微相分离结构聚氨酯膜的丁醇/水体系渗透汽化分离

制备了端羟基聚丁二烯-聚氨酯（HTPB-PU）和端羟基聚丁二烯-乙烯基三乙氧基硅烷-聚氨酯（HTPB-VTES-PU）两种聚氨酯膜。采用傅立叶变换红外光谱（FT-IR）、差示扫描量热仪（DSC）和透射电镜（TEM）分析表征了两种膜的结构,结果发现,HTPB-PU有两个玻璃化转变温度,其膜具有一定程度的微相分离结构;HT...     

Electric-Field-Induced Ionic Sieving at Planar Graphene Oxide Heterojunctions for Miniaturized Water Desalination

Layered graphene oxide membranes (GOMs) offer a unique platform for precise sieving of small ions and molecules due to controlled sub-nanometer-wide interlayer distance and versatile surface chemistry. Pristine and chemically modified GOMs effectively block organic dyes and nanoparticles, but fail to exclude smaller ions with hydrated diameters less than 9 Å. Toward sieving of small inorganic salt ions, a number of strategies are proposed by reducing the interlayer spacing down to merely several angstroms. However, one critical challenge for such compressed GOMs is the extremely low water flux (<0.1 Lm⁻² h⁻¹ bar⁻¹) that prevents these innovative nanomaterials from being used in real-world applications. Here, a planar heterogeneous graphene oxide membrane (PHGOM) with both nearly perfect salt rejection and high water flux is reported. Horizontal ion transport through oppositely charged GO multilayer lateral heterojunction exhibits bi-unipolar transport behavior, blocking the conduction of both cations and anions. Assisted by a forward electric field, salt concentration is depleted in the near-neutral transition area of the PHGOM. In this situation, deionized water can be extracted from the depletion zone. Following this mechanism, a high rejection rate of 97.0% for NaCl and water flux of 1529 Lm⁻² h⁻¹ bar⁻¹ at the outlet via an inverted T-shaped water extraction mode are achieved.     

亲水性高分子-陶瓷复合膜的制备与表征

采用均质的氧化铝支撑体和不同表面层孔径的非对称氧化铝支撑体直接接枝聚丙烯酸(PAA)制备亲水性PAA-Al2O3复合膜。对所制备出复合膜的红外光谱(IR)分析、光电子能谱(XPS)分析、扫描电子显微镜(SEM)分析和表面的水接触角分析表明,成功地制备出了PAA-Al2O3复合膜。在相同实验条件下对所制备的复合膜进行纯水和纯乙醇的通量实验以及质量分数95%乙醇的脱水分离试验表明,最适合用于制备PAA-Al2O3复合膜的陶瓷膜支撑体是孔径为2～3μm的均质氧化铝支撑体,用其制备的复合膜的分离因子为139.33,通量为0.61kg/(m2.h),可以达到分离效率高、通量较大的效果.     

Calcinable Polymer Membrane with Revivability for Efficient Oily‐Water Remediation

Fouling of polymeric membranes remains a major challenge for long‐term operation of oily‐water remediation. The common reclamation methods to recycle fouled membranes have the issues of either incomplete degradation of organic pollutants or damage to filter membranes. Here, a calcinable polymer membrane with effective reclamation after fouling is reported, which shows full recovery of the original oil/water separation efficiency. The membrane is made of polysulfonamide/polyacrylonitrile fibers by emulsion electrospinning, followed by hydrothermal decoration of TiO₂ nanoparticles. The bonding structured fibrous membrane displays outstanding thermal stability in air (400 °C), strong acid/alkali resistance (at the pH range from 1 to 13), and robust tensile strength. As a result, the chemically fouled polymeric membrane can be easily reclaimed without decreasing in separation performance and mechanical properties by annealing treatment. As a proof‐of‐concept, the as‐prepared membrane is integrated into a wastewater separation tank, which achieves a high water flux over 3000 L m^?2 h^?1 and oil rejection efficiency of 99.6% for various oil‐in‐water emulsions. The presented strategy on membrane fabrication is believed to be an effective remedy for membrane fouling, and should apply in a wider field of filtration industry.     

