Facilitate Gas Transport through Metal‐Organic Polyhedra Constructed Porous Liquid Membrane

Type II porous liquids are demonstrated to be promise porous materials. However, the category of porous hosts is very limited. Here, a porous host metal–organic polyhedra (MOP‐18) is reported to construct type II porous liquids. MOP‐18 is dissolved into 15‐crown‐5 as an individual cage (5 nm). Both the molecular dynamics simulations and experimental gravimetric CO₂ solubility test indicate that the inner cavity of MOP‐18 in porous liquids is unoccupied by 15‐crown‐5 and is accessible to CO₂. Thus, the prepared porous liquids show enhanced gas solubility. Furthermore, the prepared porous liquid is encapsulated into graphene oxide (GO) nanoslits to form a GO‐supported porous liquid membrane (GO‐SPLM). Owing to the empty cavity of MOP‐18 unit cages in porous liquids that reduces the gas diffusion barrier, GO‐SPLM significantly enhances the permeability of gas.     

高分子分离膜材料及其研究进展

膜材料是膜研究的主要内容,从理论与应用两个角度对高分子分离膜材料进行阐述,先从分离膜的分离机制、分离性能及类别展开介绍,总结各类常见的高分子分离膜材料的性能特点及适用性,针对近年来高分子分离膜材料的合成和制备、改性与应用等研究成果进行概述,通过分析并总结分离膜材料的结构与性能之间的关系,对未来开发新型高分子分离膜材料作出展望。     

膜拆分法分离制备手性药物

手性是自然界的一种普遍现象,天然存在的手性化合物很多,构成生物体的基本物质如氨基酸、糖类和蛋白质等也都是手性分子.外消旋体药物的手性拆分目前在单一手性药物的制备上仍占有极其重要的地位.手性拆分膜包括基于对映体间亲和性差异的固体膜和基于选择性萃取的液膜两大类.膜分离技术具有能耗低、易于连续操作等优点,被普遍认为是进行大规模手性拆分非常有潜力的方法之一,具有良好的应用前景.手性拆分膜技术引起了国内外研究者们的广泛关注,并成为膜学界研究的新热点.     

微孔二氧化硅膜的制备、氢气分离以及水热稳定性研究

利用溶胶-凝胶法在Υ-Al₂O₃/α-Al₂O₃多孔支撑体上合成了微孔二氧化硅膜,并用IR、TG、FESEM、N₂吸附以及气体渗透等手段对二氧化硅膜进行了研究.结果表明,200℃时H₂的渗透率达到2.3×10^-7mol·m^-2·Pa^-1·s^-1,H₂/CO₂的分离系数为8.0,然而当二氧化硅膜长期暴露于潮湿环境时,由于水气与孔表面羟基相互作用引起二氧化硅膜孔结构的崩溃,最终导致H₂渗透率和H₂/CO₂分离系数剧烈下降.     

有机溶剂分离膜结构和膜材料设计理论研究

综述现存有机溶剂分离膜的不同结构特点，分析膜结构对溶剂渗透性能的影响．围绕溶剂渗透过程的溶解-扩散机理模型，重点阐述预测溶解性的溶液热力学理论和计算扩散系数的自由体积理论，强调化工热力学理论对新型溶剂分离膜开发的指导作用．在此基础上，提出膜材料和膜结构相互协调，利用物性推算法进行有机溶剂分离膜材料设计的思想．     

Anion Substitution in Porous Aromatic Frameworks: Boosting Molecular Permeability and Selectivity for Membrane Acetylene Separation

Precise tailoring of pore chemistry is indispensable for efficient membrane gas separation, particularly for the challenging acetylene system. Here, a strategy called “anion substitution” is reported, to strengthen the interaction between anions and acetylene within the pores, for radically improving gas selectivity and permeability. The anions F⁻ and OH⁻ are infixed in iPAF-1 to replace the original Cl⁻ ion. Their small anionic radii allow retention of the original high porosity of iPAF-1-Cl in iPAF-1-F and iPAF-1-OH. Highly basic F⁻ and OH⁻ confined in the pores attract acidic acetylene strongly and preferentially. Nanoparticles of iPAF-1 are processed to form mixed matrix membranes, represented by iPAF-1-OH/6FDA-ODA. The prepared membranes exhibit remarkable performance in separating acetylene from ethylene and ethane. Transplantation of porous and functional iPAF-1-OH into 6FDA-ODA significantly enhances both acetylene permeability (sevenfold) and permselectivity (fivefold) for acetylene over ethylene and ethane, which is crucial for membrane acetylene gas separation.     

