Comparative analysis of vibration spectra of dispersive silicas and their components

Comparative analysis has been carried out on a set of partial basis spectra of the doubly amplitude-weighted density of vibration states (AWDS) of four dispersive silica: aerosil A380, silica gels SG20 and SG100 (with pore sizes 20 and 100 A), and aerogel AG200 with mass density 200 kg/m3. The set of basis spectra includes the vibration spectra of frameworks, and of the hydroxyl and aqueous components of the surface zone of the above compounds. Aerosils, silica gels, and aerogels have been found to be radically different structural forms of amorphous silica, both from the viewpoint of their frameworks and their surface zones. The basis spectra considered represent a collection of “fingerprints” of the structure-dynamic properties of the compounds studied, which allows us to formulate a qualitatively new approach to computational modeling of dispersive silicas.