基于共价有机框架材料的纳滤膜制备研究进展

共价有机框架(COFs)材料是由有机结构单元通过共价键连接形成的多孔纳米材料,具有比表面积大、孔隙率高、结构规整有序、稳定性好的优点,是制备高性能分离膜的理想材料,因而在纳滤膜研究领域引起广泛关注.文章综述了近几年来研究者利用掺杂法、层层组装法、界面聚合法、原位生长法等制备COFs纳滤膜的研究成果,对不同制膜方法的特点...     

共价有机骨架化合物的制备与应用研究进展

共价有机骨架化合物（COFs）是一种由有机单体通过共价键连接形成的、具有周期性网络结构的新型多孔结晶聚合物。共价有机骨架材料具有孔道规则、重量密度低、稳定性能良好以及较大的比表面积等优势,COFs已在气体存储、光电、催化、储能等方面有着广泛的应用。该文主要综述了COFs材料的特点以及它在气体储存与分离、光电、吸附等领域的应用,并与金属有机骨架材料进行了对比,总结了COFs材料的发展现状和存在的问题,并对这种材料的功能和应用范围的拓展进一步做了展望。     

共价有机骨架(COFs)膜及其在气体分离方面的应用分析

低碳烯烃和烷烃的分离是化工领域的难题,膜的气体分离工艺技术是减少对环境的影响和降低运营成本的一种理想方法。传统聚合膜通常受到渗透率和选择性权衡的限制。共价有机骨架(COFs)含有丰富且规则的孔道结构的优点从而可实现超快透过且高度选择性的性能。然而,COFs的孔道大小通常大于低碳烷烃的分子动力学直径,3D共价有机骨架(COFs)中的孔道虽然通过设计互穿结构可以将孔道缩小到5埃到7埃之间,可以实现低碳烷烃的筛分作用,但3D COFs膜的传输阻力要远大于层状原子厚片形式的2D COFs膜。本文对共价有机骨架(COFs)膜及其在气体分离方面的应用进行了介绍分析,为国内利用膜分离气体提供参考。     

凹凸棒黏土改性聚合物材料的研究进展

综述了聚合物／凹凸棒黏土（AT）复合材料近年来的研究进展。聚合物／AT复合材料的制备方法主要包括原位聚合（复合）法和共混法，两种方法均可以获得AT良好分散的复合材料。AT使聚合物基体的力学性能、结晶学性能和耐热性能都有改善；但是不同体系的力学性能改善程度不同，AT可用作聚合物的有效的成核剂。机理在于AT的纳米效应、在基体中的定向作用和强的界面相互作用。最后，对聚合物／AT复合材料的发展趋势进行了展望。     

有机纳米多孔聚合物(NOPs)概述

人为二氧化碳大量排放被认为是全球变暖的原因之一,但当前捕捉CO2的方法需耗费大量能量。固体吸附剂吸附法是一个潜在捕集二氧化碳的方法。多孔有机骨架材料因其高的比表面积、高的物理化学稳定性、轻质的骨架结构成为二氧化碳吸附领域的研究热点,本文简单介绍了目前有机纳米微孔种类及其二氧化碳吸附应用。     

多孔共价三嗪骨架的简易合成及碘捕获研究

采用廉价的三聚氯氰与六苯基苯通过一锅法合成了一种共价三嗪骨架材料(CTF-HPB)。利用红外光谱和固体核磁碳谱研究其化学结构。热失重分析表明CTF-HPB具有良好的热稳定性。CTF-HPB的比表面积高达1 159 m²/g。在75℃下,CTF-HPB对碘的吸附量高达2 183 mg/g。其次,对CTF-HPB碘吸附过程进行动力学分析,符合伪一级动力学模型,为物理吸附。此外,在120℃下,碘吸附饱和的CTF-HPB在360 min后对碘的释放率高达88%。碘吸附循环测试表明经4次循环测试后CTF-HPB仍可吸附1 935 mg/g的碘。高的碘吸附量预示着CTF-HPB在碘捕获方面具有潜在的应用价值。     

