Abstract: A basic sol containing amorphous SiO2 particles was prepared by sol-gel process with TEOS ( tetraethoxysilane ) as precursor in alcohol system. A solution containing polymer of MTES ( methyltriethoxysilane ) was also prepared under acidic condition. The mixed sol was tested by the small angle X-ray scattering (SAXS) at Station of Beijing Synchrotron Radiation Facility (BSRF). The average rotation radius, the average particle diameter, the percentage of scattering particles, the thickness of interface layer and the specific inner surface area between the two phases were calculated. With the assistant of photon correlation spectrum (PCS) and transmission electronic microscopy (TEM), the microstructure of TEOS-MTES mixed sol was obtained in which SiO2 particles were interlinked through the polymers of MTES. By SAXS experiment, we found negative deviation from the Porod law on all the samples, which showed clearly interface layer between the two phases in mixed sol.

Key words: Sol, SiO₂, TEOS(tetraethoxysilane), MTES