辐射接枝法制备离子交换膜的研究现状

聚合物离子交换膜有多种制备方法，其中高分子材料辐射引发接枝功能性单体是一种文献中屡见报道且简单可行的方法．通过在不同聚合物基体上接枝各种类型的单体，可以改变接枝膜的电化学性能、物理化学等性能．丈中详细介绍了不同的高分子基材辐射接枝各类单体制备聚合物离子交换膜的研究现状．     

聚烯烃分离膜表面改性研究进展

综述了聚烯烃类分离膜表面改性研究的主要进展,着重介绍了高能辐射接枝、光引发接枝、等离子体接枝、表面臭氧处理、以及超临界CO2状态下接枝等表面改性方法的特点,分析了改性后聚烯烃膜的性能,并对聚烯烃分离膜表面改性进行了展望。     

聚丙烯腈分离膜改性研究进展及其应用

综述了聚丙烯腈分离膜改性研究新进展,包括表面接枝、复合、共聚合、聚合物化学反应、分子印迹法等,着重介绍了改性聚丙烯腈分离膜在渗透蒸发、生物大分子的固定化、徽滤、超滤、气体分离、人工脏器以及模拟生物膜等方面的应用。     

聚丙烯膜表面光接枝聚合

对聚合物表面进行接枝聚合是一种有效的材料改性方法。近年来,S.Tazuke,Y.Ogiwara,高志民等人做了一些用紫外光引发接枝方面的工作,获得了较满意的结果。为提高聚丙烯(简称为PP)膜的光稳定性,我们研究了将一种受阻胺类光稳定剂,甲基丙烯酸2,2,6,6-四甲基哌啶醇酯(简称为MTMP)光接枝到PP膜表面的聚合过程。     

等离子体引发HEMA的RAFT接枝聚合改性聚丙烯多孔膜

采用等离子体引发的可逆加成-断裂链转移(RAFT)接枝聚合法,以甲基丙烯酸羟乙酯(HEMA)为单体,对聚丙烯(PP)多孔膜表面作了亲水改性.研究了接枝聚合动力学,并以FT-IR、SEM、压汞、水通量等方法研究了改性膜的表面结构形态及孔结构.结果表明,等离子体引发的RAFT接枝聚合速率显著低于普通等离子体引发的接枝聚合速率.表面接枝率随着接枝聚合时间的延长呈线性增长趋势,同时改性膜的孔径和水通量随之减小.     

壳聚糖固体聚合物电池用膜

壳聚糖是甲壳素脱乙酰基的产物，具有良好的成膜性、生物相容性、环保以及价格低廉等特点。作为一种碱性高分子膜材料，近年来已成为聚电解质研究领域中的研究热点。本文综述了壳聚糖固体聚合物电池用膜的研究现状，其改性工艺主要包括共混、化学改性、质子酸掺杂、无机盐掺杂等方法，比较了各种工艺处理后壳聚糖固体聚合物电解质膜的性能差异，并就壳聚糖固体聚合物电解质膜中离子传导机理中有待解决的问题进行探讨，并提出了进一步改进壳聚糖固体聚合物电解质膜性能的研究思路。     

聚偏氟乙烯微孔膜的亲水化改性及功能化研究进展

聚偏氟乙烯(PVDF)微孔膜的亲水化改性方法有物理共混、化学共聚、表面涂覆、表面化学处理、表面接枝等几种。其中物理共混和表面涂覆法比较成熟且已获得应用，而PVDF微孔膜的表面化学处理、等离子体或光引发改性技术以及环境敏感性等将成为PVDF微孔膜的改性和功能化研究的主要方向。     

低温等离子体对聚合物多孔膜的亲水化改性

综述了低温等离子体在聚合物多孔膜表面亲水化改性领域的研究与应用进展。在简要介绍等离子体技术的原理、方法的基础上,讨论了Ar、He、O2、N2、CO2、H2O、NH2和SO2等非反应性和反应性气体的等离子体表面处理,烷基醇、烷基胺、烯丙基醇和烯丙基胺等饱和及不饱和单体的等离子体沉积聚合,以及烯类单体的等离子体引发的接枝聚合等等离子体方法,对膜表面和膜孔壁的化学组成和形态结构、膜亲水性的获得及其时效性、膜水通量和蛋白质抗污染性等方面的影响。     

