填充碳分子筛的PDMS膜渗透蒸发分离性能研究

采用自制的碳分子筛,制造了填充碳分子筛的硅橡胶（PDMS）膜,研究了膜对含苯的烯水溶液的渗透蒸发的分离性能,考察了填充剂,料液浓度等因素对膜的分离性能的影响。     

液晶化载体促进传递膜的研究

合成了两种侧链液晶高分子(PSC—Ⅱ),得到具有冠醚和液晶的双重功能的载体．用核磁共振光谱(^1HNMR)和红外光谱(IR)证实了它们的结构．示差扫描热分析(DSC)实验证明了它们都具有热致液晶性．用聚丙烯膜(Celgard 2400)作支撑体,侧链液晶高分子作载体,采用不同的制膜方法,研究了Na^ 、K^ 离子选择性渗透通过膜的传递性能．对实验结果进行了讨论,指出了选择合理的成膜方法对传递性能影响是主要因素．     

A lithium poly(pyromellitic acid borate) gel electrolyte membrane for lithium-ion batteries

Lithium poly(pyromellitic acid borate) (PPAB) was synthesized via polymerization of lithium tetramethanolatoborate and silylated pyromellitic acid. The synthesized material was characterized by Fourier transformation infrared spectroscopy, ¹¹B nuclear magnetic resonance, scanning electron microscopy, and thermogravimetric analysis. And electrochemical characterizations were carried out on the blended PPAB/PVDF-HFP membrane. The PPAB-based composite membrane exhibits high lithium ionic conductivity, a broad electrochemical window and a high lithium-ion transference number. The battery cells assembled with the PPAB/PVDF-HFP/EC:PC composite membrane as the electrolyte perform reasonably well not only at elevated temperature but also at room temperature with good cyclability and discharge capacity, making the material suitable for applications in lithium-ion batteries.     

The effects of quenching on the phase structure of vinylidene fluoride segments in PVDF-HFP copolymer and PVDF-HFP/PMMA blends

The phase characteristics of vinylidene fluoride (VDF) segments in vinylidene fluoride (VDF) and hexafluoropropylene (HFP) copolymer (PVDF-HFP) under different quenching temperature were investigated by infrared spectroscopy (FTIR) and X-ray diffraction (XRD) measurements. It was found that the α and β crystalline phases of VDF segments formed in PVDF-HFP as those in pure PVDF. Compared with pure PVDF, HFP segments affected the β phase formation obviously. Increasing of quenching temperature would decrease the fraction of β phase in the quenched PVDF-HFP films, and the films thicker than 8 μm were not in favor of the β phase transformation. Blending PVDF-HFP with small amounts of PMMA (≤10 wt%) yielded great effects on the crystal phase of VDF segments. But higher blending degree of PMMA couldn't increase the formation of β phase further.     

Novel sodium alginate composite membranes prepared by incorporating cobalt(III) complex particles used in pervaporation separation of water–acetic acid mixtures at different temperatures

The present paper is our continuing effort to develop a new type of sodium alginate (NaAlg) composite membrane by incorporating cobalt(III)(3-acetylpyridine-o-aminobenzoylhydrazone) (Co-APABZ) complex as filler particles in different ratios. Membranes were prepared by solution casting followed by solvent evaporation and crosslinked with glutaraldehyde. Pervaporation (PV) performance of the prepared composite membranes was assessed in terms of flux and selectivity and these data were compared with the pristine NaAlg membrane in PV dehydration of water–acetic acid mixtures. Pristine Co-APABZ particles in crystalline form were prepared and characterized by the solid state X-ray diffraction (XRD) technique, while the NaAlg/Co(III)composite membranes were characterized by thermogravimetry (TGA) and dynamic mechanical thermal analyzer (DMTA). X-ray crystal structure of Co-APABZ has shown that the complex formed was crystalline in nature with six lattice water molecules, which are interconnected by hydrogen bonds linking together to form cyclic hexamers that are analogous to cyclohexane, creating water channels for an easy transport of water molecules. TGA indicated no changes in thermal stability of the membranes due to the presence of Co-APABZ in the NaAlg matrix. DMTA confirmed NaAlg crosslinking with glutaraldehyde. Effects of Co-APABZ content, membrane thickness, temperature and feed water compositions on membrane performance were investigated to find an optimum PV performance of the membranes developed. NaAlg composite membranes in the presence of Co-APABZ particles preferentially absorbed water molecules to facilitate diffusion of water through the membranes and thus enhance the selectivity to water. However, the amount of Co-APABZ present in the NaAlg matrix and the degree of membrane swelling has an effect on membrane performance. Selectivity of 174 for water with a flux of 0.123 kg/m² h was obtained for 5 wt.% Co-APABZ containing NaAlg matrix, when tested for the feed mixture containing 10 wt % water. The present results are superior to the previously published data based on NaAlg membranes. This article is CEPS communication #110.     

