РАЗРАБОТКА И ПОИСК ФУНКЦИОНАЛЬНОСТЕЙ НОВЫХ ОРГАНОКРЕМНЕЗЕМНЫХ ГИБРИДНЫХ НАНОКОМПОЗИТОВ С ВКЛЮЧЕНИЕМ БИОПОЛИМЕРОВ ХИТОЗАНА В СИЛОКСАНОВУЮ ОСНОВУ ПРИ ИХ ПРЕОБРАЗОВАНИИ В МОНОДИСПЕРСНЫЕ ЧАСТИЦЫ МЕЗОПОРИСТОГО КРЕМНЕЗЕМА

Abstract

A new universal approach to the biomimetic synthesis of hybrid organosilicate nanocomposites with texture and functionality good control has been developed, which consists in the use of biomacromolecules as mesogenic templates. The main strategy is to combine the self-association of polysaccharide nanorods with the flexibility of the sol-gel process in the chemistry of siloxane oligomers formed at various pH values of 3, 5, 8. The measured isotherms of low-temperature nitrogen adsorption-desorption by samples obtained at pH 5 and 8 refer to isotherms of type IV (a) characteristic of mesoporous adsorbents. The isotherms are dominated by the triangular hysteresis H2(a), which is due to network effects in ordered mesoporous materials of the SBA-16 and KIT-5 types. The isotherms of the samples obtained at pH 3 are of the hybrid type (I+IV) with the H4 hysteresis inherent in microporous adsorbents with slit-like mesopores between agglomerates of silica particles. It is shown that the control of the textural properties of hybrid nanocomposites and porous silica is possible by changing the temperature of thermal activation of organosilicate samples and the pH value of the silica gel precipitation medium. The advantage of the developed synthesis is the formation of new functionalities on the surface of silica through its heat treatment while maintaining the polysaccharide template either as its own functional basis or as a carbon resource.