Surface characterization of ultramicro spherical particles of silica prepared by w/o microemulsion method

Abstract Ultramicro spherical particles of colloidal silica were prepared by the hydrolysis of tetraethoxysilane in the water pool of a water-in-oil (isooctane) microemulsion using Aerosol-OT. The average diameter of the silica spheres obtained, was of the order of 10 nm and their surface areas were about 100-300 m 2 g −1 . The nitrogen adsorption isotherms of this material show that the particles have micropores, in contrast to colloidal nonporous silica particles such as aerosils and those in silica sols having a similar size of particle.