干法制备聚合物锂离子电池用PVDF-HFP隔膜的研究

采用相转化法(干法)以PVDF-HFP(聚偏氟乙烯-六氟丙烯共聚物)为本体聚合物制备了聚合物锂离子电池用隔膜.通过扫描电镜对隔膜形貌进行分析,研究了在干法制膜过程中空气湿度对隔膜形貌和性质的影响.采用交流阻抗技术和PC(碳酸丙烯酯)浸入实验分别测定了隔膜的电导率和吸液率.采用吸液率最高,相对湿度50%下制备的隔膜装配电池,测其电化学性质.电池首次充放电效率为88.3%,第五周可达99.4%,表现出良好的电化学性能.     

分离有机物/水混合物的聚丙烯酸膜研究进展

介绍了聚丙烯酸（PAA）的不同类型分离膜的制备工艺,及在有机物／水混合物中的渗透汽化（PV）分离性能,重点讨论了交联剂浓度、高分子网络结构、支撑膜和共混膜性能对膜分离性能的影响,简要分析了操作参数如料液浓度、操作温度等影响因素,并提出了PAA膜在今后研究开发中的方向,     

Plasma-treated polyethersulfone coated with crosslinked poly(vinyl alcohol): composite membranes for pervaporation dehydration of ethanol

Composite membranes with crosslinked poly(vinyl alcohol) matrix as selective layer coated on a polyethersulfone supporting porous layer were prepared aiming at separating ethanol/water mixtures by pervaporation. A polyethersulfone asymmetric microporous membrane was synthesized by the wet phase inversion process. The support membrane was then exposed to air plasma to activate the surface. The selective dense layer was obtained by coating of PVA and a crosslinking agent over the polyethersulfone substrate, followed by thermal treatment. The morphology was examined by scanning electron microscopy (SEM) for both, support membrane and the coated polymeric layers. Surface physicochemical properties were evaluated through measuring the contact angle (θ) and the estimation of surface free energy (γ_S) and adhesion work. The surface chemical composition of support membrane and coated hydrophilic layers were characterized by infrared spectra with horizontal attenuated total reflectance (FT-IR/HATR). The swelling degree of PVA dense membranes, and the pervaporation performance of the crosslinked PVA/PES composite membranes, manufactured with several coating steps, were evaluated with water/ethanol (20/80 wt%) mixtures at temperatures in the range of 30–60 C. Results of the effective pervaporation dehydration of ethanol are discussed in terms of membrane morphology and the solution-diffusion transport mechanism.     

聚乙烯-乙烯醇磺酸锂/聚偏氟乙烯-六氟丙烯锂离子电池隔膜的制备及性能

以聚乙烯-乙烯醇的磺化物（EVOH-SO₃Li）和聚偏氟乙烯-六氟丙烯（PVDF-HFP）为原料,利用高压静电纺丝技术纺制成高孔隙率、纤维粗细均匀的EVOH-SO₃Li/PVDF-HFP复合隔膜材料。利用FTIR、SEM、万能拉伸试验仪、TGA、BMP3电化学工作站和电池检测系统对EVOH-SO₃Li/PVDF-HFP隔膜进行测试分析。测试结果表明:EVOH-SO₃Li/PVDF-HFP隔膜形成致密的三维网络结构,纤维粗细均匀,孔径均一,EVOH-SO₃Li/PVDF-HFP隔膜的孔隙率和吸液率分别为85%和437%;与纯EVOH-SO₃Li隔膜相比,EVOH-SO₃Li/PVDF-HFP复合隔膜的拉伸强度最大值从2.17 MPa提高至8.33 MPa,起始热分解温度升高至310℃,并表现出良好的电化学性能和电池性能。其中电化学稳定窗口由5.6 V增至5.8 V,界面阻抗由425.51 Ω降低至115.24 Ω,离子电导率由1.592×10-3 S/cm提高至3.102×10-3 S/cm;采用EVOH-SO₃Li/PVDF-HFP隔膜组装的锂离子电池在0.5 C放电电流下循环100次后容量保持率为96.65%。      

聚四氟乙烯微孔膜及其无机粒子共混膜的结构及性能

以聚乙烯醇(PVA)为成膜载体,由聚四氟乙烯(PTFE)分散乳液制得PTFE微孔膜,通过对不同烧结温度的研究得出PTFE烧结模型,在烧结初期有利于PTFE形成微孔结构.在成膜体系中引入纳米无机粒子,得到PTFE/无机粒子共混平板膜.研究了无机粒子对共混膜结构及性能的影响,结果表明PTFE与碳酸钙(CaCO_3)粒子的粘结性差,在烧结成型过程中PTFE基质相与CaCO_3产生界面相分离形成微孔,形成的界面微孔不同于PTFE双向拉伸产生的纤维-结点状裂隙孔结构.共混膜经适当拉伸后孔隙率显著提高.     

