Density, Specific Surface Area and Particle Size Distribution of Surface-treated Silica

Abstract

Density, specific surface area and particle size distribution of surface-treated silica were examined. As silica, Aerosil 130 (specific surface area: ca 150 m²/g) was selected. γ-Methacryloxypropyltrimethoxysilane (γ-MPTS), Vinyltrimethoxysilane (VTMS) and Vinyltrichlorosilane (VCLS) were used to coat the surface of silica by varying the concentration in the wet process. Density was decreased in accordance with the increase in the concentration of the coupling agent. The density of silica treated with VCLS showed a distinct turning point at 11 mg/ml. The specific surface area of the silica treated with γ-MPTS was quickly decreased to 22 mg/ml, and that of the silica treated with VTMS and VCLS was decreased to 5.5 mg/ml. The median diameter of silica showed a tendency to increase in accordance with the increase in the concentration of the coupling agent.