▎ 摘　　要

For graphene-based composites, the dynamics of polymers confined between graphene sheets are a key parameter governing the overall mechanical properties of bulk materials. Here, we used neutron reflectivity (NR) to measure the diffusion dynamics of polymer melts confined between graphene oxide (GO) surfaces. From the NR results, we found that the diffusion coefficients of poly(methyl methacrylate) (PMMA) between the GO sheets were dramatically reduced by more than 1 order of magnitude when the film thickness was less than similar to 3 times the gyration radius of the bulk polymer (R-g), whereas the diffusion of the polystyrene (PS) films sandwiched between GO sheets was only three times slower as the PS thickness decreased from similar to 8 R-g to 1 R-g. This difference was due to the fact that the polymer-GO interaction significantly influences the dynamics of confined polymer melts.