鉴于典型的增强型PEM(Gore-SELECT®)在寻求新的替代品方面的重要作用,我们首次证明了具有孔填充能力的半结晶聚(醚醚酮)膜的强大功能,这是迄今为止最多的。用于直接甲醇燃料电池的甲醇阻隔的有效聚合物材料。聚(醚醚酮)基质的稳定结构有助于降低溶胀行为,从而限制了甲醇在高浓度甲醇溶液中跨膜的渗透。磷钨酸盐离子液体的无机改性剂赋予多孔质子传导质子的能力。为了改善磷钨酸根离子液体和惰性基质的相互作用,通过聚多巴胺和聚乙烯亚胺的共沉积反应对多孔基质进行预改性。聚多巴胺和聚乙烯亚胺在基质中的固定改性剂可降低离子液体和磷钨酸盐的泄漏。研发的复合膜可实现高达0.11 S cm的质子传导性增强在80°C时为-1,得益于磷钨酸离子液体的优异质子传导能力,并表现出极低的甲醇穿越(4.5×10 -7 cm 2 s -1)和良好的选择性(12.22×10 4 S s cm)-3)相比,这些的Nafion 1
An Acidity Scale of 1,3-Dialkylimidazolium Salts in Dimethyl Sulfoxide Solution
作者:Yuan Chu、Hui Deng、Jin-Pei Cheng
DOI:10.1021/jo070973i
日期:2007.9.1
Equilibrium acidities of 16 1,3-dialkylimidazolium-type ionic liquid (IL) molecules (1−16) were systematically measured by the overlapping indicator method at 25 °C in dimethylsulfoxide (DMSO) solution. The pKa values were observed to range from 23.4 for IL 12 to 19.7 for IL 6 (Tables 1 and 2), responding mainly to structural variations on the cation moiety. Excellent agreement between the spectrophotometrically
16 1,3-二烷基型离子液体(IL)的分子(平衡酸度1 - 16)进行了系统的通过重叠指示剂法在25℃下在二甲亚砜(DMSO)溶液中测定的。观察到p K a值范围从IL 12的23.4到IL 6的19.7 (表1和2),主要是对阳离子部分的结构变化作出反应。用分光光度法测定的p K a与由NMR滴定得出的1,3,4,5-四甲基咪唑双(三氟甲磺酰基)酰亚胺(12)的吻合度与获得的p K的紧密匹配性文献中所报道数据的实际值提供了对本工作的酸度测量的可信度。讨论了咪唑环上的取代基效应和抗衡离子对离子液体酸度的影响。
The impact of sulfur functionalisation on nitrogen-based ionic liquid cations
作者:Ana R. Santos、Magnus W. D. Hanson-Heine、Nicholas A. Besley、Peter Licence
DOI:10.1039/c8cc05515g
日期:——
the impact of sulfur containing substituents on the electronic structure of a series of N-based cations, all with a common anion, [NTf2]−. The experiments reveal complexity and perturbation of delocalised systems which cannot be easily interpreted by NMR and XPS alone, DFT provides critical insight into bonding and underpins the assignment of spectra and development of deconstruction models for each
Direct methylation and trifluoroethylation of imidazole and pyridine derivatives
作者:Jie Zhang、George Robert Martin、Darryl D. DesMarteau
DOI:10.1039/b307230d
日期:——
Direct methylation or trifluoroethylation of imidazole and pyridine derivatives using N-methyl bis((perfluoroalkyl)sulfonyl)imides or trifluoroethyl phenyliodonium bis((trifluoromethyl)sulfonyl)imide affords high yields of the corresponding salts. This methodology provides a simple route to a variety of room temperature ionic liquids (RTILs).
r2GX-ray(r) - 1} for these ionic liquids. It was supposed that the NH · · · O hydrogenbond causes the cation–anion orientation variations. To obtain further insight into the hydrogenbond in the PIL, MD simulations performed and agreed well with the experiments. According to spatial distribution functions (SDF) for the three ionic liquids, the O atom of TFSA− prefers the NH hydrogen of the imidazolium that