A high-surface-area silica-clay composite material

The crystalline clay layers of K10 montmorillonite (M), which is an acid-ac tivated clay, could be transformed by a hydrothermal process using a mixtur e of surfactant and amorphous silica into silica-bonded K10 montmorillonite (SBM). Using this hydrothermal surfactant process, the surface area of cla y could be increased substantially from 197 m(2) g(-1) (M) to 736 m(2) g(-1 ) (SBM). Being a new high-surface-area silica-clay composite material, SBM is shown to be a potentially new environmental material as it has been foun d to have very good acidic, adsorptive, and catalytic properties. (C) 1999 Elsevier Science B.V. All rights reserved.