کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
691988 | 1460450 | 2011 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Effects of cations and anions on transport properties in tetrafluoroborate-based ionic liquids
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
تکنولوژی و شیمی فرآیندی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The self-diffusion coefficient, diffusion radius, dissociation and association degree, and transport numbers of various cations (methylpyrrolidinium, 1-methyl-2-oxopyrrolidinium, methylpiperidinium, ethylmorpholinium, and methylmorpholinium) and tetrafluoroborate anion in ionic liquids are measured by observing 1H and 19F nuclei using the pulsed-field gradient spin-echo (PGSE) NMR technique at various temperatures. The self-diffusion coefficients determined for the cations and anions of ionic liquids by PGSE NMR method exhibit tetrafluoroborate anion have higher value than cations over a wide temperature range. The temperature dependence of the self-diffusion coefficient obeys the Vogel-Tamman-Fulcher (VTF) equation, and the VTF parameters were presented. The self-diffusion coefficient is analyzed in terms of the Stokes-Einstein equation and the Nernst-Einstein equation, the hydrodynamic radius of ILs is calculated from Stokes-Einstein equation and the molar conductivity (ÎNMR) calculated from the Nernst-Einstein equation is derived without considering ionic association. The dissociation degree of cations and anions range from 72 to 86% for [PipMe][BF4], [PyrMe][BF4], [MorMe][BF4], and [MorEt][BF4], whereas the ratio is 32% for [PyrOMe][BF4] at 303Â K, this difference can be explained by taking the ionic association into consideration for [PyrOMe][BF4].
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of the Taiwan Institute of Chemical Engineers - Volume 42, Issue 3, May 2011, Pages 513-522
Journal: Journal of the Taiwan Institute of Chemical Engineers - Volume 42, Issue 3, May 2011, Pages 513-522
نویسندگان
Tzi-Yi Wu, I-Wen Sun, Shr-Tusen Gung, Ming-Wei Lin, Bor-Kuan Chen, H. Paul Wang, Shyh-Gang Su,