsmen in ], ].<ref>], , ''History of Science and Technology in Islam''.</ref> | |||
===Medieval Europe=== | |||
] window]] | |||
Glass objects from the 7th and 8th centuries have been found on the island of ] near ]. These form an important link between Roman times and the later importance of that city in the production of the material. Around 1000 AD, an important technical breakthrough was made in Northern Europe when soda glass, produced from white pebbles and burnt vegetation was replaced by glass made from a much more readily available material: ] obtained from wood ashes. From this point on, northern glass differed significantly from that made in the Mediterranean area, where soda remained in common use.<ref>{{cite web| url = http://nautarch.tamu.edu/class/anth605/File5.htm| title = Glass Conservation | accessdate = 2007-03-21| author = Donny L. Hamilton | publisher = Conservation Research Laboratory, Texas A&M University}}</ref> | |||
Until the 12th century, ] -- glass to which metallic or other impurities had been added for coloring -- was not widely used. | |||
The 11th century saw the emergence in ] of new ways of making sheet glass by blowing spheres. The spheres were swung out to form cylinders and then cut while still hot, after which the sheets were flattened. This technique was perfected in 13th century ]. | |||
The ] was used up to the mid-19th century. In this process, the ] would spin approximately 9 ] (4 kg) of molten glass at the end of a rod until it flattened into a disk approximately 5 ] (1.5 ]) in diameter. The disk would then be cut into panes. | |||
===Late medieval Northern Europe=== | |||
Glass making in late medieval Northern Europe is discussed in the article on ]. | |||
=== Murano glassmaking === | |||
{{main|Murano glass|Venetian glass}} | |||
The center for glassmaking from the 14th century was the island of ], which developed many new techniques and became the center of a lucrative export trade in ], ]s, and other luxury items. What made Venetian ] significantly different was that the local quartz pebbles were almost pure ], and were ground into a fine clear sand that was combined with ] obtained from the ], for which the Venetians held the sole ]. The clearest and finest glass is tinted in two ways: firstly, a small or large amount of a natural coloring agent is ground and melted with the glass. Many of these coloring agents still exist today; for a list of coloring agents, see below. Black glass was called '''obsidianus''' after ] stone. A second method is apparently to produce a black glass which, when held to the light, will show the true color that this glass will give to another glass when used as a dye. <ref name=Agricola1>]'']'', Textbook of Mineralogy, M.C. Bandy, J. Bandy, Mineralogical Society of America, 1955, Page 111 Retrieved 12 September 2007 </ref> | |||
The Venetian ability to produce this superior form of glass resulted in a trade advantage over other glass producing lands. ]’s reputation as a center for glassmaking was born when the Venetian Republic, fearing fire might burn down the city’s mostly wood buildings, ordered glassmakers to move their foundries to Murano in 1291. Murano's glassmakers were soon the island’s most prominent citizens. Glassmakers were not allowed to leave the Republic. Many took a risk and set up glass furnaces in surrounding cities and as far afield as England and the Netherlands. | |||
== Glass art == | |||
{{main|Glass art}} | |||
] being created at the ], ]]] | |||
] with items inside the glass, ]]] | |||
Beginning in the late 20th century, glass started to become highly collectible as art. Works of art in glass can be seen in a variety of museums, including the Chrysler Museum, the Museum of Glass in Tacoma, the Metropolitan Museum of Art, the Toledo Museum of Art, and ], in ], which houses the world's largest collection of glass art and history, with more than 45,000 objects in its collection.<ref name=Corning>{{cite web |title= Corning Museum of Glass|url=http://www.cmog.org/index.asp?pageId=1276|accessdate=2007-10-14|format= }}</ref> | |||
Several of the most common techniques for producing glass art include: ], kiln-casting, fusing, slumping, pate-de-verre, flame-working, hot-sculpting and cold-working. Cold work includes traditional ] work as well as other methods of shaping glass at room temperature. Glass can also be cut with a diamond saw, or copper wheels embedded with abrasives, and polished to give gleaming facets; the technique used in creating ] <ref>{{cite web |title=Waterford Crystal Vistors Centre|url=http://www.waterfordvisitorcentre.com/|accessdate=2007-10-19|format= }}</ref>. Art is sometimes etched into glass via the use of acid, caustic, or abrasive substances. Traditionally this was done after the glass was blown or cast. In the 1920s a new mould-etch process was invented, in which art was etched directly into the mould, so that each cast piece emerged from the mould with the image already on the surface of the glass. This reduced manufacturing costs and, combined with a wider use of colored glass, led to cheap glassware in the 1930s, which later became known as Depression glass<ref>{{cite web |title=Depression Glass|url=http://www.glassonweb.com/articles/article/201/|accessdate=2007-10-19|format= }}</ref>. As the types of acids used in this process are extremely hazardous, abrasive methods have gained popularity. | |||
Objects made out of glass include not only traditional objects such as vessels (]s, ]s, ]s, and other containers), ], ], ]s, but an endless range of ] and installation art as well. Colored glass is often used, though sometimes the glass is painted, innumerable examples exist of the use of ]. | |||
The ] has a collection of extremely detailed models of flowers made of painted glass. These were ] by ] and his son Rudolph, who never revealed the method he used to make them. The Blaschka ] are still an inspiration to glassblowers today. <ref> </ref> | |||
== See also == | == See also == | ||
{{div col}} | |||
* ] | |||
* ] transparent ceramic | |||
* ] | |||
* ] | |||
* ] | |||
* ] | * ] | ||
* ] | * ] | ||
* ] | * ] | ||
* ] | * ] | ||
* ] | |||
{{div col end}} | |||
== References == | == References == | ||
{{reflist|colwidth=30em}} | |||
== External links == | |||
{{reflist|2}} | |||
{{Sister project links| wikt=no | commons=Category:Glass | b=no | n=no | q=Glass | s=no | v=yes | voy=no | species=no | d=no}} | |||
* {{cite EB1911|wstitle=Glass |volume=12 |short=x}} | |||
== Bibliography == | |||
<!-- DO NOT ADD COMMERCIAL LINKS TO THIS LIST--> | |||
* from The Canadian Museum of Civilization. | |||
* Noel C. Stokes; ''The Glass and Glazing Handbook''; ]; SAA HB125–1998 | |||
* by George W. Waltz, February 1951, '']''. | |||
* Brugmann, Birte. ''Glass Beads from Anglo-Saxon Graves: A Study on the Provenance and Chronology of Glass Beads from Anglo-Saxon Graves, Based on Visual Examination''. Oxbow Books, 2004. ISBN 1-84217-104-6 | |||
* from the Corning Museum of Glass: a collection of articles, multimedia, and virtual books all about glass, including the . | |||
*{{cite book | last = Gowlett| first = J.A.J. | title = High Definition Archaeology: Threads Through the Past| publisher = Routledge| date = 1997| isbn = 0415184290}} | |||
<!-- DO NOT ADD COMMERCIAL LINKS TO THIS LIST--> | |||
*{{cite book | last = Ghosh | first = Amalananda | title = An Encyclopaedia of Indian Archaeology|publisher = BRILL| date = 1990| isbn = 9004092625}} | |||
==External links== | |||
{{wiktionary}} | |||
{{commonscat}} | |||
* | |||
* | |||
* | |||
* | |||
* | |||
* | |||
* | |||
* | |||
* | |||
* | |||
{{Glass science}} | {{Glass science}} | ||
{{Glass forming}} | {{Glass forming}} | ||
{{ |
{{Glass makers and brands}} | ||
{{Authority control}} | |||
] | ] | ||
] | ] | ||
] | |||
] | ] | ||
] | ] | ||
] | ] | ||
] | ] | ||
] | |||
{{Link FA|af}} | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] |
Latest revision as of 08:57, 23 January 2025
Transparent non-crystalline solid material This article is about the material. For other uses, see Glass (disambiguation).
Glass is an amorphous (non-crystalline) solid. Because it is often transparent and chemically inert, glass has found widespread practical, technological, and decorative use in window panes, tableware, and optics. Some common objects made of glass are named after the material, e.g., a "glass" for drinking, "glasses" for vision correction, and a "magnifying glass".
