Abstract :
The functionalization of xerogels for use in chromatography and catalysis was carried out by solubilization of amorphous
silica using a soxhlet extractor. Xerogels were prepared by sol–gel method using tetraethoxysilane, TEOS, ethanol, and water in
a 1/3/10 molar ratio with HCl and HF as catalysts. The samples were prepared in monolithic form and dried at 70 8C and 550 8C
for 1 h each. After functionalization, changes in textural and morphological characteristics of xerogels were investigated by
means of nitrogen gas adsorption, positron annihilation lifetime spectroscopy (PALS), and scanning electron microscopy
(SEM). As the analysis methods are based on different physical principles, the results are complementary, leading to a good
knowledge of the texture of the samples studied.