二维共价有机框架膜的构筑及其气体分离研究进展

二维共价有机框架材料由于具有层状堆积结构,构筑单元丰富、孔道规整且精确可调、易于修饰功能基团,具有良好的化学、机械和热稳定性能,相较于其它晶体材料,二维共价有机框架在制备气体分离膜时的成膜性更好,有望制备成超薄膜。本文从二维共价有机框架膜的制备、性能改善及气体分离应用研究三个方面进行综述,并对其研究前景进行展望。     

金属有机骨架混合基质水处理分离膜研究进展

金属有机骨架（MOFs）晶体由无机金属离子和有机配体通过自组装合成,具有高的孔隙率和可调节的窗口尺寸,可使MOFs混合基质膜在水处理时同步获得高通量和高截留率,有望突破传统分离膜的渗透性和选择性之间此消彼长的trade-off效应。本文综述了MOFs的典型构造、影响MOFs混合基质膜性能的关键因素、MOFs混合基质膜的制备方法、MOFs颗粒改善混合基质膜水传输和溶质分离性能的原理以及MOFs混合基质膜在水处理微滤/超滤、纳滤/反渗透和正渗透领域的最新研究进展。最后总结了MOFs混合基质膜在水处理领域的未来发展亟待解决的关键问题,主要包括高性能、低成本膜的可控制备、膜结构和性能之间定量构效关系的深入探索以及如何拓宽其应用范围等,对加快MOFs混合基质膜的产业化进程具有指导意义。     

改善聚合物共混材料界面相容性的研究进展

本文综述了聚合物共混材料界面相容性的概念、理论基础以及改善相容性的方法和增容技术的应用，简要介绍了原住复合材料的发展趋势和正弦脉动流场从物理的角度对共混物起到了增容的作用。     

共价有机框架材料的制备及对染料吸附性能的研究

利用溶剂热法合成了一种二维的共价有机框架（DMTP-TAPB COF）材料。通过X射线衍射仪（XRD）、扫描电子显微镜（SEM）和热重分析仪（TGA）对合成材料的结构、形貌和性能进行了详细的研究。然后研究了制备的共价有机框架材料对于靛蓝胭脂红染料（IC）的吸附能力,考察了不同吸附时间、不同p H和不同靛蓝胭脂红的初始浓度对吸附性能的影响。实验结果表明,制备的二维共价有机框架材料具有良好的结晶度和均匀的形貌。同时,DMTP-TAPB COF对靛蓝胭脂红具有较高的吸附能力（330.5 mg/g）和移除效率（84.5%）,吸附过程符合准二级动力学方程和Langmuir吸附模型。该研究表明共价有机框架材料作为污染物的吸附剂具有广阔的应用前景。     

A melamine-based covalent organic framework nanomaterial as a nanofiller in polyethersulfone mixed matrix membranes to improve separation and antifouling performance

This research reported developing a polyethersulfone (PES) membrane using covalent organic frameworks (COFs) nanoparticle with a mean dimension of 30 nm. The SNW-1 (Schiff-based network) COF was synthesized using precursors of melamine and terephthalic acid and then characterized by XRD, SEM, TEM, and FTIR analyses. The influence of different loadings of the COF was evaluated on the permeability, antifouling behavior and dye/salt rejection. The addition of SNW-1 caused a reduction in surface roughness and an improvement in hydrophilicity of the nanocomposite membranes, which improved their flux and fouling resistance considerably. The improvement of water flux, 2.6 times, was observed by adding 0.5 wt% COF to the membrane matrix. The 0.5 wt% COF membrane presented the best water permeability, 38.9 L/m² h bar BSA solution flux, dye rejection of 98.7% for Reactive Green 19 and 62.6% for Reactive yellow 39, 52.9% Na₂SO₄ and 24.5% NaCl salt rejections. Zeta potential and salt rejection trend indicated a negative surface charge on the nanocomposite membrane. Fouling experiments by BSA protein solution exhibited that the FRR reached 88.9% for 2 wt% COF membrane. Thus, employing SNW-1 into PES matrix resulted in a promising nanofiltration membrane for dye separation and moderate salt separation with suitable antifouling properties.     

