Chinese Acad Sci, Inst Coal Chem, State Key Lab Coal Convers, Taiyuan 030001, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
Small angle X-ray scattering (SAXS) with synchrotron radiation as X-ray source has been used to study the structure of Sig xerogels prepared by sol-gel process. All SAXS profiles in this paper deviate from Porod's law and show negative or positive deviation. In order to obtain the information of pore in SiO2 xerogels, we have proposed the corresponding methods to correct the negative and positive deviations from Pored's law. Then, the average pore diameter of SiO2 xerogels is determined with Debye's method and Guinier's method, separately, and the results are found to be close to each other. The average diameters fall in the rang1 3-25 nm for samples prepared under various conditions. The results of SAXS are also close to that determined by N-2 adsorption method at 77 K with ASAP2000.