borate glass

File:HARMONY BORAX WORKS, DEATH VALLEY, CA.jpg

Borate glasses have a more complex action of alkali (or other modifier) ions than silicate glasses.{{cite web |url=http://www.ptc.tugraz.at/specmag/struct/sb.htm |title=Glasses - Alkali Borate Glasses |access-date=2013-05-28 |url-status=dead |archive-url=https://web.archive.org/web/20141201021600/http://www.ptc.tugraz.at/specmag/struct/sb.htm |archive-date=2014-12-01 }} In silicates, depolymerisation occurs due to the oxygen added alongside the alkali or modifier ions introducing non-bridging oxygen, whereas in borate glasses it can also lead to the conversion of trigonal planar BO3 units into singly charged BO4 tetrahedra,{{cite journal |last1=Alderman |first1=Oliver |last2=Tagiara |first2=Nagia |last3=Slagle |first3=Ian |last4=Gabrielsson |first4=Rebecca |last5=Boggs |first5=Piper |last6=Wagner |first6=Molly |last7=Rossini |first7=Aaron |last8=Martin |first8=Steve |last9=John |first9=Sophia |last10=Rocha |first10=Leilani |last11=Wilson |first11=Robert |last12=Hawbaker |first12=Harry |last13=Hannon |first13=Alex |last14=Kamitsos |first14=Efstratios |last15=Feller |first15=Steve |title=A Review of the Fraction of Four-Coordinated Boron in Binary Borate Glasses and Melts |journal=Reports on Progress in Physics |date=28 March 2025 |doi=10.1088/1361-6633/adc69c |url=https://iopscience.iop.org/article/10.1088/1361-6633/adc69c|url-access=subscription |doi-access=free }} thereby increasing, rather than decreasing the network connectivity and polymerisation. Borate glasses also have major differences in their optical and other properties.{{Cite journal|doi = 10.5402/2012/428497|title = A Review on Infrared Spectroscopy of Borate Glasses with Effects of Different Additives|year = 2012|last1 = Gautam|first1 = Chandkiram|last2 = Yadav|first2 = Avadhesh Kumar|last3 = Singh|first3 = Arbind Kumar|journal = ISRN Ceramics|volume = 2012|pages = 1–17|doi-access = free}}

The single largest use of boron compounds in the world (accounting for half of total global use) is the production of certain types of boron-treated glass fiber for insulating and structural fiberglass.{{Cite web |url=http://ec.europa.eu/enterprise/sectors/chemicals/files/docs_studies/annex_use_glass_glass_fibre_en.pdf |title=Archived copy |access-date=2013-05-29 |archive-date=2013-12-28 |archive-url=https://web.archive.org/web/20131228233038/http://ec.europa.eu/enterprise/sectors/chemicals/files/docs_studies/annex_use_glass_glass_fibre_en.pdf |url-status=dead }} In these uses the boron may be present as borax or boron oxide, and adds to the structural strength of the glass as borosilicate, or is added as a fluxing agent to decrease the melting temperature of pure silica, which is difficult to extrude as fibers and work with in pure form, due to the high temperatures involved.

References

Category:Glass