Fe_2O_3-SiO_2复合粒子的制备及其PU共混膜的氧氮分离性能

采用共沉淀与复配2种方法制备了Fe2O3-SiO2复合纳米粒子,将其添加到聚氨酯(PU)膜中,研究了粒子复合方式对PU共混膜力学性能和O2、N2分离性能的影响。结果表明,通过共沉淀法制备的Fe2O3-SiO2粒子粒径小且均匀,内部存在硅铁固溶体结构,其PU共混膜的机械强度和氧氮分离性能优于复配法制备的Fe2O3/SiO2粒子;当Fe2O3-SiO2添加量为10%时,PU共混膜的O2渗透系数为13.35 Barrer,O2/N2理论分离因子为7.14。     

聚乙烯烯醇／聚邻羟基苯甲烯丙胺混成膜Co（Ⅱ）含量对氧—氮分离的影响

含钴螯合膜具有选择性束氧能力，作为一种固氧载体，有利于氧气的运输。处理混有邻羟基苯醛的聚乙烯醇（ＰＶＡ）和聚丙烯酰胺（ＰＡＡｍ），得到Ｓｃｈｉｆｆ基膜，进而制得螯合膜。通过ＦＴＩＲ频率的变化，可以观察到Ｏ－Ｏ伸展峰在１１５０ｃｍ＾－１处，位于膜内的钴和进入的氧之间，氧通过Ｓｃｈｉｆｆ基膜的渗透率是２．０１－２．９８×１０＾１３「（ｃｍ＾３（ＳＴＰ）．ｃｍ／ｃｍ＾２．ｓ．ｃｍＨｇ」，氧的选择性渗透范     

共混改性法对有机分离膜影响进展

有机聚合物如聚砜类、聚偏氟乙烯类、醋酸纤维素类、聚烯烃类等具有优良特性,是重要的膜材料。然而,膜污染问题限制了膜的应用。共混改性法操作简单,改性和成膜同时进行,效果稳定,通过共混改性法对有机聚合物膜进行膜改性可以有效降低膜污染。一方面通过共混亲水性聚合物、两亲性聚合物、两性离子聚合物对有机聚合物膜进行膜改性,制备改性膜的防污性和渗透性等性能均有不同程度的提升;另一方面,共混如TiO₂、SiO₂、碳纳米管（CNTs）、Al₂O₃、氧化石墨烯（GO）和ZrO₂等无机纳米粒子也可以制备高性能分离膜。本文从以上两方面综述了共混改性法的研究进展和存在的问题,并指出了通过共混改性提升膜的抗污染等性能是今后主要的发展趋势。     

有机/有机混合物渗透汽化分离膜材料的研究进展

综述了有机，有机混合物渗透汽化分离膜材料的最新研究进展，详细讨论了共混膜、共聚膜以及改性膜的研究情况，并对渗透汽化膜材料的研究前景进行了展望。     

P(MMA-co-HEA)/PVDF共混分离膜的制备及性能研究

以甲基丙烯酸甲酯(MMA)为主要单体,以丙烯酸羟乙酯(HEA)为功能单体,利用自由基溶液聚合制备了共聚物P(MMA-co-HEA),与聚偏氟乙烯(PVDF)进行共混,制成分离膜。通过改变功能单体HEA的含量,制得一系列分离膜,分别测试其FTIR、TG、SEM、水接触角、水通量、牛血清蛋白(BSA)截留率以及耐污染性能。发现亲水组分P(MMA-co-HEA)的引入能显著改善共混膜的亲水性,随着HEA含量的提高,其水通量、热稳定性和耐污染性能都逐渐提升,对BSA的截留率有所降低。其中MMA:HEA为3:2时共混膜的整体性能最好。     

氧氮玻璃的研究进展

氧氮玻璃具有比氧化物玻璃更高的密度、折射率、杨氏模量、玻璃转变温度、软化温度和导电性能,更优异的化学稳定性,在陶瓷焊接,核废料固化,陶瓷增韧等方面都有广泛的应用前景.本文介绍了氧氮玻璃的系统、氧氮玻璃的制备方法、氧氮玻璃的结构、性能和氧氮玻璃的应用.     

聚硅氧烷系富氧膜的研究与开发

化工工艺中,经常把过滤、萃取、蒸馏和重结晶等单元操作组合起来进行分离精制,这些单元操作都伴有相变化,消耗很多能量。膜分离法不发生相变化,耗能少,越来越受到人们的关注。离子交换膜、反渗透膜、超滤膜等已完全进入实用阶段,用途日益广泛。 近年来,许多人把膜分离技术用于气体分离。把空气的氧进行浓缩的富氧膜技术,在燃烧、医疗等领域已有广泛应用。美国GE公司开发的制备医用富氧空气的     

