载Ag磁性可回收抗菌纳米复合材料研究

发布时间：2018-05-15 05:01

本文选题：抗菌 + 磁性纳米粒子　；参考：《南京理工大学》2016年硕士论文

【摘要】：Ag纳米粒子具有抗菌广谱、高效以及抗耐药性的特点,是一类备受关注的纳米抗菌剂。但单纯的Ag纳米颗粒容易团聚且分散在溶液中无法分离,这会大大降低其抗菌活性。因此,选择合适的基材用于负载Ag纳米粒子是至关重要的。本文分别选用Fe304磁性纳米粒子和氧化石墨烯(GO)作为固定Ag纳米粒子的基底,且分别引入接触抗菌的壳聚糖(CS)和聚4-乙烯基吡啶的季吡啶盐,成功制备了两类具有双重抗菌作用的可回收载Ag磁性纳米抗菌材料。具体内容如下：1、载Ag磁性壳聚糖纳米粒子体系：采用化学共沉淀法制备出Fe3O4磁性纳米粒子,通过原位引发聚合将乙二胺改性的壳聚糖聚丙烯酸(ECS/PA)或壳聚糖/聚甲基丙烯酸-β-羟乙酯(CS/PAEMA)包覆到磁核表面,最后以PVP为还原剂和分散剂在纳米粒子表面固定Ag纳米粒子,分别得到两种载Ag磁性壳聚糖纳米粒子(Fe3O4@ECS/PAA-Ag 和 Fe3O4@CS/PAEMA-Ag)。利用红外光谱(FTIR)、透射电镜(TEM)、-射线衍射分析(XRD)、热重分析(TGA)对制得的两种载Ag纳米粒子的形貌和结构进行了系统的表征分析。选用革兰氏阴性菌(E. coli)和革兰氏阳性菌(S. aureus)分别对两种磁性壳聚糖纳米粒子体系做了一系列的抗菌性能测试(抑菌圈测试、抗菌动力学测试和循环抗菌测试)。结果表明：两种载Ag磁性壳聚糖纳米粒子有很强的抗菌能力,2.5 h对两种菌的杀菌效率接近100%。与载Ag前相反,载Ag后的纳米粒子对E. coli的抗菌活性更高。而且,在不经过任何水和溶剂洗涤的十轮抗菌测试后,Fe3O4@ECS/PAA-Ag纳米粒子还能分别杀灭99.72%的E. coli和99.63%的S. aureus,表现出了非常高效持久的抗菌性能。2、载Ag磁性氧化石墨烯纳米复合材料体系：先将1-溴正己烷和3-溴丙基三甲氧基硅烷与聚4-乙烯基吡啶季铵化,得到季吡啶盐聚合物(BNPVP),再将其通过与油酸(OA)配体置换偶联到磁核表面,得到Fe3O4@BNPVP。之后将Fe3O4@BNPVP固定到GO表面,并在其表面锚定Ag纳米颗粒,得到载Ag磁性氧化石墨烯纳米复合材料(GO-Fe3O4@BNPVP-Ag).利用1H NMR和红外光谱(FTIR)先对BNPVP的结构进行表征,并确定其季铵化程度,再用红外光谱(FTIR)、X-射线衍射分析(XRD)、紫外-可见(UV-Vis)、透射电镜(TEM)、拉曼光谱(Ramman)对制得的GO-Fe3O4@BNPVP-Ag纳米复合材料的形貌和结构进行了系统的表征分析。选用革兰氏阴性菌(E. coli)和革兰氏阳性菌(S. aureus)对纳米复合材料做了一系列的抗菌性能测试(抑菌圈测试、抗菌动力学测试和MIC、MBC值的测定)。结果表明：GO-Fe3O4@BNPVP-Ag纳米复合材料对E. coli和S. aureus都有很强的抗菌性能,2.5 h对两种菌的杀菌效率都达到了100%,且通过抗菌动力学测试和MIC、MBC值可以发现,固定了Fe3O4@BNPVP的载Ag氧化石墨烯比单纯载Ag的氧化石墨烯抗菌活性高,说明聚合物季吡啶盐BNPVP起到了协同抗菌的作用。另外,Fe3O4磁性纳米粒子的引入能在抗菌后方便回收。
[Abstract]:Silver nanoparticles are a kind of nanometer antimicrobial agents with wide spectrum, high efficiency and resistance to drug resistance. However, simple Ag nanoparticles are easy to agglomerate and can not be separated in solution, which greatly reduces their antibacterial activity. Therefore, it is very important to select the appropriate substrate for loading Ag nanoparticles. In this paper, Fe304 magnetic nanoparticles and graphene oxide (GOO) were used as the substrates to immobilize Ag nanoparticles, respectively, and the contact antimicrobial chitosan (CS) and poly4-vinylpyridine quaternary pyridine salts were introduced, respectively. Two kinds of magnetic nanocrystalline antibacterial materials with dual antimicrobial activity were successfully prepared. The specific contents are as follows: 1, Ag loaded magnetic chitosan nanoparticles system: Fe3O4 magnetic nanoparticles were prepared by chemical coprecipitation. Chitosan modified by ethylene diamine (PVP) or chitosan / poly (尾 -hydroxyethyl methacrylate) (CSP / PAEMA) were coated on the surface of magnetic core by in situ polymerization. Finally, Ag nanoparticles were immobilized on the surface of nanoparticles with PVP as reductant and dispersant. Two