Open AccessTwo fractal structures of methyl-modified Silica gels by SAXS
Author(s) -
Yao Xu,
Zhihong Li,
Wenhao Fan,
Wu Dong,
Yuhan Sun,
Jun Wang,
Dong Bao-Zhong
Publication year - 2003
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.52.442
Subject(s) - small angle x ray scattering , fractal , materials science , scattering , microstructure , diffraction , fractal dimension , synchrotron radiation , particle (ecology) , transmission electron microscopy , crystallography , chemical engineering , optics , composite material , nanotechnology , chemistry , physics , mathematical analysis , oceanography , mathematics , engineering , geology
With tetraethoxysilane Si(OC2H5)4TEOS and methyltriethoxysilane CH3Si(OC2H5)3,MTES as precursors, two kinds of methyl-modified silica gels were prepared by the two-step method and co-hydrolysis method. The gels were tested at the small angle x-ray scattering(SAXS) Station of Beijing Synchrotron Radiation Facility(BSRF). We calculated the average particle diameter and the special surface area between the two phases. On the basis of these data the fractal characters of gels were analyzed, and two fractal structures were found in all the samples. The two fractal dimensions indicated two fractal structures on two scales, i.e., from primary SiO2 particles to first-aggregates and from first-aggregates to clusters. Aided by transmission electronic microscope(TEM) we confirmed the two different microstructures of the gels prepared using the two different methods. It can be said that SAXS is a powerful technigue to study microstructures of gel systems by studying its fractal structure.