Graphene/cyclodextrin-based nanocomposite hydrogel with enhanced strength and thermo-responsive ability

Dual crosslinked system has been proved to be an efficient method to obtain tough and high strength hydrogels. Herein, we synthesized a novel graphene oxide/p(acrylamide-co-poly(ethylene glycol) methyl ether methacrylate)/α-cyclodextrin (GO/P(AM-co-PEGMA)/CD) physical dual crosslinked hydrogel via copolymerization of AM and PEGMA in the α-CD/GO solution. The polymer main chains adsorb onto the GO surface resulting in the first crosslinked system and multiple hydrogen bonds between α-CDs that thread on the PEGMA side chains establish the second crosslinked system. The GO/P(AM-co-PEGMA)/CD hydrogel exhibits favorable tensile properties with fracture strain of 1800% and high fracture stress of 660 kPa; in addition, the hydrogel can bear large compressive stress (2.7 MPa) at strain of 85% without rupture. Furthermore, physical dual crosslinked system endows the GO/P(AM-co-PEGMA)/CD hydrogel with thermoplastic ability and thermo-responsive shape memory behavior. This facial one-pot method will contribute to design and application of high performance hydrogel.