Surface modification of graphene oxide for preparing self‐healing nanocomposite hydrogels

Abstract In this work, graphene oxide (GO) and vinyl modified GO (V‐GO)‐based nanocomposite hydrogels with improved mechanical property and self‐healing ability have been synthesized and characterized. GO first was synthesized by modified Hummer's method using graphite powder and then functionalized with vinyl groups by using (3‐mercaptopropyl) trimethoxysilane (MPTS) via silanization method. The GO and V‐GO nanoparticles were characterized by FT‐IR, UV–vis spectroscopy, SEM, and dynamic light scattering technique (DLS). Hydrogels were obtained by in‐situ free‐radical polymerizations of acrylamide (AAm) and [3‐(methacryloylamino)propyl] trimethylammonium chloride (MAPTAC) monomers in the presence of GO and V‐GO nanoparticles. The effects of the amount of GO and V‐GO on the gelation profile and viscoelastic characteristics of the hydrogels were studied. The pH‐responsive action, swelling behavior, and swelling kinetics of the hydrogels with various GO and V‐GO contents were also evaluated. The mechanical performance of nanocomposite cationic hydrogels prepared with GO and V‐GO nanosheets was compared to the neat AAm‐MAPTAC hydrogels. The self‐healing ability of the hydrogels were elucidated as a function of the amount of GO and V‐GO nanosheets bound to the polymer network by physical interactions and chemical cross‐links, respectively.