液膜用高分子表面活性剂性能研究

本文介绍液膜用高分子表面活性剂PSN_(-89414)的性能,通过界面张力测定,用表面活性剂分子在界面上吸附理论导出公式求得Span80,PS_(-89414)的界面吸附平衡常数K_(?)及S_(af)的数值,结果表明,K_(?)、S_(af)数值愈大的表面活性剂制得乳状液愈稳定,液膜溶胀愈小。PSN_(-89414)的W/O/W乳状液体系用于稀土分离,速度快,从浓度1.2g/L的稀土溶液浓集到103g/L。     

液膜用高分子表面活性剂性能研究

本文介绍液膜用高分子表面活性剂PSN_(-89414)的性能,通过界面张力测定,用表面活性剂分子在界面上吸附理论导出公式求得Span80,PSN_(-89414)的界面吸附平衡常数K_(s)及S_(sf)的数值,结果表明,K_(s)、S_(sf)数值愈大的表面活性剂制得乳状液愈稳定,液膜溶胀愈小。PSN_(-89414)的W/O/W乳状液体系用于稀土分离,速度快,从浓度1.2g/L的稀土溶液浓集到103g/L。     

PDMS低温热解制备有机/无机膜的研究

以聚二甲基硅氧烷(PDMS)为前驱体聚合物, 采用浸渍法在支撑体上涂覆制备PDMS支撑膜, 将其在惰性气氛下350~480℃低温热解, 制备有机/无机膜。考察了制膜工艺条件对膜气体分离性能的影响; 并借助于TG和FT-IR测试手段探讨了PDMS 的热解过程及化学结构的变化; 采用SEM对有机/无机膜的微观形貌进行表征。研究表明, 采用低温热解法可以成功制备出气体分离性能良好的有机/无机膜。该膜既保留了有机膜的柔韧性, 又具有无机膜的热稳定性好的优点, 并表现出良好的气体渗透性能和选择性。PDMS制膜液的浓度、浸渍次数、复合膜的热解温度及基体孔径和性质等因素对有机/无机膜的气体分离性能以及膜层结构有较大的影响。在最佳工艺条件下制备的有机/无机膜其O₂渗透通量为21.2 GPU(1 GPU=7.501×10^-12 m³(STP)/(m²?s?Pa)), O₂/N₂分离系数为2.28。     

CO2‐Philic Separation Membrane: Deep Eutectic Solvent Filled Graphene Oxide Nanoslits

CO₂ capture and sequestration is an energy‐intensive industry to deal with the global greenhouse effect. Membrane separation is considered a cost‐effective method to mitigate the emission of CO₂. Though good separation performance and stability have been reported, supported ionic liquid membranes are still not widely applied for CO₂ separation due to the high cost. As a novel analogous solvent to ionic liquid, deep eutectic solvent retains the excellent merits of ionic liquid and is cheap with facile preparation. Herein, a highly CO₂‐philic separation membrane is constructed by nanoconfining choline chloride/ethylene glycol (ChCl/EG) deep eutectic solvent into graphene oxide nanoslits. Molecular dynamic simulation results indicate that the confinement makes a difference to the structure of the nanoconfined ChCl/EG liquid from their bulk, which remarkably facilitates CO₂ transport. By tuning the molar ratio of ChCl/EG and thickness of the membrane, the resultant membrane exhibits outstanding separation performance for CO₂ with excellent selectivity over other light gases, good long‐term durability, and thermal stability. This makes it a promising membrane for selective CO₂ separation.     

陶瓷分离膜的发展历史与趋势

对陶瓷分离膜的发展历史与应用现状进行了较全面的综述，并就我国发展陶瓷分离膜的若干技术问题展开了讨论。     

Continuous Covalent Organic Frameworks Membranes: From Preparation Strategies to Applications

Covalent organic frameworks (COFs) are porous crystalline polymeric materials formed by the covalent bonding of organic units. The abundant organic units library gives the COFs species diversity, easily tuned pore channels, and pore sizes. In addition, the periodic arrangement of organic units endows COFs regular and highly connected pore channels, which has led to the rapid development of COFs in membrane separations. Continuous defect-free and high crystallinity of COF membranes is the key to their application in separations, which is the most important issue to be addressed in the research. This review article describes the linkage types of covalent bonds, synthesis methods, and pore size regulation strategies of COFs materials. Further, the preparation strategies of continuous COFs membranes are highlighted, including layer-by-layer (LBL) stacking, in situ growth, interfacial polymerization (IP), and solvent casting. The applications in separation fields of continuous COFs membranes are also discussed, including gas separation, water treatment, organic solvent nanofiltration, ion conduction, and energy battery membranes. Finally, the research results are summarized and the future prospect for the development of COFs membranes are outlined. More attention may be paid to the large-scale preparation of COFs membranes and the development of conductive COFs membranes in future research.     