Glass is most often formed by rapid cooling (quenching) of the molten form. Some glasses such as volcanic glass are naturally occurring, and obsidian has been used to make arrowheads and knives since the Stone Age. Archaeological evidence suggests glassmaking dates back to at least 3600 BC in Mesopotamia, Egypt, or Syria. The earliest known glass objects were beads, perhaps created accidentally during metalworking or the production of faience, which is a form of pottery using lead glazes.
Due to its ease of formability into any shape, glass has been traditionally used for vessels, such as bowls, vases, bottles, jars and drinking glasses. Soda–lime glass, containing around 70% silica, accounts for around 90% of modern manufactured glass. Glass can be coloured by adding metal salts or painted and printed with vitreous enamels, leading to its use in stained glass windows and other glass art objects.
The refractive, reflective and transmission properties of glass make glass suitable for manufacturing optical lenses, prisms, and optoelectronics materials. Extruded glass fibres have applications as optical fibres in communications networks, thermal insulating material when matted as glass wool to trap air, or in glass-fibre reinforced plastic (fibreglass).
Microscopic structure
Main article: Structure of liquids and glassesThe standard definition of a glass (or vitreous solid) is a non-crystalline solid formed by rapid melt quenching. However, the term "glass" is often defined in a broader sense, to describe any non-crystalline (amorphous) solid that exhibits a glass transition when heated towards the liquid state.
Glass is an amorphous solid. Although the atomic-scale structure of glass shares characteristics of the structure of a supercooled liquid, glass exhibits all the mechanical properties of a solid. As in other amorphous solids, the atomic structure of a glass lacks the long-range periodicity observed in crystalline solids. Due to chemical bonding constraints, glasses do possess a high degree of short-range order with respect to local atomic polyhedra. The notion that glass flows to an appreciable extent over extended periods well below the glass transition temperature is not supported by empirical research or theoretical analysis (see viscosity in solids). Though atomic motion at glass surfaces can be observed, and viscosity on the order of 10–10 Pa s can be measured in glass, such a high value reinforces the fact that glass would not change shape appreciably over even large periods of time.
Formation from a supercooled liquid
Main articles: Glass transition and Glass formation Unsolved problem in physics : What is the nature of the transition between a fluid or regular solid and a glassy phase? "The deepest and most interesting unsolved problem in solid state theory is probably the theory of the nature of glass and the glass transition." —P.W. Anderson (more unsolved problems in physics )For melt quenching, if the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crystallization is prevented and instead, the disordered atomic configuration of the supercooled liquid is frozen into the solid state at Tg. The tendency for a material to form a glass while quenched is called glass-forming ability. This ability can be predicted by the rigidity theory. Generally, a glass exists in a structurally metastable state with respect to its crystalline form, although in certain circumstances, for example in atactic polymers, there is no crystalline analogue of the amorphous phase.
Glass is sometimes considered to be a liquid due to its lack of a first-order phase transition where certain thermodynamic variables such as volume, entropy and enthalpy are discontinuous through the glass transition range. The glass transition may be described as analogous to a second-order phase transition where the intensive thermodynamic variables such as the thermal expansivity and heat capacity are discontinuous. However, the equilibrium theory of phase transformations does not hold for glass, and hence the glass transition cannot be classed as one of the classical equilibrium phase transformations in solids.
Occurrence in nature
Main articles: Volcanic glass, Impactite, and FulguriteGlass can form naturally from volcanic magma. Obsidian is a common volcanic glass with high silica (SiO2) content formed when felsic lava extruded from a volcano cools rapidly. Impactite is a form of glass formed by the impact of a meteorite, where Moldavite (found in central and eastern Europe), and Libyan desert glass (found in areas in the eastern Sahara, the deserts of eastern Libya and western Egypt) are notable examples. Vitrification of quartz can also occur when lightning strikes sand, forming hollow, branching rootlike structures called fulgurites. Trinitite is a glassy residue formed from the desert floor sand at the Trinity nuclear bomb test site. Edeowie glass, found in South Australia, is proposed to originate from Pleistocene grassland fires, lightning strikes, or hypervelocity impact by one or several asteroids or comets.
- A piece of volcanic obsidian glass
- Moldavite, a natural glass formed by meteorite impact, from Besednice, Bohemia
- Tube fulgurites
- Trinitite, a glass made by the Trinity nuclear-weapon test
- Libyan desert glass
History
Main article: History of glassNaturally occurring obsidian glass was used by Stone Age societies as it fractures along very sharp edges, making it ideal for cutting tools and weapons.
Glassmaking dates back at least 6000 years, long before humans had discovered how to smelt iron. Archaeological evidence suggests that the first true synthetic glass was made in Lebanon and the coastal north Syria, Mesopotamia or ancient Egypt. The earliest known glass objects, of the mid-third millennium BC, were beads, perhaps initially created as accidental by-products of metalworking (slags) or during the production of faience, a pre-glass vitreous material made by a process similar to glazing.
Early glass was rarely transparent and often contained impurities and imperfections, and is technically faience rather than true glass, which did not appear until the 15th century BC. However, red-orange glass beads excavated from the Indus Valley Civilization dated before 1700 BC (possibly as early as 1900 BC) predate sustained glass production, which appeared around 1600 BC in Mesopotamia and 1500 BC in Egypt.
During the Late Bronze Age, there was a rapid growth in glassmaking technology in Egypt and Western Asia. Archaeological finds from this period include coloured glass ingots, vessels, and beads.
Much early glass production relied on grinding techniques borrowed from stoneworking, such as grinding and carving glass in a cold state.
The term glass has its origins in the late Roman Empire, in the Roman glass making centre at Trier (located in current-day Germany) where the late-Latin term glesum originated, likely from a Germanic word for a transparent, lustrous substance. Glass objects have been recovered across the Roman Empire in domestic, funerary, and industrial contexts, as well as trade items in marketplaces in distant provinces. Examples of Roman glass have been found outside of the former Roman Empire in China, the Baltics, the Middle East, and India. The Romans perfected cameo glass, produced by etching and carving through fused layers of different colours to produce a design in relief on the glass object.
In post-classical West Africa, Benin was a manufacturer of glass and glass beads. Glass was used extensively in Europe during the Middle Ages. Anglo-Saxon glass has been found across England during archaeological excavations of both settlement and cemetery sites. From the 10th century onwards, glass was employed in stained glass windows of churches and cathedrals, with famous examples at Chartres Cathedral and the Basilica of Saint-Denis. By the 14th century, architects were designing buildings with walls of stained glass such as Sainte-Chapelle, Paris, (1203–1248) and the East end of Gloucester Cathedral. With the change in architectural style during the Renaissance period in Europe, the use of large stained glass windows became much less prevalent, although stained glass had a major revival with Gothic Revival architecture in the 19th century.
During the 13th century, the island of Murano, Venice, became a centre for glass making, building on medieval techniques to produce colourful ornamental pieces in large quantities. Murano glass makers developed the exceptionally clear colourless glass cristallo, so called for its resemblance to natural crystal, which was extensively used for windows, mirrors, ships' lanterns, and lenses. In the 13th, 14th, and 15th centuries, enamelling and gilding on glass vessels were perfected in Egypt and Syria. Towards the end of the 17th century, Bohemia became an important region for glass production, remaining so until the start of the 20th century. By the 17th century, glass in the Venetian tradition was also being produced in England. In about 1675, George Ravenscroft invented lead crystal glass, with cut glass becoming fashionable in the 18th century. Ornamental glass objects became an important art medium during the Art Nouveau period in the late 19th century.
Throughout the 20th century, new mass production techniques led to the widespread availability of glass in much larger amounts, making it practical as a building material and enabling new applications of glass. In the 1920s a mould-etch process was developed, in which art was etched directly into the mould so that each cast piece emerged from the mould with the image already on the surface of the glass. This reduced manufacturing costs and, combined with a wider use of coloured glass, led to cheap glassware in the 1930s, which later became known as Depression glass. In the 1950s, Pilkington Bros., England, developed the float glass process, producing high-quality distortion-free flat sheets of glass by floating on molten tin. Modern multi-story buildings are frequently constructed with curtain walls made almost entirely of glass. Laminated glass has been widely applied to vehicles for windscreens. Optical glass for spectacles has been used since the Middle Ages. The production of lenses has become increasingly proficient, aiding astronomers as well as having other applications in medicine and science. Glass is also employed as the aperture cover in many solar energy collectors.
