The influence of multiscale fillers on the rheological and mechanical properties of carbon-nanotube–silica-reinforced epoxy composite

Abstract Multiscale fillers were fabricated through synthesis of carbon nanotubes (CNTs) on silica microparticles by the use of chemical vapor deposition. Three types of catalyst precursors with different concentrations and reaction times were investigated to find the optimal conditions for CNT synthesis. The produced multiscale fillers of CNT–silica were incorporated within epoxy resin to fabricate a multiscale composite. Rheological analysis and tensile and impact tests were performed to study the effect of fillers on the structural properties of composites. The rheological results demonstrated a similar viscous behavior between CNT–silica suspensions and epoxy, which implies that there was no critical increase of viscosity. Significant improvements in the elastic modulus and tensile and impact strength were achieved for epoxy matrix filled with the optimal fraction of multiscale fillers. The reinforcing efficiency of multiscale fillers was evaluated by comparing the results of micromechanical models with experimental data.