Hydroxyl groups in high-purity silica glass

Abstract

IR absorption spectra of high-purity silica glass ( SiO 2 ) of different types containing from 0.1 to 10 3 ppm of hydroxyl (OH) groups were studied and quantum-chemical calculations of different OH structures in the silica glass network were performed. On their basis a new approach to the problem of OH groups embedded in the glass network was proposed. It was shown that OH groups in high-purity SiO 2 occur mainly singly rather than as paired groups. Some of them are linked by hydrogen bonds to bridging oxygen atoms and not to each other, as is considered now. A new decomposition of the fundamental OH-stretching vibrational band into components was proposed.