In the 21st century, glass manufacturers have developed different brands of chemically strengthened glass for widespread application in touchscreens for smartphones, tablet computers, and many other types of information appliances. These include Gorilla Glass, developed and manufactured by Corning, AGC Inc.'s Dragontrail and Schott AG's Xensation.
Physical properties
Optical
Main article: Optical glassGlass is in widespread use in optical systems due to its ability to refract, reflect, and transmit light following geometrical optics. The most common and oldest applications of glass in optics are as lenses, windows, mirrors, and prisms. The key optical properties refractive index, dispersion, and transmission, of glass are strongly dependent on chemical composition and, to a lesser degree, its thermal history. Optical glass typically has a refractive index of 1.4 to 2.4, and an Abbe number (which characterises dispersion) of 15 to 100. The refractive index may be modified by high-density (refractive index increases) or low-density (refractive index decreases) additives.
Glass transparency results from the absence of grain boundaries which diffusely scatter light in polycrystalline materials. Semi-opacity due to crystallization may be induced in many glasses by maintaining them for a long period at a temperature just insufficient to cause fusion. In this way, the crystalline, devitrified material, known as Réaumur's glass porcelain is produced. Although generally transparent to visible light, glasses may be opaque to other wavelengths of light. While silicate glasses are generally opaque to infrared wavelengths with a transmission cut-off at 4 μm, heavy-metal fluoride and chalcogenide glasses are transparent to infrared wavelengths of 7 to 18 μm. The addition of metallic oxides results in different coloured glasses as the metallic ions will absorb wavelengths of light corresponding to specific colours.
Other
See also: List of physical properties of glass, Corrosion § Corrosion of glass, and Strength of glassIn the manufacturing process, glasses can be poured, formed, extruded and moulded into forms ranging from flat sheets to highly intricate shapes. The finished product is brittle but can be laminated or tempered to enhance durability. Glass is typically inert, resistant to chemical attack, and can mostly withstand the action of water, making it an ideal material for the manufacture of containers for foodstuffs and most chemicals. Nevertheless, although usually highly resistant to chemical attack, glass will corrode or dissolve under some conditions. The materials that make up a particular glass composition affect how quickly the glass corrodes. Glasses containing a high proportion of alkali or alkaline earth elements are more susceptible to corrosion than other glass compositions.
The density of glass varies with chemical composition with values ranging from 2.2 grams per cubic centimetre (2,200 kg/m) for fused silica to 7.2 grams per cubic centimetre (7,200 kg/m) for dense flint glass. Glass is stronger than most metals, with a theoretical tensile strength for pure, flawless glass estimated at 14 to 35 gigapascals (2,000,000 to 5,100,000 psi) due to its ability to undergo reversible compression without fracture. However, the presence of scratches, bubbles, and other microscopic flaws lead to a typical range of 14 to 175 megapascals (2,000 to 25,400 psi) in most commercial glasses. Several processes such as toughening can increase the strength of glass. Carefully drawn flawless glass fibres can be produced with a strength of up to 11.5 gigapascals (1,670,000 psi).
Further information on the tiny glass flakes formed during glass vial manufacturing: SpiculeReputed flow
The observation that old windows are sometimes found to be thicker at the bottom than at the top is often offered as supporting evidence for the view that glass flows over a timescale of centuries, the assumption being that the glass has exhibited the liquid property of flowing from one shape to another. This assumption is incorrect, as once solidified, glass stops flowing. The sags and ripples observed in old glass were already there the day it was made; manufacturing processes used in the past produced sheets with imperfect surfaces and non-uniform thickness (the near-perfect float glass used today only became widespread in the 1960s).
A 2017 study computed the rate of flow of the medieval glass used in Westminster Abbey from the year 1268. The study found that the room temperature viscosity of this glass was roughly 10 Pa·s which is about 10 times less viscous than a previous estimate made in 1998, which focused on soda-lime silicate glass. Even with this lower viscosity, the study authors calculated that the maximum flow rate of medieval glass is 1 nm per billion years, making it impossible to observe in a human timescale.
Types
Silicate glasses
Silicon dioxide (SiO2) is a common fundamental constituent of glass. Fused quartz is a glass made from chemically pure silica. It has very low thermal expansion and excellent resistance to thermal shock, being able to survive immersion in water while red hot, resists high temperatures (1000–1500 °C) and chemical weathering, and is very hard. It is also transparent to a wider spectral range than ordinary glass, extending from the visible further into both the UV and IR ranges, and is sometimes used where transparency to these wavelengths is necessary. Fused quartz is used for high-temperature applications such as furnace tubes, lighting tubes, melting crucibles, etc. However, its high melting temperature (1723 °C) and viscosity make it difficult to work with. Therefore, normally, other substances (fluxes) are added to lower the melting temperature and simplify glass processing.
Soda–lime glass
Main article: Soda–lime glassSodium carbonate (Na2CO3, "soda") is a common additive and acts to lower the glass-transition temperature. However, sodium silicate is water-soluble, so lime (CaO, calcium oxide, generally obtained from limestone), along with magnesium oxide (MgO), and aluminium oxide (Al2O3), are commonly added to improve chemical durability. Soda–lime glasses (Na2O) + lime (CaO) + magnesia (MgO) + alumina (Al2O3) account for over 75% of manufactured glass, containing about 70 to 74% silica by weight. Soda–lime–silicate glass is transparent, easily formed, and most suitable for window glass and tableware. However, it has a high thermal expansion and poor resistance to heat. Soda–lime glass is typically used for windows, bottles, light bulbs, and jars.
Borosilicate glass
Borosilicate glasses (e.g. Pyrex, Duran) typically contain 5–13% boron trioxide (B2O3). Borosilicate glasses have fairly low coefficients of thermal expansion (7740 Pyrex CTE is 3.25×10/°C as compared to about 9×10/°C for a typical soda–lime glass). They are, therefore, less subject to stress caused by thermal expansion and thus less vulnerable to cracking from thermal shock. They are commonly used for e.g. labware, household cookware, and sealed beam car head lamps.
Lead glass
Main article: Lead glassSee also: Lead poisoningThe addition of lead(II) oxide into silicate glass lowers the melting point and viscosity of the melt. The high density of lead glass (silica + lead oxide (PbO) + potassium oxide (K2O) + soda (Na2O) + zinc oxide (ZnO) + alumina) results in a high electron density, and hence high refractive index, making the look of glassware more brilliant and causing noticeably more specular reflection and increased optical dispersion. Lead glass has a high elasticity, making the glassware more workable and giving rise to a clear "ring" sound when struck. However, lead glass cannot withstand high temperatures well. Lead oxide also facilitates the solubility of other metal oxides and is used in coloured glass. The viscosity decrease of lead glass melt is very significant (roughly 100 times in comparison with soda glass); this allows easier removal of bubbles and working at lower temperatures, hence its frequent use as an additive in vitreous enamels and glass solders. The high ionic radius of the Pb ion renders it highly immobile and hinders the movement of other ions; lead glasses therefore have high electrical resistance, about two orders of magnitude higher than soda–lime glass (10 vs 10 Ω⋅cm, DC at 250 °C).
Aluminosilicate glass
Aluminosilicate glass typically contains 5–10% alumina (Al2O3). Aluminosilicate glass tends to be more difficult to melt and shape compared to borosilicate compositions but has excellent thermal resistance and durability. Aluminosilicate glass is extensively used for fibreglass, used for making glass-reinforced plastics (boats, fishing rods, etc.), top-of-stove cookware, and halogen bulb glass.
Other oxide additives
The addition of barium also increases the refractive index. Thorium oxide gives glass a high refractive index and low dispersion and was formerly used in producing high-quality lenses, but due to its radioactivity has been replaced by lanthanum oxide in modern eyeglasses. Iron can be incorporated into glass to absorb infrared radiation, for example in heat-absorbing filters for movie projectors, while cerium(IV) oxide can be used for glass that absorbs ultraviolet wavelengths. Fluorine lowers the dielectric constant of glass. Fluorine is highly electronegative and lowers the polarizability of the material. Fluoride silicate glasses are used in the manufacture of integrated circuits as an insulator.
Glass-ceramics
Main article: Glass-ceramicGlass-ceramic materials contain both non-crystalline glass and crystalline ceramic phases. They are formed by controlled nucleation and partial crystallisation of a base glass by heat treatment. Crystalline grains are often embedded within a non-crystalline intergranular phase of grain boundaries. Glass-ceramics exhibit advantageous thermal, chemical, biological, and dielectric properties as compared to metals or organic polymers.