玻璃分离膜的研究进展

介绍了无机膜的发展,重点介绍了玻璃膜的分类、制备方法、类型以及应用。     

富氧膜性能测试新方法

本文建立了一种富氧膜富氧性能测试新方法——恒压空气容量分析法——本法可同时测定富氧空气流量、氧气含量、氧气及氮气透过率、氧氮分离系数等参数。它为膜材料的设计、工艺参数的选择提供了一种方便快速的研究手段。     

Enhanced compatibility and selectivity in mixed matrix membranes for propylene/propane separation

Mixed matrix membranes (MMMs) based on metal–organic framework (MOF) have great promising application in separation of gas mixtures. However, achieving a good interfacial compatibility between polymer and MOF is not straightforward. In this work, focusing on one of the most challenging olefin/paraffin separations: propylene/propane (C₃H₆/C₃H₈), we demonstrate that modification of the MOF filler via dopamine polymerization using a double solvent approach strongly improves interfacial compatibility. The resulting membranes show an outstanding separation performance and long-term stability with propylene permeability nearly 90 Barrer and propylene/propane selectivity close to 75. We anticipate that similar MOF modification strategies may help solve the problem of interface defects in the manufacture of MMMs and be extended to other porous fillers.     

Effective gas separation through graphene oxide containing mixed matrix membranes

In the present study, graphene oxide (GO) was incorporated into poly(vinylidene fluoride) (PVDF) and chemically modified PVDF (M‐PVDF) to prepare mixed matrix membranes (MMMs) for gas separation application. Performed analyses proved appropriate dispersion of exfoliated GO sheets in polymer matrices and sufficient compatibility at the interfacial phases. M‐PVDF based MMMs were thermally and mechanically more stable relative to the PVDF‐based MMMs. The oxygen containing functional groups in M‐PVDF was probably the main reason for this more stability. PVDF/GO MMMs rendered low gas permeability and high selectivity. Both impermeable GO sheets and crystalline phases of PVDF were responsible for such behavior. On the other hand, interestingly gas permeability of M‐PVDF/GO MMMs was enhanced while no substantial decline was recorded in gas selectivity. For instance, He and CO₂ permeability was increased 12.46% and 25.89%, respectively, compared to the pure PVDF membrane. This behavior originated from functional groups of M‐PVDF and the interaction of these groups with GO sheets. Since GO often amplified gas barrier properties of polymers, such increscent would be appreciable. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46271.     

金属-有机骨架材料在气体膜分离中的研究进展

金属-有机骨架材料(metal-organic frameworks,MOF)由于具有高比表面积、大孔隙率、功能性孔道结构以及种类多样性等特征,在储气、分离、催化、载药和光学等领域受到重视。其中,制备纯MOF膜或基于MOF的混合基质膜(mixed matrix membranes,MMMs)并用于气体分离,被认为具有潜在的应用前景。目前为止,实验合成的MOF材料种类已有两万种,为了快速筛选出合适的MOF材料作为膜材料,计算化学的方法可以极大地缩减MOF膜的研究周期,并有助于指导实验合成高效膜分离材料。本文分别从计算和实验两方面介绍了MOF膜在气体分离中的研究进展,分析表明,MOF膜的研究总体上向功能性更强、稳定性更高的方向发展,但是利用计算方法建立MOF膜的构效关系还存在一定的难度。因此,建立MOF膜的结构与性能表征的新概念、新方法,并利用MOF膜的结构-性能关系指导实验合成高稳定性、低成本的膜材料将是未来MOF膜的发展方向。     

酸性气体分离膜的研究现状及进展

当前,气体分离膜是一种环保绿色的分离技术,本文概括了目前用于去除CO2的商业膜材料(醋酸纤维素、聚酰亚胺和含氟聚合物),对不同膜的物理化学性质,气体渗透特性等进行了介绍。     

用纳滤膜分离混合无机电解质溶液的性能评价方法

提出一个新的混合无机电解质溶液的纳滤膜分离性能的评价方法。该评价方法将纳滤膜分离性能表述为某种离子在膜中的透过率,其值与混合电解质总浓度、各种离子的当量分数和同号离子之间通过纳滤膜的竞争作用有关。首先根据一些双组分无机电解质溶液的纳滤膜分离实验获得离子的竞争系数,然后采用几种不同组成不同浓度的混合电解质溶液（NaCl和NaF;NaCl和KCl;NaF、NaCl和NaNO3;NaCl、NaNO3和Na2SO4;NaF、NaCl、NaNO3和Na2SO4）通过ESNA 1膜的透过实验验证该评价方法的适用性。结果表明混合电解质溶液总浓度和离子的当量分数是影响各种离子通过纳滤膜的表观透过率的主要因素,评价方法预测值与实验数据相符合。说明该方法适用于评价含有单价阳离子的混合无机电解质溶液的纳滤膜分离性能。     

Zeolite imidazolate framework (ZIF)-based mixed matrix membranes for CO2 separation: A review

Mixed matrix membranes (MMMs), which combine the good separation performance of inorganic materials with the low cost of polymers, have emerged as a research hotspot for gas separation membranes. Zeolite imidazolate frameworks (ZIFs) are widely used as fillers to prepare MMMs owing to their advantageous characteristics, such as adjustable pore channels, unsaturated sites, and easy functionalization. For MMMs, three directions can be employed as criteria for improvement compared with pristine polymeric membranes. In this article, the progress of ZIF-based MMMs is reviewed from the aspects of sole-ZIF-based MMMs and modified ZIF-based MMMs. Both strategies improve the separation performance through different improvement directions and mechanisms. Our analysis shows that the synergistic effect of the modified filler can change the structure of the membranes, such as by improving the filler–polymer interface voids, which provides a foundation to overcome the trade-off effect to a certain extent. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48968.     

