Editing Vycor

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'''Vycor''' is the brand name of [[Corning Incorporated|Corning's]] high-silica, high-temperature [[glass]]. It provides very high [[thermal shock]] resistance. Vycor is approximately 96% [[silica]] and 4% [[boron trioxide]], but unlike pure [[fused silica]], it can be readily manufactured in a variety of shapes.{{Citation needed|date=February 2024}} Vycor can be subject to prolonged usage at 900 °C.<ref>{{Cite journal |last=Nordberg |first=Martin E. |date=November 1944 |title=PROPERTIES OF SOME VYCOR-BRAND GLASSES * |url=https://ceramics.onlinelibrary.wiley.com/doi/10.1111/j.1151-2916.1944.tb14473.x |journal=Journal of the American Ceramic Society |language=en |volume=27 |issue=10 |pages=299–305 |doi=10.1111/j.1151-2916.1944.tb14473.x |issn=0002-7820|url-access=subscription }}</ref>

Vycor products are made by a multi-step process. First, a relatively soft alkali-borosilicate
glass is melted and formed by typical glassworking techniques into the desired shape. This is heat-treated, which causes the material to separate into two intermingled "phases" with distinct chemical compositions. One phase is rich in alkali and boric oxide and can be easily dissolved in [[acid]]. The other phase is mostly silica, which is [[Solubility|insoluble]]. The glass object is then soaked in a hot acid solution, which leaches away the soluble glass phase, leaving an object which is mostly silica. At this stage, the glass is [[porosity|porous]]. Finally, the object is heated to more than 1200&nbsp;°C, which consolidates the porous structure, making the object shrink slightly and become non-porous. The finished material is classified as a "reconstructed glass".{{Citation needed|date=February 2024}}

For some applications the final step is skipped, leaving the glass porous. Such glass has a high affinity for water and makes an excellent [[getter]] for water vapour. It is widely used in science and engineering.{{Citation needed|date=February 2024}}

Vycor has an extremely low coefficient of thermal expansion, just one quarter that of [[Pyrex]].<ref>{{cite web |title=Properties of VYCOR Code 7913 96% Silica High Temperature Glass |url=http://csmedia2.corning.com/LifeSciences//media/pdf/Description_of_VYCOR_Code_7913.pdf |publisher=Corning Glass, Inc. |access-date=2014-12-20}}</ref> This property makes the material suitable for use in applications that demand very high dimensional stability, such as [[metrology]] instruments, and for products that need to withstand high thermal-shock loads. Vycor also has [[ultraviolet]] transmission to about 250&nbsp;nm<ref name="vycor7913">{{cite web |title=Corning Vycor® 7913 UV-Transmitting Glass |url=http://www.matweb.com/search/datasheettext.aspx?matid=748 |website=www.matweb.com |publisher=Corning |access-date=3 December 2019}}</ref> and is used in some [[germicidal lamp]]s.  Based on a reference thickness of 1mm, Vycor glass has an approximately 90% transmission spectra from ~300&nbsp;nm to 3100&nbsp;nm.<ref>{{cite web |title=VYCOR® Code 7913 Optical Transmission |url=https://www.pgo-online.com/intl/curves/vycor_kurve.html |website=Präzisions Glas & Optik GmbH |access-date=23 October 2020}}</ref>

Immersing the porous glass in certain chemical solutions before the final consolidation step produces a colored glass that can withstand high temperatures without degrading. This is used for colored glass [[Filter (optics)|filter]]s for various applications.{{Citation needed|date=February 2024}}

Corning manufactures Vycor products for high-temperature applications, such as evaporating dishes.{{Citation needed|date=February 2024}}

Porous vycor is a prototypical matrix material for the study of [[confined liquid]] physics.{{Citation needed|date=February 2024}}

Vycor can also be used for removal of <sup>231</sup>Pa and <sup>233</sup>Pa in fuel recycling.<ref>{{Cite report |url=http://dx.doi.org/10.2172/4347358 |title=ADSORPTION OF PROTACTINIUM ON UNFIRED VYCOR: FINAL HOT-CELL EXPERIMENTS. |last1=Goode |first1=J. H. |last2=Moore |first2=J. G. |date=1967-01-01 |publisher=Office of Scientific and Technical Information (OSTI)|doi=10.2172/4347358 }}</ref>

==References==
{{reflist}}

*{{cite book | last=Elmer | first=Thomas H. | title=Engineered Materials Handbook, Vol. 4: Ceramics and Glasses |editor=Schneider, Samuel J.| access-date=2006-05-31 | year=1991 | publisher=ASM International | location=Materials Park, OH | isbn=0-87170-282-7 | pages=427–32 | chapter=Porous and Reconstructed Glasses | chapter-url=http://www.corning.com/lightingmaterials/images/porous.pdf }}
*{{cite book | title=ornl 3830 Chemical Separation Processes for Uranium and Plutonium | year=1965 | url=https://de.scribd.com/document/50118967/ornl-3830-Chemical-Separation-Processes-for-Uranium-and-Plutonium }}

==External links==
*[http://www.corning.com/lifesciences/us_canada/en/technical_resources/product_guid/glass/vycor.aspx Corning Inc.] Manufacturer's website
*[http://www.Momentivequartz.com Momentive Performance Materials, Inc.] Quartz and Low Softening Point Glass (LSPG) Manufacturer
*[http://glassproperties.com/phase-separation/ Phase separation in borosilicate and alkali earth silicate glasses]

{{Glass makers and brands}}

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