The most commercially important property of glass-ceramics is their imperviousness to thermal shock. Thus, glass-ceramics have become extremely useful for countertop cooking and industrial processes. The negative thermal expansion coefficient (CTE) of the crystalline ceramic phase can be balanced with the positive CTE of the glassy phase. At a certain point (~70% crystalline) the glass-ceramic has a net CTE near zero. This type of glass-ceramic exhibits excellent mechanical properties and can sustain repeated and quick temperature changes up to 1000 °C.
Fibreglass
Main articles: Fiberglass and Glass woolFibreglass (also called glass fibre reinforced plastic, GRP) is a composite material made by reinforcing a plastic resin with glass fibres. It is made by melting glass and stretching the glass into fibres. These fibres are woven together into a cloth and left to set in a plastic resin. Fibreglass has the properties of being lightweight and corrosion resistant and is a good insulator enabling its use as building insulation material and for electronic housing for consumer products. Fibreglass was originally used in the United Kingdom and United States during World War II to manufacture radomes. Uses of fibreglass include building and construction materials, boat hulls, car body parts, and aerospace composite materials.
Glass-fibre wool is an excellent thermal and sound insulation material, commonly used in buildings (e.g. attic and cavity wall insulation), and plumbing (e.g. pipe insulation), and soundproofing. It is produced by forcing molten glass through a fine mesh by centripetal force and breaking the extruded glass fibres into short lengths using a stream of high-velocity air. The fibres are bonded with an adhesive spray and the resulting wool mat is cut and packed in rolls or panels.
Non-silicate glasses
Besides common silica-based glasses many other inorganic and organic materials may also form glasses, including metals, aluminates, phosphates, borates, chalcogenides, fluorides, germanates (glasses based on GeO2), tellurites (glasses based on TeO2), antimonates (glasses based on Sb2O3), arsenates (glasses based on As2O3), titanates (glasses based on TiO2), tantalates (glasses based on Ta2O5), nitrates, carbonates, plastics, acrylic, and many other substances. Some of these glasses (e.g. Germanium dioxide (GeO2, Germania), in many respects a structural analogue of silica, fluoride, aluminate, phosphate, borate, and chalcogenide glasses) have physicochemical properties useful for their application in fibre-optic waveguides in communication networks and other specialised technological applications.
Silica-free glasses may often have poor glass-forming tendencies. Novel techniques, including containerless processing by aerodynamic levitation (cooling the melt whilst it floats on a gas stream) or splat quenching (pressing the melt between two metal anvils or rollers), may be used to increase the cooling rate or to reduce crystal nucleation triggers.
Amorphous metals
Main article: Amorphous metalIn the past, small batches of amorphous metals with high surface area configurations (ribbons, wires, films, etc.) have been produced through the implementation of extremely rapid rates of cooling. Amorphous metal wires have been produced by sputtering molten metal onto a spinning metal disk.
Several alloys have been produced in layers with thicknesses exceeding 1 millimetre. These are known as bulk metallic glasses (BMG). Liquidmetal Technologies sells several zirconium-based BMGs.
Batches of amorphous steel have also been produced that demonstrate mechanical properties far exceeding those found in conventional steel alloys.
Experimental evidence indicates that the system Al-Fe-Si may undergo a first-order transition to an amorphous form (dubbed "q-glass") on rapid cooling from the melt. Transmission electron microscopy (TEM) images indicate that q-glass nucleates from the melt as discrete particles with uniform spherical growth in all directions. While x-ray diffraction reveals the isotropic nature of q-glass, a nucleation barrier exists implying an interfacial discontinuity (or internal surface) between the glass and melt phases.
Polymers
Important polymer glasses include amorphous and glassy pharmaceutical compounds. These are useful because the solubility of the compound is greatly increased when it is amorphous compared to the same crystalline composition. Many emerging pharmaceuticals are practically insoluble in their crystalline forms. Many polymer thermoplastics familiar to everyday use are glasses. For many applications, like glass bottles or eyewear, polymer glasses (acrylic glass, polycarbonate or polyethylene terephthalate) are a lighter alternative to traditional glass.
Molecular liquids and molten salts
Molecular liquids, electrolytes, molten salts, and aqueous solutions are mixtures of different molecules or ions that do not form a covalent network but interact only through weak van der Waals forces or transient hydrogen bonds. In a mixture of three or more ionic species of dissimilar size and shape, crystallization can be so difficult that the liquid can easily be supercooled into a glass. Examples include LiCl:RH2O (a solution of lithium chloride salt and water molecules) in the composition range 4<R<8. sugar glass, or Ca0.4K0.6(NO3)1.4. Glass electrolytes in the form of Ba-doped Li-glass and Ba-doped Na-glass have been proposed as solutions to problems identified with organic liquid electrolytes used in modern lithium-ion battery cells.
Production
Main articles: Glass production, Float glass, and GlassblowingFollowing the glass batch preparation and mixing, the raw materials are transported to the furnace. Soda–lime glass for mass production is melted in glass-melting furnaces. Smaller-scale furnaces for speciality glasses include electric melters, pot furnaces, and day tanks. After melting, homogenization and refining (removal of bubbles), the glass is formed. This may be achieved manually by glassblowing, which involves gathering a mass of hot semi-molten glass, inflating it into a bubble using a hollow blowpipe, and forming it into the required shape by blowing, swinging, rolling, or moulding. While hot, the glass can be worked using hand tools, cut with shears, and additional parts such as handles or feet attached by welding. Flat glass for windows and similar applications is formed by the float glass process, developed between 1953 and 1957 by Sir Alastair Pilkington and Kenneth Bickerstaff of the UK's Pilkington Brothers, who created a continuous ribbon of glass using a molten tin bath on which the molten glass flows unhindered under the influence of gravity. The top surface of the glass is subjected to nitrogen under pressure to obtain a polished finish. Container glass for common bottles and jars is formed by blowing and pressing methods. This glass is often slightly modified chemically (with more alumina and calcium oxide) for greater water resistance.
Once the desired form is obtained, glass is usually annealed for the removal of stresses and to increase the glass's hardness and durability. Surface treatments, coatings or lamination may follow to improve the chemical durability (glass container coatings, glass container internal treatment), strength (toughened glass, bulletproof glass, windshields), or optical properties (insulated glazing, anti-reflective coating).
New chemical glass compositions or new treatment techniques can be initially investigated in small-scale laboratory experiments. The raw materials for laboratory-scale glass melts are often different from those used in mass production because the cost factor has a low priority. In the laboratory mostly pure chemicals are used. Care must be taken that the raw materials have not reacted with moisture or other chemicals in the environment (such as alkali or alkaline earth metal oxides and hydroxides, or boron oxide), or that the impurities are quantified (loss on ignition). Evaporation losses during glass melting should be considered during the selection of the raw materials, e.g., sodium selenite may be preferred over easily evaporating selenium dioxide (SeO2). Also, more readily reacting raw materials may be preferred over relatively inert ones, such as aluminium hydroxide (Al(OH)3) over alumina (Al2O3). Usually, the melts are carried out in platinum crucibles to reduce contamination from the crucible material. Glass homogeneity is achieved by homogenizing the raw materials mixture (glass batch), stirring the melt, and crushing and re-melting the first melt. The obtained glass is usually annealed to prevent breakage during processing.
Colour
Main article: Glass coloring and color markingColour in glass may be obtained by addition of homogenously distributed electrically charged ions (or colour centres). While ordinary soda–lime glass appears colourless in thin section, iron(II) oxide (FeO) impurities produce a green tint in thick sections. Manganese dioxide (MnO2), which gives glass a purple colour, may be added to remove the green tint given by FeO. FeO and chromium(III) oxide (Cr2O3) additives are used in the production of green bottles. Iron (III) oxide, on the other-hand, produces yellow or yellow-brown glass. Low concentrations (0.025 to 0.1%) of cobalt oxide (CoO) produce rich, deep blue cobalt glass. Chromium is a very powerful colouring agent, yielding dark green. Sulphur combined with carbon and iron salts produces amber glass ranging from yellowish to almost black. A glass melt can also acquire an amber colour from a reducing combustion atmosphere. Cadmium sulfide produces imperial red, and combined with selenium can produce shades of yellow, orange, and red. Addition of copper(II) oxide (CuO) produces a turquoise colour in glass, in contrast to copper(I) oxide (Cu2O) which gives a dull red-brown colour.
