期刊
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
卷 15, 期 23, 页码 9281-9287出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/c3cp51132d
关键词
-
Newly synthesised halogen-free boron based ionic liquids (hf-BILs) composed of chelated orthoborate anions and phosphonium cations have hydrolytic stability, low melting point and outstanding wear and friction reducing properties. We report here the peculiarities of self-diffusion in one representative from this class, trihexyltetradecylphosphonium bis(mandelato)borate, [P-6,P-6,P-6,P-14][BMB], in the temperature range of its practical interest, 20-100 degrees C. NMR techniques demonstrated complicated diffusional behaviour - the ionic liquid can exist in one or two liquid phases. In the low-temperature range (20-50 degrees C), two phases coexist where the cations, [P-6,P-6,P-6,P-14], are contained mainly in the phase with slower diffusion coefficients while the anions, [BMB], are in the phase with faster diffusion coefficients. Cations have lower diffusion coefficients with a factor of 20 as compared with the anions, an effect which is caused by aggregation of cations into domains due to so-called hydrophobic interaction of their hydrocarbon chains. As the temperature rises above 60 degrees C, the two phases merge into one where both ions have equal diffusion coefficients. This is caused by thermal motion making the cation domains smaller in size and more easily interacting with anions. As a result, anions and cations diffuse in this high-temperature range as a pair.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据