Reducing active layer thickness of polyamide composite membranes using a covalent organic framework interlayer in interfacial polymerization

Polyamide(PA)-based thin-film composite membranes exhibit enormous potential in water purification, owing to their facile fabrication, decent performance and desirable stability. However, the thick PA active layer with high transport resistance from the conventional interfacial polymerization hampers their applications. The controllable fabrication of a thin PA active layer is essential for high separation efficiency but still challenging. Herein,a covalent organic framework TpPa-1 interlayer was firstly deposited on a polyethersulfone(PES) substrate to reduce the thickness of PA active layer in interfacial polymerization. The abundant pores of TpPa-1 increase the local concentration of amine monomers by adsorbing piperazine molecules, while hydrogen bonds between hydrophilic groups of TpPa-1 and piperazine molecules slow down their diffusion rate. Arising from those synergetic effects, the PA active layer is effectively reduced from 200 nm to 120 nm. By optimizing TpPa-1 interlayer and PA active layer, the water flux of resultant membranes can reach 171.35 L·m~(-2)·h~(-1)·MPa~(-1), which increased by 125.4% compared with PA/PES membranes, while the rejection rates of sodium sulfate and dyes solution remained more than 90% and 99%, respectively. Our strategy may stimulate rational design of ultrathin PA-based nanofiltration membranes with high performances.     

Evaluation of a modified spray-applied interfacial polymerization method for preparation of nanofiltration membranes

Nanofiltration (NF) membranes were fabricated by using piperazine (PIP) and trimesoyl chloride (TMC) by conventional and spray-applied interfacial polymerization methods, studying the effect of the application method for both phases, the number of applied layers, and the displacement speed for the spray application. A polysulfone ultrafiltration membrane was used as support. NF membranes were characterized by different spectroscopic, microscopic, and physicochemical techniques. Rejection capacity was evaluated for sodium chloride (NaCl), sodium sulfate (Na₂SO₄), and magnesium sulfate (MgSO₄) salts; the decreasing rejection order was Na₂SO₄ > MgSO₄ > NaCl for each NF membrane. NF membrane prepared with one layer of the sprayed out TMC solution and conventional application of PIP solution exhibited the highest salt rejection (99% for 1000 ppm Na₂SO₄) and a permeated flux of 10.28 L m⁻² h⁻¹ at 0.55 MPa. The modified method is a facile-reproducible preparation methodology that reduces the consumption of time, effort, and reagents leading to a scalable manufacturing process for separation technology. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48129.     

耐溶剂纳滤膜的制备与应用研究进展

有机溶剂纳滤(organic solvent nanofiltration,OSN)是近年来快速发展起来的一项新型纳滤膜分离技术,具有广阔的应用前景。耐溶剂纳滤(solvent-resistant NF,SRNF)膜的制备是OSN技术发展的关键,也是目前的研究热点之一。本文侧重阐述了SRNF膜在制备及应用方面的进展,着重介绍了相转化法、界面聚合法、自组装法及有机-无机杂化法等SRNF膜制备方法。相转化法是目前国内外SRNF膜制备研究常用的方法,但该法所制备的膜皮层较厚,通量明显偏小;界面聚合法SRNF膜制备的相关研究目前较少,但由于其皮层非常薄,因此是SRNF膜制备发展的一大趋势;自组装膜有较好的耐溶剂性能;加入无机物可以提高耐有机溶剂性,有机-无机杂化法的膜制备是SRNF膜制备的趋势之一。同时简单介绍了SRNF膜的应用,并对未来SRNF膜研究的方向提出了建议。     

界面聚合技术制备分离膜的研究进展

界面聚合技术具有许多优良性能,如反应条件温和、可控性强、可以实现自封闭和自终止等,被广泛应用于分离膜制备中。本文阐述了界面聚合技术的原理,详细介绍了界面聚合在膜分离中的应用情况,包括纳滤膜、反渗透膜和气体分离膜,并综述了界面聚合技术在微胶囊、导电聚合物、纤维材料等方面的应用现状。最后,对界面聚合技术制备分离膜的研究前景进行了展望。     