- Iron(II) oxide and chromium(III) oxide additives are often used in the production of green bottles.
- Cobalt oxide produces rich, deep blue glass, such as Bristol blue glass.
- Different oxide additives produce the different colours in glass: turquoise (copper(II) oxide), purple (manganese dioxide), and red (cadmium sulfide).
- Red glass bottle with yellow glass overlay
- Amber-coloured glass
- Four-colour Roman glass bowl, manufactured c. 1st century B.C.
Uses
Architecture and windows
Main articles: Architectural glass and WindowSoda–lime sheet glass is typically used as a transparent glazing material, typically as windows in external walls of buildings. Float or rolled sheet glass products are cut to size either by scoring and snapping the material, laser cutting, water jets, or diamond-bladed saw. The glass may be thermally or chemically tempered (strengthened) for safety and bent or curved during heating. Surface coatings may be added for specific functions such as scratch resistance, blocking specific wavelengths of light (e.g. infrared or ultraviolet), dirt-repellence (e.g. self-cleaning glass), or switchable electrochromic coatings.
Structural glazing systems represent one of the most significant architectural innovations of modern times, where glass buildings now often dominate the skylines of many modern cities. These systems use stainless steel fittings countersunk into recesses in the corners of the glass panels allowing strengthened panes to appear unsupported creating a flush exterior. Structural glazing systems have their roots in iron and glass conservatories of the nineteenth century
Tableware
Main articles: Tableware and List of glasswareGlass is an essential component of tableware and is typically used for water, beer and wine drinking glasses. Wine glasses are typically stemware, i.e. goblets formed from a bowl, stem, and foot. Crystal or Lead crystal glass may be cut and polished to produce decorative drinking glasses with gleaming facets. Other uses of glass in tableware include decanters, jugs, plates, and bowls.
- Wine glasses and other glass tableware
- Dimpled glass beer pint jug
- lead crystal cut glass
- A glass decanter and stopper
Packaging
Main article: Container glassThe inert and impermeable nature of glass makes it a stable and widely used material for food and drink packaging as glass bottles and jars. Most container glass is soda–lime glass, produced by blowing and pressing techniques. Container glass has a lower magnesium oxide and sodium oxide content than flat glass, and a higher silica, calcium oxide, and aluminium oxide content. Its higher content of water-insoluble oxides imparts slightly higher chemical durability against water, which is advantageous for storing beverages and food. Glass packaging is sustainable, readily recycled, reusable and refillable.
For electronics applications, glass can be used as a substrate in the manufacture of integrated passive devices, thin-film bulk acoustic resonators, and as a hermetic sealing material in device packaging, including very thin solely glass based encapsulation of integrated circuits and other semiconductors in high manufacturing volumes.
Laboratories
Main article: Laboratory glasswareGlass is an important material in scientific laboratories for the manufacture of experimental apparatus because it is relatively cheap, readily formed into required shapes for experiment, easy to keep clean, can withstand heat and cold treatment, is generally non-reactive with many reagents, and its transparency allows for the observation of chemical reactions and processes. Laboratory glassware applications include flasks, Petri dishes, test tubes, pipettes, graduated cylinders, glass-lined metallic containers for chemical processing, fractionation columns, glass pipes, Schlenk lines, gauges, and thermometers. Although most standard laboratory glassware has been mass-produced since the 1920s, scientists still employ skilled glassblowers to manufacture bespoke glass apparatus for their experimental requirements.
- A Vigreux column in a laboratory setup
- A Schlenk line with four ports
- Graduated cylinders
- Erlenmeyer flask
Optics
Glass is a ubiquitous material in optics because of its ability to refract, reflect, and transmit light. These and other optical properties can be controlled by varying chemical compositions, thermal treatment, and manufacturing techniques. The many applications of glass in optics include glasses for eyesight correction, imaging optics (e.g. lenses and mirrors in telescopes, microscopes, and cameras), fibre optics in telecommunications technology, and integrated optics. Microlenses and gradient-index optics (where the refractive index is non-uniform) find application in e.g. reading optical discs, laser printers, photocopiers, and laser diodes.
Modern Art
Main articles: Studio glass, Art glass, and Glass artThe 19th century saw a revival in ancient glassmaking techniques including cameo glass, achieved for the first time since the Roman Empire, initially mostly for pieces in a neo-classical style. The Art Nouveau movement made great use of glass, with René Lalique, Émile Gallé, and Daum of Nancy in the first French wave of the movement, producing coloured vases and similar pieces, often in cameo glass or lustre glass techniques.
Louis Comfort Tiffany in America specialised in stained glass, both secular and religious, in panels and his famous lamps. The early 20th century saw the large-scale factory production of glass art by firms such as Waterford and Lalique. Small studios may hand-produce glass artworks. Techniques for producing glass art include blowing, kiln-casting, fusing, slumping, pâte de verre, flame-working, hot-sculpting and cold-working. Cold work includes traditional stained glass work and other methods of shaping glass at room temperature. Objects made out of glass include vessels, paperweights, marbles, beads, sculptures and installation art.
- The Portland Vase, Roman cameo glass, about 5–25 AD
- Byzantine cloisonné enamel plaque of St Demetrios, c. 1100, using the senkschmelz or "sunk" technique
- Émile Gallé, Marquetry glass vase with clematis flowers (1890–1900)
- Glass vase by Art Nouveau artist René Lalique
- Clara Driscoll Tiffany lamp, laburnum pattern, c. 1910
- A glass sculpture by Dale Chihuly, The Sun, at the "Gardens of Glass" exhibition in Kew Gardens, London
- The Glass Flowers by Leopold and Rudolf Blaschka, exhibited at the Harvard Museum of Natural History
See also
- Aluminium oxynitride transparent ceramic
- Fire glass
- Flexible glass
- Glass in green buildings
- Kimberley points
- Prince Rupert's drop
- Smart glass
References
- ASTM definition of glass from 1945
- ^ Zallen, R. (1983). The Physics of Amorphous Solids. New York: John Wiley. pp. 1–32. ISBN 978-0-471-01968-8.
- Cusack, N.E. (1987). The physics of structurally disordered matter: an introduction. Adam Hilger in association with the University of Sussex press. p. 13. ISBN 978-0-85274-829-9.
- ^ Scholze, Horst (1991). Glass – Nature, Structure, and Properties. Springer. pp. 3–5. ISBN 978-0-387-97396-8.
- ^ Elliot, S.R. (1984). Physics of Amorphous Materials. Longman group ltd. pp. 1–52. ISBN 0-582-44636-8.
- Neumann, Florin. "Glass: Liquid or Solid – Science vs. an Urban Legend". Archived from the original on 9 April 2007. Retrieved 8 April 2007.
- ^ Gibbs, Philip. "Is glass liquid or solid?". Archived from the original on 29 March 2007. Retrieved 21 March 2007.
- "Philip Gibbs" Glass Worldwide, (May/June 2007), pp. 14–18
- Salmon, P.S. (2002). "Order within disorder". Nature Materials. 1 (2): 87–8. doi:10.1038/nmat737. ISSN 1476-1122. PMID 12618817. S2CID 39062607.
- Ashtekar, Sumit; Scott, Gregory; Lyding, Joseph; Gruebele, Martin (2010). "Direct Visualization of Two-State Dynamics on Metallic Glass Surfaces Well Below Tg". J. Phys. Chem. Lett. 1 (13): 1941–1945. arXiv:1006.1684. doi:10.1021/jz100633d. S2CID 93171134.
- Vannoni, M.; Sordini, A.; Molesini, G. (2011). "Relaxation time and viscosity of fused silica glass at room temperature". Eur. Phys. J. E. 34 (9): 9–14. doi:10.1140/epje/i2011-11092-9. PMID 21947892. S2CID 2246471.
- Anderson, P.W. (1995). "Through the Glass Lightly". Science. 267 (5204): 1615–16. doi:10.1126/science.267.5204.1615-e. PMID 17808155. S2CID 28052338.
- Phillips, J.C. (1979). "Topology of covalent non-crystalline solids I: Short-range order in chalcogenide alloys". Journal of Non-Crystalline Solids. 34 (2): 153. Bibcode:1979JNCS...34..153P. doi:10.1016/0022-3093(79)90033-4.
