Preparation of raspberry-like SiO<inf>2</inf> nanoparticles and thermo-mechanical properties of its epoxy composites

Abstract

Raspberry-like SiO 2 (R-SiO 2 ) nanoparticles were prepared by electrostatic self-assembly of two different sizes SiO 2 nanoparticles under the help of polyelectrolytes, which would be removed by further calcination. The R-SiO 2 /epoxy composites were fabricated then by a solvent-free curing process. The morphology of R-SiO 2 and fracture morphology of their epoxy composites were observed by scanning electron microscopic (SEM). Thermo-mechanical properties including storage modulus, glass transition temperature (T g ) and coefficient of thermal expansion (CTE) are critical properties for SiO 2 /epoxy composites. To observe these parameters, dynamic mechanical analysis (DMA) and thermomechanical analysis (TMA) were used, respectively. The results showed that the R-SiO 2 particles could be used as effective fillers on increasing T g and decreasing CTE of the epoxy composites.