二维材料构筑的CO2分离膜研究进展

二维材料由于其独特的纳米片结构，已广泛应用于设计高气体渗透通量和选择性的分离膜中.石墨烯类、二维金属有机骨架、二维过渡金属碳化物/碳氮化物等二维材料中构筑的纳米及纳米尺度孔道为分子输运提供了特殊的通道，它们是高渗透性和高选择性分子筛分的根本原因.本文综述了近年来二维材料基CO₂分离膜的研究进展，包括材料种类、分离膜的制备方法、分离性能及分离机制，并对二维材料基CO₂分离膜的应用前景进行了总结与展望.     

消息报道

正宁波材料所在气体吸附分离材料研究中取得新进展金属有机框架材料(MOF)是一类新型的有机-无机杂化多孔晶体材料,具有高比表面积、孔容、孔隙率和孔径可调等特性,在氢气、甲烷和二氧化碳等气体的吸附分离领域受到了广泛关注。近年来很多MOF或MOF/聚合物复合气体分离膜不断被设计与开发出来,然而这些膜材料很难同时兼有气体的高渗透性和高选择性,而且以氧化铝陶瓷管为载体制备的MOF基分离膜很容易产生缺陷,     

二维片层材料用于构筑气体分离膜的研究进展

二维片层材料因其独特的片层结构、高比表面积和良好的机械性能等特性,在气体分离膜中得到了广泛关注。首先简单归纳了气体在无孔片层和多孔片层材料中的传递机理,之后重点讨论了用于气体分离的二维片层材料无机膜和高分子-无机杂化膜的研究现状。     

MOFs有机-无机杂化膜的制备及应用研究进展

综述了基于金属有机骨架(MOFs)材料发展而来的有机-无机杂化膜的制备方法及其在气体分离、渗透汽化和纳滤等领域的应用.其中,气体分离主要介绍了杂化膜材料对H2、CO2和CH4等混合气体的分离性能;渗透汽化则基于溶剂脱水或者水相中有机物的去除等领域的应用而展开;纳滤主要介绍了杂化膜材料对小分子物质的分离性能.同时,还阐述了杂化膜材料在以上应用中所起的作用.最后总结了这种材料在研究过程中所面临的主要挑战,并对今后的发展做出了展望.     

改善MOFs/聚合物混合基质膜气体分离性能的策略

混合基质膜(MMMs)是一类新型的膜材料,其结合了有机相和无机相的优势,具有良好的渗透选择性,广泛用于气体分离领域.金属有机骨架材料(MOFs)因具有高孔隙率和可调节孔径等优势已成为一种新型的有机-无机杂化填料,被广泛研究用来制备具有增强分离性能的MMMs.然而,这种MMMs常出现界面缺陷、MOFs填料分散性差等劣化气体分离性能的问题.近年来为解决这些问题,研究了改善MOFs/聚合物MMMs气体分离性能的各种策略,包括MOFs的官能化、MOFs的调控、MOFs的包裹、聚合物的改性、MOFs和聚合物的匹配,这些策略也为改善除MOFs外其他填料填充的MMMs的气体分离性能提供借鉴.随着研究的深入,用于气体分离的MMMs的性能将逐渐得到改进,并有望实现商业化大规模生产.     

宁波材料所在金属有机框架膜研究方面取得新进展

正金属有机框架化合物(MOF)是近年来发展起来的一类由无机金属中心与有机官能团通过共价键或离子键相互联接、共同构筑的具有规整孔道结构的新型多孔晶体材料,在气体吸附和储存、分离、催化、光电、传感等领域具有广泛的应用前景。其中沸石咪唑类金属有机框架化合物(ZIF)由于其均匀规整孔道结构和较高热稳定性,沸石咪唑类金属有机框架膜的合成和应用研究最近引起人们的极大兴趣,逐渐成为气体分离膜的研究热点。但由于沸石咪唑类金属有机框架膜通常     

蝶烯基微孔聚合物气体分离膜的研究进展

在气体分离膜领域,传统膜材料常面临着气体渗透性与选择性相互制约的难题,寻求新型聚合物膜材料并探寻分子设计规律成为首要任务.本文综述了一类新型聚合物——蝶烯基聚合物近十年内的研究进展,着重阐述了蝶烯分子在不同种类气体分离膜材料(聚酰亚胺、聚苯并嗯唑和自具微孔聚合物等)的结构、调控方式及气体分离性能,考察了碟烯结构在优化气...     

碳点在膜技术中的应用进展

碳点(CDs)是一种新型的零维碳基材料，其具有超小尺寸、亲水性强、丰富的表面官能团、易于合成和良好的水溶性等优异特性.通过调控CDs的性质可以提高复合膜的水通量和分离性能，将其引入膜材料中对开发高渗透性和高选择性复合膜具有重要意义.因此，CDs在膜分离领域展现了巨大的应用前景.本文介绍了CDs或改性CDs的合成方法，总结了CDs复合膜的制备及其在气体分离、水净化、有机溶剂分离等领域的应用，并对CDs在膜技术领域的应用中所面临的机遇与挑战进行了展望.     