- Folmer, J.C.W.; Franzen, Stefan (2003). "Study of polymer glasses by modulated differential scanning calorimetry in the undergraduate physical chemistry laboratory". Journal of Chemical Education. 80 (7): 813. Bibcode:2003JChEd..80..813F. doi:10.1021/ed080p813.
- Loy, Jim. "Glass Is A Liquid?". Archived from the original on 14 March 2007. Retrieved 21 March 2007.
- "Obsidian: Igneous Rock – Pictures, Uses, Properties". geology.com.
- "Impactites: Impact Breccia, Tektites, Moldavites, Shattercones". geology.com.
- Klein, Hermann Joseph (1 January 1881). Land, sea and sky; or, Wonders of life and nature, tr. from the Germ. [Die Erde und ihr organisches Leben] of H.J. Klein and dr. Thomé, by J. Minshull.
- Giaimo, Cara (June 30, 2017). "The Long, Weird Half-Life of Trinitite". Atlas Obscura. Retrieved July 8, 2017.
- Roperch, Pierrick; Gattacceca, Jérôme; Valenzuela, Millarca; Devouard, Bertrand; Lorand, Jean-Pierre; Arriagada, Cesar; Rochette, Pierre; Latorre, Claudio; Beck, Pierre (2017). "Surface vitrification caused by natural fires in Late Pleistocene wetlands of the Atacama Desert". Earth and Planetary Science Letters. 469 (1 July 2017): 15–26. Bibcode:2017E&PSL.469...15R. doi:10.1016/j.epsl.2017.04.009. S2CID 55581133.
- ^ Ward-Harvey, K. (2009). Fundamental Building Materials. Universal-Publishers. pp. 83–90. ISBN 978-1-59942-954-0.
- "Digs Reveal Stone-Age Weapons Industry With Staggering Output". National Geographic News. 13 April 2015. Archived from the original on 3 October 2019.
- ^ Julian Henderson (2013). Ancient Glass. Cambridge University Press. pp. 127–157. doi:10.1017/CBO9781139021883.006.
- "Glass Online: The History of Glass". Archived from the original on 24 October 2011. Retrieved 29 October 2007.
- "All About Glass | Corning Museum of Glass". www.cmog.org.
- Karklins, Karlis (January 2013). "Simon Kwan – Early Chinese Faience and Glass Beads and Pendants". BEADS: Journal of the Society of Bead Researchers.
- Kenoyer, J.M (2001). "Bead Technologies at Harappa, 3300–1900 BC: A Comparative Summary". South Asian Archaeology (PDF). Paris. pp. 157–170. Archived (PDF) from the original on 8 July 2019.
{{cite book}}
: CS1 maint: location missing publisher (link) - McIntosh, Jane (2008). The Ancient Indus Valley: New Perspectives. ABC-CLIO. p. 99. ISBN 978-1-57607-907-2.
- "How did Manufactured Glass Develop in the Bronze Age? - DailyHistory.org". dailyhistory.org.
- Wilde, H. "Technologische Innovationen im 2. Jahrtausend v. Chr. Zur Verwendung und Verbreitung neuer Werkstoffe im ostmediterranen Raum". GOF IV, Bd 44, Wiesbaden 2003, 25–26.
- Douglas, R.W. (1972). A history of glassmaking. Henley-on-Thames: G T Foulis & Co Ltd. p. 5. ISBN 978-0-85429-117-5.
- Whitehouse, David (2003). Roman Glass in the Corning Museum of Glass, Volume 3. Hudson Hills. p. 45. ISBN 978-0-87290-155-1.
- The Art Journal. Virtue and Company. 1888. p. 365.
- Brown, A.L. (November 1921). "The Manufacture of Glass Milk Bottles". The Glass Industry. 2 (11). Ashlee Publishing Company: 259.
- Aton, Francesca, Perfectly Preserved 2,000-Year-Old Roman Glass Bowl Unearthed in the Netherlands, Art News, January 25, 2022
- McGreevy, Nora, 2,000-Year-Old Roman Bowl Discovered Intact in the Netherlands, National Geographic, January 28, 2022
- Dien, Albert E. (2007). Six Dynasties Civilization. Yale University Press. p. 290. ISBN 978-0-300-07404-8.
- Silberman, Neil Asher; Bauer, Alexander A. (2012). The Oxford Companion to Archaeology. Oxford University Press. p. 29. ISBN 978-0-19-973578-5.
- ^ "glass | Definition, Composition, & Facts". Encyclopedia Britannica. 2 October 2023.
- Oliver, Roland, and Fagan, Brian M. Africa in the Iron Age, c500 B.C. to A.D. 1400. New York: Cambridge University Press, p. 187. ISBN 0-521-20598-0.
- Keller, Daniel; Price, Jennifer; Jackson, Caroline (2014). Neighbours and Successors of Rome: Traditions of Glass Production and use in Europe and the Middle East in the Later 1st Millennium AD. Oxbow Books. pp. 1–41. ISBN 978-1-78297-398-0.
- Tutag, Nola Huse; Hamilton, Lucy (1987). Discovering Stained Glass in Detroit. Wayne State University Press. pp. 11. ISBN 978-0-8143-1875-1.
- Packard, Robert T.; Korab, Balthazar; Hunt, William Dudley (1980). Encyclopedia of American architecture. McGraw-Hill. pp. 268. ISBN 978-0-07-048010-0.
- ^ [REDACTED] One or more of the preceding sentences incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Glass". Encyclopædia Britannica. Vol. 12 (11th ed.). Cambridge University Press. p. 86.
- Freiman, Stephen (2007). Global Roadmap for Ceramic and Glass Technology. John Wiley & Sons. p. 705. ISBN 978-0-470-10491-0.
- "Depression Glass". Archived from the original on 2 December 2014. Retrieved 19 October 2007.
- Gelfand, Lisa; Duncan, Chris (2011). Sustainable Renovation: Strategies for Commercial Building Systems and Envelope. John Wiley & Sons. p. 187. ISBN 978-1-118-10217-6.
- Lim, Henry W.; Honigsmann, Herbert; Hawk, John L.M. (2007). Photodermatology. CRC Press. p. 274. ISBN 978-1-4200-1996-4.
- Bach, Hans; Neuroth, Norbert (2012). The Properties of Optical Glass. Springer. p. 267. ISBN 978-3-642-57769-7.
- McLean, Ian S. (2008). Electronic Imaging in Astronomy: Detectors and Instrumentation. Springer Science & Business Media. p. 78. ISBN 978-3-540-76582-0.
- ^ "Glass Applications – Glass Alliance Europe". Glassallianceeurope.eu. Retrieved 1 March 2020.
- Enteria, Napoleon; Akbarzadeh, Aliakbar (2013). Solar Energy Sciences and Engineering Applications. CRC Press. p. 122. ISBN 978-0-203-76205-9.
- "Gorilla Glass maker unveils ultra-thin and flexible Willow Glass". Physics News. Archived from the original on 6 November 2013. Retrieved 1 November 2013.
- "Xensation". Schott. Archived from the original on 3 November 2013. Retrieved 1 November 2013.
- Fingas, Jon (19 July 2018). "Gorilla Glass 6 gives phones a better shot at surviving multiple drops". Engadget.
- ^ Bach, Hans; Neuroth, Norbert (2012). The Properties of Optical Glass. Springer. pp. 1–11. ISBN 978-3-642-57769-7.
- White, Mary Anne (2011). Physical Properties of Materials, Second Edition. CRC Press. p. 70. ISBN 978-1-4398-9532-0.
- Carter, C. Barry; Norton, M. Grant (2007). Ceramic Materials: Science and Engineering. Springer Science & Business Media. p. 583. ISBN 978-0-387-46271-4.
- Mysen, Bjorn O.; Richet, Pascal (2005). Silicate Glasses and Melts: Properties and Structure. Elsevier. p. 10.
- ^ "Industrial glass – Properties of glass". Encyclopedia Britannica.
- Mattox, D.M. (2014). Handbook of Physical Vapor Deposition (PVD) Processing. Cambridge University Press. p. 60. ISBN 978-0-08-094658-0.
- Zarzycki, Jerzy (1991). Glasses and the Vitreous State. Cambridge University Press. p. 361. ISBN 978-0-521-35582-7.
