Preparation And Characterization Of Montmorillonite-graphene-based Antibacterial Composites

Humans are often infected by microorganisms such as harmful bacteria,viruses and yeast in the living environment.In particular,the extensive use of soluble antibacterial agents that have a great destructive effect on human health and the environment seriously undermines the balance of environmental microorganisms,leading to the emergence of harmful microbial species such as super bacteria.So how to effectively control microbial infection has become an urgent problem to be solved.Therefore,it is important to develop insoluble long-acting antibacterial agents with high activity,environmental friendliness,safety,stability and low toxicity.In this paper,two new montmorillonite-graphene-based antibacterial composites were prepared by loading montmorillonite-graphene or its oxide as carrier and loading nano-copper(CuNPs)and cetylpyridinium bromide(CPB)respectively.Its composition and antibacterial activity were studied.The specific work is as follows:1.The montmorillonite-graphene-based antibacterial composite(MMT-rGO-CuNPs)loaded with nano-copper was synthesized by loading montmorillonite-reduced graphene oxide(MMT-rGO)as carrier.Its chemical structure,elemental composition,morphology,antibacterial activity,adsorption performance and cytotoxicity were analyzed by various characterization methods.The results show that the electrostatic adsorption of MMT-rGO-CuNPs antibacterial complex against S.aureus is stronger than that of E.coli,so its antibacterial activity against S.aureus is higher than that of E.coli,and its cytotoxicity is lower than Nano-copper-loaded polyvinylpyrrolidone(PVP-CuNPs).2.The montmorillonite-graphene oxide loaded with cetylpyridinium bromide antibacterial compound(GM-CPB)was prepared by loading montmorillonite-graphene oxide(GM)as carrier and loading cetylpyridinium bromide(CPB).The chemical structure,elemental composition,morphology,thermogravimetric analysis,antibacterial activity,adsorption performance,sustained release properties and cytotoxicity were analyzed.It is found that the loading of CPB in GM-CPB is higher than that of graphene oxide-based loaded with cetylpyridinium bromide antibacterial composite(GO-CPB);GM-CPB has better adsorption to bacteria,the antibacterial activity of GM-CPB is higher than that of GO-CPB;the release rate of GM-CPB is also lower than that of CPB and GO-CPB,so GM-CPB has better sustained release performance and long-lasting effect;GM-CPB has lower cytotoxicity than CPB.