脱溶剂速度对聚砜/磺化聚砜合金膜结构和性能的影响

介绍了铸膜液温度、成膜过程中的蒸发时间、环境湿度、凝胶浴温度对聚砜/磺化聚砜合金膜的渗透、分离性能的影响.随环境相对湿度、凝胶浴温度增大,合金膜的水通量增大,截留率下降;蒸发时间延长,合金膜的水通量通过一个极大值,截留率呈现下降趋势.     

磺化聚乙烯离子交换膜渗透汽化分离二氧六环／水混合物研究

本文用非均相光化学氯磷化反应制得了亲水的耐有机溶剂耐酸碱的磺化聚乙烯离子交换膜．膜截面离子基因密度与反应程度有关．该膜对近恒沸组成的二氧六环／水混合液显示出很高的渗透汽化分离系数和透过速率．研究了对离子、离子交换容量、料液浓度和温度对分离性能的影响．通过膜内水合离子形成“水通道”模型讨论了渗透机理．膜内离子基团密度估计及水的表观渗透活化能的大小支持“水通道”的存在．     

丙烯腈类共聚物膜用于醇,水分离的研究：Ⅱ.丙烯腈与马来酸酐…

本文采用氧化还原引发体系合成了丙烯腈与马来酸酐共聚物，各首次将此共聚物制成了醇，水分离用的渗透蒸发膜，研究了不同马来酸酐含量的共聚物膜碱中的水解规律，考察了共聚物，料液温度，料液浓度等条件对膜的醇，水分离性能的影响关系以及水解前，后膜性能的变化结果表明，当共聚物中马来酸酐含量大于０．０６９（摩尔分数）时，水解前，后膜性能有很大的变化，分离因子，渗透通量和膜强度都普遍提高。另外，还发现该共聚物膜与其     

醇/水混合物在磺化聚乙烯中空纤维阴离子交换膜中的渗透汽化

通过对聚乙烯中空纤维光化学氯磺化反应,继而胺化和季胺化,制备了磺化聚乙烯中空纤维阴离子交换膜。以恒沸组成的异丙醇/水和85wt%乙醇/水为料液,测定了不同抗衡离子膜的渗透汽化性能。表明:该膜有极高的选择性,分离系数和渗透通量与抗衡离子密切相关,对卤素离子,α_W/A大小次序为I~->Br~->Cl~-;通量大小次序与之相反。三种抗衡离子膜的平衡吸收实验表明,该阴离子膜的选择渗透性不仅与醇水在膜中的溶解度有关,而且取决于平均扩散系数。     

丙烯腈类共聚物膜用于醇、水分离的研究——Ⅱ.丙烯腈与马来酸酐共聚物膜

本文采用氧化还原引发体系合成了丙烯腈与马来酸酐共聚物,首次将此共聚物制成了醇、水分离用的渗透蒸发膜,研究了不同马来酸酐含量的共聚物膜在碱中的水解规律,考察了共聚物组成,料液温度,料液浓度等条件对膜的醇、水分离性能的影响关系以及水解前、后膜性能的变化,结果表明,当共聚物中马来酸酐含量大于0.069(摩尔分数)时,水解前、后膜性能有很大的变化,分离因子,渗透通量和膜强度都普遍提高。另外,还发现该共聚物膜与其它透水性膜不同,对低乙醇含量的乙醇—水混合液不能透过。     

磺化聚乙烯中空纤维离子交换膜渗透汽化分离异丙醇/水混合液研究

离子交换膜作为醇/水和其他有机水溶液的渗透汽化分离膜有很好的选择性^[1-3]。其中尤以磺化聚乙烯离子交换膜最为显著。用磺化聚乙烯离子膜分离恒沸组成的异丙醇/水和乙醇/水(85:15wt%)混合物^[4]、近恒沸组成的二氧六环/水混合物^[5],透过物中水含量大于99%,而且保持了较高的渗透通量。但上述实验均使用的平板型膜,大型平板膜组件的加工制造昂贵而困难,况且膜在分离运行过程中会随料液浓度的变化发生溶胀与收缩,使固定的平面膜起皱在收缩时又可能被拉破。为了提高单位组件内的膜面积(中空纤维组件的膜装填密度为平板式的60-100倍),发展中空纤维型膜及其组件势在必行。本文首次报道磺化聚乙烯中空纤维阳离子交换膜对异丙醇/水的渗透汽化性能。     

