纳米多孔材料混合基质膜制备及分离性能研究

发布时间：2018-04-22 22:32

本文选题：纳米多孔材料 + MOFs　；参考：《北京化工大学》2017年博士论文

【摘要】：气体分离和水处理是关系生产和生活的两个重要分离方面。高效分离技术在其中发挥着重要作用,膜分离技术因简单高效、节能环保、易于产业化等特点,具有广阔的发展前景。膜材料的开发是膜分离技术发展的核心,其中聚合物膜和无机膜得到了广泛的研究。聚合物膜具有优异的成膜性能,但是难以得到兼具高的通量和选择性的膜材料。无机膜可以兼具高的通量和选择性,但是生产大面积无缺陷膜比较困难。为此以聚合物为基底,无机物为添加物制备混合基质膜(mixed matrix membranes, MMMs )是结合两者优势,弥补不足的有效方法。纳米多孔材料如金属-有机骨架材料(metal-organic frameworks,MOFs),金属-有机多面体(metal-organic polyhedron, MOP)等材料具有多样的化学性质、结构可调性等,作为添加物制备MMMs具有独特的优势。本文从MMMs分离应用角度出发,在新型纳米多孔添加物材料的设计、MMMs制备及其性能研究方面做了系统的研究。主要的研究内容为:1、采用具有大的孔尺寸、空金属位、丰富-NH2官能团及高稳定性的NH2-MIL-101(Cr)作为添加物,自具微孔聚合物(PIM-1)为基底,制备了不同 NH2-MIL-101(Cr)添加量的 NH2-MIL-10I(Cr)/PIM-1 MMMs,研究了NH2-MIL-101(Cr)添加量及其添加时的干燥状态对膜气体分离性能影响。在CO2/N2的分离中,NH2-MIL-101(Cr)在低添加量5 wt %时,NH2-MIL-101(Cr)/PIM-1 MMM 的 C02通量较 PIM-1 膜的 C02通量达到了39.0 %的提高量,同时C02/N2选择性也有了一定增加。主要原因是NH2-MIL-101(Cr)大的孔道结构在膜中形成了更多的的气体通道,从而使膜的气体通量得到了有效提高,同时NH2-MIL-101(Cr)自身对C02的亲和作用也有利于CO2通过膜材料,对分离效果具有积极作用。2、离子液体的结构及化学性质具有多样性,其中一些功能化的离子液体(task-specific ionic liquid, TSIL)具有优异的CO2分离性能,然而离子液体粘度大,易泄露的特点限制了其应用范围。在MOFMMMs的研究中,对MOFs的改性修饰可以赋予其更多的功能性。本工作中以MOF材料作为TSIL的多孔载体,TSIL作为MOF的功能修饰物,制备了 TSIL在MOF孔道中分布的TSIL与MOF的复合材料(TSIL@MOF),进一步以TSIL@MOF为添加物制备了 MMMs,研究了膜的气体分离性能。结果显示,TSIL@MOF添加量为5 wt%时,MMM的C02通量和C02/N2分离选择性得到了同时提高,成功跨越了 Robeson限制。3、对于MMMs而言,添加物团聚沉降一直是阻碍其发展的关键问题。为此,我们选用了功能化的金属-有机多面体作为添加物,聚砜(PSF)为基底,制备了新型混合基质膜(MOP/PSFMMMs)。MOP可以和PSF—样溶于制膜溶剂,有效缓解了膜制备过程中的团聚沉降问题。同时功能化的MOP材料可有效增强分离效果,在对C02/CH4混合气的分离中,当MOP添加量为12 wt %时,膜的C02通量和CO2/CH4分离因子得到了同时提高,与纯PSF的分离性能相比其提高量分别为81 %和60 %。4、UiO-66(Zr)具有良好的亲水性,孔尺寸为6.0A,可有效进行染料废水的分离,同时具有优异的稳定性。工作中以UiO-66作为添加物制备了不同UiO-66添加量的膜材料(UiO-66/PES MMMs),并进行了全面的膜水处理性能测试。在UiO-66添加量为1.0wt%时,UiO-66/PES膜水通量较PES膜水通量提高了 60 %,同时膜的染料截留率及膜抗污染性能也得到了提升。5、氧化石墨烯(GO)具有良好的亲水及化学性质,作为添加物制备水处理膜具有巨大的应用价值。为了使GO性能得到最大限度的发挥,同时赋予其更多的功能性,本工作中将UiO-66负载至GO层间制备了具有多孔分子筛性质的UiO-66与GO复合材料(UiO-66@GO),并以UiO-66@GO为添加物制备了一系列不同添加物添加量的混合基质膜(UiO-66@GO/PES MMMs),系统研究了膜的水处理性能。结果表明,在UiO-66@GO添加量为3.0 wt %时,UiO-66@GO/PES膜的水通量较PES和GO/PES膜的水通量分别提高了 351 %和78 %,同时具有良好的染料截留性能和膜抗污染性能,性能均优于相应的PES和GO/PES膜性能。
[Abstract]:Gas separation and water treatment are two important separation aspects of production and life. High efficiency separation technology plays an important role. Membrane separation technology has a broad development prospect because of its simple efficiency, energy saving and environmental protection, easy industrialization and so on. The development of membrane materials is the core of membrane separation technology, in which polymer membrane and no Film has been widely studied. Polymer films have excellent film forming properties, but it is difficult to obtain high flux and selective membrane materials. Inorganic membranes can have high flux and selectivity. However, it is difficult to produce large area without defect films. Polymer as the substrate and inorganic additives are used to prepare the mixed matrix film (mixe D matrix membranes, MMMs) is an effective method to combine the two advantages. The nano porous material, such as metal organic skeleton material (metal-organic frameworks, MOFs), metal organic polyhedron (metal-organic polyhedron, MOP), has a variety of chemical properties, structure tunability, etc. as additive, MMMs has a unique method. Special advantages. From the point of view of MMMs separation application, this paper makes a systematic study on the design of new nano porous additive materials, MMMs preparation and its properties. The main research contents are as follows: 1, using large pore size, empty metal position, rich -NH2 functional group and high stability NH2-MIL-101 (Cr) as additives. NH2-MIL-10I (Cr) /PIM-1 MMMs with different amounts of NH2-MIL-101 (Cr) added to the pore polymer (PIM-1) was prepared. The effect of NH2-MIL-101 (Cr) addition and the drying state on the