Effect of nanoparticles on interfacial properties of carbon fibre–epoxy composites

This study assessed the effect of rigid nanoparticles on fibre–matrix adhesion in fibre-reinforced polymer composites by means of a transverse fibre bundle (TFB) test method with the fibre bundle transversely embedded in the middle of the TFB specimens. Fracture surfaces of the TFB specimens were examined by scanning electron microscopy and transmitting electron microscopy to identify dispersion and morphologies of nanoparticles on and near the fibre–matrix interfaces. A finite element analysis was conducted to identify the distribution and magnitude of the thermal residual stresses within the TFB specimen to correlate the TFB tensile strength with the fibre/matrix interfacial strength. The coefficient of thermal expansion and cure volume shrinkage of matrices with different amounts of nanosilca particles were experimentally evaluated and were included in the FE simulation. Results showed that the addition of nanosilica particles in the epoxy matrix did not noticeably affect the interfacial bonding behaviour between fibres and matrix.