膜技术处理含油废水的研究

介绍了膜技术在含油废水处理中的特点和应用前景,针对含油废水的性质,探讨了膜类型的选择、操作压差、膜面流速、操作温度、膜污染及清洗等因素对膜技术处理含油废水的影响.通常情况下,操作压力过大时,膜通量随压力变化较小,而低于该压力时,膜通量随操作压力的增大而提高;膜面流速和温度对膜通量的影响和操作压力的影响类似;膜经过合适的清洗可以基本恢复膜通量.还介绍了膜技术在油田含油废水处理中的实例和存在的问题,并进一步指出今后的发展方向是研究开发经济、高效的污水处理技术,尤其是膜技术和微生物法结合处理油田含油废水的技术.     

Weak-reduction graphene oxide membrane for improving water purification performance

Two-dimensional(2 D) materials are promising candidates for advanced water purification membranes.In this work, UV reduced GO(Ur GO) membranes on the support of polyvinylidene fluoride(PVDF) had been fabricated for wastewater treatment. The reduction degree of GO membrane on the effect of water purification performance was investigated, and it was found that the weak-reduction GO membrane exhibited the optimal performance of removing pollutant from wastewater than GO membrane. Besides,scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectra and contact angle tests were used to characterize the physical and chemical properties of the Ur GO membranes, and the permeance and rejection ability of the as-prepared filtration membranes were determined. Due to the weak-reduction of GO, pristine graphitic sp2 domains increased with slightly decreasing D-spacing. Thus,the Ur GO membrane showed a higher water flux of 38.27 L m~(-2)h~(-1) bar~(-1), which was improved more than 270% compared to GO membrane, and dyes rejection increased. Those outstanding performances indicated that the Ur GO membrane could effectively regulate the contradiction of the trade-off balance between flux and rejection, and hold great potential in real-world waste-water purification.     

掺杂无机纳米粒子的阿魏酸分子印迹复合膜的制备

分子印迹膜是一种兼具分子印迹技术与膜分离技术双重优点的新兴技术,但由于有机膜的力学强度较小,在分离过程中容易使印迹孔穴的空间变形和互补官能团位置的失稳,使得其分离效率大大降低。文中使用紫外光引发原位聚合的方法,以聚偏氟乙烯(PVDF)作为支撑膜,将无机纳米材料和铸膜液共混制备了含有无机纳米材料的阿魏酸分子印迹复合膜。利用红外光谱和扫描电镜测试了膜的结构和表面形貌,发现纳米粒子是以纯物理方式共混的,且都分散在孔的周围,有利于维持膜的孔穴结构。通过平板超滤装置对改性膜的分离性能、水通量和承压能力进行了研究,结果表明,添加质量分数0.5%18 nm TiO_2的改性膜性能最好,承压能力在0.4 MPa以上,分离因子在3.4左右,水通量为6696 L/(m~2·h)。     

光催化TiO_2复合分离膜的制备技术

纳米TiO2复合分离膜集过滤、光催化降解、自清洁、防垢、提高膜通量等功能于一体,能有效解决传统膜分离系统存在的膜污染和膜通量衰减的问题,对发展新型的膜分离技术、开发纳米光催化新材料,以及在节水减排和中水回用等方面具有重要的应用价值。TiO2复合分离膜涉及TiO2纳米晶的合成和固载化工艺、多孔陶瓷载体的选择、烧结工艺及复合膜的稳定性。本文对目前国内外使用的TiO2复合分离膜的各种制备工艺和方法进行了归纳、总结和分析,并对其今后的发展和应用提供了建议。     

