Preparation of Chitosan Magnetic Microspheres

用共沉淀法制备Fe3O4磁性纳米粒子,并对其用油酸进行表面改性,继而采用沉淀聚合法制备壳聚糖磁性微球。考察了沉淀剂浓度、乳化剂种类、Fe3O4的改性等条件对制备微球的影响。应用扫描电镜、红外谱图、接触角仪、粒径分析仪及磁铁吸附对壳聚糖磁性微球的形态与特性进行了表征。研究结果表明,在适宜的沉淀剂浓度、复合乳化剂、Fe3O4经油酸改性等条件下,可以制得平均粒径为150 nm、单分散性好且磁性明显的壳聚糖磁性微球。The Fe3O4 nanoparticles were prepared by co-precipitation method and modified by oleic acid.Chitosan magnetic microspheres were then prepared by precipitation polymerization method.The results demonstrated that the concentration of the precipitant,the type of emulsion and the modification of the iron oxide were the most effective parameters for the preparation of the microspheres.The SEM,IR and DLS results indicated that the diameter of the microspheres was about 150nm and the microspheres were uniformly distributed.The magnetic test showed the microspheres were magnetic sensitive.国家自然科学基金(50573063);; 教育部新世纪优秀人才计划项目;; 高等学校博士点专项基金(2005038401);; 厦门大学人才基金(0000X071C1

Preparation and Characterization of p(NIPAM-co-AA)/TiO_2 Composite Microspheres

用溶胶凝胶法制备了二氧化钛(TIO2)纳米粒子,并用硅烷偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷(γ-MPS)对其表面进行改性,继而采用光引发自由基聚合制备了聚(n-异丙基丙烯酰胺-CO-丙烯酸)/TIO2复合微球。考察了共聚单体丙烯酸(AA)、表面活性剂司盘80(SPAn80)在反应体系中的加入量对制备微球的影响,并比较了不同干燥方法对微球形态的影响。结果表明:合适的单体加入量、表面活性剂用量以及干燥方法可制备出分散性和球形度较好的复合微球。TiO2 nanoparticles were prepared by sol-gel method and modified with γ-MPS.Poly(NIPAM-co-AA)/TiO2 was prepared via UV-initiated radical polymerization.The effects of AA and Span80 contents,and different drying methods were investigated.The results demonstrated that the content of the co-monomer,the concentration of the surfactant and the drying method played significant roles in the preparation of the microspheres.国家自然科学基金项目(No.20976145

Experience in constructing the marine environment science national experimental teaching demonstration centre

结合建设国家级实验教学示范中心的经验,介绍了海洋环境科学实验教学中心改革与建设的思路、措施、成效和示范辐射作用,旨在加快实验教学改革和实验室建设,促进优质资源整合和共享,培养有创新精神和实践能力的高素质海洋环境科学人才。Based on the experience in constructing the national experimental teaching demonstration centre of marine environment,Xiamen University,elaborated on the guidelines,measures,objectives,the demonstration and radiating role,aiming to in speed up the step of experimental teaching reform and construction of laboratory,promote the superior resources integration and sharing,and cultivate the innovation spirit and the practice ability of the high-quality marine environmental science personnel

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 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

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

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

Analyzing solubility and diffusion of solvents in novel hybrid materials of poly(vinyl alcohol)/gamma-aminopropyltriethoxysilane by inverse gas chromatography

Novel hybrid materials were prepared through sol-gel reaction of poly(vinyl alcohol) (PVA) and c-aminopropyltriethoxysilane (APTEOS). Solubility and diffusion behavior of a series of solvents in the PVA/APTEOS hybrid materials were studied by inverse gas chromatography (IGC) fitted with a packed column. Solubility thermodynamics parameters at infinite dilution, such as the activity coefficient Omega(infinity)(1) and the solubility coefficient S of solvents in the hybrid materials, the partial molar excess free energy of mixture Delta G(m), and the Flory-Huggins interaction parameter chi(infinity)(12) were determined. The infinite dilution diffusion coefficients D-infinity of the solvents in the hybrid materials were also calculated. Effects of APTEOS content in the stationary phase and the column temperature on the solubility and diffusion of solvents in the hybrid materials were investigated. The hybrid material containing 5.0 wt% APTEOS has the strongest interaction with water, the largest S and D-infinity for water, and the hybrid material has a promising application in membrane separation, such as pervaporation dehydration of alcohol solution. The solubility parameter delta(2) of the hybrid materials was estimated, and it decreased with increasing APTEOS content. The dependence of D-infinity on temperature was in good agreement with the Arrhenius equation