Preparation of silica-pillared clays with micro- and meso-pores using aminopropyltriethoxysilane and tetraethoxysilane

Silica-pillared clays with micro- and meso-pores were prepared from montmorillonite, aminopropyltriethoxysilane(APS) and tetraethoxysilane(TEOS) with polyvinyl alcohol(PVA). The silica precursors were synthesized by the sol–gel method, of which the molar ratio of TEOS to APS was varied from 0 to 1.5. Most of the loaded silica precursors reacted with clay. The pore properties and structures of the pillared clays were investigated. Based on X-ray diffraction measurements, the basal spacings of the silica-pillared clays increased from 2.1 to 4.3 nm with the increase silica amount in the loaded precursor. As with the basal spacings, the peaks of the pore size distribution shifted up to 2.6 nm. The specific surface areas and pore volumes tended to increase with an increase in the loaded silica contents.