PVDF-HFP基复合多孔聚合物电解质膜的研制

聚偏氟乙烯-六氟丙烯共聚物(PVDF-HFP)多微孔膜在锂离子电池领域中具有很好的应用前景.采用Bellcore制膜法,用纳米材料对PVDF-HFP为基质的聚合物微孔膜材料进行了改性.利用XRD,SEM,交流阻抗等测试手段对电解质膜的晶体结构、微观形貌、电化学性能等进行了表征.结果表明:改性后聚合物电解质膜的孔隙率增加、结晶度降低,PVDF-HFP/SiO2和PVDF-HFP/Al2O3聚合物电解质隔膜的电导率(20℃)分别达到2.762×10-3S/cm和3.517×10-3S/cm,相应的离子迁移数分别为0.80和0.82.     

Proteomic analisys of protein extraction during hemofiltration with on-line endogenous reinfusion (HFR) using different polysulphone membranes

In end-stage renal disease patients, extracorporeal dialytic therapy is not able to prevent the accumulation of toxins related to the uremic syndrome, a severe complication that increases morbidity and mortality rate. In this paper, hemoFiltration with on-line Reinfusion (HFR) architecture is used to evaluate the effect of a more permeable membrane on the extraction of medium–high molecular weight molecules. The aim of this study was to compare two polysulphone membranes for convective chamber: polyphenylene High Flux (pHF) and polyphenylene Super High-Flux (pSHF). Fourteen patients were subjected to HFR with pHF and pSHF membranes and ultra filtrate (UF) samples were collected to evaluate molecular weight cut-off (MWCO) and to identify extracted proteins. Furthermore, image analysis software was used in order to evaluate change in protein extraction during the dialysis. The quantification of four proteins by immunoassay demonstrates a higher permeability of pSHF membrane. Two-dimensional electrophoresis (2-DE) gels showed, for both membranes, the greater number of protein spots at 235 min. Some of the identified proteins, involved in nephropathic disease complications, were compared to assess differences in extraction during dialytic treatment by PDQuest analysis. UF proteomic analysis demonstrated a different behavior for the two membranes; pHF membrane was more permeable at the beginning of HFR treatment (15 min), while pSHF membrane at the end of treatment (235 min). Proteomic analysis is a suitable approach to investigate the behavior of different membranes during dialysis. Results indicated that pSHF membrane offers the higher permeability, and showed higher efficiency in removal of middle molecules related to uremic syndrome.     

低温等离子体液相接枝NVP改性PAN膜

采用液相等离子体接枝技术改性聚丙烯腈(PAN)膜,在PAN膜表面引入亲水性单体氮乙烯吡咯烷酮(NVP).通过傅立叶红外光谱、DSC、XPS对PAN改性膜进行了表征,研究了单体浓度、温度、接枝时间对PAN改性膜纯水通量的影响,考察了在不同单体接枝温度下,PAN改性膜对NaCl、MgSO4混合盐体系的分离性能.     

低温等离子体接枝改性PVDF膜

采用低温等离子体接枝技术改性聚偏氟乙烯膜(PVDF),在PVDF膜表面引入疏水性单体苯乙烯,达到改变膜表面孔径的大小和孔径分布的目的.通过傅立叶红外光谱仪(FTIR-ATR)对改性前后的PVDF膜表面进行了结构分析,考察了PVDF膜接枝前后官能团的变化.采用示差扫描量热仪(DSC)分析了PVDF改性前后膜的孔径分布,考察了改性条件对膜孔径大小和分布的影响.通过扫描电子显微镜(SEM)和原子力显微镜(AFM)观测了PVDF膜改性前后表面形貌的变化.研究了接枝温度、接枝时间等接枝条件对PVDF改性膜纯水通量的影响.结果表明,随着照射时间和接枝时间的延长,PVDF改性膜的孔径分布变窄,纯水通量下降,接枝率提高.     