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。     

聚4-乙烯基吡啶原位修饰PVDF膜及其负载磷钨杂多酸催化剂的研究

以聚偏氟乙烯(polyvinylidene fluoride,PVDF)微滤膜为基膜,4-乙烯基吡啶(4-vinylpyridine,4VP)为功能单体,采用表面引发电子活化再生原子转移自由基聚合(SI-AGET ATRP)法在基膜表面原位改性,并通过接枝聚合物侧链上的吡啶基团与Keggin型磷钨杂多酸(H3PW12O40·n H2O,HPW)之间的静电作用,制备了新型混合催化膜.实验结果表明,接枝聚合过程表现出"活性"/可控表面引发接枝聚合性质,基膜表面接枝聚合物量随聚合反应时间呈现线性增加,当反应时间为16 h,聚合物接枝量达到2.25 mg/cm2,聚合物接枝量的增多致使其相互堆积并坍塌,造成膜表面出现块状聚集体.然后,利用溴代十六烷对接枝聚合物进行季铵化改性,制得表面含有吡啶鎓盐的阳离子复合膜,通过接枝聚合物侧基中的吡啶和吡啶鎓盐基团与磷钨杂多酸之间的静电作用促使其在改性膜表面上有效负载.负载后的磷钨杂多酸均匀的分布在膜表面及孔道中,并保持其化学结构.负载催化剂前后膜的接触角从80.4°减小到57.8°,体现了亲水性催化剂的负载对膜表面润湿性的显著影响.     

聚(2,5-二氧基苯胺)膜修饰电极的电化学及催化性质

二甲氧基苯胺;电沉积;氧化;化学修饰电极;聚(2;5-二氧基苯胺)膜修饰电极的电化学及催化性质     

The Research on Polymer Microcapsulation for Cell Technology

Microcapsulation is a technology that enwrapped the solid or liquid or some gas matter with membrane materials to form microparticles(i.e.microcapsules). The materials of microcapsule is composed of naturnal polymers or modified naturnal polymers or synthesized polymers. The water-soluble core matter can only use oil-soluble wall materials, and vice versa.Synthesized methods of polymer microcapsulesSynthesized methods with monomers as raw materialsThis kind of methods include suspension polymerization, emulsion polymerization, dispersal polymerization, precipitation polymerization,suspension condensation polymerization, dispersal condensation polymerization, deposition condensation polymerization, interface condensation polymerization, and so on.Synthesized methods with polymers as raw materialsThese methods are suspension cross-linked polymerization, coacervation phase separation,extraction with solvent evaporation, polymer deposition, polymer chelation, polymer gel,solidification of melting polymer, tray-painted ways, fluidized bed ways, and so forth.Polymer materials to synthesize microcapsules2.1. Naturnal polymer materialsThe characteristics of this kind of materials are easy to form membrane, good stability and no toxicity. The polymer materials include lipids(liposome), amyloses, proteins, plant gels, waxes, etc.2.2. Modified polymer materialsThe characteristics of these materials are little toxicity, high viscidity(viscosity), soluble salt materials. But they cannot be used in water, acidic environment and high temperature environment for a long time. The materials include all kind of derivants of celluloses.2.3. Synthesized polymer materialsThe characteristics of the materials are easy to form membrane, good stability and adjustment of membrane properties. The synthesized polymer materials include degradable polymers(PLA, PGA,PLGA, PCL, PHB, PHV, PHA, PEG, PPG and the like) and indegradable polymers(PA, PMMA,PAM, PS, PVC, PB, PE, PU, PUA, PVA and otherwise).The applications of polymer microcapsules in cell technologyThe "artificial cell" is the biological active microcapsule used in biological and medical fields.The applications of cells (including transgenic cells, the same as artificial cells) technology include several aspects as follows:3.1. Microcapsulation of artificial red cell3.2. Microcapsule of artificial cell of biological enzyme3.3. Microcapsule of artificial cell of magnetic material3.4. Microcapsule of artificial cell of active carbon3.5. Microcapsule of active biological cell     

