Preparation Of N-halamine Copolymer Nanospheres And Their Antibacterial Performance

With the continuous development of human society,a series of public health events caused by pathogenic bacteria and viruses,including bacteria,pose a serious threat to human health worldwide.The use of a series of antibiotics has effectively alleviated this problem.However,excessive dependence on and use of antibiotics,exacerbated the super bacteria（drug-resistant bacteria）production,human suffering from bacterial infection disease risk increased again.Therefore,exploring efficient and broad-spectrum antibacterial materials is crucial for human health and ecological security.N-halamine antibacterial agents have gradually attracted the attention of researchers because of their broad-spectrum,high-efficiency antibacterial effects and renewability.In particular,N-halamine can effectively avoid the production of drug-resistant bacteria.In this paper,a series of copolymer nanospheres with N-halamine antibacterial unit were designed and synthesized by using N-halamine antibacterial unit precursor（hydantoin derivative）,styrene and acrylate as comonomers.The main research contents and results are as follows:1.The main types of antibacterial agents and antibacterial materials,and the main synthesis methods of polymer antibacterial materials reviewed.Secondly,the research progress of N-halamine antibacterial agents and the synthesis methods and application fields of N-halamine antibacterial materials are summarized.2.N-halamine copolymer nanospheres（P（Cl A-St B）NPs）were successfully synthesized by emulsion polymerization and chlorination using 3-allyl-5,5-dimethylhydantoin（AMH）as the N-halamine antibacterial unit precursor,styrene（St）and butyl acrylate（BA）as comonomers,water/ethanol mixed solution as the reaction medium,and potassium persulfate（KPS）as the initiator.The microstructure,particle size and structure of P（AMH-St B）NPs and P（Cl A-St B）NPs were characterized by FT-IR,SEM,EDS,Size and XPS.The antibacterial activity of P（Cl A-St B）NPs was studied with Gram-negative bacteria（E.coil）and Gram-positive bacteria（S.aureus）as representatives,and the antibacterial mechanism of P（Cl A-St B）NPs was discussed.The results showed that hemispherical P（Cl A-St B）NPs were successfully synthesized when the monomer ratio was AMH/BA/St=2/1/1.SEM results showed that the microstructure of the microspheres did not change before and after chlorination.The antibacterial rates of P（Cl A-St B）NPs against E.coli and S.aureus reached 89.5%and 93.5%,respectively,showing broad-spectrum and excellent antibacterial activity.3.Amphiphilic N-halamine copolymer nanoparticles（P（Cl V-NA）NPs）were successfully synthesized by emulsion polymerization and chlorination using 3-（4-vinylbenzyl）-5,5-dimethylhydantoin（VBDN）as the precursor of N-halamine antibacterial unit,N-vinylpyrrolidone（NVP）and BA as comonomers,H₂O/Et OH mixed solution as reaction solvent and azobisisobutyronitrile（AIBN）as initiator.The morphology and structure of P（VBN-NA）NPs and P（Cl V-NA）NPs were characterized by FT-IR,SEM,EDS,Size and XPS.The antibacterial activity of P（Cl V-NA）NPs was evaluated by E.coil and S.aureus,and the antibacterial mechanism was explored by E.coil.The results showed that P（Cl A-NA）NPs exhibited good antibacterial activity at a certain concentration.At a concentration of 5 mg/m L,the antibacterial rates against E.coil and S.aureus reached 89%and 85.9%,respectively.4.N-halamine zwitterionic copolymer nanoparticles（P（Cl V-MA）NPs）were successfully synthesized by one-pot two-step self-assembly and chlorination using VBDN as the precursor of N-halamine antibacterial unit,benzyl methacrylate（Bl Me）and methacryloylethyl sulfobetaine（SBMA）as comonomers,KPS as initiator,and H₂O/Et OH mixed solution as solvent.The structure,morphology and particle size of P（VBN-MA）NPs and P（Cl V-MA）NPs were characterized by FT-IR,SEM,EDS,Size and XPS.The self-assembly behavior was verified by SEM.The self-assembly behavior of P（VBN-MA）NPs was discussed by SEM.The antibacterial activity and mechanism of P（Cl V-MA）NPs against E.coli and S.aureus were evaluated.The results showed that the prepared P（Cl V-MA）NPs had efficient and broad-spectrum antibacterial activity against E.coli and S.aureus.P（Cl V-MA）NPs were added to the commercially available coatings,giving the coatings excellent antibacterial properties.In summary,a series of copolymer nanospheres with N-halamine antibacterial precursors were prepared by using hydantoin derivatives as N-halamine antibacterial unit precursors and cheap styrene and acrylate as comonomers,and further halogenated to obtain a series of nanospheres with high efficiency and broad-spectrum antibacterial activity.It is expected to be applied in many fields such as biomedicine,water treatment,agricultural antibacterial and fine chemicals,and lay an experimental foundation for the preparation of antibacterial materials with excellent properties such as high efficiency,broad spectrum and prevention of drug-resistant bacteria.