Design And Synthesis Of N-halamine-modified Antibacterial Composites And Their Antibacterial Properties

Certain recent,more and more people have paid attention to the improvement of living standards,especially for healthy qualified life.There are however numerous pathogenic microorganisms around human beings,posing an increasing threat to human health.To eliminate this threat,antimicrobial agents or coatings having capability of disinfection of drinking water or surfaces to prevent infection risk is highly required.Widespread microbes have developed antibiotic-resistance,which has gained a great public concern.To date,with the continuous research on N-halamines,some researchers have extended the chemistry of antibacterial N-halamines to the field of nanoscience,and developed N-halamine nanomaterials with diverse chemical structures.In this test,several different N-halamine-modified composites have been synthesized by using four different N-halamine precursors,including 5,5-dimethylhydantoin（DMH）,cyanuric acid（CA）,2,2,6,6-tetramethyl pipradrol（TMP）,and hyaluronic acid（HA）,have been selected as starting materials,followed by investigations on structural characterization,performance,stability,and antibacterial activity.The precursors of N-halamine,TS-DMH,were synthesized by binding 5,5-dimethylhydantoin（DMH）onto 3-chloropropyl-trimethoxysilane（CPS）.The synthesized TS-DMH and tetraethoxysilane（TEOS）were co-hydrolyzed,and by the assistance of Fourier infrared spectroscopy（FTIR）,scanning electron microscopy（SEM）,etc.,the final product was proved to be DMH modified silica nanoparticles with spherical morphology and good monodispersity.Three N-halamine precursors,including 5,5-dimethylhydantoin（DMH）,cyanuric acid（CA）,2,2,6,6-tetramethyl pipradrol（TMP）,were chemically anchored onto the surface of silica nanoparticles,coupled with chlorination,to obtain three different SiO₂@N-halamine.The sphere-like morphology and nanosize of SiO₂@N-halamine was confirmed by SEM technique.The oxidability of the final three products can be determined by the iodometric method,which proves the formation of N-halamines on the surface of silica nanoparticles.Two nanocomposite fibers,PAN-DCBMH and PAN-DBDMH,were synthesized by the advanced electrospinning technique.The morphology of nanocomposites was confirmed by SEM technique,and then impact of electrospinning precursor on the morphology and size of nanofibers was investigated.The antibacterial results showed that the two nanocomposite fibers,PAN-DCBMH and PAN-DBDMH,had good antibacterial activity against the selected bacteria E.coli and S.aureus.Herein,the hyaluronic acid-based N-halamine was prepared by using hydrophilous hyaluronic acid as the raw material.Compared with the traditional halogen-based disinfectant sodium hypochlorite,the as-synthesized hyaluronic acid-based N-halamine has higher stability and chlorine fixing ability.After antibacterial evaluations,the as-synthesized hyaluronic acid-based N-halamine has good antibacterial activity against E.coli and S.aureus.The present research would lay a theoretical foundation for the subsequent development of antimicrobial composites and have scientific value and practical potent in the fields related to prevention and control of disease.