改性壳聚精膜用于醇水混合液分离的研究──Ⅲ．超细粉末填充壳聚精膜

首次制备了用Ｓｉ３Ｎ４，ＳｉＯ２，ＴｉＨ４超细粉末填充的改性壳聚精膜，并将其用于乙醇／水混合液的分离中。实验表明壳聚糖膜经超细粉末填充后强度增大，溶胀度减小。用于乙醇／水混合液渗透蒸发分离时，分离因子和渗透通量都有提高，并在填充量为１６．７％附近出现极大值。随着料液中乙醇含量的增大，渗透通量减小，分离因子增大；随着料液温度的升高渗透通量显著增大，分离因子则稍有下降。并简单讨论了超细粉末在乙醇／水混合液分离中的作用。     

PSF-SPES共混中空纤维超滤膜制备的研究

以聚砜(PSF)、磺化聚醚砜(SPES)和醋酸纤维素(CA)为膜材料,水为内凝胶剂,采用干湿法制备了PSF-SPES共混中空纤维超滤膜,探讨了PSF-SPES铸膜液中SPES离子交换容量(IEC)、SPES浓度、添加剂、外凝胶剂的选择和热处理对膜性能的影响。所得共混超滤膜性能如下:w=0.0 0 1的Na2SO4截留率19.9%,通量62 L/(h.m2.MPa);w=0.001的PEG4000截留率78.2%,通量85 L/(h.m2.MPa)。此外,以PSF-SPES中空纤维为支撑膜,采用醋酸纤维素作为涂层液,研究了CA/PSF-SPES复合超滤膜性能,讨论了CA/PSF-SPES共混中空纤维超滤膜结构。     

二次生长法制备高分离性能的PHI分子筛膜

通过二次生长法在α-Al2O3支撑体表面合成了PHI分子筛膜,考察了晶种合成方式、二次生长合成温度及时间对形成PHI分子筛膜的影响.采用X射线衍射(XRD)、扫描电子显微镜(SEM)对合成膜进行表征.结果表明:载体表面合成出了PHI分子筛;二次生长法合成出的PHI分子筛膜连续、致密,膜厚约为20 μm.利用渗透汽化技术对甲醇、乙醇、异丙醇和叔丁醇等不同分子尺寸的醇/水体系进行分离性能的研究,同时考察原料液中水含量对所制备的PHI分子筛膜的分离性能的影响.结果表明:PHI分子筛膜对几种醇水体系都具有良好的分离效果,随着水含量的增加,水的渗透通量呈增大趋势,乙醇和甲醇的理想分离因子有所降低,异丙醇和叔丁醇的理想分离因子增大.     

改性壳聚糖膜用于醇水混合液分离的研究(Ⅱ)─壳聚糖－羧甲基纤维素共混物膜

制备了壳聚糖(CS)─羧甲基纤维素(CMC)共混物膜(I-2),对其成膜反应、溶胀度、交联度及拉伸强度进行了研究,结果表明,壳聚糖与羧甲基纤维素共混物在成膜的同时还发生交联反应;当CS/CMC=1时,交联度最大,此时共混物膜不溶于稀醋酸水溶液。首次将此共混物膜用于乙醇/水混合液的分离,该膜具有优良的醇水分离性能,当CS/CMC=1时,渗透通量和分离因子皆达到最大值[J=0.9kg/(m²·h),a=800,90wt%乙醇,45℃],且该膜的分离因子基本上不随温度变化,醇水透过I-2膜的表现活化能△E为32.6kJ/mol.对CS/CMC2+2+2+2+次序递增,分离因子变化次序则刚好相反。     

Influences of solution property and charge density on the self-assembly behavior of water-insoluble polyelectrolyte sulfonated poly(sulphone) sodium salts