Photoinduced graft polymerization of 2-methacryloyloxyethyl phosphorylcholine on polyethylene membrane surface for obtaining blood cell adhesion resistance

Phospholipid polymer, poly[2-methacryloyloxyethyl phosphorylcholine (MPC)], was grafted with polyethylene (PE) membrane using photoinduced polymerization technique to make the membrane resistant to cell adhesion. The water contact angle on the PE membrane grafted with poly(MPC) decreased with an increase in the photopolymerization time. This decrease corresponded to the increase in the amount of poly(MPC) grafted on the PE surface. The same graft polymerization procedure was applied using other hydrophilic monomers, such as acrylamide (AAm), N-vinylpyrrolidone (VPy) and methacryloyl poly(ethylene glycol) (MPEG). These monomers were also polymerized to form grafted chains on the PE membrane, and the grafting was confirmed with X-ray photoelectron spectroscopy. Analysis of amount and distribution of plasma proteins at the plasma-contacting surface of the original and the modified PE membranes were analyzed using immunogold assay. The grafting of poly(MPC) and poly(VPy) on PE membrane reduced the plasma protein adsorption significantly compared with that on the original PE membrane. However, the PE membranes grafted with poly(AAm) or poly(MPEG) did not show any effects on protein adsorption. Platelet adhesion on the original and modified PE membranes from platelet-rich plasma was also examined. A large number of platelets adhered and activated on the original PE membrane. Grafting with poly(AAm) did not suppress platelet adhesion, but grafting with poly(MPC) or poly(VPy) on the PE membrane was effective in preventing platelet adhesion. It is concluded that the introduction of the phosphorylcholine group on the surface could decrease the cell adhesion to substrate polymer.     

Surface modification of nanofiltration membranes to improve the removal of organic micro-pollutants (EDCs and PhACs) in drinking water treatment: Graft polymerization and cross-linking followed by functional group substitution

A commercially available thin film composite (TFC) polyamide (PA) nanofiltration (NF) membrane was chemically modified to improve its rejection capacity for selected organic micro-pollutants categorized as endocrine disrupting chemicals (EDCs) and pharmaceutically active compounds (PhACs): bisphenol-A (BPA), ibuprofen, and salicylic acid. The raw NF membrane was altered using the following modification sequence: graft polymerization (methacrylic acid (MA)-membrane); cross-linking of grafted polymer chains (ethylene diamine (ED)-membrane); and, substitution of functional groups (succinic acid (SA)-membrane). Attenuated total reflective Fourier transform infrared (ATR-FTIR) was used to verify each modification in the sequence: the formation of amide bonds; graft polymerization and cross-linking; and, increased carboxylic acids on the modified membrane. Based on zeta-potential and contact angle measurements, graft polymerization increased the negative charge and hydrophilicity of the raw membrane, while cross-linking replaced carboxylic acid with amide bonds, which made the modified membrane almost neutral at pH 6.5. The water fluxes of the ED- and SA-membranes were similar to that of the raw membrane; however, the water flux of the MA-membranes varied with polymerization time (the membrane polymerized for 15 min revealed ≥20% higher flux than the raw membrane). BPA rejection by the raw membrane was substantially improved from 74% to ≥95% after this series of modifications. However, the rejection capacity of the ED-membrane for ibuprofen and salicylic acid was slightly reduced compared with those of the MA-membrane, which was polymerized for 15 min, due to the lack of an electrical repulsion mechanism. The SA-membrane recovered its negative surface charge and showed a clear enhancement in the rejection of all pollutants.     

