Poly(vinyl alcohol)/Silica Organic-Inorganic Hybrid Membranes for Pervaporation Dehydration

亲水性高分子渗透蒸发膜在水溶液中易溶胀，化学改性可有效提高其在水溶液中的稳定性和渗透选择性，但常以牺牲渗透通量为代价。本文以降低水溶液中高分子膜的溶胀、提高对水的渗透性和渗透选择性为出发点，以硅氧烷前驱体为无机组分，制备了系列聚乙烯醇(PVA)/硅有机无机–杂化膜，用于乙醇渗透蒸发脱水。用实验和分子模拟考察乙醇水溶液溶胀PVA膜的结构和性能特点；采用分子模拟技术初选出合适的硅氧烷前驱体对PVA杂化改性，再用反相气相色谱法(IGC)进一步预测和验证所选材料的分离性能；最后以γ–氨丙基三乙氧基硅氧烷(APTEOS)和1,2–双(三乙氧基硅)乙烷(BTEE)为前驱体制备PVA/硅杂化膜，考察其物化结...Hydrophilic polymeric membranes are easily swollen in an aqueous solution, resulting in a decrease of selectivity. They were normally modified by chemical crosslinking to reduce their swelling and increase selectivity, while accompanied with a sacrifice in water permeability. Therefore, the objective of this work is to decrease the swelling of polymeric membranes in an aqueous solution and enhance...学位：工学博士院系专业：化学化工学院化学工程与生物工程系_工业催化学号：2062006015327

Preparation and permeation characteristics of novel PVA/APTEOS hybrid membranes

采用溶胶-凝胶法制备了聚乙烯醇(PVA)/γ-氨丙基三乙氧基硅氧烷(APTEOS)有机/无机杂化膜。用FTIR和XRD对杂化膜进行了表征。测定了膜在乙醇/水溶液中的溶胀行为。考察了杂化膜对85%(质量)的乙醇/水溶液的渗透蒸发分离性能。加入APTEOS降低了PVA的结晶度,有效控制了膜的溶胀,呈现出优良的分离性能。随着APTEOS含量的增加,杂化膜的选择性急剧增加,在5.0%(质量)时达到最大值;同时膜的渗透通量迅速增加。解决了PVA膜trade-off效应。Novel organic-inorganic hybrid membranes were prepared through sol-gel reaction of poly(vinyl alcohol)(PVA)with γ-aminopropyl-triethoxysilane(APTEOS).The resulting membranes were characterized with Fourier transform infrared spectroscopy and wide-angle X-ray diffraction.The swelling degree of PVA and PVA/APTEOS hybrid membranes in water/ethanol mixture was determined.The pervaporation performance was investigated by separation of water/ethanol mixture at 50℃.The effect of APTEOS content on the pervaporation performance was studied.The decrease in swelling degree with increasing APTEOS content was due to the formation of hydrogen and covalent bonds in the membrane matrix.The crystalline region of PVA decreased with increasing APTEOS content.The separation factor for water increased,and then decreased when APTEOS content was more than 5.0%(mass).The hybrid membrane containing 5.0%(mass) APTEOS exhibited the highest separation factor.However the permeation rate increased remarkably with increasing APTEOS content.The trade-off relation of the PVA membrane was solved,and the PVA/APTEOS hybrid membranes showed high pervaporation properties.国家自然科学基金项目(50573063);; 高等学校博士点专项基金(20050384013)~

Permeation and characterization of TiO_2/PVA hybrid membranes

通过纳米TiO2粒子填充改性制备了新型TiO2/PVA杂化膜。红外光谱表明纳米TiO2表面的羟基与聚乙烯醇(PVA)链上的羟基存在较强的氢键作用。扫描电镜显示当TiO2的质量分数低于1.5%时,在PVA中分散均匀。X射线衍射显示纳米TiO2的加入降低了膜的结晶度。通过对含水质量分数低于20%的水/乙醇体系的脱水研究了该杂化膜的渗透性能,考察了TiO2粒子填充量、料液质量分数和温度与膜分离性能之间的关系。渗透通量J随着TiO2、水质量分数和温度的升高而增加,分离因子随着温度和水质量分数的升高而下降,在TiO2质量分数为1.5%时分离因子达到最佳值。40℃下分离质量分数85%的乙醇水溶液,分离因子可达1 590,渗透通量为0.049kg/(m2.h)。Novel nanometer-sized TiO2 filled polyvinyl alcohol(PVA) membranes were prepared.Fourier transform infrared(FTIR) indicates that there is a strong hydrogen-bond interaction between PVA and TiO2.Scanning electron microscope(SEM) shows that TiO2 particles are well distributed in the membrane matrix when TiO2 mass fraction is less than 1.5%.X-ray diffraction(XRD) reveals that the crystallinity of the hybrid membrane is lower than that of the PVA membrane.The permeation properties of the membrane was studied through the dehydration of water/ethanol system,of which water mass fraction is less than 20%,and the effects of TiO2 mass fraction,feed water mass fraction and temperature on the permeation properties of the membrane were investigated.The results show that the permeation flux J increases with increasing TiO2 mass fraction,feed water mass fraction and temperature.Meanwhile,the separation factor α decreases with increasing the feed water mass fraction and temperature.Separation factor arrives at an optimal value when TiO2 mass fraction is 1.5%.The separation factor and permeation flux reach 1 590 and 0.049 kg/(m2·h) respectively for the separation of mass fraction 85% ethanol/water solution at 40 ℃.国家自然科学基金资助项目(50573063);; 教育部新世纪优秀人才支持计划资助项

