“膜”法世界——膜材料的发展与应用*

膜材料作为新材料“十三五”规划专项工程之一,在工业和日常生活中起着非常重要的作用。依据材质不同,介绍了现有常见的有机膜、无机膜、新型膜材料,阐述了近年来膜在水处理、气体分离、电池隔膜和燃料电池等方面的应用发展,说明了膜材料在疫情防护材料中的用途,并对膜材料未来的发展做了总结和展望。     

分子筛膜反应器的研究进展

分子筛膜具有规整的微孔结构(<1 nm), 耐高温高压、 抗有机溶剂, 在液相和气相小分子分离中受到广泛关注. 分子筛膜可以与催化反应耦合于一体构成膜反应器, 使反应过程与组分分离同时进行, 促进反应平衡移动, 达到反应强化的效果. 本文概述了近十年不同类型分子筛膜反应器在催化反应中的应用研究进展, 并对分子筛膜反应器未来的发展趋势进行了展望.     

然聚电解质壳聚糖/羧甲基壳聚糖配合物膜的研制

制备了一种新型聚电解质膜壳聚糖/羧甲基壳聚糖配合物膜, 并对膜的结构进行了初步表征; 同时考察了不同配比的配合物膜对模型蛋白质溶菌酶的吸附性能. 结果表明, 在碱性条件下(pH＝9.2), 随着羧甲基壳聚糖含量的增加, 膜对溶菌酶的吸附能力也随之增强; 当羧甲基壳聚糖的含量为w＝40%时, 膜的吸附性能较佳, 可达92 mg/g.     

澄清溶液体系二次生长法NaA型沸石膜的生长机制及膜厚的控制合成

用晶种涂层二次生长成膜法研究了在含水量不同的澄清溶液合成体系中NaA型沸石膜的生长及沸石膜厚度的控制合成.用SEM,TEM和XRD表征手段分析了沸石膜的形成过程和微结构.在载体表面不涂晶种而直接合成则不易形成连续沸石膜;用晶种涂层二次法可以很容易形成均匀的连续膜.合成液中水量的高低强烈影响沸石膜的生长速率、形成结构和膜的厚度.在高水量(水硅摩尔比为2000)的合成体系中沸石生长速率慢,膜主要通过晶种层中的晶粒长大,交织成膜,且膜只有一层结构;而在低水量(水硅摩尔比为750)的合成体系中沸石生长速率快,膜则通过晶种层表面晶粒向外生长、交织成膜,而膜具有两层结构.通过调变合成液的水量可有效地控制沸石膜层的厚度,并能制得非常均匀、连续的膜.     

聚乙烯醇缩丁醛LB膜制备及其对硬脂酸镉LB膜的修饰

研究了PVB单分子膜的π～A曲线和稳定性,沉积了优质LB膜,发现将PVB与CdSt₂形成交替异质的LB膜能提高膜的光学质量;在CdSt₂LB膜的上面封装PVBLB膜能保持CdSt₂LB膜的结构。     

然聚电解质壳聚糖/羧甲基壳聚糖配合物膜的研制

制备了一种新型聚电解质膜壳聚糖/羧甲基壳聚糖配合物膜, 并对膜的结构进行了初步表征; 同时考察了不同配比的配合物膜对模型蛋白质溶菌酶的吸附性能. 结果表明, 在碱性条件下(pH＝9.2), 随着羧甲基壳聚糖含量的增加, 膜对溶菌酶的吸附能力也随之增强; 当羧甲基壳聚糖的含量为w＝40%时, 膜的吸附性能较佳, 可达92 mg/g.     

聚酰亚胺微孔膜疏水化用于膜蒸馏

采用聚合物表面涂覆改性的方法，将疏水性聚合物硅橡胶涂覆在聚酰亚胺亲水微孔膜上，制得了具有良好膜蒸馏性能的聚酰亚胺疏水微孔复合膜。研究了涂覆工艺条件对所得聚酰亚胺疏水微孔复合膜的膜蒸馏性能的影响。结果表明，控制适当工艺条件可制得具有高膜蒸馏通量的聚酰亚胺微孔复合膜，其透过系数可达２．１７×１０－３ｋｇ／ｍ２·ｈ·Ｐａ。该改性聚酰亚胺疏水微孔复合膜使用３７ｄ后，截留率仍保持在９９．５％以上，具有较长使用寿命。     

石墨烯及氧化石墨烯对分离膜改性的方法、效能和作用机理

石墨烯及氧化石墨烯由于其独有的性质在分离膜领域引起广泛关注。本文综合分析了石墨烯及氧化石墨烯在分离膜改性方面的几种典型应用,即共混膜、多孔石墨烯膜和层状排列氧化石墨烯膜,并结合其制备方法、效能和作用机理进行阐述。结果表明,相转化法制备的共混膜可以提高膜通量和截留率、增加膜的亲水性并有效抑制膜污染,但是其并不能充分发挥氧化石墨烯独有的结构和性能优势,具有一定的局限性;层薄和机械性能强的完美结合使石墨烯可以通过打孔形成分离性能较好的多孔石墨烯膜,但是制备大片石墨烯的难度和不成熟的打孔技术限制了其进一步发展;而层状排列的氧化石墨烯膜可充分发挥氧化石墨烯材料的特性,以层间间距作为主要运输通道有利于充分发挥氧化石墨烯高输运速率的优点和高选择性的特性,为开创下一代高通量、高选择性、强抗污染性的高性能分离膜提供了重要思路。     

