Surface structure of silica gel reacted with 3-mercaptopropyltriethoxysilane and 3-aminopropyltriethoxysilane: formation of the S-S bridge structure and its characterization by Raman scattering and diffuse reflectance Fourier transform spectroscopic studies

Silica gel samples, modified with 3-mercaptopropyltriethoxysilane, and their S-S-bridged samples have been prepared. In order to characterize the microstructure of the surface of these silica get samples, Raman scattering and diffuse reflectance Fourier transform IR spectra. of these samples have been examined by comparison with Raman spectra of various n-alkyl disulfides and their related silane polymers. The S-S and C-S stretch modes characteristic of the CH(2)SSCH(2) segment, in addition to the SH and C-S stretch modes of the CH(2)SH segment, have been assigned for these silica gel samples. It has been found that, even on the surface of the silica gel, a specific conformer is stabilized about the CH(2)SSCH(2) segment.