Abstract

The results are presented on studies of the content of Lewis and Brønsted centers on the internal surface of high-silica porous glass (PG) obtained by the through chemical etching of alkali-borosilicate glass with the two-frame structure, including the one modified by an isothermal treatment in an electric furnace in air in the temperature range from 120 to 750°C. The content of the active surface centers is determined by the adsorption of the acid-base indicators with different рK_а values. For all samples under investigation, the predominance of hydroxyl groups over siloxane ones is established, which indicates a high degree of surface hydroxylation; and the extreme dependence of the content of surface centers on the heat treatment temperature with the pronounced maximum at 650°C is found.

中文翻译：

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热改性高硅多孔玻璃吸附中心的形成特征

摘要

通过对具有两框架结构的碱硼硅酸盐玻璃进行化学刻蚀获得的高二氧化硅多孔玻璃（PG）内表面上的Lewis和Brønsted中心含量的研究，给出了结果，包括在电炉中于120至750°C的空气中进行等温处理。活性表面中心的内容是由与不同的р酸碱指示剂吸附测定ķ _а值。对于所研究的所有样品，确定了羟基优先于硅氧烷基的优势，这表明表面羟基化程度高。并且发现表面中心含量对热处理温度的极端依赖性，在650℃时有明显的最大值。