▎ 摘　　要

The effects of supercritical CO2 (scCO(2)) on polymer chains' mobility and graphene nanoplatelets (GNPs) exfoliation and distribution in a microcellular foaming process are investigated by the molecular dynamics (MD) simulations and experiments. The results of MD simulations and visualization analysis confirm that the synergistic effect of scCO(2) molecules and polystyrene (PS) chains is beneficial for them to penetrate into the interlayer of GNPs during the scCO(2) treatment at high saturation pressure. The scanning electron microscope images show that some cells exist in the interlayer of GNPs in the foam fabricated in the highest saturation pressure and shortest depressurization time. With foaming in different depressurization time, the growing cells facilitate the movement of GNPs after their exfoliation, leading to alignment around the cells. As compared to large diameter GNPs, the GNPs with small diameter rearrange easily and distribute more homogeneously due to lower resistance of GNPs' movement.(c) 2021 Elsevier Ltd. All rights reserved.