Experimental studies on treating humid acid solution by photocatalytic oxidation

以腐殖酸类物质作为废水中有机物的代表,研究了水体中腐殖酸在纳米TIO2颗粒上的吸附行为及以此为催化剂对水中腐殖酸进行的光催化氧化行为。考察了不同催化剂质量浓度、初始PH值、腐殖酸初始质量浓度等因素对腐殖酸去除率的影响。结果表明:腐殖酸在TIO2颗粒上的平衡吸附量对溶液的初始PH值依赖性很小;初始PH值降低、腐殖酸初始质量浓度减小,均能显著提高腐殖酸的去除率。同时将光催化氧化与单纯紫外线照射的去除率作对比,光催化氧化法明显优于单纯紫外线照射。Humid acid(HA) is the representation of organic matter in wastewater.The behaviors of adsorption and photocatalytic oxidation of HA in water on TiO2 particles were studied.The effects of different factors on removal of HA from water were investigated,such as mass concentration of catalyst,initial value of pH,initial mass concentration of HA,etc.The results show that the adsorption amount of HA in balance on TiO2 particles is independent of initial pH value of the solution.The removal efficiency of HA is improved greatly with the decreasing of initial pH value and initial mass concentration of HA.Comparing the removal efficiency of photocatalytic oxidation with that of ultraviolet radiation alone,the photocatalytic oxidation is better than ultraviolet radiation alone.厦门大学人才引进基金项目(0000X071C1

Advances in inorganic particle filled polymeric membranes

[中文文摘]根据有机、无机组分间相互作用类型对有机-无机杂化膜进行了分类,重点论述了无机粒子填充型有机-无机杂化膜的最新研究进展,归纳了此类杂化膜的优异性能,总结了无机粒子的物理化学性能、含量、尺寸及其与聚合物的相容性等因素对此类杂化膜结构和性能的主要影响。最后提出了目前研究中存在的一些问题,并对其发展做出了简要的述评。[英文文摘]Hybrid organic-inorganic membranes are being classified according to the links between the organic and inorganic components ,the advances in inorganic particles filled polymeric membranes are reviewed emphatically. The superior properties of this kind of hybrid membranes are briefly discussed and some influencing factors such as physical and chemical properties ,content ,size of inorganic particles and its compatibility with polymers on the morphology and characteristics of the hybrid membranes are illustrated. Finally , some problems which existed in the present research are pointed out and a brief comment on their development is given.国家自然科学基金项目(50573063);高等学校博士点专项基金项目(20050384013

Advances in Structure Controls and Modifications of PIMs Membranes for Gas Separation

自具微孔高分子(POlyMErS Of InTrInSIC MICrOPOrOSITy,PIMS)是近年来出现的一种新型有机微孔材料,由含有扭曲结构的刚性单体聚合而成,具有比表面积高、化学和物理性质稳定、微孔结构可控等优点,在均相催化、氢气储存等方面表现出巨大的应用潜力。因其优越的气体分离性能,PIMS气体分离膜更是吸引了众多研究者的关注,发展迅速。本文总结了PIMS的分类及其在气体分离膜中的应用,重点介绍了PIMS气体分离膜的结构调控与改性方面的研究进展,分析了PIMS的分子结构与气体分离性能间的内在关联,最后提出了目前研究中存在的一些问题并对其发展做出了简要的评述。Polymers of intrinsic microporosity( PIMs),as novel microporous organic polymers polymerized by rigid monomers that have sites of contortion,have great application potential in homogeneous catalysis and hydrogen storage due to their high specific surface,chemical and physical stability and pore size controllability.Particularly,PIMs composed of polymer chains attract more attention in gas separation membranes due to their superior gas separation properties and good solubility.Here,the classification and applications of PIMs as well as the properties including stability,gas permeability and gas selectivity of PIMs gas membrane are introduced.The structure controls and modifications of PIMs gas membrane and the relationship between molecular structures and gas separation properties are described in detail.Finally,the problems existed in the present research are pointed out and a brief comment on the development is given.国家自然科学基金项目(No.21306155); 高等学校博士点专项科研基金(No.20120121120013); 中央高校科研业务费项目(No.2012121029)资助~

