Abstract

Silica hydrogel was synthesized by the reaction of liquid sodium silicate with sulfuric acid. The condensation polymerization of the synthesized hydrogel was carried out via an aging process under the acidic or alkaline conditions. Nano porous silica with the pore size below 3 nm and surface area of 715m2/g, was obtained by the above processes in acidic ranges(pH : 3~5). The pore size and surface area of the silica varied with pH, and in alkaline ranges(pH : 8~10), those were 21 nm and 300m2/g respectively. The characteristics of the silica varied with the thermal treatment which caused the change of surface area, pore volume and pore diameter.

• Keywords: Porous silica;Sodium silicate;Pore size;Surface area;Silanol group;