performance of the membrane gas separation was studied. The flux of NH2-MIL-101 (Cr) at a low addition of 5% in the separation of CO2/N2 was compared. The C02 flux of PIM-1 film reached 39%, and the selectivity of C02/N2 also increased. The main reason was that the large pore structure of NH2-MIL-101 (Cr) formed more gas channels in the membrane, so that the gas flux of the membrane was improved effectively, and the affinity of NH2-MIL-101 (Cr) to C02 was also beneficial to CO2 through. The membrane material has a positive effect on the separation effect.2, the structure and chemical properties of ionic liquids have diversity, and some of the functional ionic liquids (task-specific ionic liquid, TSIL) have excellent CO2 separation properties. However, the ionic liquid viscosity is large and the leaking characteristics limit its application range. In the study of MOFMMMs, it is necessary The modified modification of MOFs can give it more functional properties. In this work, MOF is used as a porous carrier of TSIL and TSIL as a functional modifier of MOF. The TSIL and MOF (TSIL@MOF) of TSIL in the MOF channel is prepared. The MMMs is prepared by TSIL@MOF additive. The gas separation performance of the membrane is studied. The results show that the gas separation performance of the membrane is obvious. When the amount of TSIL@MOF is 5 wt%, the C02 flux and C02/N2 separation selectivity of MMM have been improved simultaneously, and the Robeson restriction.3 has been successfully crossed. For MMMs, the accumulation of additive agglomeration has been a key problem that hinders its development. Therefore, we have chosen the functionalized metal organic polyhedron as the additive and polysulfone (PSF) as the base, A new mixed matrix film (MOP/PSFMMMs).MOP can be used to solve the aggregation problem in the process of membrane preparation, which can effectively alleviate the agglomeration of the membrane in the preparation process. Meanwhile, the functionalized MOP material can effectively enhance the separation effect. In the separation of C02/CH4 mixture, the C02 flux and CO2/CH4 separation factor of the membrane are obtained when the addition of MOP is 12 wt%. At the same time, compared with the separation performance of pure PSF, the improvement amount is 81% and 60%.4 respectively. UiO-66 (Zr) has good hydrophilic property and the pore size is 6.0A. It can effectively separate the dye wastewater and have excellent stability. In the work, the membrane materials with different UiO-66 additions (UiO-66/PES MMMs) are prepared with UiO-66 as additives. When the amount of UiO-66 was 1.0wt%, the water flux of UiO-66/PES membrane was increased by 60% than that of PES membrane. Meanwhile, the dye interception and membrane fouling performance of the membrane were increased by.5, and graphene oxide (GO) had good hydrophilic and chemical properties. As an additive, the water treatment membrane was huge. In order to maximize the performance of the GO and give it more functionality, the UiO-66 and GO composites (UiO-66@GO) with the properties of porous molecular sieve (UiO-66@GO) were prepared from the GO layer to the GO layer, and a series of mixed matrix membranes (U) with different additives were prepared with UiO-66@GO as additives. IO-66@GO/PES MMMs), the water treatment performance of the membrane was studied systematically. The results showed that the water flux of UiO-66@GO/PES film increased by 351% and 78% than that of PES and GO/PES film when the amount of UiO-66@GO was 3 wt%, and the performance of the membrane was better than that of the corresponding PES and GO/PES membrane.

【学位授予单位】：北京化工大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TQ051.893

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