The Effect of Chemical Modification of the Surface by Oxysilanes on Changes in the Structural and Phase States of Highly Porous Aluminum Oxyhydroxides at Annealing up to 1200°C

Changes in the composition and physicochemical properties of porous monolithic 3D nanostructures of aluminum oxyhydroxides (porous monolithic aluminum oxides, PMAO) chemically modified in methyltrimethoxysilane vapors have been studied by thermal-analysis methods. The conditions of formation and compositions of organosilicon compounds on the PMAO surface have been determined, a high degree of hydrolysis (91%) of the alkoxy groups of the modifier during chemisorption has been confirmed. The dependence of the composition of the porous nanocomposite structure (Al2O3–SiO2) on the conditions of chemical and thermal treatment has been investigated. General changes in the chemical composition of the nanocomposite when using different annealing times in the range from 100 to 1200°C has been described.