燃料电池用碱性阴离子交换膜的研究进展

碱性阴离子交换膜(AAEM)是碱性阴离子交换膜燃料电池(AAEMFC)的核心部件,起到阻隔阴阳两极和传导OH-的双重作用,其性能好坏直接影响到AAEMFC的性能和使用寿命。从膜的结构和制备方法分类,综述了碱性阴离子交换膜燃料电池用有机-无机杂化膜、掺杂型膜及均相膜的特性和研究现状。     

基于氢键的阴离子比色探针的合成和性质研究

以5-溴水杨醛和4-苯基-3-氨基硫脲合成了一种新型希夫碱类阴离子比色探针,研究了该探针对常见阴离子的比色响应特性。结果表明,在DMSO体系中加入氟离子、乙酸根离子和磷酸二氢根离子后,探针的最大吸波长从352 nm红移到398 nm,肉眼可观察到溶液的颜色从淡黄色变成了黄色,而其它的阴离子如氯离子、溴离子和碘离子的加入基本不引起溶液紫外-可见吸收波长的任何变化。因此,这种探针可以用来识别氟离子、乙酸根离子和磷酸二氢根离子。     

Voltammetric reduction of 4-nitroimidazole derivatives: Influence of the N-1 substitution in protic and aprotic media

The voltammetric reduction of 1-methyl- and 1-H- 4-nitroimidazole derivatives was studied in different protic and aprotic media to investigate the influence of the N-1 substitution in the mechanism of reduction, the susceptibility of the nitro group to reduction, and the stability of the nitro radical anion.The elucidation of their voltammetric behavior was carried out using differential pulse polarography and cyclic voltammetry with two different mixed media (Britton-Robinson/ethanol: 70/30 and DMF/citrate: 60/40) and an aprotic media (DMF) at the mercury electrode. In addition, we used UV-vis spectroscopy for the study of their chemistry in solution and quantum-chemical calculations to evaluate LUMO energies, HOMO and LUMO energy gaps, dipole moments and electron affinity, using water and DMF as solvents.The mechanism of reduction was strongly dependent on both the substitution at the N-1 position and the nature of the media. In all media, the methyl-substituted derivative (M-4-NImOH) was always more easily reduced than the demethylated species (H-4-NImOH). On the other hand, the nitro radical anion from M-4-NImOH was more stable than the nitro radical anion from H-4-NImOH.     

Adsorption and separation of rhenium(VII) using N‐methylimidazolium functionalized strong basic anion exchange resin

BACKGROUND: Rhenium is a rare and valuable metal coexisting with molybdenum in molybdenite and sulfide copper ores and is hard to separate. Methods such as solvent extraction, ion exchange, adsorption, precipitation, etc. have been used to separate and purify Re(VII), and resin ion exchange has been widely investigated and used owing to its convenient operation and relatively low‐cost. The main challenge comes from the preparation of resins having high performance and stability. In an earlier study, an N‐methylimidazolium functionalized strong basic anion exchange resin was successfully synthesized and used for Cr(IV) extraction. This paper, reports on further synthesis and application of this resin for adsorption and separation of Re(VII) and Mo(VI), especially from copper arsenic filter cake. RESULTS: At pH 6.25, Re(VII) and Mo(VI) can be effectively separated with the N‐methylimidazolium functionalized strong basic anion exchange resin, giving a Re(VII) recovery of up to 93.3%, but only 5.1% for Mo(VI). When using the copper arsenic filter cake sample 89.1% Re(VII) recovery was achieved. CONCLUSION: The N‐methylimidazolium functionalized strong basic anion exchange resin exhibited high selectivity and recovery for Re(VII) in a mixed system. © 2012 Society of Chemical Industry     

阴离子分离柱的研制及其在食品中的应用

本文介绍了低压离子色谱仪使用的阴离子分离柱的制备，进行了Ｆ－、Ｃｌ－、Ｂｒ－；Ｆ－、Ｃｌ－、ＮＯ、Ｂｒ－、ＮＯ、ＳＯ混合阴离子的色谱分离，分离速度快，分离效果好，进行了重现性试验，标准偏差符合分析化学要求；午餐肉中ＮＯ、ＮＯ的分离检测获得满意结果。     

树脂富集钼精矿焙烧烟尘浸出液中铼的研究

用201×7强碱性凝胶型离子交换树脂对钼精矿焙烧烟尘浸出液中的铼进行分离富集工艺条件研究.通过对溶液中主要金属离子存在状态的分析,选择用对浸出液进行氧化预处理,再进行离子交换吸附的工艺.用静态法对影响离子交换效果的因素进行了探索性研究.结果表明,烟尘浸出液经氧化预处理后,用201×7树脂在常温,pH=9.0时可以对浸出液中的铼有效富集,并且对溶液中的钼基本上不吸附,树脂对铼的表观饱和吸附容量为92m g/g.     

高纯碱再生除盐系统阴树脂的优点

从阴树脂的再生度、周期制水量、碱耗、出水水质及经济性能比较等方面，对阴树脂用工业碱及高纯碱再生时的各项性能指标的试验结果进行了对比，高纯碱再生除盐系统阴树脂具有明显的优点，可推广使用。     

New modifications of poly(vinyl alcohol)s and their applications

Poly(vinyl alcohol) (PV-OH), prepared from poly(viny) acetate), is used widely in many industries. Various grades have been produced, with different degree of polymerization and degree of hydrolysis. Recently, novel modified (PV-OH)s with anion, cation, silanol or hydrophobic groups have been studied and developed. They have new properties in addition to those of ordinary PV-OH and have new applications. The methods of modification and the characteristics and some applications of the modified polymers are described.     

估算正负离子标准水合焓的一种简易方法

提出了一个估算正负离子标准水合焓ΔhHmθ(Mn±)的简易公式。ΔhHmθ(Mn±)的计算值与报道值相对误差在8%以内。用所建立的计算式预估了一些已知ΔhHmθ(Mn±)和ΔfHmθ(Mn±,aq,∞)或ΔfHmθ(Mn±,g)值的气态正负离子的标准生成焓ΔfHmθ(Mn±,g)和正负水合离子的标准生成焓ΔfHθm(Mn±,aq,∞)。