Preparation of composite membranes by means of plasma polymerization of tiophene

The structure and the charge transport properties of poly(ethylene terephthalate) track membranes modified in a thiophene plasma were studied. It was found that polymer deposition on the surface of a track membrane via the plasma polymerization of thiophene results in composite membranes that, in the case of the formation of a semipermeable layer, exhibit conductivity asymmetry—rectifying effect—in electrolyte solutions. It was shown that chemical doping with iodine or photo-oxidation of the polymer layer produced in plasma leads to alteration in the electrochemical properties of plasma-modified membranes.     

Protein adsorption on polymer-modified silica particle surface

Silicon substrate surface and silica particle surface were modified with five kinds of polymers, poly(2-methoxyethyl methacrylate) (pMEMA), poly(2-hydroxyethyl methacrylate) (pHEMA), poly(acrylamide) (pAAm), poly(methyl methacrylate) (pMMA), and poly(styrene) (pSt), using a combined polymerization of surface-initiated polymerization that gives dense polymer chain layers and atom transfer radical polymerization (ATRP) that yields polymers with a narrow molecular weight distribution. Measurements of water contact angle and polymer chain amount on the modified silicon substrate surface and adsorption amounts of proteins (albumin and fibrinogen) on the modified silica particle surface revealed that the amount of polymer on the modified surface greatly affects the suppression of protein adsorption on the surface.     

聚吡咯/碳纳米管分子印迹修饰电极对槲皮素的选择性测定

制备了一种新颖的可对槲皮素分子进行选择性测定的分子印迹聚合物膜修饰电极.在碳纳米管(CNT)独特的结构和力学性能作用下,以吡咯(Py)为功能单体,槲皮素为模板分子,电聚合方法制备了槲皮素的分子印迹聚合物膜修饰电极(PPy/CNT/GCEMIP).用电化学交流阻抗法研究了该修饰电极的界面性质,用循环伏安法和差分脉冲伏安法...     

表面自由基链转移反应制备聚合物修饰的固定相

 利用巯丙基修饰硅胶的自由基链转移反应 ,在硅胶表面原位引发自由基聚合 ,制备了聚甲基丙烯酸甲酯修饰的反相高效液相固定相。通过红外吸收光谱 (FTIR)、拉曼光谱、热失重 (TGA)和元素分析对该固定相进行了表征。该固定相对含氧芳香化合物、多环芳烃等均有良好的分离能力。     

Synthesis of bilayer composite nanomembranes with conductivity asymmetry

The structure and electrochemical properties of polyethylene terephthalate track membranes modified in acetylene plasma are studied. It is found that polymer deposition on the track membrane surface using acetylene polymerization in plasma results in the case of formation of a semipermeable layer covering pores in formation of a composite nanomembrane featuring asymmetry of conductivity in solutions of electrolytes: a rectifying effect similar to that of a p-n junction in semiconductors. It is shown that the observed effect of conductivity asymmetry is caused by a significant decrease in the diameter of pores in the plasma-deposited polymer layer and a change in the pore geometry, same as existence of an interface between the initial membrane and polymer layer that have a different concentration of carboxyl groups in the surface layer. The impedance spectroscopy method allowed obtaining information on ion transfer in the studied membranes.     

Preparation and transport properties of PPy/PVDF composite membrane

In this work, composite cation‐exchange membrane was prepared by chemical polymerization of pyrrole on the surface of the poly(vinylidene fluoride) (PVDF) membrane using ferric ions. The changes in the surface morphologies of non‐modified and polymer‐modified PVDF membrane were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, and atomic force microscopy. The ion‐exchange capacity, water uptake, and fixed group concentration of the composite membrane were investigated. The polypyrrole/PVDF composite membrane was used for the removal of copper (II), chromium (III), iron (III), and aluminum (III) ions from aqueous solution with Donnan dialysis experiments. The flux values (J) and recovery factors (RF) of Cu(II), Cr(III), Fe(III), and Al(III) were obtained. Because of the smaller ion charge and hydration volume, the transport of the Cu(II) ion is higher than that of the other metals. Copyright © 2011 John Wiley & Sons, Ltd.