INS and IR Studies of Intermolecular Interaction at the Silicone-Fumed Silica Interface. 2. Fumed Silica

Surface vibrations of the varied-surface-silylation-degree silylated fumed silica fine particles have been studied by inelastic neutron scattering at low temperature and by DRIFT at room temperature. The changes in the amplitude-weighted density of states spectra are recorded which might be attributed to sterical restrains caused by the densification of the trimethysiloxy units packing on the surface of the silylated particles at the graft ratio exceeding 70%. Assignment of the observed spectra is done on the basis of the solution of the direct and inverse spectral problems with the force field initially determined quantum-chemically.