- Thomas, Alfred; Jund, Michael (2013). Collision Repair and Refinishing: A Foundation Course for Technicians. Cengage Learning. p. 365. ISBN 978-1-133-60187-6.
- ^ Gardner, Irvine Clifton; Hahner, Clarence H. (1949). Research and Development in Applied Optics and Optical Glass at the National Bureau of Standards: A Review and Bibliography. U.S. Government Printing Office. p. 13. ISBN 9780598682413.
- Dudeja, Puja; Gupta, Rajul K.; Minhas, Amarjeet Singh (2016). Food Safety in the 21st Century: Public Health Perspective. Academic Press. p. 550. ISBN 978-0-12-801846-0.
- Bengisu, M. (2013). Engineering Ceramics. Springer Science & Business Media. p. 360. ISBN 978-3-662-04350-9.
- Batchelor, Andrew W.; Loh, Nee Lam; Chandrasekaran, Margam (2011). Materials Degradation and Its Control by Surface Engineering. World Scientific. p. 141. ISBN 978-1-908978-14-1.
- ^ Chawla, Sohan L. (1993). Materials Selection for Corrosion Control. ASM International. pp. 327–328. ISBN 978-1-61503-728-5.
- Shaye Storm (2004). "Density of Glass". The Physics Factbook: An encyclopedia of scientific essays. Wikidata Q87511351.
- "Glass Strength". www.pilkington.com. Archived from the original on 26 July 2017. Retrieved 24 November 2017.
- Kenneth Chang (29 July 2008). "The Nature of Glass Remains Anything but Clear". The New York Times. Archived from the original on 24 April 2009. Retrieved 29 July 2008.
- Gulbiten, Ozgur; Mauro, John C.; Guo, Xiaoju; Boratav, Olus N. (3 August 2017). "Viscous flow of medieval cathedral glass". Journal of the American Ceramic Society. 101 (1): 5–11. doi:10.1111/jace.15092. ISSN 0002-7820.
- Gocha, April (3 August 2017). "Glass viscosity calculations definitively debunk the myth of observable flow in medieval windows". The American Ceramic Society.
- ^ "Mining the sea sand". Seafriends. 8 February 1994. Archived from the original on 29 February 2012. Retrieved 15 May 2012.
- ^ "Glass – Chemistry Encyclopedia". Archived from the original on 2 April 2015. Retrieved 1 April 2015.
- ^ B.H.W.S. de Jong, "Glass"; in "Ullmann's Encyclopedia of Industrial Chemistry"; 5th edition, vol. A12, VCH Publishers, Weinheim, Germany, 1989, ISBN 978-3-527-20112-9, pp. 365–432.
- ^ Spence, William P.; Kultermann, Eva (2016). Construction Materials, Methods and Techniques. Cengage Learning. pp. 510–526. ISBN 978-1-305-08627-2.
- "Properties of PYREX®, PYREXPLUS® and Low Actinic PYREX Code 7740 Glasses" (PDF). Corning, Inc. Archived (PDF) from the original on 13 January 2012. Retrieved 15 May 2012.
- "AR-GLAS® Technical Data" (PDF). Schott, Inc. Archived (PDF) from the original on 12 June 2012.
- Shelby, J.E. (2017). Introduction to Glass Science and Technology. Royal Society of Chemistry. p. 125. ISBN 978-0-85404-639-3.
- Schwartz, Mel (2002). Encyclopedia of Materials, Parts and Finishes (Second ed.). CRC Press. p. 352. ISBN 978-1-4200-1716-8.
- Shackelford, James F.; Doremus, Robert H. (12 April 2008). Ceramic and Glass Materials: Structure, Properties and Processing. Springer Science & Business Media. p. 158. ISBN 978-0-387-73362-3.
- Askeland, Donald R.; Fulay, Pradeep P. (2008). Essentials of Materials Science & Engineering. Cengage Learning. p. 485. ISBN 978-0-495-24446-2.
- "Glass Ingredients – What is Glass Made Of?". www.historyofglass.com. Archived from the original on 23 April 2017. Retrieved 23 April 2017.
- Pfaender, Heinz G. (1996). Schott guide to glass. Springer. pp. 135, 186. ISBN 978-0-412-62060-7. Archived from the original on 25 May 2013. Retrieved 8 February 2011.
- Doering, Robert; Nishi, Yoshio (2007). Handbook of semiconductor manufacturing technology. CRC Press. pp. 12–13. ISBN 978-1-57444-675-3.
- ^ Holand, Wolfram; Beall, George H. (2012). Glass Ceramic Technology. John Wiley & Sons. pp. 1–38. ISBN 978-1-118-26592-5.
- Richerson, David W. (1992). Modern ceramic engineering : properties, processing and use in design (2nd ed.). New York: Dekker. pp. 577–578. ISBN 978-0-8247-8634-2.
- ^ Parkyn, Brian (2013). Glass Reinforced Plastics. Elsevier. pp. 3–41. ISBN 978-1-4831-0298-6.
- Mayer, Rayner M. (1993). Design with reinforced plastics. Springer. p. 7. ISBN 978-0-85072-294-9.
- ^ "Properties of Matter Reading Selection: Perfect Teamwork". www.propertiesofmatter.si.edu. Archived from the original on 12 May 2016. Retrieved 25 April 2017.
- ^ "Fibreglass | glass". Encyclopedia Britannica. 28 August 2024.
- Greer, A. Lindsay; Mathur, N (2005). "Materials science: Changing Face of the Chameleon". Nature. 437 (7063): 1246–1247. Bibcode:2005Natur.437.1246G. doi:10.1038/4371246a. PMID 16251941. S2CID 6972351.
- Rivera, V. A. G.; Manzani, Danilo (30 March 2017). Technological Advances in Tellurite Glasses: Properties, Processing, and Applications. Springer. p. 214. ISBN 978-3-319-53038-3.
- Jiang, Xin; Lousteau, Joris; Richards, Billy; Jha, Animesh (1 September 2009). "Investigation on germanium oxide-based glasses for infrared optical fibre development". Optical Materials. 31 (11): 1701–1706. Bibcode:2009OptMa..31.1701J. doi:10.1016/j.optmat.2009.04.011.
- J. W. E. Drewitt; S. Jahn; L. Hennet (2019). "Configurational constraints on glass formation in the liquid calcium aluminate system". Journal of Statistical Mechanics: Theory and Experiment. 2019 (10): 104012. arXiv:1909.07645. Bibcode:2019JSMTE..10.4012D. doi:10.1088/1742-5468/ab47fc. S2CID 202583753.
- C. J. Benmore; J. K. R. Weber (2017). "Aerodynamic levitation, supercooled liquids and glass formation". Advances in Physics: X. 2 (3): 717–736. Bibcode:2017AdPhX...2..717B. doi:10.1080/23746149.2017.1357498.
- Davies, H. A.; Hull J. B. (1976). "The formation, structure and crystallization of non-crystalline nickel produced by splat-quenching". Journal of Materials Science. 11 (2): 707–717. Bibcode:1976JMatS..11..215D. doi:10.1007/BF00551430. S2CID 137403190.
- Klement, W. Jr.; Willens, R.H.; Duwez, Pol (1960). "Non-crystalline Structure in Solidified Gold-Silicon Alloys". Nature. 187 (4740): 869. Bibcode:1960Natur.187..869K. doi:10.1038/187869b0. S2CID 4203025.
- Liebermann, H.; Graham, C. (1976). "Production of Amorphous Alloy Ribbons and Effects of Apparatus Parameters on Ribbon Dimensions". IEEE Transactions on Magnetics. 12 (6): 921. Bibcode:1976ITM....12..921L. doi:10.1109/TMAG.1976.1059201.
- Ponnambalam, V.; Poon, S. Joseph; Shiflet, Gary J. (2004). "Fe-based bulk metallic glasses with diameter thickness larger than one centimeter". Journal of Materials Research. 19 (5): 1320. Bibcode:2004JMatR..19.1320P. doi:10.1557/JMR.2004.0176. S2CID 138846816.
- "Metallurgy Division Publications". NIST Interagency Report 7127. Archived from the original on 16 September 2008.