Two sulfonated poly(sulphone) sodium salts (SPSF) with different molecular weights and ionic exchange capacities in a N,N-dimethyl formamide/water (DMF-H2O) mixed solvent with various DMF contents were selected as a model system for investigating the influences of solvent composition, solution properties, and charge density of polyelectrolytes on the layer-by-layer (LbL) self-assembly of water-insoluble polyelectrolytes. Poly(dimethyldiallylammonium chloride) (PDDA) in aqueous solution was used as the counterpart. The PDDA/SPSF multilayer films grew nearly linearly with the layer numbers regardless of the volume fraction of DMF, phiDMF, in the SPSF solutions. The total absorption amount of the PDDA/SPSF multilayer films was strongly dependent on the charge density of the SPSF molecules and the phiDMF value of the SPSF solutions. Minimum values of absorption amount were observed at phiDMF = 0.6 to approximately 0.7. The surface hydrophobicity and roughness of the multilayer films can be tuned by varying phiDMF. These observations were rationalized in terms of the chain dimension and the ionization degree of the SPSF molecules as a function of phiDMF, which was characterized by the intrinsic viscosity ([eta]SPSF) and conductivity (LSPSF) of the SPSF solutions. The results indicate that the molecular structures of the DMF-H2O mixed solvent strongly affect the solution properties of SPSF, which in turn determine the growth behavior and physical properties of the PDDA/SPSF multilayer films.     

Comparison of Electrochemical Synthesis of Ammonia by Using Sulfonated Polysulfone and Nafion Membrane with Sm1.5Sr0.5NiO4

Polysulfone (PSF) and sulfonated polysulfone (SPSF) were synthesized and characterized by IR spectrum. Sm_1.5Sr_0.5NiO₄ (SSN) and Ni‐Ce_0.8Sm_0.2O_2?δ (Ni‐SDC, Ni‐samarium doped ceria) were prepared and characterized by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). Ammonia was synthesized from wet hydrogen and dry nitrogen with applied voltage, using SSN as cathode, Ni‐SDC as anode, Nafion and SPSF as proton membrane respectively. The performances of Nafion and SPSF membranes in ammonia synthesis were investigated and compared at atmospheric pressure and low temperature (25–100°C). The results demonstrated that the proton conducting performances of Nafion and SPSF membranes were similar and the highest rates of evolution of ammonia were up to 1.05×10^?8 and 1.03×10^?8 mol·cm^?2·s^?1 respectively at 80°C and 2.5 V.     

Proton conducting composite membranes from polysulfone and heteropolyacid for fuel cell applications

The viability of using composite membranes of heteropolyacid (HPA)/polysulfone (PSF), HPA/sulfonated polysulfone (SPSF) for use in proton exchange membrane fuel cells (PEMFC) was investigated. PSF and its sulfonated polymer, SPSF was solution‐blended with phosphotungstic acid, a commercially available HPA. Fourier transform infrared (FTIR) spectroscopy of the HPA–40/SPSF composite exhibited band shifts showing a possibility of intermolecular hydrogen bonding interaction between the HPA additive and the sulfonated polymer. The composite membranes exhibited improved mechanical strength and low water uptake. The conductivity of the composite membrane, HPA–40/SPSF, consisting of 40 wt % HPA and 60 wt % SPSF [with a degree of Sulfonation (DS) of 40%] exhibited a conductivity 0.089 S/cm at room temperature that linearly increased upto 0.14 S/cm at 120 °C, whereas the widely used commercial membrane Nafion 117, exhibited a room temperature conductivity of 0.1 S/cm that increased to only 0.12 S/cm at 120 °C. In contrast, the composite of HPA–40/PSF exhibited a proton conductivity of 0.02 S/cm at room temperature that increased only to 0.07 S/cm at a temperature of 100 °C. The incorporation of HPA into SPSF not only rendered the membranes suitable for elevated temperature operation of PEMFC but also provides an inexpensive alternative compared to Nafion. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1538–1547, 2005     

磷酸掺杂的聚苯并咪唑复合膜在高温质子交换膜燃料电池中的应用

磷酸掺杂的聚苯并咪唑复合膜在高温质子交换膜燃料电池中的应用     

SELECTIVE SEPARATION OF WATER-ETHANOL MIXTURES THROUGH COPOLYMERIC MEMBRANES: Ⅰ. ACRYLIC ACID AND ACRYLONITRILE COPOLYMER AND ITS IONIZED MEMBRANES

