超亲水—水下超疏油膜材料的制备及其在油水分离上的研究

发布时间：2018-08-17 11:37

【摘要】：水污染问题一直是人类生活中亟待解决的问题之一。水中的污染物通常包括不溶于水的如油类,以及溶于水的如染料污染物等。对于含油废水的处理,普通分离方法已经渐渐无法满足实际需求。近年来,对于具有特殊润湿性材料应用于油水分离的研究越来越多,其中包括超疏水-超亲油以及超亲水一水下超疏油材料等。鉴于本文主要针对水包油乳状液的处理,而且超亲水—水下超疏油材料在水中超疏油的特性可以在分离过程中很好的避免油相的污染,所以本文旨在以简单的方法制备不同的具有水下超疏油特性的膜材料并研究它们处理含油废水的性能。首先,对传统的高分子膜材料PVDF膜进行改性。根据结合粗糙表面的构建以及适当的亲水改性来获得特殊润湿性的规律,通过多巴胺和硅烷偶联剂(KH550)的共同作用在PVDF膜表面接枝亲水的TiO2纳米颗粒,通过调节反应物中各组分的比例获得一系列的改性膜。当多巴胺与KH550比例为1:1,TiO2纳米颗粒加量为40mg时所获得的改性膜性能最佳。其中多巴胺和硅烷偶联剂除了起负载纳米颗粒的作用之外,还起着提高亲水性的作用,而TiO2纳米颗粒的主要目的是为了在膜表面获得粗糙的结构。对原膜以及这些改性膜材料分别通过扫描电子显微镜(SEM),全反射傅里叶红外光谱分析仪(ATR-FTIR)以及X射线光电子能谱分析仪(XPS)等表征手段证明了其结构和化学组成。并且对这些膜进行了润湿性分析,最终对其水处理性能进行了评价,这种膜对不同种类的水包油乳状液分离通量分别为400～600 L·m-2·h1,且分离效率均在99%左右。接着,为了实现对水中不溶的油和可溶的染料污染物的同时分离,制备了氧化石墨烯(GO)/埃洛石纳米管(HNTs)的复合膜材料,其中为了获得均匀的膜材料,HNTs预先用多巴胺进行了改性以提高其分散性。当GO与PHNTs比例为1:1,并且加入乙二胺之后所获得的改性膜综合性能最佳。与超亲水PVDF膜中的Ti02纳米颗粒作用类似,HNTs在整个复合膜材料中除了起着增加GO膜的层间距来提高通量的作用之外,还起着提供粗糙表面结构的作用,此外,在反应体系中还加入了适量的乙二胺(ED)来提高亲水性、提供吸附位点等。对一系列GO复合膜材料都通过扫描电子显微镜(SEM),原子力显微镜(AFM)以及X射线光电子能谱分析仪(XPS)等表征手段进行了结构和化学组成上的分析。并且对这些膜的润湿性进行了评价,最终对其染料分离性能、油水分离性能以及同时含有这两类污染物的废水的处理性能进行了评价,结果表明这种复合膜对同时含有油污和染料的废水中废料的分离效率均达到了 99%以上。
[Abstract]:Water pollution is one of the most urgent problems in human life. Pollutants in water usually include water insoluble such as oil and water soluble such as dye pollutants. For the treatment of oily wastewater, the common separation method has been unable to meet the actual needs. In recent years, more and more researches have been done on the application of special wettable materials to the separation of oil and water, including super-hydrophobic and super-oil-hydrophobic and ultra-hydrophilic-hydrophobic and ultra-hydrophobic. In view of the treatment of oil-in-water emulsion in this paper, and the characteristics of super-hydrophilic and ultra-hydrophobic materials in water can avoid the contamination of oil phase in the separation process. The purpose of this paper is to prepare different membrane materials with the characteristics of ultra-oil thinning and to study their performance in treating oily wastewater by simple method. Firstly, the traditional polymer membrane PVDF membrane was modified. According to the law of special wettability obtained by combining the construction of rough surface and proper hydrophilic modification, the TiO2 nanoparticles were grafted on the surface of PVDF membrane by the interaction of dopamine and silane coupling agent (KH550). A series of modified membranes were obtained by adjusting the proportion of components in the reactants. When the ratio of dopamine to KH550 is 1: 1, the best performance of the modified membrane is obtained when the dosage of 40mg is 1: 1, and the ratio of dopamine to KH550 is 1: 1. In addition to supporting nanoparticles, dopamine and silane coupling agents also play a role in enhancing hydrophilicity, while the main purpose of TiO2 nanoparticles is to obtain rough structure on the membrane surface. The structure and chemical composition of the original films and the modified films were proved by scanning electron microscope (SEM) (SEM), total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) respectively. The wettability of these membranes was analyzed, and the water treatment performance of the membranes was evaluated. The separation fluxes of these membranes for different kinds of oil-in-water emulsion were 400 ~ 600L m ~ (-2) h ~ (-1), and the separation efficiency was about 99%. Then, in order to separate insoluble oil and soluble dye pollutants simultaneously, the composite membrane material of graphene oxide (GO) / allorite nanotube (HNTs) was prepared. In order to obtain homogeneous HNTs, dopamine was used to improve the dispersion of HNTs. When the ratio of go to PHNTs is 1: 1, and ethylenediamine is added, the comprehensive properties of the modified membranes are the best. The effect of Ti02 nanoparticles in superhydrophilic PVDF membrane is similar to that in the whole composite membrane, which not only increases the layer spacing of go membrane to increase the flux, but also provides rough surface structure. A proper amount of ethylenediamine (ED) was added to the reaction system to improve hydrophilicity and provide adsorption sites. A series of go composite membrane materials were characterized by scanning electron microscope (SEM) (SEM), atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS). The wettability of these membranes was evaluated. Finally, the performance of dye separation, oil and water separation and the treatment of wastewater containing these two kinds of pollutants were evaluated. The results show that the separation efficiency of the composite membrane is over 99% for the waste water containing both oil and dye.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ051.893

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