亲水性混合纤维素酯微孔膜对O/W乳液的破乳

亲水性混合纤维素酯微孔膜对O/W乳液的破乳;破乳机理;膜污染和清洗;混合纤维素酯膜     

邻香草醛分子印迹聚合物膜的制备及其透过选择性质的研究

采用紫外光引发原位聚合的方法制备了具有支撑膜的邻香草醛分子印迹聚合物膜. 紫外光度法测定了模板分子和功能单体之间的结合常数和化学计量比(n＝2). 用傅立叶红外光谱和扫描电镜分别测定了膜的结构和表面形貌; 膜渗透实验结果表明在干扰物存在时印迹膜对模板分子表现出良好的选择透过性能. 研究了分子印迹聚合物膜透过的机理、并为分子印迹技术应用于传感器领域增加了理论和实验方法.     

直接甲醇燃料电池中质子交换膜的研究进展

质子交换膜是直接甲醇燃料电池(DMFC)的关键部件之一. 本文系统地介绍了近三年来DMFC中质子交换膜研究的最新进展.     

含杂萘联苯结构聚合物膜的直接甲醇燃料电池性能

质子交换膜是直接甲醇燃料电池(DMFC)的关键组成部分. 通过磺化制备了磺化杂萘联苯聚醚酮(SPPEK)、磺化杂萘联苯聚醚砜(SPPES)和磺化杂萘联苯聚醚砜酮(SPPESK)三种含杂萘联苯结构的新质子交换膜, 测试了其热稳定性、质子导电性和甲醇透过性能. SPPESK的热分解温度比相近离子交换容量(IEC)的SPPEK和SPPES约低100 ℃, 三种膜均具有良好的导电和阻醇性能; 分别以三种膜为电解质组装DMFC考察了其性能, DMFC的开路电压随膜的阻醇性的提高而增大, 三种膜的开路电压均高于Nafion115膜, 但在较高电流密度的区域三种新膜的性能均比Nafion115膜差.     

低甲醇透过直接甲醇燃料电池

复合膜;甲醇透过率;低甲醇透过直接甲醇燃料电池     

A novel proton-exchange porous silicon membrane production method for μDMFCs

This study introduces a new production method to use as a porous silicon-based proton exchange membrane for μDMFCs. In this respect, EIS, fuel crossover test, and fuel cell performance test at the μDMFC sample cell are performed at room temperature on a porous silicon-based membrane that was produced for passive mode μDMFC as a proton exchange membrane. The reason for performing the fuel crossover test is to ensure the silicon opened pores along the silicon wafer and to examine the fuel permeability of the membrane. The fuel crossover test shows that the fuel cell provides energy for about 60 min with a 50 mL fuel. EIS reveals proton permeability of proton exchange membrane. The calculated value of the conductivity of the membrane is 0.0016 S/cm. OCV of the system is 0.4V, whereas values (with highest power density is 0.1 mW/cm²and with the highest current density is 0.39 mA/cm²) are low. However, porous silicon is not a natural proton conductor. Hence, these values can be increased by different ways such as porous silicon functionalized, or serial connection of fuel cells. On the other hand, the value of OCV is consistent with the previous studies. In sum, this study presents a simple, cost-effective, and short time-consuming method for the production of porous silicon as proton-conducting membrane behavior.     

直接甲醇燃料电池膜电极的研究与进展

膜电极(MEA)是直接甲醇燃料电池(DMFC)的核心部件。文中对MEA的研究现状从4个方面进行了详细评述。首先,对组成MEA的关键材料,如电催化剂、质子交换膜、扩散层的研究进展进行了介绍,认为开发低温高效、贵金属载量低的电催化剂以及研制低成本、低甲醇渗透的非氟质子交换膜是MEA关键材料的研究方向。第二,对于MEA的制备方法,文中对以GDL为支撑体的GDE法和以PEM为支撑体的CCM法进行了详细的评述,认为CCM法是今后MEA制备工艺的重要发展方向。第三,关于MEA的表征技术,认为采用电化学方法结合现代谱学技术仍是未来一段时间对MEA表征的主要手段。第四,介绍了MEA数学模型的研究现状,DMFC数学模型的研究是以PEMFC的模型为基础建立起来的,但是建立DMFC的数学模型更为复杂,认为今后对DMFC膜电极模型的研究要充分考虑阳极二氧化碳与甲醇水溶液的两相流问题以及阴极甲醇渗透对电池性能影响的问题。最后,对直接甲醇燃料电池膜电极未来的发展进行了展望。     

