Particle porosity and relative permittivity of epoxy/hollow silica nanocomposites

In this paper, we investigated the relation between particle porosity and relative permittivity of epoxy/hollow silica nanocomposites. The hollow silica nanoparticle comprised a silica nanoparticle containing a nanometric pore. If an air pore inside the hollow silica nanoparticle remain unfilled with epoxy resin, the hollow silica nanoparticle can be used as a lower-permittivity filler for epoxy composite. It was confirmed that particle porosity of epoxy/hollow silica nanocomposites was about 70 vol% experimentally. Relative permittivity of epoxy/hollow silica nanocomposites was lower than that of unfilled epoxy resin. To verify the measurement results of the permittivity, the permittivity calculation model of epoxy/hollow silica nanocomposites was constructed with using a finite element method (FEM). The hollow silica nanoparticles were simply modeled as spherical hollow nanoparticles. Finally, we discussed whether the pore of the hollow silica nanoparticles affected the low permittivity of epoxy/hollow silica nanocomposites.