کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9765829 | 1499371 | 2005 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Intermolecular interaction between the pendant chain of perfluorinated ionomer and methanol
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی معدنی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
A comparison between water and methanol on the interaction with a pendant chain model for perfluorosulfonic ionomers (PFI), CF3OCF2CF2SO3â, was made by using molecular orbital calculation. Intermolecular interaction energy (Eint) of the most stable complex for CF3OCF2CF2SO3â + CH3OH, where methanol associates with sulfonic acid group, is â10.38 kcal/mol at the MP2/aug-cc-pVDZ//B3LYP/6-31 + G* level, and it is almost the same with that of CF3OCF2CF2SO3â + H2O complex (â10.58 kcal/mol). Since an association of methanol to the sulfonic acid group is quite advantageous in energy, it is expected that, similarly to water, methanol would likely populate around the acidic site. On the contrary, according to a systematic Eint analysis for 500 random configurations, dissimilar distribution of Eint was observed for methanol compared with water. This is because methyl group substitution reduces oxygen surface area and causes more attractive dispersion energy with CF3OCF2CF2SO3â by about 1.0 kcal/mol on average compared with water. To see how the difference in the interaction energy affects the solvation structure of methanol and water to the PFI, molecular dynamics simulations of a CF3OCF2CF2SO3â molecule in methanol solutions have also been carried out at the methanol concentration of 10-90 mol%. Consequently, water probably associates with the sulfonic acid group-pushing methanol close to hydrophobic sites. It was also observed that methanol molecule tends to point its methyl group toward the solute at hydrophobic sites. These results demonstrated that methanol should locate in the vicinity of hydrophobic site compared with water due to methyl group substitution.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Fluorine Chemistry - Volume 126, Issues 9â10, October 2005, Pages 1312-1320
Journal: Journal of Fluorine Chemistry - Volume 126, Issues 9â10, October 2005, Pages 1312-1320
نویسندگان
Shingo Urata, Jun Irisawa, Akira Takada, Seiji Tsuzuki, Wataru Shinoda, Masuhiro Mikami,