kinds of Ag loaded magnetic chitosan nanoparticles, Fe _ 3O _ 4 and Fe _ 3O _ 4 @ CSR / PAEMA-AgN, were obtained respectively. The morphology and structure of the two Ag loaded nanoparticles were characterized by FTIR, TEM, TGA and TGA. Gram-negative bacteria Ecoli and Gram-positive bacteria Saureus were used to test the antimicrobial properties of two kinds of magnetic chitosan nanoparticles (antimicrobial circle test, antimicrobial kinetics test and cyclic antibacterial test respectively). The results showed that the bactericidal efficiency of two kinds of Ag loaded magnetic chitosan nanoparticles was close to 100% for 2.5 h. On the contrary, the antifungal activity of Ag loaded nanoparticles against E. coli was higher. And, After ten rounds of antimicrobial tests without any water or solvent washing, Fe3O4DEP / PAA-Ag nanoparticles also killed 99.72% of E. coli and 99.63% of Saureus, respectively, showing very high and lasting antibacterial properties of 0.2, Ag loaded magnetic graphene oxide nanocomposite. Feed system: 1-bromo-n-hexane and 3-bromopropyltrimethoxy silane and poly (4-vinylpyridine) quaternary ammonium, The quaternary pyridine polymer, BNPVPN, was synthesized and coupled to the surface of the magnetic nucleus by substitution with oleic acid (OAA) ligands to obtain Fe3O4BNPVPs. Then the Ag nanoparticles were immobilized on the surface of go and the Ag loaded GO-Fe _ 3O _ 4O _ 4 nanocomposites were obtained. The structure of BNPVP was characterized by 1H NMR and FTIR, and the degree of quaternization was determined. The morphology and structure of GO-Fe3O4@BNPVP-Ag nanocomposites were characterized by FTIR X-ray diffraction, UV-Vis-UV, TEM and Raman spectra. Gram-negative bacteria Ecoli and Gram-positive bacteria Saureus were used to test the antimicrobial properties of nanocomposites (bacteriostasis test, antimicrobial kinetics test and MICMBC value measurement). The results showed that the bactericidal efficiency of the BNPVP-Ag nanocomposites against E. coli and S. aureus was 100% for 2.5 h, and the bactericidal efficiency of the two nanocomposites was 100%. The results showed that the antimicrobial kinetics test and MICMBC value showed that the bactericidal efficiency of the two nanocomposites was 100%. The antibacterial activity of Fe3O4@BNPVP loaded graphene oxide was higher than that of pure Ag loaded graphene oxide, indicating that the polymer quaternary pyridine salt BNPVP had synergistic antibacterial effect. In addition, Fe _ 3O _ 4 magnetic nanoparticles can be easily recovered after antibacterial.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB383.1;TB34

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