INS and IR studies of intermolecular interaction at the silicone-fumed silica interface. 3. Adsorption complexes

Surface vibrations of a five-member polydimethylsiloxane oligomer Si5 adsor bed at different cover ages on hydroxylated and silylated fumed silica have been studied by inelastic neutron scattering at low temperature and by DRI FT at room temperature. The changes in the AWDS spectra are recorded which might be attributed to immobilization of the adsorbed molecules on the surf ace, as well as to the pressure effect on the TMS units of substrate caused by adsorbed molecules. Assignment of the observed spectra is done on the b asis of the solution of the direct and inverse spectral problems with the f orce field initially determined quantum-chemically.