Effect of Formation Conditions on the Functional Composition of the Surface of High-Silica Porous Glass

Abstract

The possibility of controlling the content and ratio of Brønsted acid to Lewis base centers on the surface of high-silica porous glass (PG) with various compositions based on two-phase alkali-borosilicate glass by varying the conditions of the preparation of PG during the acid work-up of the initial glass is shown. The results demonstrate the possibility to control the features of the surface of the PG, and in particular, the ratio of silanol to siloxane structures.

Selective Synthesis of 2,2,4,4-Tetrasilylpentasilane

“…These results may be explained with surface catalysis. A freshly cleaned borosilicate surface is acidified by the hydroxyl groups M–O–H (M = Si, B, or Al) . These surface hydroxyl groups may play an important role in the catalyzed selective conversion of NPS to BNS (eq ).…”

“…A freshly cleaned borosilicate surface is acidified by the hydroxyl groups M−O−H (M = Si, B, or Al). 10 These surface hydroxyl groups may play an important role in the catalyzed selective conversion of NPS to BNS (eq 1). As the reaction progresses, these surface hydroxyl groups can gradually be silanized by the formation of M−O−Si bonding to become deactivated (or passivated).…”