- Mendelev, M.I.; Schmalian, J.; Wang, C.Z.; Morris, J.R.; K.M. Ho (2006). "Interface Mobility and the Liquid-Glass Transition in a One-Component System". Physical Review B. 74 (10): 104206. Bibcode:2006PhRvB..74j4206M. doi:10.1103/PhysRevB.74.104206.
- "A main research field: Polymer glasses". www-ics.u-strasbg.fr. Archived from the original on 25 May 2016.
- Carraher, Charles E. Jr. (2012). Introduction to Polymer Chemistry. CRC Press. p. 274. ISBN 978-1-4665-5495-5.
- Ruby, S.L.; Pelah, I. (2013). "Crystals, Supercooled Liquids, and Glasses in Frozen Aqueous Solutions". In Gruverman, Irwin J. (ed.). Mössbauer Effect Methodology: Volume 6 Proceedings of the Sixth Symposium on Mössbauer Effect Methodology New York City, January 25, 1970. Springer Science & Business Media. p. 21. ISBN 978-1-4684-3159-9.
- Levine, Harry; Slade, Louise (2013). Water Relationships in Foods: Advances in the 1980s and Trends for the 1990s. Springer Science & Business Media. p. 226. ISBN 978-1-4899-0664-9.
- Dupuy J, Jal J, Prével B, Aouizerat-Elarby A, Chieux P, Dianoux AJ, Legrand J (October 1992). "Vibrational dynamics and structural relaxation in aqueous electrolyte solutions in the liquid, undercooled liquid and glassy states" (PDF). Journal de Physique IV. 2 (C2): C2-179–C2-184. Bibcode:1992JPhy4...2C.179D. doi:10.1051/jp4:1992225. S2CID 39468740. Archived (PDF) from the original on 9 May 2020. European Workshop on Glasses and Gels.
- Hartel, Richard W.; Hartel, AnnaKate (2014). Candy Bites: The Science of Sweets. Springer Science & Business Media. p. 38. ISBN 978-1-4614-9383-9.
- Charbel Tengroth (2001). "Structure of Ca0.4K0.6(NO3)1.4 from the glass to the liquid state". Phys. Rev. B. 64 (22): 224207. Bibcode:2001PhRvB..64v4207T. doi:10.1103/PhysRevB.64.224207.
- "Lithium-Ion Pioneer Introduces New Battery That's Three Times Better". Fortune. Archived from the original on 9 April 2017. Retrieved 6 May 2017.
- Glassblowing at the Encyclopædia Britannica
- "PFG Glass". Pfg.co.za. Archived from the original on 6 November 2009. Retrieved 24 October 2009.
- Code of Federal Regulations, Title 40,: Protection of Environment, Part 60 (Sections 60.1-end), Revised As of July 1, 2011. Government Printing Office. October 2011. ISBN 978-0-16-088907-3.
- Ball, Douglas J.; Norwood, Daniel L.; Stults, Cheryl L. M.; Nagao, Lee M. (24 January 2012). Leachables and Extractables Handbook: Safety Evaluation, Qualification, and Best Practices Applied to Inhalation Drug Products. John Wiley & Sons. p. 552. ISBN 978-0-470-17365-7.
- Chisholm, Hugh, ed. (1911). "Glass" . Encyclopædia Britannica. Vol. 12 (11th ed.). Cambridge University Press. pp. 87–105.
- "windshields how they are made". autoglassguru. Retrieved 9 February 2018.
- Pantano, Carlo. "Glass Surface Treatments: Commercial Processes Used in Glass Manufacture" (PDF). Archived (PDF) from the original on 9 September 2015.
- ^ "Glass melting, Pacific Northwest National Laboratory". Depts.washington.edu. Archived from the original on 5 May 2010. Retrieved 24 October 2009.
- Fluegel, Alexander. "Glass melting in the laboratory". Glassproperties.com. Archived from the original on 13 February 2009. Retrieved 24 October 2009.
- ^ Mukherjee, Swapna (2013). The Science of Clays: Applications in Industry, Engineering, and Environment. Springer Science & Business Media. p. 142. ISBN 978-9-4007-6683-9.
- Walker, Perrin; Tarn, William H. (1990). CRC Handbook of Metal Etchants. CRC press. p. 798. ISBN 978-1-4398-2253-1.
- ^ Langhamer, Antonín (2003). The Legend of Bohemian Glass: A Thousand Years of Glassmaking in the Heart of Europe. Tigris. p. 273. ISBN 978-8-0860-6211-2.
- "3. Glass, Colour and the Source of Cobalt". Internet Archaeology. doi:10.11141/ia.52.3.
- Chemical Fact Sheet – Chromium Archived 2017-08-15 at the Wayback Machine www.speclab.com.
- David M Issitt. Substances Used in the Making of Coloured Glass 1st.glassman.com.
- Shelby, James E. (2007). Introduction to Glass Science and Technology. Royal Society of Chemistry. p. 211. ISBN 978-1-84755-116-0.
- ^ Nicholson, Paul T.; Shaw, Ian (2000). Ancient Egyptian Materials and Technology. Cambridge University Press. p. 208. ISBN 978-0-521-45257-1.
- Weller, Bernhard; Unnewehr, Stefan; Tasche, Silke; Härth, Kristina (2012). Glass in Building: Principles, Applications, Examples. Walter de Gruyter. pp. 1–19. ISBN 978-3-0346-1571-6.
- ^ "The rise of glass buildings". Glass Times. 9 January 2017. Retrieved 1 March 2020.
- Patterson, Mic (2011). Structural Glass Facades and Enclosures. Jon Wiley & Sons. p. 29. ISBN 978-0-470-93185-1.
- Hynes, Michael; Jonson, Bo (1997). "Lead, glass and the environment". Chemical Society Reviews. 26 (2): 145. doi:10.1039/CS9972600133.
- "Cut glass | decorative arts". Encyclopedia Britannica.
- "High temperature glass melt property database for process modeling"; Eds.: Thomas P. Seward III and Terese Vascott; The American Ceramic Society, Westerville, Ohio, 2005, ISBN 1-57498-225-7
- "Why choose Glass?". FEVE.
- Sun, P.; et, al. (2018). "Design and Fabrication of Glass-based Integrated Passive Devices". 2018 19th International Conference on Electronic Packaging Technology (ICEPT). pp. 59–63. doi:10.1109/ICEPT.2018.8480458. ISBN 978-1-5386-6386-8. S2CID 52935909.
- Letz, M.; et, al. (2018). "Glass in Electronic Packaging and Integration: High Q Inductances for 2.35 GHZ Impedance Matching in 0.05 mm Thin Glass Substrates". 2018 IEEE 68th Electronic Components and Technology Conference (ECTC). pp. 1089–1096. doi:10.1109/ECTC.2018.00167. ISBN 978-1-5386-4999-2. S2CID 51972637.
- Lundén, H.; et, al. (2014). "Novel glass welding technique for hermetic encapsulation". Proceedings of the 5th Electronics System-integration Technology Conference (ESTC). pp. 1–4. doi:10.1109/ESTC.2014.6962719. ISBN 978-1-4799-4026-4. S2CID 9980556.
- ^ Zumdahl, Steven (2013). Lab Manual. Cengage Learning. pp. ix–xv. ISBN 978-1-285-69235-7.
- "Science Under Glass". National Museum of American History. 29 July 2015. Archived from the original on 10 March 2020. Retrieved 4 March 2020.
- Basudeb, Karmakar (2017). Functional Glasses and Glass-Ceramics: Processing, Properties and Applications. Butterworth-Heinemann. pp. 3–5. ISBN 978-0-12-805207-5.
- "Scientific Glassblowing | National Museum of American History". Americanhistory.si.edu. 17 December 2012. Archived from the original on 11 March 2020. Retrieved 4 March 2020.
- Arwas, Victor (1996). The Art of Glass: Art Nouveau to Art Deco. Papadakis Publisher. pp. 1–54. ISBN 978-1-901092-00-4.
- "A-Z of glass". Victoria and Albert Museum. Retrieved 9 March 2020.
External links
- "Glass" . Encyclopædia Britannica. Vol. 12 (11th ed.). 1911.
- The Story of Glass Making in Canada from The Canadian Museum of Civilization.
- "How Your Glass Ware Is Made" by George W. Waltz, February 1951, Popular Science.
- All About Glass from the Corning Museum of Glass: a collection of articles, multimedia, and virtual books all about glass, including the Glass Dictionary.