六元环型磺化聚酰亚胺类质子交换膜

磺化聚酰亚胺是一类很有希望在燃料电池中获得应用的质子交换膜材料。本文对近年来六元环型磺化聚酰亚胺的制备、磺化聚酰亚胺质子交换膜的各项性能做了一定的归纳与分析。重点介绍了耐水性、耐久性、离子交换容量、质子电导率四个方面的测试方法及影响因素,指出目前存在的问题并预测了今后重点研究的方向。     

Removal of high concentrations of H2S from simulated natural gas by Acidithiobacillus ferrooxidans immobilized on polyurethane foam

A chemo‐biochemical process for desulfurization of simulated natural gas containing hydrogen sulfide (H₂S) was investigated. The results showed that using polyurethane foam as a support for immobilization of Acidithiobacillus ferrooxidans obtained good biological oxidation performance and the maximum oxidation rate of ferrous iron was 4.12 kg m^?3 h^?1. Moreover, a semi‐empirical formula was set up for calculating theoretical ferrous oxidation rate as a function of influent Fe²⁺ and Fe²⁺ concentration in the bioreactor. The integrated chemical and biological process achieved removal efficiencies of about 80% when treating high concentrations of H₂S (15 000 ± 100 ppmv). © 2012 Society of Chemical Industry     

A novel method to graft carbon nanotube onto carbon fiber by the use of a binder

A novel method is developed for grafting multiwall carbon nanotubes (MWNTs) onto the surface of polyacrylonitrile‐based high strength (T300GB) carbon fiber. Functionalized MWNTs were well dispersed in the PVA solution and the carbon fiber was dip‐coated in this solution. After heat treatment of the coated carbon fiber under a nitrogen atmosphere, MWNTs with carboxyl groups were grafted onto the functionalized carbon fiber via chemical interaction. The resulting materials were characterized by Fourier transform infrared (FTIR), X‐ray photoelectron spectroscopy (XPS), Field emission scanning electron microscopy (FESEM), Raman spectrum and mechanical testing. FESEM observations revealed uniform coverage of carbon nanotubes on carbon fiber. The carbon fiber grafted with MWNTs improved the tensile strength by 12% with respect to the pristine carbon fiber. These results are supportive of good interfacial bonding between the carbon nanotubes (CNTs) and carbon fiber. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Effects of N,N′-Ethylenebis(stearamide) on the Properties of Poly(ethylene terephthalate)/Organo-montmorillonite Nanocomposite

Poly(ethylene terephthalate)/organo-montmorillonite (PET/OMMT) nanocomposites were melt-compounded using twin screw extruder followed by injection molding. N,N′-ethylenebis(stearamide) (EBS) was selected as a dispersing agent to improve the dispersibility and exfoliation of OMMT clay in PET matrix. Morphological properties of the PET/OMMT nanocomposites were examined by using X-ray diffraction analysis, transmission electron microscopy and atomic force microscopy. Thermal properties of the nanocomposites were characterized by using dynamic mechanical thermal analysis. It was found that the OMMT are well dispersed and exfoliated in the presence of EBS. Remarkable enhancement in impact strength and storage modulus of PET/OMMT was achieved by the addition of EBS.     

D-101大孔树脂吸附纯化葡萄籽原花青素的研究

采用D-101大孔树脂对葡萄籽乙醇提取液中原花青素进行吸附纯化。研究了乙醇浓度、洗脱流速、乙醇体积对原花青素纯化效果的影响。结果表明,树脂体积为10 mL,上样量为50 mL,上样流速为1 mL/min,用50%的乙醇洗脱,洗脱剂体积为50 mL,洗脱流速为1.5 mL/min时的纯化效果最好,此条件下的原花青素解吸率为84.60%。     

RAFT聚合制备温敏性含糖共聚物

采用酶促法合成了含糖单体6-O-乙烯基己二酸-D-吡喃型葡萄糖酯(OVAG),使用可逆加成链断裂转移自由基聚合法(RAFT聚合)将N-异丙基丙烯酰胺(NIPAAm)和OVAG共聚,制备分散度(PDI)低且具有温度敏感性的含糖高聚物Poly(NIPAAm-co-OVAG)。用1HNMR,傅里叶变换红外光谱(FTIR),凝胶渗透色谱(GPC)对聚合物进行了表征。通过透射电子显微镜(TEM)发现自组装形成的聚合物胶束结构规整且粒径均匀。通过紫外-可见光谱对聚合物温敏性检查表明,共聚物的低临界溶解温度(LCST)可以通过共聚单体的比例进行调控。当NIPAAm与OVAG的摩尔比为14∶1时,共聚物的LCST值为36℃,在人体温度下可以形成纳米胶束,在药物载体方面拥有广阔前景。     

噁草酮在水稻及其环境中的残留分析方法

[目的]采用气相色谱法建立噁草酮在水稻及其环境系统中的残留分析方法。[方法]探索了水稻及稻田环境中噁草酮残留量的GC-ECD分析方法,样品均用二氯甲烷提取,二氯甲烷萃取,层析柱净化后经GC-ECD测定。[结果]噁草酮的最小检出量为1.0×10-12g(以3倍信噪比计),在上述噁草酮残留量分析测定条件下,噁草酮的最低检出质量浓度分别为稻田水0.005 mg/L,土壤、植株、糙米和稻壳中0.005 mg/kg。水样、土样、植株、稻米和稻壳中甲维盐的添加回收率83.08%~106.11%,变异系数1.14%~9.20%。[结论]均符合农药残留分析方法的技术要求。     

单宁酸在碳掺杂蒙脱土修饰电极上的电化学行为及测定

制备了碳掺杂蒙脱土修饰电极(C-MMT/GCE),采用循环伏安法研究了单宁酸在该修饰电极上的电化学行为。结果表明,该电极过程受吸附-扩散混合控制,转移电子数等于质子数n=m=1,电极有效面积A eff=0.092 cm2,扩散系数D=1.66×10-5cm2/s。单宁酸的氧化峰电流与其浓度在8.0×10-6~4.0×10-4mol/L呈线性关系,检出限为1.0×10-6mol/L,并测得单宁酸试样的回收率为97.6%~102.8%。该修饰电极具有良好的重现性。