聚酰亚胺／磺化聚芳醚砜共混中空纤维膜用于醇／醚气相分离的研究

甲醇／ 甲基叔丁基醚的分离是目前具有实用意义的重要研究课题之一．文中采用气流吹扫式操作,研究了不同共混比的磺化聚芳醚砜／ 聚酰亚胺中空纤维膜对甲醇／ 甲基叔丁基醚气相混合体系的分离性能,以及不同操作条件对分离性能的影响．结果表明,共混改性聚酰亚胺膜具有非常高的醇／ 醚分离系数,有很好的应用前景．     

PU/PVDF共混中空纤维膜结构与性能

采用熔体纺丝后拉伸的方法制备了聚氨酯(PU)/聚偏氟乙烯(PVDF)共混中空纤维膜,研究了拉伸对共混膜形态结构的影响,通过测定水通量随透膜压力的变化讨论了PU/PVDF共混中空纤维膜的压力响应性能,并对不同拉伸倍数所得膜压力响应性能差异进行了研究.结果表明,拉伸过程增大了聚合物间界面微孔的通透性,有效地提高了膜的水通量;且随拉伸倍数的提高,PU/PVDF共混中空纤维膜界面微孔的回复性有所提高.     

聚丙烯酸盐与聚乙烯醇共混膜醇水混合物分离性能研究

将自制的丙烯酸、甲基丙烯酸Ｎ,Ｎ－二甲基氨基乙酯共聚物与聚乙烯醇（ＰＶＡ）共混蛊渗透汽化膜,研究了膜对混合液的吸收溶解性能和分离性能,发现共混膜优先透水,与ＰＶＡ膜相比,选择性有所下降而透过速率得到很大提高,尤其是分离９５％的乙醇水溶液仍有较大的渗透通量。选择合适的共聚单体比例及聚盐含量能得到性能较好的共混膜。当共聚单体比例为２、聚盐含量为１６．３％时,共混分离９５％乙醇水溶液分离系数约为９００,     

S-layer proteins as supporting scaffoldings for functional lipid membranes

A great challenge is the coupling of very sensitive microelectronic devices to wet biological systems in the generation of biomimetic sensors. Lipid membranes on solid supports (electrodes or semiconductors) may become the matrix of future bioelectronic devices probing and controlling biomolecular processes for scientific and technical applications. A sufficient electrical isolation between the coupling region and the surrounding electrolyte is mandatory. An attached lipid membrane with integral natural or designed proteins may be the material of choice if the biological components are kept in a proper environment. To retain the fluidity and stability of the lipid membrane and to provide an ion reservoir and space for bulky integral proteins, a separating layer composed of crystalline arrays of monomolecular proteinaceous subunits, termed S-layer, can be self-assembled on metal or semiconductor surfaces. In this way S-layer-supported lipid membranes are biomimetic structures mimicking the supramolecular principle of archeal cell envelopes. These composite architectures may ascend toward exciting new key devices, particularly in fields of membrane protein-based biosensors or lab-on-a-chip technology.     

不对称聚乙烯醇缩丁醛超滤膜的形成

采用浸没沉淀相转化法在二甲基乙酰胺(DMAC)、N-甲基吡咯烷酮(NMP)、二甲基甲酰胺(DMF)及二甲亚砜(DMSO)等4种溶剂下制备了聚乙烯醇缩丁醛(PVB)超滤膜,铸膜液组成为PVB-溶剂二元体系,水为非溶剂.利用扫描电子显微镜(SEM)观察了PVB膜的表面形貌与断面结构,并对其渗透及分离性能进行了测试,同时着重讨论了PVB膜表面结构的形成机理.结果表明,溶剂种类不仅决定了PVB-溶剂二元体系的热力学稳定性,同时也影响了其成膜过程的动力学效应;PVB膜断面结构受溶剂-非溶剂相互扩散速度的控制,而膜表面形貌则是铸膜液平衡热力学与成膜动力学结合的结果;不同溶剂的PVB超滤膜纯水通量大小的顺序依次为DMSO＞DMAC＞DMF＞NMP,其截留分子量则分别在40 000～50 000道尔顿之间.     

Preparation and characterization of polymeric plasticized membranes (PPM) embedding a crown ether carrier application to copper ions transport

Polymeric plasticized membranes (PPM) are a new perspective to solve the stability problems of supported liquid membranes to perform the simultaneous separation, concentration and purification of valuable species from aqueous solutions.Cellulose triacetate (CTA) membranes containing the crown ether dibenzo-18-crown-6 (DB18C6) as a fixed carrier were prepared and their performance tested for the transport of copper(II) ions. This study showed that PPM properties were influenced by the membrane composition. The transport studies revealed that diffusion rate was dependent on film thickness, the presence of a plasticizer, 2-nitrophenyloctylether, which plays also a critical role on the membrane physical characteristics (especially malleability) and the quantity of fixed crown ether. Porosimetry analyses showed conversely to other works with different carriers that all the membranes prepared are not porous for all membrane compositions. However, SEM analysis revealed a porous texture when the quantity of crown ether is higher than that of CTA. FTIR, X-ray and TGA characterizations showed that all the constituents of the membrane remain unaltered within the membrane without chemical interactions between them (no presence of new bonds in the FTIR spectra). Hence, transport mechanism of the copper(II) ions seems to be a jumping from site to site.