有机框架膜在气体分离中的研究进展

高渗透性、高选择性和高稳定性的膜材料是决定膜分离过程效率的关键。有机框架膜（organic framework membranes,OFMs）具有孔隙率高、孔道长程有序、易于官能化修饰、稳定性强等特点,在气体膜分离领域具有重要发展前景。综述了有机框架膜的化学组成、结构特征、制备方法及其在二氧化碳捕集与分离、烯烃/烷烃分离及稀有气体分离等气体分离过程中的应用。最后,对有机框架膜在气体分离领域的机遇和挑战进行了总结,并对其发展方向进行了展望。     

制备聚酰胺复合膜中界面聚合反应添加剂研究进展

聚酰胺复合膜以其优良的稳定性及良好的分离选择性成为水处理和化工分离领域应用范围最广的分离材料之一。聚酰胺复合膜一般采用界面聚合法制备,由于界面聚合反应活性高、反应参数多,致使界面层结构难以控制,膜的渗透性或选择性不理想。因此,如何有效调控膜结构,实现膜的高渗透性或选择性是目前面临的重要挑战。近期诸多研究表明,在水相或有机相中引入添加剂可以改变油水界面张力进而调控单体界面扩散速率及界面分布,或通过改变反应机理影响聚合反应速率,最终实现对界面层结构和膜性能的调控。本文从添加剂种类、性质和调控作用等角度总结了近年来添加剂对复合膜结构及性能调控的研究进展,分析了现有研究存在的问题,并建议从微观层面探究界面过程的物理化学性质以及开发高时间分辨率原位表征方法等。     

Poly(amide imide)s and poly(amide imide) composite membranes by interfacial polymerization

Novel amic acid diamines (AADs) (2‐carboxyterephthalamido‐bis(alkyl or aryl amine)s, H₂N? X? NH(O?)C? C₆H₃(COOH)? C(?O)NH? X? NH₂, where X is were synthesized by reacting trimellitic anhydride chloride with aromatic or aliphatic diamines in dimethylformamide at 5–10 °C. Poly(amide imide)s (PAIs) with an amide to imide ratio of three in the polymer chains were prepared by interfacial polycondensation of the AADs in aqueous alkaline solution with isophthaloyl chloride or terephthaloyl chloride in dichloromethane at ambient temperature to form poly(amide amic acid)s, followed by their subsequent thermal cycloimidization. All of the PAIs were soluble in polar aprotic solvents such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide and N‐methylpyrrolidone, and have inherent viscosities in the range 0.15–0.48 dL g^?1. The polymers were characterized by IR and NMR spectroscopy, TGA and DSC techniques. The PAIs have initial decomposition temperatures in the range 250–460 °C in air, and glass transition temperatures of 128–320 °C, depending upon the structures of the monomers. Composite membranes containing a poly(amide amic acid) and poly(amide imide) barrier layer on the top of a porous polyethersulfone support were prepared by in situ interfacial polymerization of the AADs in aqueous alkaline solution with trimesoyl chloride in hexane, and subsequent curing. The performances of these membranes were evaluated by using aqueous feed solutions containing 2000 ppm NaCl, Na₂SO₄ or CaCl₂. Copyright © 2006 Society of Chemical Industry     

Synthesis and characterization of poly(amide–imide)s and their precursors as materials for membranes

Water soluble diamine amic acids (DAAs) were synthesized by reacting aliphatic diamines with pyromellitic dianhydride. Poly(amide–amic acid)s (PAAs) were prepared by interfacial polycondensation of DAAs in aqueous sodium hydroxide solution with isophthaloyl chloride in dichloromethane. Poly(amide–imide)s (PAIs) containing alternating (amide–amide)–(imide–imide) sequences were obtained by thermal cycloimidization of the PAA films at 175°C for 4 h in a forced air woven. The PAIs were readily soluble in polar aprotic solvents such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, and N‐methyl‐2‐pyrrolidone. The inherent viscosities of the polymers are in the range of 0.97–1.7 dL/g. The polymers were characterized by IR, ¹H nuclear magnetic resonance (NMR), and thermogravimetric analysis (TGA). Thin film composite membranes containing PAA ultrathin barrier layer were prepared by in situ interfacial polycondensation of DAA in water with trimesoyl chloride or isophthaloyl chloride in hexane on the surface of a porous polysulfone membrane. The membranes were characterized for water permeability and for the separation of NaCl and Na₂SO₄. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1721–1727, 2000