Preparation And Characterization Of Environmental Responsiveness Hydrogels Based On Graphene

Supramolecular hydrogels based on organic-inorganic hybrid have broadapplication prospects like biosensing, drug delivery, tissue engineering, and other fields due to the unique characteristics, such as the controllable gelation process, the mild conditions for preparation and the stability for injection. Those hydrogels are mainly include organic macromolecule and inorganic nanomaterial. Supramolecular hydrogels resulting from self-assembly of a-CD and poly(ethylene glycol)(PEG) are often used as the organic build body due to the good biocompatibility and low biological toxicity, and graphene can be served as inorganic matrix, because of it’s great physical and chemical properties.Hummer’s method was adopted to perpare the oxide graphene (GO). The morphology, dispersion condition and degree of oxidation of GO were characterized by XRD, XPS, TGA. In order to increase the water-solubility of graphene oxide, polyethylene glycol monomethyl ether (MPEG) with good water-soluble was grafted to the edge of the graphite oxide to form the organic-inorganic hybrid materials GO-MPEG. The GO-MPEG was added into saturated KPF6solution with a certain amount of the pure MPEG to build the hydrogel. The gel properties were characterized using a rotary rheological.A pH-responsive copolymer was performed based on2-(dimethylamino) ethyl methacrylate (DMAEMA) and hydroxyethyl methacrylate (HEMA) using azobisisobutyronitrile as the initiator. The copolymer was then esterified branched chain having naphthalene ring-containing polymers. This polymer can fabricated the supramolecular hydrogels via their inclusion complexation with β-cyclodextrin (β-CD). We also study the pH-responsive property of the hydrogel via rotary rheological.MPEG-b-PNIPAM-b-MPEG block copolymer was synthesized by RAFT method, its structure was charactered by FTIR, NMR. GO-MPEG was dropped into a-CD solution to self-assembled hybrid hydrogels with the structure of pseudopolyrotaxane. The characterizations indicated the temperature response of gel, and also verified the possibility to be a drug delivery. This study broaden the application in drug delivery for environment responsive gel.The above researches introduce the formation of organic-inorganic hybrid hydrogel with MPEG-grafted polymer, KPF6and a-CD. Modified Hummer’s method was adopted to perpare the oxide graphene (GO), which improved the oxidation properties of GO. In order to increase the water-solubility of graphene oxide, polyethylene glycol monomethyl ether (MPEG) with good water-soluble was grafted to the edge of the graphite oxide to form the organic-inorganic hybrid materials GO-MPEG. The mechanical properties of the gel corresponding was increased. The hydrogels have salt responsive, pH responsive and temperature responsive characteristics. This work have potential application involving tissue engineering material, biosensor and drug controlled release carrier. The study involves frontier of material science and supramolecular chemistry, which has a certain value of academic and application.