Removal of water from aroma aqueous mixtures using pervaporation processes

In the field of food technology the main applications of pervaporation through hydrophilic membranes are the removal or extraction of water from aroma azeotropic aqueous mixtures. In this study, experiments for removal of water containing aroma compounds of ethanol, propanol, butanol, hexanol, ethyl acetate and acetic acid were performed through a composite, plate and frame type hydrophilic PVA (poly vinyl alcohol) membrane in a 0.5 m² plane module at constant feed temperature and permeate Vacuum pressure. The analysis is presented in terms of variations in permeation flux and separation factor. The results show the decrease in separation factor as well as permeation flux with the increase of alcohol in feed. Hexanol does not permeate through PVA membrane. Activity coefficient of water is higher than that of organic. Pervaporation selectivity differ from Liquid-vapor thermodynamic equilibrium.     

新型五孔PVDF共混改性膜抗污染性能研究

观察新型五孔PVDF共混改性纤维膜SEM形貌特征,测量改性膜的接触角和临界通量,1#(PVDF/PMMA/TPU)、2#(PVDF/PMMA/PVC)共混改性膜分别在次临界和超临界通量下进行过滤实验.结果表明:PVDF共混改性膜具有优良的微观结构,且1#共混膜性能较好;1#共混膜的接触角比2#共混膜小;1#、2#共混膜的临界通量分别为10和14L/(m2.h);1#共混膜比2#共混膜抗污染性能好;次临界通量下共混膜的运行比超临界通量下的稳定.两种共混膜分别在次临界通量下采用单独超滤和混凝+超滤工艺处理某市地表水,得出混凝+超滤工艺处理效果较好,且1#共混膜比2#共混膜处理效果好.     

颗粒物质控制膜污染的增强型膜生物反应器工艺的研究

用于废水处理的膜生物反应器工艺(MBR),是指通过膜过滤实现活性污泥与产水的分离的新型生化法处理废水技术.由于MBR具有占地面积小和出水水质好的优点,膜生物反应器成功应用到废水处理中的案例正在迅速增加.膜污染是MBR废水处理工艺面临的主要问题之一.膜污染会导致膜的渗透性能降低,为此必须通过化学清洗才能恢复膜的性能.为了实现无化学清洗的MBR工艺,研究使用持续物理冲刷去除膜污染层的方法.在活性污泥中加入颗粒物质(粉料),通过这些颗粒物质的持续冲刷作用实现去除膜污染层的目的.经过8个多月的实验,膜组件的渗透性能保持不变,通量可以达到40 L/(m2.h)以上.系统安装了在线的浊度仪作为产水质量的检测,在试验过程中,浊度始终没有变化.作为对比,同时也进行了一个参照实验(MBR标准工艺,没有加入颗粒物质),实验结果表明,传统的MBR工艺的膜组件渗透性能会不断下降导致通量下降,需要进行化学清洗.新型MBR工艺高通量和无需化学清洗的优势,将极大地提高MBR工艺的成本效益.     

Selective membranes in water and wastewater treatment: Role of advanced materials

Membrane separation has enjoyed tremendous advances in relevant material and engineering sciences, making it the fastest growing technology in water treatment. Although membranes as a broad-spectrum physical barrier have great advantages over conventional treatment processes in a myriad of applications, the need for higher selectivity and specificity in membrane separation is rising as we move to target contaminants at trace concentrations and to recover valuable chemicals from wastewater with low energy consumption. In this review, we discuss the drivers, fundamental science, and potential enabling materials for high selectivity membranes, as well as their applications in different water treatment processes. Membrane materials and processes that show promise to achieve high selectivity for water, ions, and small molecules—as well as the mechanisms involved—are highlighted. We further identify practical needs, knowledge gaps, and technological barriers in both material development and process design for high selectivity membrane processes. Finally, we discuss research priorities in the context of existing and future water supply paradigms.     