Membrane Engineering: Phase Separation in Polymeric Giant Vesicles

Cell membranes exhibit elaborate lipidic patterning to carry out a myriad of functions such as signaling and trafficking. Domain formation in giant unilamellar vesicles (GUVs) is thus of interest for understanding fundamental biological processes and to provide new prospects for biocompatible soft materials. Lipid rearrangements in lipidic GUVs and lipid/polymer GUVs are extensively studied whereas polymer/polymer hybrid GUVs remain evasive. Here, the focus is on the thermodynamically driven phase separation of amphiphilic polymers in GUVs. It is demonstrated that polymer phase separation is entropically dictated by hydrophobic block incompatibilities and that films topology can help to determine the outcome of polymeric phase separation in GUVs. Lastly, Janus‐GUVs are obtained and GUVs exhibit a single large domain by using a compatibilizing hydrophobic block copolymer.     

Hydrogen Isotope Separation in Confined Nanospaces: Carbons,Zeolites, Metal–Organic Frameworks,and Covalent Organic Frameworks

One of the greatest challenges of modern separation technology is separating isotope mixtures in high purity. The separation of hydrogen isotopes can create immense economic value by producing valuable deuterium (D) and tritium (T), which are irreplaceable for various industrial and scientific applications. However, current separation methods suffer from low separation efficiency owing to the similar chemical properties of isotopes; thus, high‐purity isotopes are not easily achieved. Recently, nanoporous materials have been proposed as promising candidates and are supported by a newly proposed separation mechanism, i.e., quantum effects. Herein, the fundamentals of the quantum sieving effect of hydrogen isotopes in nanoporous materials are discussed, which are mainly kinetic quantum sieving and chemical‐affinity quantum sieving, including the recent advances in the analytical techniques. As examples of nanoporous materials, carbons, zeolites, metal–organic frameworks, and covalent organic frameworks are addressed from computational and experimental standpoints. Understanding the quantum sieving effect in nanospaces and the tailoring of porous materials based on it will open up new opportunities to develop a highly efficient and advanced isotope separation systems.     

用一种不含流动载体的乳状液膜迁移并分离金属离子的研究

本文报道了无流动载体的甲苯乳状液膜体系的制备及迁移金属离子的行为,试验了当内相试剂分别为EDTA,Na_4P_2O_7,Na_2S_2O_3,HNO_3等时,改变外相介质条件,迁移铅、锌、镉、汞等金属离子的情况,对迁移机理进行了探讨。选择了适宜的乳状液膜体系,对铅、锌、镉、汞等金属离子的分离进行了研究。     

用一种不含流动载体的乳状液膜迁移并分离金属离子的研究

本文报道了无流动载体的甲苯乳状液膜体系的制备及迁移金属离子的行为,试验了当内相试剂分别为EDTA,Na。P_2O_7,Na_2S_2O_3 ,HNO_3等时,改变外相介质条件,迁移铅、锌、镉、汞等金属离子的情况,对迁移机理进行了探讨。选择了适宜的乳状液膜体系,对铅、锌、镉、汞等金属离子的分离进行了研究。     

卟啉基多孔有机聚合物的合成、表征及其气体吸附性能研究

本文以对溴苯甲醛和三甲基硅烷基乙炔(TMSA)为原料合成了5,10,15,20-四(4-乙炔基苯基)卟啉(TEPP)和5,10,15,20-四(4-溴基苯基)卟啉(TBPP),TEPP和TBPP通过Sonogashira偶联反应合成了卟啉基多孔有机聚合物(P-POP)。分别采用1 H NMR、XRD、SEM、FT-IR、吸脱附对P-POP的结构和性能进行了表征。研究结果表明P-POP呈现无规块状形貌且部分结晶,在950℃以内具有良好的热稳定性。孔结构分析表明P-POP具有较高孔隙率,BET比表面积达659.9m2/g,总孔容为0.7cm3/g,孔径分布范围为5~20nm,且P-POP在273K下对CO2表现出良好的吸附能力,最大吸附值达25.2cm3/g。     

乳状液膜法分离高钼低钨料液中钨钼的研究

根据钙资源利用中钙料液含少量钨的具体实际，对此类高钙低钨料液采用三烷基氧化膦（ＴＲＰＯ）为载体、ＮａＯＨ为反萃试剂的液膜体系来分离钨钼。考察了影响钨钼分离的诸因素，得到了分离钨钼的最佳操作条件。在此条件下，钼的浓度为０．０５２１ｍｏｌ／Ｌ，ＷＯ３与Ｍｏ的质量分数为１０％的料液经一级间歇液膜过程，在内水相可得到纯度为１００％的钼。