聚偏氟乙烯-Nafion共混膜的制备及阻醇质子导电性能研究

直接甲醇燃料电池 (Ｄｉｒｅｃｔｍｅｔｈａｎｏｌｆｕｅｌｃｅｌｌ,ＭＤＦＣ)以高效、清洁和燃料储运方便等优点成为一类极具发展潜力的新型动力源 .但目前ＤＭＦＣ中普通使用的全氟磺酸膜 (如ＮａｆｉｏｎＴＭ 系列膜 )阻醇性能太差 ,导致大量甲醇从阳极穿过膜直接透到阴极 ,造成燃料的浪费和电池整体性能的下降 .据文献报道 ,即使甲醇浓度低到 1ｍｏｌ Ｌ ,也有近40 %的醇透过膜 .缺乏高性能的阻醇质子导电聚合物电解质膜是制约ＤＭＦＣ发展的瓶颈之一 .已有一些研究人员致力于新型膜材料的开发 ,如有人研制了聚苯并咪唑膜[1] 及各种掺杂…     

Characterization and performance of proton exchange membranes for direct methanol fuel cell: Blending of sulfonated poly(ether ether ketone) with charged surface modifying macromolecule

Modification of sulfonated poly(ether ether ketone) (SPEEK) membrane was attempted by blending charged surface modifying macromolecule (cSMM). The modified membrane was tested for direct methanol fuel cell (DMFC) application; i.e. a SPEEK/cSMM blend membrane was compared to a SPEEK membrane and a Nafion 112 membrane for the thermal and mechanical stability, methanol permeability, and proton conductivity. Thermal and mechanical stability of the blended membrane were slightly reduced from the SPEEK membrane but still higher than the Nafion 112 membrane. The blend membrane was found to be promising for DMFC applications because of its lower methanol diffusivity (2.75 × 10⁻⁷ cm² s⁻¹) and higher proton conductivity (6.4 × 10⁻³ S cm⁻¹), than the SPEEK membrane. A plausible explanation was given for the favorable effect of cSMM blending.     

Sulfonated poly(ether ether ketone)/poly(vinylpyrrolidone) acid–base polymer blends for direct methanol fuel cell application

Acid–base polymer blends for polymer electrolyte membranes have been prepared by blending sulfonated poly(ether ether ketone) (SPEEK) with poly(vinylpyrrolidone) (PVP) to reduce methanol uptake and to decrease methanol permeability while maintaining high proton conductivity. The acid‐base interaction occurring on the sulfonic acid group and on the tertiary amide group was characterized by FTIR and DMA. As the composition of PVP lowered than 20 wt % in the blends, the acid–base interaction causes great reduction on methanol uptake and the methanol permeability; however, the proton conductivity is still high. In this work, membrane–electrode assemblies (MEAs) have been prepared for direct methanol fuel cell (DMFC) from both blend membrane and Nafion 117. DMFC single cell performance was also evaluated. Results confirmed that SPEEK (with the degree of sulfonation (DS) = 69%) blended with PVP (M_n = 1,300,000) with a ratio of 80/20 (w/w) exhibits higher open‐circuit voltages (OCV) and lower polarization loss than those of Nafion 117. These acid–base blends will be suitable for DMFC application. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 565–572, 2006     

燃料电池用质子交换膜的研究进展

质子交换膜是燃料电池的重要组成部分。本文介绍了全氟磺酸膜的优缺点,对其进行改进的方法以及新型质子交换膜的发展情况,重点讨论了各类质子交换膜的制备、结构、性质以及它们在质子交换膜燃料电池(PEMFC)或直接甲醇燃料电池(DMFC)的应用,最后提出质子交换膜的发展趋势。     

Sulfonated poly(ether sulfone)/sulfonated polybenzimidazole blend membrane for fuel cell applications

Polymer blending is used to modify or improve the dimensional and thermal stability of any two different polymers or copolymers. In this study, both sulfonated polybenzimidazole homopolymer (MS-p-PBI 100) and sulfonated poly(aryl ether benzimidazole) copolymers (MS-p-PBI 50, 60, 70, 80, 90) were successfully synthesized from commercially available monomers. The chemical structure and thermal stability of these polymers was characterized by ¹H NMR, FT-IR and TGA techniques. Blend membranes (BMs) were prepared from the salt forms of sulfonated poly(ether sulfone) (PES 70) and MS-p-PBI 100 using dimethylacetamide (DMAc). These blend membranes exhibited good stability in boiling water. The blending of 1 wt.% of MS-p-PBI 100 and 99 wt.% of PES 70 to produce the blend membrane BM 1 reduced membrane swelling, thus leading to good dimensional stability and comparable proton conductivity. Hence, BM 1 was chosen for the fabrication of a membrane electrode assembly (MEA) for proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC) applications. This paper reports on PEMFC and DMFC performance under specific conditions.