Increasing the Porosity of Silica Particles by Reducing the Thickness of Nanochannel Walls and Producing an Additional System of Micropores

— We have developed a technique for the preparation of submicron spherical micro- and mesoporous silica particles via basic hydrolysis of organosilanes in an ethanol–water–ammonia mixture in the presence of cylindrical alkyl amine micelles. The particles synthesized in the presence of diethoxy(3-glycidyloxypropyl)methylsilane have been shown to contain cylindrical SiO 2 nanochannels with an inner diameter of 3 nm, characteristic of nanostructured M41S-type materials, but with a smaller wall thickness (0.5 instead of 0.7 nm). Owing to this, the specific surface area and volume of pores increased from 750 to 1200 m 2 /g and from 0.5 to 0.7 cm 3 /g, respectively. The addition of 3-(methacryloyloxy)propyltrimethoxysilane to the reaction mixture leads to further increase in these parameters (up to 1400 m 2 /g and 0.8 cm 3 /g) owing to micropore formation in the nanochannel walls.