Effect of Preparation Ph on Pore Structure of Silica-Gels

Surface characterization of silica gels prepared at different gelation pH from water glass and sulphuric acid were made by argon adsorption at 77 K using continuous volumetric method. While microporous silica gels prepared in the pH range of 1-3 had BET surface areas of 504-571 m2 g-1, total pore volumes of 0.26-0.31 cm3 g-1 and micropore volumes of 0.16-0.23 cm3 g-1, mesoporous silica gels prepared in the pH range of 3.36-0.65 had BET surface areas of 374-530 m2 g-1 and pore volumes of 0.61-0.79 cm3 g-1.