Preparation And Antibacterial Properties Of Polymer Modified Graphene Oxide And Its Hydrogel Composites

In recent years,the frequent outbreaks of bacteria and viruses have seriously affected people’s normal life.Therefore,the study of broad-spectrum antibacterial nanocomposites is very promising.However,most antibacterial materials have some disadvantages,such as single sterilization mechanism and non-reusability.Based on the current situation,the combined use of graphene oxide(GO),quaternary ammonium salt(QAs)and N-halamine can improve the antibacterial activity and combine their various sterilization mechanisms.At the same time,graphene oxide can provide richer sterilization routes and larger specific surface area,which is beneficial to the grafting of quaternized N-halamine.It makes full use of the advantages of physical sterilization of graphene oxide,charge adsorption of quaternary ammonium salt,reuse of N-halamine and efficient sterilization.Based on the preparation and antibacterial properties of polymer modified graphene oxide and its hydrogel composites,the following two aspects are carried out:(1)Preparation and antibacterial properties of quaternized N-halamine modified graphene oxide nanoparticles.In order to combine a variety of sterilization methods,a multi-way fungicide that can be recycled was prepared.In this study,quaternized N-halamine was grafted onto GO to enrich the germicidal pathway and improve the germicidal efficacy.Graphene oxide grafted with poly(4-vinylpyridine)was synthesized by in-situ free radical polymerization using graphene oxide nanoparticles as polymer skeleton,and then3-bromopropyl-5-5-dimethylhydantoin was grafted by quaternization to prepare quaternized graphene oxide modified by N-halamine.The micro-morphology and structure of the samples were characterized and analyzed by X-ray photoelectron spectroscopy(XPS),infrared spectrum(FTIR)and scanning electron microscope(SEM).The germicidal efficacy of nanocomposites against Staphylococcus aureus and Escherichia coli represented was also studied.The results showed that it had good synergistic antibacterial effect,and the fungicide showed high inactivation rate against E.coli and S.aureus(>99.9%).The prepared materials have great application potential in antibacterial coatings,water treatment and biomaterials.(2)Preparation of modified graphene oxide hydrogel wound dressing and its effect on wound healing of infection.Giving antibacterial ability to hydrogels is very promising in tissue repair,but most of the synthesis methods of antibacterial hydrogels have high cost and low yield,and need to go through many tedious multi-step reactions to obtain antibacterial function.In this study,based on simple melt blending,a quaternary ammonium halogen amine modified graphene oxide hydrogel was prepared for the treatment of infectious skin defects.The micro-morphology of the samples was characterized by scanning electron microscope(SEM),infrared spectroscopy(FTIR)and X-ray powder diffractometer(XRD).The sample has obvious reticular structure and the pore size is relatively uniform.The sample is slow-release and the action time is prolonged.The hydrogel has good antibacterial properties and low toxicity.At the same time,wound healing experiments in vivo show that the hydrogel can resist wound bacterial infection and accelerate the process of wound healing,and has a broad application prospect in the field of biomedicine.