二维MXene材料在气体传感器领域的应用进展

MXene材料是由前过渡金属碳、氮化物组成的无机化合物,二维MXene及其复合材料具有类石墨烯层状结构、高比表面积、优异的导电性和丰富的表面活性位点,近年来在材料领域成为研究热点.本文聚焦二维MXene材料在气体传感器领域的应用前景,从MXene和气敏性能等角度进行了综述,重点对MXene及其(无机/有机)复合材料用作...     

新型二维材料光催化与电催化研究进展

二维材料以其丰富多样的性能受到广泛关注。该类材料具有极高的比表面积, 可以作为光催化剂和电催化剂, 在环境领域和可再生能源领域具有较大的开发和应用前景。本文综述了三种新型二维材料的结构性能, 即二维过渡金属碳/氮化物(MXenes)、类石墨相氮化碳(g-C₃N₄)以及黑磷(BP)在光催化或电催化领域的研究进展及改性方式; 对二维材料催化性能的改性进行了总结, 并展望了今后的研究方向。     

Synthetic Two‐Dimensional Materials: A New Paradigm of Membranes for Ultimate Separation

Microporous membranes act as selective barriers and play an important role in industrial gas separation and water purification. The permeability of such membranes is inversely proportional to their thickness. Synthetic two‐dimensional materials (2DMs), with a thickness of one to a few atoms or monomer units are ideal candidates for developing separation membranes. Here, groundbreaking advances in the design, synthesis, processing, and application of 2DMs for gas and ion separations, as well as water desalination are presented. This report describes the syntheses, structures, and mechanical properties of 2DMs. The established methods for processing 2DMs into selective permeation membranes are also discussed and the separation mechanism and their performances addressed. Current challenges and emerging research directions, which need to be addressed for developing next‐generation separation membranes, are summarized.     

Microporous Organic Materials for Membrane‐Based Gas Separation

Membrane materials with excellent selectivity and high permeability are crucial to efficient membrane gas separation. Microporous organic materials have evolved as an alternative candidate for fabricating membranes due to their inherent attributes, such as permanent porosity, high surface area, and good processability. Herein, a unique pore‐chemistry concept for the designed synthesis of microporous organic membranes, with an emphasis on the relationship between pore structures and membrane performances, is introduced. The latest advances in microporous organic materials for potential membrane application in gas separation of H₂, CO₂, O₂, and other industrially relevant gases are summarized. Representative examples of the recent progress in highly selective and permeable membranes are highlighted with some fundamental analyses from pore characteristics, followed by a brief perspective on future research directions.     

Polycrystalline Advanced Microporous Framework Membranes for Efficient Separation of Small Molecules and Ions

Advanced porous framework membranes with excellent selectivity and high permeability of small molecules and ions are highly desirable for many important industrial separation applications. There has been significant progress in the fabrication of polycrystalline microporous framework membranes (PMFMs) in recent years, such as metal–organic framework and covalent organic framework membranes. These membranes possess small pore sizes, which are comparable to the kinetic diameter of small molecules and ions on the angstrom scale, very low thickness, down to tens to hundreds of nanometers, highly oriented crystalline structures, hybrid membrane structures, and specific functional groups for enhancing membrane selectivity and permeability. Recent advances in the fabrication methods of advanced PMFMs are summarized. Following this, four emerging separation applications of these advanced microporous framework membranes, including gas separation, water desalination, ion separation, and chiral separation, are highlighted and discussed in detail. Finally, a summary and some perspectives of future developments and challenges in this exciting research field are presented.     

Graphynes for Water Desalination and Gas Separation

Selective transport of mass through membranes, so‐called separation, is fundamental to many industrial applications, e.g., water desalination and gas separation. Graphynes, graphene analogs yet containing intrinsic uniformly distributed pores, are excellent candidates for highly permeable and selective membranes owing to their extreme thinness and high porosity. Graphynes exhibit computationally determined separation performance far beyond experimentally measured values of commercial state‐of‐the‐art polyamide membranes; they also offer advantages over other atomically thin membranes like porous graphene in terms of controllability in pore geometry. Here, recent progress in proof‐of‐concept computational research into various graphynes for water desalination and gas separation is discussed, and their theoretically predicted outstanding permeability and selectivity are highlighted. Challenges associated with the future development of graphyne‐based membranes are further analyzed, concentrating on controlled synthesis of graphyne, maintenance of high structural stability to withstand loading pressures, as well asthe demand for accurate computational characterization of separation performance. Finally, possible directions are discussed to align future efforts in order to push graphynes and other 2D material membranes toward practical separation applications.     