交联型聚芳醚基阴离子交换膜的制备及性能研究

燃料电池由于能量转化率高、环境友好等优点,是最具应用前景的能量转化装置之一。阴离子交换膜作为燃料电池的核心部件,仍存在低电导、高溶胀等问题.这里,通过设计聚芳醚结构使其侧链末端含有碳碳双键,在Grubbs二代催化剂作用下进行烯烃复分解反应接枝离子基团,利用剩余不饱和双键在高温下的交联反应,制备出交联型聚芳醚基阴离子交换膜.由于亲水性侧链与疏水性主链的不兼容性,使膜内形成了有利于离子传输的微相分离结构,交联膜的最高电导率达到81.1mS/cm(80℃).此外,交联结构能有效地抑制膜的溶胀,交联膜C-FPAE-PH-1.5在30℃下的溶胀率仅为7.51%,表现出优异尺寸稳定性.C-FPAE-PH-1.5膜在60℃下1mol/L KOH水溶液中浸泡360h后,保留了93.1%的电导率,表现出优异的耐碱性能.国家自然科学基金(21576226

A Fully Flexible Potential Model for Carbon Dioxide

A fully flexible potential model for carbon dioxide has been developed to predict the vapor-liquid coexistence properties using the NVT-Gibbs ensemble Monte Carlo technique (GEMC). The average absolute deviation between our simulation and the literature experimental data for saturated liquid and vapor densities is 0.3% and 2.0%, respectively. Compared with the experimental data, our calculated results of critical properties (7.39 Mpa, 304.04 K, and 0.4679 g.cm(-3)) are acceptable and are better than those from the resealing the potential parameters of elementary physical model (EPM2). The agreement of our simulated densities of supercritical carbon dioxide with the experimental data is acceptable in a wide range of pressure and temperature. The radial distribution function estimated at the supercritical conditions suggests that the carbon dioxide is a nonlinear molecule with the C=O bond length of 0.117 nm and the O=C=O bond angle of 176.4 degrees, which are consistent with Car-Parrinello molecular-dynamics (CPMD), whereas the EPM2 model shows large deviation at supercritical state. The predicted self-diffusion coefficients are in agreement with the experiments.National Natural Science Foundation of China [50573063]; Program for New Century Excellent Talents in University of the State Ministry of Education [NCET-05-0566]; Specialized Research Fund for the Doctoral Program of Higher Education of China [2005038401

哌啶阳离子功能化侧链型阴离子交换膜的制备

燃料电池因其能量转化率高、污染小等特点,成为当前的研究热点.然而,作为关键部件的阴离子交换膜仍然存在离子电导率低、耐碱性能差等缺点,这限制了燃料电池的发展.利用威廉姆森成醚反应在聚醚酮主链接枝哌啶鎓盐,成功制备了侧链型阴离子交换膜.设计的哌啶鎓盐通过长柔性亚甲基与主链相连,使膜内形成有利于高效离子传输的微相分离结构,PEKCQA-1.0膜在80℃的电导率高达72.7mS/cm.此外,哌啶阳离子基团离主链较远,减弱了对主链的吸电子作用;同时,环型结构的哌啶阳离子具有一定的空间位阻,减少了OH~-对阳离子基团的攻击,使膜表现出优异的耐碱性能.PEK-CQA-0.8膜在60℃下1mol/L KOH水溶液中浸泡360h后,离子电导率仅下降了8.8%,有望应用于碱性燃料电池.国家自然科学基金面上项目(21376194,21576226

Properties of hybrid SPEK-C/GO composite proton exchange membranes

采用共混制备了一系列磺化含酚酞侧基聚芳醚酮(SPEk-C)/氧化石墨烯(gO)复合质子交换膜,系统地研究了gO含量对复合膜性能的影响。结果表明,gO含量对膜的离子交换容量、稳定性、质子电导率和甲醇渗透率等有重要影响。复合膜质子电导率随gO含量增加而提高,gO含量为2%和5%的复合膜在80℃下质子电导率均在10-1 S·CM-1以上。80℃下,gO含量为5%的复合膜甲醇渗透率为6.69x10-7 CM2·S-1,低于同温度下复合前SPEk-C膜1个数量级。复合后膜的化学稳定性增强,离子交换容量和含水率均有提高,相对选择性明显增大,最高达SPEk-C的18.2倍。A series of sulfonated phenolphthalein side poly(aryl ether ketone)(SPEK-C)/graphene oxide(GO) hybrid composite proton exchange membranes was fabricated.The effect of GO as a filler blending with SPEK-C was investigated systematically.The results indicated that GO content in the membrane had a great influence on ionic exchange capacity, stability, proton conductivity and methanol permeability.The proton conductivity was enhanced with increasing GO content.Moreover, the proton conductivity of the composite membranes with 2% and 5% GO was all above 10-1 S·cm-1 at 30℃.The composite membrane containing 5% GO exhibited methanol permeability of 6.7×10-8 cm2·s-1 at 30℃, which was one order of magnitude lower than that of SPEK-C membrane.The ionic exchange capacity, stability and water uptake were enhanced, and the relative selectivity reached up to 18.2 times higher than that of the SPEK-C membrane.福建省科技计划项目(2014H0043