Effects of reducing atmosphere and iron content on UV transmission property of alkali-silicate and alkali-borosilicate glasses

• Published in: Journal of non-crystalline solids 2023-03, Vol.604, p.122135, Article 122135
• Main Authors: Shi, Wangming, Ding, Mengzhao, Luo, Lida, Ding, Linfeng, Li, Hong, Wang, Qingwei
• Format: Article
• Language: English
• Subjects: Boron structure; Borosilicate glass; Iron oxide; Iron reduction index; Reducing atmosphere; Ultraviolet transmittance
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2023.122135

•The UV transmittance of alkali-silicate and alkali-borosilicate glasses with different reducing atmosphere were studied.•Different reducing atmosphere not only affects [BO4] content in alkali-borosilicate glass, but also changes IRI greatly.•The αFe(III)/αFe(II) ratio derived is 4.19 for the BR-glass series and 3.93 for the BFR-glass series at 254 nm.•There is nonlinear relationship or effect of iron content on the UV transmittance for alkali-borosilicate glass, the effect is greater at a lower Fe(III) amount. The effects of the reducing atmosphere during glass melting and the iron content in glass on the ultraviolet (UV) transmission property of borosilicate and silicate glasses were studied. The reducing atmosphere is controlled by the amount of citric acid in each glass batch. The effects of reducing atmosphere on the glass UV transmittance were examined in terms of the distribution of trigonal boron (BO3) and tetrahedral boron (BO4) units and iron reduction index (IRI). Our study reveals that the reducing atmospheres not only had a significant effect on the boron-oxygen structure of alkali-borosilicate glass, but also on the UV transmittance. In addition, IRI has a significant effect on the UV transmittance at a wavelength of 254 nm, with a relative change up to 461%. The iron oxidation state was found to affect the UV absorption coefficient of ferric ion (Fe(III) has about four times greater than that of ferrous ion (Fe(II)) at 254 nm.