新型耐酸复合纳滤膜的制备与性能

为解决传统纳滤膜耐酸性较差的问题,以多孔聚砜超滤膜为基膜,以三亚乙基四胺、对苯二甲酸（TPA）与1,3,6-萘三磺酰氯为原料,采用界面聚合法制备一种新型复合纳滤膜,并对膜的形貌、亲水性、表面电荷、分离性能和耐酸性等进行了研究。研究结果表明,TPA的加入使膜的亲水性、电负性和耐酸性都有所提高;当TPA的添加质量分数为0.15%时,所制备的复合纳滤膜性能最好,其纯水通量可达17.0 L/(m2·h),对MgSO4的截留率可达91.3%。浸泡于质量分数为3%的HCl和20%的H2SO4溶液30 d后,该膜呈现出较好的稳定性能。本复合纳滤膜对工业酸性废水处理具有潜在的应用价值。     

Fabrication of Transferable Perforated Isoporous Membranes on Versatile Solid Substrates via the Breath Figure Method

Isoporous separation membranes have received considerable attention because of the high‐resolution performance and energy‐saving characteristics. Isoporous membranes prepared by the breath figure method rely on special substrates such as water and ice because solid substrates such as polyethylene terephthalate films, which are widely used in commercial processes, often lead to nonthrough pores. In this work, it is found that highly ordered through‐pore membranes can be fabricated on hydrophilic glass surface when using polymers that are able to form ordered membranes at low concentrations. On the basis of this finding, a facile strategy is proposed to fabricate isoporous membranes on various solid substrates by introducing a water‐soluble polymer interlayer. The multifunctional interlayer promotes the spreading of membrane‐forming solutions, enables the formation of through pores, and simplifies the transfer to macroporous supports to form composite membranes. The versatility of the proposed strategy is verified by using different substrates including highly hydrophobic polytetrafluoroethylene film and using different water‐soluble polymers as the interlayer. Furthermore, the high‐resolution separation performance of the isoporous composite membranes has been demonstrated by the filtration of yeasts under gravitational pressure.     

CaCl2对聚丙烯腈超滤膜性能的影响

在PAN／DMAC体系里，研究了添加剂CaCl2对聚丙烯腈超滤膜性能的影响，通过膜的纯水通量，切割分子量曲线以及场发射扫描电镜对所制得的膜进行了表征及研究．与无添加剂的PAN／DMAC体系相比，CaCl2的加入降低了膜液的黏度，提高了膜的纯水通量，而对膜的切割分子量无明显的影响．     

Amphiphilically Modified Porous Polymeric Nanosandwich-Based Membranes for Rapid and Efficient Water Treatment

Low removal efficiency, long treatment time, and high energy consumption hinder advanced and eco-friendly use of traditional adsorbents and separation membranes. Here, a class of amphiphilically modified 2D porous polymeric nanosandwich is designed and is subsequently assembled into adsorptive membranes. The 2D nanosandwich is gifted with high porosity and excellent pore accessibility, demonstrating rapid adsorption kinetics. The as-assembled membrane integrates unimpeded interlayer channels and well-developed, amphiphilic, and highly accessible intralayer nanopores, leading to ultrafast water permeation (1.2 × 10⁴ L m⁻² h⁻¹ bar⁻¹), high removal efficiency, and easy regeneration. The family of the membrane can be expanded by changing amphiphilic functional groups, further providing treatment of a wide-spectrum of pollutants, including aromatic compounds, pesticide, and pharmaceuticals. It is believed that the novel amphiphilically modified adsorptive membrane offers a distinct water treatment strategy with ultrahigh water permeation and efficient pollutants removal performances, and provides a multiple-in-one solution to the detection and elimination of pollutants.     

