Multi-scale simulation of SU8 and SU8-graphene nanocomposites: Bridging atomistic to macroscale peridynamics

SU8 is a commercial epoxy-Novolac resin, a negative-tone photoresist with outstanding mechanical properties. Its nanocomposites have also been considered as research materials. In order to obtain insights into the SU8 nanocomposites with graphene, the present work was conducted to simulate the mechanical properties using multi-scale simulation method including atomistic, meso, and macro scales. The study started by molecular dynamics, then moved to coarse grain, and nally reached macroscale. The methodology applied throughout the work was Peridynamics. Top-down and bottom-up loops were required to conrm the total results. Tensile deformation was applied to a 2D plane at the upmost scale to create an internal pressure. It was transferred to the lower scale in the next step as the external pressure. The procedure continued down until the molecular scale was reached. However, bottom-up strategy required a bridging model to link molecular scale to the upper scales. The check points were the deformation values, which had to be in the same order independent of top-down or bottom-up movement. With 2.1 wt.% graphene in SU8, the increases in Young's, bulk, and shear moduli were calculated (62, 200, and 82%, respectively) compared to the neat SU8.