金属—有机骨架材料的吸附与膜分离性能研究

发布时间：2018-03-26 14:37

  本文选题：金属-有机骨架材料　切入点：分子模拟　出处：《北京化工大学》2015年博士论文

【摘要】：最近,多孔材料如沸石和金属-有机骨架(Metal-Organic Framework, MOF)材料在化学工程和材料科学领域取得了重要发展。特别地,MOF材料具有独特的属性(孔尺寸可控性、结构可设计性及化学功能化),使其在吸附分离、膜分离、催化和生物医药等方面受到了广泛的关注。另外,作为实验研究的补充,分子模拟在揭示MOF材料的微观机理、建立材料结构-性能(构效)关系以及材料设计等方面表现出了极大的优势。本文利用实验与分子模拟相结合的方法,对MOF材料在水相中有机芳香分子吸附分离及气相吸附/膜分离中的应用进行了研究,主要工作如下：1、以水稳定的MIL-68(Al)材料为例,实验测定了水溶液中苯胺吸附等温线并验证了计算模型。进一步,系统地研究了水相中苯胺在32种MOF材料中的吸附行为,并分析了MOF材料吸附苯胺的构效关系。结果表明,在低浓度下,苯胺吸附热和材料自由体积对苯胺吸附同时起重要作用；在高浓度下,苯胺吸附量取决于材料的自由体积。另外,本工作提出了用于苯胺回收的最佳MOF材料的设计要求,并以此计算设计了一系列高性能材料。2、由于苯胺、苯酚具有相近的分子尺寸和沸点,有效分离苯胺／苯酚体系存在技术挑战。本工作结合实验与分子模拟方法,研究了废水中苯胺／苯酚在柔性MIL-53(Al)材料中吸附分离行为。结果表明,在客体分子吸附过程中骨架柔性起了很重要的作用,因此能极大强化苯胺／苯酚的分离。与传统吸附剂相比,MIL-53(A1)具有很高的苯胺吸附容量和苯胺／苯酚分离选择性。因此,MIL-53(A1)可以作为这一体系分离的理想吸附剂。3、以变压吸附工艺为例,采用分子模拟方法,研究了湿度条件下112种不同类型MOF材料用于天然气净化的构效关系。本工作以吸附选择性、目标组分工作容量和再生性为评价标准,提出了湿度条件下MOF材料设计的要求,并筛选了理想的应用材料。4、采用了一种便宜且生物可兼容的MOF材料,MIL-88B(Fe),与Matrimid(?)5218聚合物掺杂制备了MIL-88B(Fe)/Matrimid混合基质膜用于能源气体(H2/CH4)净化；测试了MIL-88B(Fe)/Matrimid膜的H2/CH4单组分和等摩尔混合组份的渗透分离性能。实验结果表明,由于分子筛效应,MIL-88B(Fe)掺杂能强化混合基质膜中H2的通量但是会阻碍CH4的传质,因此强化了H2/CH4分离性能。在298 K和3 bar下,与纯聚合物膜相比,含10% MIL-88B(Fe)的混合基质膜中H2的通量和H2/CH4分离因子分别提高了16%和66%。另外,升高操作温度能强化MIL-88B(Fe)/Matrimid膜的H2/CH4分离性能。5、MOF膜后改性是提高其气体分离性能的一种有效策略。然而,目前报道的改性方法需要MOF材料具备能参与反应的功能团,因而限制了这种方法的应用。为此,本工作提出了一种简单的膜改性方法用于C02捕集。仿生的聚多巴胺几乎对任何材料都具有很强的黏附性。并且聚多巴胺含有大量的氨基和羟基,能对CO2形成强的吸附作用位点。作为概念验证试验,本工作采用聚多巴胺对典型的ZIF-8膜进行化学修饰。实验结果表明,在298 K和1 bar下,修饰后的ZIF-8膜表现出优异的CO2分离性能,CH4/CO2和N2/C02选择性分别为19.0,4.56和5.91,超过了对应的努森选择性(4.69,1.65和1.25)。为了说明这一方法的通用性,本工作进一步用聚多巴胺对氧化石墨烯GO进行修饰,制备了具有C02选择性的GO膜。这些工作表明,聚多巴胺可以作为膜后改性一个便捷和强大平台。
[Abstract]:Recently, porous materials such as zeolites and metal organic frameworks (Metal-Organic Framework, MOF) materials have made important progress in the field of chemical engineering and materials science. In particular, the MOF material has unique properties (pore size controllability, structure design and function of the chemical), in adsorption separation, membrane separation. Catalysis and biomedicine have been widely concerned. In addition, as a supplement to the experimental study, molecular simulation on the micro mechanism of MOF materials, building material structure property relationship (QSAR) and materials design has shown great advantages. This method using a combination of experimental and molecular simulation of. MOF material / organic phase adsorption and gas adsorption and separation of aromatic molecules in the aqueous phase in the application of membrane separation were studied, the main work is as follows: 1, the water stable MIL-68 (Al) materials were measured in aqueous solution In the aniline adsorption isotherm and verify the calculation model. Further, systematically studied the adsorption behavior of aniline in aqueous phase of 32 kinds of MOF materials, and analyzes the structure-activity relationship of MOF adsorption of aniline. The results showed that under low concentration of aniline, adsorption heat and material free volume also plays an important role in the adsorption of aniline in; under high concentration, the free volume of aniline adsorption depends on the material. In addition, this work proposes the design requirements for the recovery of aniline best MOF material, and calculated and designed a series of high performance materials because of.2, aniline, phenol with molecular size and close boiling point, effective separation of aniline / phenol system are technical challenges this work combined with experiment and molecular simulation method of aniline in wastewater and phenol in flexible MIL-53 (Al) adsorption behavior of materials. The results show that the guest molecules in the adsorption process of bone The flexible frame plays a very important role, it can greatly strengthen the separation of aniline / phenol. Compared with the traditional adsorbent, MIL-53 (A1) has high adsorption capacity of aniline and aniline / phenol selectivity. Therefore, MIL-53 (A1) can be used as the ideal separation adsorbent.3 in transformer the adsorption process as an example, using molecular simulation method, 112 different types of MOF materials and humidity conditions for the structure-activity relationship of purification of natural gas was studied. The adsorption selectivity of target components, work capacity and regeneration as the evaluation criteria, the MOF material design of humidity conditions, and screening of application materials.4 ideal, a cheap and bio compatible materials MOF, MIL-88B (Fe), and Matrimid (?) MIL-88B prepared 5218 polymer doped (Fe) /Matrimid mixed matrix membranes for gas purification (H2/CH4); MIL-88B (test Fe)/Matrimid鑶滅殑H2/CH4鍗曠粍鍒嗗拰绛夋懇灏旀贩鍚堢粍浠界殑娓楅，

本文编号：1668271