The Preparation And Antibacterial Properties Of Metal Hybrid Nano-antibacterial Materials

Recent years,concerns over antibiotic resistance have now evolved into a vexing healthcare crisis.Previously-staple antibiotics have been rendered relatively ineffective due to the emergence of resistance among many bacteria.So it is an important subject to search efficient and broad-spectrum antibacterial materials.It provided a new direction for the research of antibacterial materials with the development of nanotechnology.Among the organic antibacterial materials,biological compounds have attracted much attention because of the biocompatibility,low cost and rare pollution.In this paper,new antibacterial agents were obtained by compositing the biological compounds and nanomaterial.Then they were applied on medicine,antibacterial cotton and wood fiber.The specific research content was as followed:1.The preparation and antibacterial activities of rosinyl quarternary ammonium compounds-gold nanorods: Gold nanorods(Au NRs)with longitudinal surface plasma resonance(LSPR)absorption above 760 nm were synthesized by seed-mediated growth method and their surface was modified with polyethylene glycol(PEG)and the synthetic rosinyl quarternary ammonium compounds(RQACs).Different bacterium,including gram-positive bacterium Staphylococcus aureus(S.aureus)and Bacillus cereus(B.cereus),gram-negative bacterium Escherichia coli(E.coli)and Pseudomonas aeruginosa(P.aeruginosa)were used to analyze the influences of concentration of RQACs-Au NRs on the inhibitory effects.Moreover,the possible mechnism was studied.The results showed that the RQACs-Au NRs performed great antibacterial activities because of the synergistic effect between RQACs and Au NRs.2.The preparation of CS-Ag NPs and antibacterial activities of the cotton fiber/ wood fiber modified with CS-Ag NPs: The Ag nanoparticles(Ag NPs)were prepared with chitosan as protect and stable agent,and with ?-Mercaptopropyltrimethoxysilane as the crosslinking agent,the synthesized Ag NPs were applied to cotton fiber/ wood fiber together by chemical bonding to obtain the durable antibacterial materials.The antibacterial effect of the cotton fiber/ wood fiber was studied with AGAR plate counting method.Additionally,the possible inhibitory mechanium was studied.The results indicated that the inhibitory rate of the fiber threated with CS-Ag NPs was up to 90% because of the synergetic effect between chitosan and Ag NPs.3.The preparation of BDCQA-Ag NPs and antibacterial activities of the cotton fiber modified with BDCQA-Ag NPs: A water soluble quaternary ammonium chitosan derivative,N-benzyl-N,N-diethyl chitosan quaternary ammonium salt(BDCQA)was synthesized and then the BDCQA-Ag NPs were prepared with BDCQA as stable agent.the Ag NPs were modified on the surface of cotton fiber to obtain the antibacterial materials.The optimum process conditions and the antibacterial activitis were discussed.The results showed that the antibacterial cotton persisted great antibacterial properties due to the synergistic effect of BDCQA and Ag NPs.The antibacterial activity could be maintained over 95% even after being exposed to 40 laundering cycles.Furthermore,the sterilization mechanism of the finished cotton fiber was explored preliminarily and it suggested that the antibacterial process of the cotton fabrics may include adsorption and sterilization two steps.