Microstructural and Interfacial Designs of Oxygen‐Permeable Membranes for Oxygen Separation and Reaction–Separation Coupling

Mixed ionic–electronic conducting oxygen‐permeable membranes can rapidly separate oxygen from air with 100% selectivity and low energy consumption. Combining reaction and separation in an oxygen‐permeable membrane reactor significantly simplifies the technological scheme and reduces the process energy consumption. Recently, materials design and mechanism investigations have provided insight into the microstructural and interfacial effects. The microstructures of the membrane surfaces and bulk are closely related to the interfacial oxygen exchange kinetics and bulk diffusion kinetics. Therefore, the permeability and stability of oxygen‐permeable membranes with a single‐phase structure and a dual‐phase structure can be adjusted through their microstructural and interfacial designs. Here, recent advances in the development of oxygen permeation models that provide a deep understanding of the microstructural and interfacial effects, and strategies to simultaneously improve the permeability and stability through microstructural and interfacial design are discussed in detail. Then, based on the developed high‐performance membranes, highly effective membrane reactors for process intensification and new technology developments are highlighted. The new membrane reactors will trigger innovations in natural gas conversion, ammonia synthesis, and hydrogen‐related clean energy technologies. Future opportunities and challenges in the development of oxygen‐permeable membranes for oxygen separation and reaction–separation coupling are also explored.     

热致重排聚合物的制备及其气体分离应用研究

近年来,以酰亚胺环邻位官能化的聚酰亚胺或聚酰胺为前驱体,经一定热处理发生结构重排,可得到另一种刚性结构聚合物——热致重排聚合物。热致重排聚合物作为一种新型的刚性微孔聚合物材料,具有较高的自由体积和比表面积,表现出非常优异的气体渗透性和分离性,因此在气体分离等领域受到了广泛关注。前驱体聚合物的化学结构、制备方法、物理性状和热处理条件(氛围、时间、温度)等都将影响热致重排反应及最终热致重排聚合物的各项性能。因此,本文介绍了热致重排聚合物的重排反应机理、研究进展及改性研究情况,并对热致重排聚合物今后的发展趋势进行了展望。     

Microstructural Engineering and Architectural Design of Metal–Organic Framework Membranes

In the past decade, a huge development in rational design, synthesis, and application of molecular sieve membranes, which typically included zeolites, metal–organic frameworks (MOFs), and graphene oxides, has been witnessed. Owing to high flexibility in both pore apertures and functionality, MOFs in the form of membranes have offered unprecedented opportunities for energy‐efficient gas separations. Reports on the fabrication of well‐intergrown MOF membranes first appeared in 2009. Since then there has been tremendous growth in this area along with an exponential increase of MOF‐membrane‐related publications. In order to compete with other separation and purification technologies, like cryogenic distillation, pressure swing adsorption, and chemical absorption, separation performance (including permeability, selectivity, and long‐term stability) of molecular sieve membranes must be further improved in an attempt to reach an economically attractive region. Therefore, microstructural engineering and architectural design of MOF membranes at mesoscopic and microscopic levels become indispensable. This review summarizes some intriguing research that may potentially contribute to large‐scale applications of MOF membranes in the future.     

Membrane Separation in Organic Liquid: Technologies,Achievements, and Opportunities

Membrane technology is one of the most promising technologies for separation and purification that is routinely and commercially employed in aqueous solutions. In comparison, its applications in organic solvents are severely underdeveloped mainly due to the poor stability of traditional polymer membranes in organic solvents. The emerging materials such as crosslinked polymers, covalent organic frameworks, metal–organic frameworks, conjugated microporous polymers, carbon molecular sieves, and graphene provide the solutions to address this problem. The membranes constructed with these novel materials show outstanding separation performance in regard to both high selectivity and solvent permeability, greatly pushing forward utilization of membrane technology in organic media. Here, an overview of the most important organic mixtures that need to be separated, the major separation processes adopted nowadays in organic solvents, and the recent progress in new developed membranes is provided.     

Electrochemically-aided membrane separation and catalytic processes

Electrochemically driven membrane separations and catalytic processes are interesting research areas which have, to date, received relatively little attention. Research into electrically-aided membrane separation and catalytic processes is currently being carried out in South Africa. The research objective is the development and characterisation of novel composite materials based on solid polyelectrolytes (SPE), containing nanoparticles of catalytically active metals, such as Pt, Ir or Pd, distributed within the polymeric matrices. An example of such an SPE matrix is a perfluorinated ion-exchange membrane. The novel composite materials (in fact, membranes) are both ionically and electronically conductive due to the presence of the metal nanoparticles. The application of potentials to conducting membranes results in the enhancement of catalytic activity as well as the selectivity of separations. The membranes based on SPE can be used for the catalytic processing of petrochemical mixtures, water treatment (disinfection, nitrate removal, etc.), oxygen, hydrogen and ozone generation, and electrically enhanced gas and vapour separations. In this paper Dr Dmitri Bessarabov briefly outlines the current status of the research, available technology and discusses challenges and possible applications.     

无机膜反应器的研究进展

膜反应器是具有反应与分离双重功能的单元集成设备,通过分离与反应的协同作用强化化学反应过程,已在加氢、脱氢、分解和氧化等苛刻反应中显示出优势。膜材料是决定膜反应器性能与应用的关键因素。重点从膜材料角度出发,介绍了致密无机膜反应器与多孔无机膜反应器的特点及发展。指出应开发高分离性能、抗污染、易于封装的膜材料,加强膜反应器质量和热量传递基本理论研究,以促进无机膜反应器早日大规模工业化应用。