高通量抗污染碳量子点/聚砜纳米复合分离膜的制备

先以4-氨基水杨酸(ASA)为原料发生水热反应合成碳量子点(CDs),随后将其共混分散在铸膜液中用非溶剂诱导相分离法制备了PSF/CDs纳米复合膜。透射电子显微镜(TEM)观测和傅里叶变换红外光谱(FTIR)证实,CDs具有小尺寸和大量亲水基团的特点。使用水接触角分析(WCA)、扫描探针显微镜(SPM)和扫描电子显微镜(SEM)对分离膜进行了表征,发现纳米复合膜具有比原始膜更好的亲水性和更多的孔洞,从而使分离膜具有更高的通量和抗污染性能。PSF/CDs膜的通量回复率(FRR)超过90%,总污染率(Rt)低于60%,且可逆型污染为主要污染源。CDs含量(质量分数)为2%的复合膜整体效果最佳。具有更强抗污染能力的纳米复合膜,其水通量甚至为纯PSF膜的3倍。     

新型TiO2光催化复合分离膜研究进展

TiO2光催化复合分离膜是近几年出现的一种集光催化和膜分离作用于一体的新型多功能复合膜,多用于水处理中.将光催化剂TiO2负载于膜表面或者内嵌于膜中,制备成光催化复合分离膜,不仅解决了TiO2的回收问题,且能在一定程度上缓解或者消除膜污染问题;在发挥光催化和膜分离作用的同时,还能产生一系列的协同作用,以加强污染物的处理...     

Cellulose Acetate and Polyetherimide Blend Ultrafiltration Membranes, I: Preparation, Characterization, and Application

Ultrafiltration (UF) techniques have particular advantages for simultaneous purification, concentration, and fractionation of macromolecules. In this study, polymeric blend ultrafiltration membranes based on cellulose acetate and polyetherimide were prepared by phase inversion technique and characterized in terms of compaction time, pure water flux (PWF), water content, membrane hydraulic resistance, and scanning electron microscopy (SEM). The blend membranes prepared were subjected to the separation of macromolecular proteins such as bovine serum albumin (BSA), egg albumin (EA), pepsin, and trypsin. The molecular weight cut-off (MWCO) of blend membranes obtained from the protein separation studies is also presented. Toxic heavy metal ions such as copper, nickel, zinc, and cadmium were subjected to separation by the blend membranes by complexing them with the polymeric ligand polyethyleneimine. The separation and permeate flux efficiencies of the blend membranes are compared with those of pure cellulose acetate membranes.     

离子液体微乳液中纳米AgCl的合成及AgCl/poly(MMA-co-AM)杂化膜的渗透汽化分离

以离子液体氯化-1-十二烷基甲基咪唑(C₁₂mimCl)为表面活性剂, 甲基丙烯酸甲酯(MMA)和丙烯酰胺(AM)混合物为油相构筑的反相微乳液合成AgCl纳米粒子。通过微乳液聚合制备AgCl/poly(MMA-co-AM)杂化膜, 用于苯-环己烷混合物的渗透汽化分离。利用紫外-可见吸收光谱(UV-Vis)和透射电镜(TEM)分析AgCl纳米粒子的形貌及结构, 利用XRD和SEM分析了杂化膜中AgCl粒子的形貌及结构, 通过杂化膜的苯-环己烷混合物(质量分数50%, 30℃)的渗透汽化实验分析了杂化膜的分离性能。结果表明: 纳米AgCl粒子的平均粒径和粒子数随微乳液中AgNO₃浓度(c_AgNO3)的增大明显增加; 增加微乳液中C₁₂mimCl浓度(c_C12mimCl), 有利于形成数量较多、 平均粒径较小的纳米AgCl粒子; AgCl/poly(MMA-co-AM)杂化膜中AgCl粒子粒径较小, 且均匀分散于poly(MMA-co-AM)基材中; 随着c _AgNO3的增加, 杂化膜的渗透通量明显增大, 分离因子先增大后减小; 而随 c _C12mimCl的增加, 杂化膜的分离因子持续增大, 渗透通量表现出先增大后减小的趋势; 杂化膜的分离因子最高可达5.0, 渗透通量约为490 g·m^-2·h^-1, 表现出较好的分离性能。