The Effects of Graphene Size and Morphology on Damping Properties of Polymer Nanocomposites

Abstract

This work investigates the improvements in damping performance of polymer nanocomposites with graphene inclusions by employing interfacial slippage mechanisms between filler and matrix. The damping improvement to the nanocomposite benefits from the large interfaces of the matrix-graphene or graphene layers between which frictional sliding occurs to dampen vibration. In particular, we have studied the effect of morphology and particle size of graphene on the damping properties of a polymer system. To this end, two types of graphene nanoparticles with different morphologies and aspect ratios were used as fillers in polystyrene matrix: single layer graphene (SLG) and graphene nanoparticles (GNP). The dynamic mechanical behavior of the two nanocomposite systems was studied. A micromechanical model, based on shear lag analysis which captures the load transfer between nanoparticles and matrix was also used to acquire a deeper understanding of the damping mechanism. The results pointed to a considerable effect of graphene morphology in facilitating (or delaying) the interfacial failure, leading to enhanced (or reduced) damping performance. The combined modeling-experimental work suggests that the wrinkles on the surface of SLG, caused by its low bending stiffness, are a major player in enhancing the interfacial shear strength (IFSS) between the polymer and the graphene, leading to ~15x improvement in IFSS.