Structure and Strength of Silica-PDMS Nanocomposites

摘要

Commercially available SiO_2 nanoparticles (Aerosil, Degussa) with varying primary particle diameter, specific surface area (SSA), degree of aggregation and structure (fractal dimension) were compounded into PDMS-based nanocomposites. Thin sections of cured nanocomposites were analyzed with TEM and small and ultra-small angle X-ray scattering (U/SAXS) with respect to nanocomposite structure such as: filler primary particle, aggregate (chemically or sinter-bonded particles) and agglomerate (physically-bonded particles). Tensile tests (Young's modulus) were used to determine the nanocomposite strength which increased with increasing filler volume fraction (up to 12 vol%) consistent with "bound rubber" theory.