氧化石墨烯纳米复合膜的制备及抗污染性能研究

发布时间：2018-02-15 15:54

本文关键词： 膜生物污染氧化石墨烯氧化石墨烯纳米银抗菌性能抗污染性能　出处：《山东大学》2015年硕士论文　论文类型：学位论文

【摘要】：膜分离技术由于具有装置简单、分离过程无相变、效率高、能耗低、无二次污染等优点,广泛应用于水净化领域。膜污染是限制膜分离技术应用的瓶颈。膜生物污染会破坏膜结构,降低膜渗透通量,提高能耗并降低膜寿命,进而加大了污水处理成本。因此开发具有抗污染性能的分离膜在海水脱盐、废水回用等领域具有重要的意义。本论文针对膜分离技术中的膜生物污染问题,以氧化石墨烯和氧化石墨烯纳米银复合材料为原料,分别通过界面聚合及真空抽滤的方法制备出高性能抗污染分离膜,在系统评估新型膜抗污染性能的基础上,解析新型膜抗生物污染的机理。论文的主要研究内容与结果如下：(1)通过界面聚合的方法将氧化石墨烯掺杂在薄膜层中,考察了氧化石墨烯的引入对聚酰胺膜结构、亲水性及分离性能的影响。扫描电镜及原子力显微镜对膜表面结构分析发现,负载氧化石墨烯后,膜表面更加粗糙。膜表面接触角分析发现,氧化石墨烯能在一定程度上改善分离膜的亲水性能。本研究以牛血清蛋白(BSA)及大肠杆菌为模型,考察了氧化石墨烯的引入对膜表面抗粘附性能的影响。分析发现氧化石墨烯改性后的膜具有较强的抗粘附性能,BSA的吸附量由原来的68.91 μg/cm2降至48.22 μg/cm2。抗菌测试分析表明,浓度为80μg/mL的氧化石墨烯溶液与大肠杆菌接触2h后,细菌死亡率高达79.3%。然而氧化石墨烯聚酰胺膜并未表现出明显的抗菌性能,但氧化石墨烯的掺杂明显的改善了膜表面亲水性能及抗污染性能,增加膜渗透通过量的同时,仍保持较高截盐率。(2)以柠檬酸钠为还原剂,通过原位制备粒径可控的氧化石墨烯纳米银复合材料,考察了氧化石墨烯纳米银复合材料的抗菌性能和机理。以大肠杆菌为模型菌,通过细菌生长动力学试验及荧光染色试验评价了氧化石墨烯纳米银复合材料的抑菌性能。结果表明原位制备的纳米银呈球状均匀分布在氧化石墨烯表面。氧化石墨烯纳米银复合材料对大肠杆菌有较强的抑菌效果,且其卓越的抑菌效果是通过氧化石墨烯与纳米银材料的协同作用来完成的。因此,氧化石墨烯纳米银是一种非常有效的抑菌材料。(3)采用氧化石墨烯纳米银复合材料为原料通过真空抽滤的方法制备出氧化石墨烯纳米银复合膜。研究结果表明,氧化石墨烯纳米银复合膜具有较好的亲水性能,且氧化石墨烯纳米银复合膜表现出了较强的抗菌性能,与细菌接触2h后,导致大约85.5%的细菌死亡。在24 h过滤过程中,氧化石墨烯纳米银复合膜的膜通量下降了46%,而醋酸纤维膜的膜通量下降了88%,氧化石墨烯纳米银复合膜表现出了较强的抗污染能力。
[Abstract]:Membrane separation technology has the advantages of simple device, no phase change, high efficiency, low energy consumption and no secondary pollution. Membrane fouling is the bottleneck limiting the application of membrane separation technology. Membrane biofilm will destroy membrane structure, reduce membrane permeation flux, increase energy consumption and reduce membrane life. Therefore, it is of great significance to develop anti-fouling separation membrane in the field of desalination of seawater and reuse of wastewater. This paper aims at the problem of membrane biological pollution in membrane separation technology. High performance anti-pollution separation membranes were prepared by interfacial polymerization and vacuum filtration from graphene oxide and graphene oxide nano-silver composite materials. The antifouling properties of the new membranes were systematically evaluated. The main contents and results of this paper are as follows: (1) the graphene oxide was doped into the film layer by interfacial polymerization, and the structure of polyamide membrane was investigated by the introduction of graphene oxide. Effects of hydrophilicity and separation properties. SEM and AFM showed that the surface of the membrane became rougher after loading graphene oxide, and the contact angle of the membrane surface was analyzed. Graphene oxide can improve the hydrophilicity of the membrane to some extent. In this study, bovine serum protein (BSA) and Escherichia coli were used as models. The effect of the introduction of graphene oxide on the anti-adhesion property of the membrane surface was investigated. It was found that the adsorption capacity of the modified graphene oxide membrane decreased from 68.91 渭 g / cm ~ 2 to 48.22 渭 g / cm ~ 2. After contact with Escherichia coli at the concentration of 80 渭 g / mL graphene oxide solution for 2 hours, the bacterial mortality was as high as 79.3%. However, the graphene oxide polyamide film did not exhibit obvious antibacterial properties. However, the doping of graphene oxide can obviously improve the hydrophilicity and antifouling performance of the membrane surface, increase the permeation flux of the membrane, and maintain a high salt interception rate. The antibacterial properties and mechanism of graphene oxide nano-silver composite were investigated by in-situ preparation of graphene oxide nano-silver composite with controllable particle size. The bacteriostatic properties of graphene oxide nanocomposites were evaluated by bacterial growth kinetics test and fluorescence staining test. The results showed that silver nanoparticles prepared in situ distributed uniformly on the surface of graphene oxide. The silver nanocomposite has strong bacteriostatic effect on Escherichia coli. And its excellent bacteriostatic effect is achieved by the synergistic action of graphene oxide and nano-silver materials. Graphene oxide nanocrystalline silver oxide is a very effective bacteriostatic material. Graphene oxide nano-silver composite membrane has good hydrophilicity, and graphene nano-silver oxide composite membrane has strong antibacterial properties. After contact with bacteria for 2 hours, about 85.5% of the bacteria died. The membrane flux of graphene oxide nano-silver composite membrane decreased by 46%, while that of acetate fiber membrane decreased by 88%. The graphene nano-silver oxide composite membrane showed strong anti-fouling ability.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ051.893;X703

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