▎ 摘　　要

In this paper, covalently linked graphene oxide-poly(ethylene glycol) methyl ether methacrylate-reversible addition-fragmentation chain transfer (GO-PEGMEMA-RAFT) and physically mixed GO-PEGMEMA hydrogel nanocomposites are synthesized. Spectroscopic and imaging techniques such as UV-vis, Fourier transform infrared, Raman spectroscopy, and transmission electron microscopy show that the PEGMEMA is successfully grafted on GO sheets. The rheology of the nanocomposites is studied by small angle oscillatory shear, which shows a competition between reinforcement and lubrication behavior of GO. In the case where lubrication effect dominates reinforcement, the covalently linked GO-PEGMEMA-RAFT has higher G' compared to the physically mixed GO-PEGMEMA. Hence, in the covalently linked system, the grafted polymer chains appear to minimize the lubrication effect.