Pebax/a-MoS2/MIP-202混合基质膜的制备及CO2分离性能

为了获得高性能的CO₂/N₂分离膜,把空气中氧刻蚀的二硫化钼（a-MoS₂）和金属有机框架材料MIP-202通过机械力化学反应制备的双功能填料作为分散相,聚醚嵌段酰胺（Pebax-1657）作为连续相,采用溶液浇铸法制备了Pebax/a-MoS₂/MIP-202混合基质膜。采用FT-IR表征了填料的化学结构,借助ATR-FTIR、SEM、TG和力学性能测试表征了混合基质膜的化学结构、微观形貌结构、热稳定性和物理力学性能。研究了水含量、双功能填料配比、含量、膜两侧压差和操作温度对膜气体分离性能的影响,并考察了模拟烟道气（CO₂/N₂体积比15/85）条件下混合基质膜的长时间运行稳定性。结果表明：在温度为25℃、膜两侧压差为0.1 MPa的操作条件下,a-MoS₂与MIP-202质量比为5∶5和双功能填料含量为6%（质量）时,膜的气体分离性能达到最优,CO₂渗透性和CO₂/N₂选择性分别为380 Barrer和124.7,超过了2019年McKeown等提出的上限值。连续测试360 h后,混合基质膜的性能没有明显降低,其平均CO₂渗透性和CO₂/N₂选择性分别为358 Barrer和120.1。这主要是由于a-MoS₂和MIP-202协同提高了膜的气体分离性能。     

Pebax/a-MoS2/MIP-202混合基质膜的制备及CO2分离性能

为了获得高性能的CO₂/N₂分离膜,把空气中氧刻蚀的二硫化钼（a-MoS₂）和金属有机框架材料MIP-202通过机械力化学反应制备的双功能填料作为分散相,聚醚嵌段酰胺（Pebax-1657）作为连续相,采用溶液浇铸法制备了Pebax/a-MoS₂/MIP-202混合基质膜。采用FT-IR表征了填料的化学结构,借助ATR-FTIR、SEM、TG和力学性能测试表征了混合基质膜的化学结构、微观形貌结构、热稳定性和物理力学性能。研究了水含量、双功能填料配比、含量、膜两侧压差和操作温度对膜气体分离性能的影响,并考察了模拟烟道气（CO₂/N₂体积比15/85）条件下混合基质膜的长时间运行稳定性。结果表明：在温度为25℃、膜两侧压差为0.1 MPa的操作条件下,a-MoS₂与MIP-202质量比为5∶5和双功能填料含量为6%（质量）时,膜的气体分离性能达到最优,CO₂渗透性和CO₂/N₂选择性分别为380 Barrer和124.7,超过了2019年McKeown等提出的上限值。连续测试360 h后,混合基质膜的性能没有明显降低,其平均CO₂渗透性和CO₂/N₂选择性分别为358 Barrer和120.1。这主要是由于a-MoS₂和MIP-202协同提高了膜的气体分离性能。     

Polysulfone/zinc oxide nanoparticle mixed matrix membranes for CO2/CH4 separation

Preparation and characterization of novel polysulfone/zinc oxide (PSf/ZnO) mixed matrix membranes (MMMs) with different ZnO loadings for high selective CO₂/CH₄ separation were aimed in this study. Scanning electron microscopy photographs demonstrated that spongy and small tear like pores in plain PSf membrane (0 wt % of ZnO) replaced with large tear like pores close to surface layer by increasing ZnO content up to 0.1 and 1 wt %. In contrast, a dense and less free volume structure was obtained in membranes having 3 and 5 wt % of ZnO. Membrane porosity increased from 28.68 to 50.51% with increasing ZnO content from 0 to 1 wt %. Then, a reduction in porosity was observed for membranes containing 3 and 5 wt % of ZnO. Atomic force microscopy images presented variation in membrane surface roughness. Surface roughness decreased from 67.64 nm for plain PSf to 47.86 nm for membrane containing 1 wt % of ZnO. While, surface roughness increased and reached to 115.5 and 122.4 nm for MMMs having 3 and 5 wt % of ZnO. Gas separation properties of PSf/ZnO MMMs were examined and CO₂/CH₄ selectivity of MMMs containing 3 and 5 wt % of ZnO were 22.29 and 54.29, respectively, in 1 bar feed pressure. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39745.