The copolymer of acrylic acid and acrylonitrile has been synthesized and pervaporation properties of the copolymeric membranes have been investigated. In order to elucidate the influence of membrane-permeate interaction on the pervaporation of water-ethanol mixtures and to prepare much improved membranes, the membranes have been treated with alkali metal, alkali earth metal and transition metal salt aqueous solutions. The treated membranes (ionized membranes) exhibited higher separation factors than the untreated membranes. The separation factors of various alkali metal cation membranes decreased in the following order : Li~+>Na~+>K~+, and the permeation rates showed an opposite tendency. The dependence of pervaporation behavior on the copolymer composition ,feed concentration and operating temperature have been studied with both ionized and non-ionized membranes. The apparent activation energies of water and ethanol permeation were calculated.     

PSF/SPSF高分子合金膜的膜材料对膜性能的影响

介绍了PSF与SPSF共混对合金膜的成膜性能和机械性能的影响 .二者共混改善了PSF的亲水性 ,提高了PSF膜的耐污染性 ,并且合金膜获得比PSF膜高的渗透通量     

Relationship between the structure of compounds and the effect of Pluronic L61 on their permeation through lipid membranes

In view of the earlier observation that the incorporation of Pluronics in lipid membranes enhances their permeability to various drugs, the relationship between the structure of a permeant and the Pluronic-induced acceleration of its membrane transport was studied. The extent of acceleration defined as the ratio of the apparent permeation rate constants in the presence and in the absence of Pluronic, k/k ₀, was determined for 21 weak acids and bases. Multiparameter correlations of the obtained data with various structural characteristics of the solutes transferable were constructed. Twelve structural parameters of the permeants were examined. The best correlation was achieved with a linear combination of the three parameters: the McGowan volume V of a compound, its proton-donating ability A, and the projection of the dipole moment of the molecule onto the normal to the membrane surface μ_Z, ln(k/k ₀) = ?0.87-0.44μ_Z + 0.31 V + 0.28A, R = 0.90. This means that Pluronic preferably accelerates the permeation of large molecules containing proton-donating groups and molecules incorporated in the lipid bilayer in such a manner that the vector of their dipole moment is aligned with the dipole potential of the membrane.     

蛋白质分子印迹膜的制备和渗透性研究

以0.45 μm混合纤维素酯膜为支载膜,丙烯酰胺为功能单体,N,N’-亚甲基双丙烯酰胺为交联剂,通过表面印迹法制备得到牛血清白蛋白分子印迹膜。实验对制备分子印迹膜所用模板分子、功能单体和交联剂用量进行探讨,并对目标分子识别渗透的条件进行了优化。结果表明,较非印迹膜而言,该分子印迹膜表现出良好的识别渗透能力。     

New evaporative light scattering detector for high temperature gel permeation chromatography

A new evaporative light scattering detector (ELSD) for the analysis of polyolefins by high temperature gel permeation chromatography (GPC) was recently introduced by Agilent Technologies. For the first time, we investigated the possibility to use this detector to measure the molecular weight distributions (MWD) of different type of polyolefines (polypropylene, linear, and low-density polyethylene). These samples were previously characterized by GPC with a differential refractive index (DRI) detector by several companies, in an interlaboratory study conducted by International Union of Pure and Applied Chemistry.^[1 Luruli, N. 2010. PHASE 1: IUPAC SEC/GPC Round Robin Project Report: Repeatability and Reproducibility of Sample Preparation and Analysis in High-Temperature SEC, http://media.iupac.org/projects/2005/2005-011-3-400_rpt-phase1_110510.pdf [Google Scholar]^] The excellent baseline stability of ELSD as compared with DRI was reflected in a better reproducibility of the measured average molecular weights. More importantly, after applying required corrections to linearize the response of the ELSD as a function of concentration, we obtained similar results as previously obtained with DRI for the MWD of analyzed resins, covering typical applications of polyolefins.