کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
638753 | 1456182 | 2007 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Nitrate and chloride transport through a smart membrane
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
تصفیه و جداسازی
پیش نمایش صفحه اول مقاله
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چکیده انگلیسی
To develop membranes having ionic selective properties under control of external stimuli is a challenge of the membrane and material scientific community. Conducting polymers swell and shrink under electrochemical control, so they are good candidates to prepare such smart membranes. The ionic transport through a new free-standing polypyrrole film working as a membrane in a diffusion cell was studied. The driving forces were transversal electric fields or concentration gradients across the film. The obtained ionic conductivity was dependent on both the electrolyte nature and concentration, as well as on the oxidation degree of the film, which was controlled by the applied external electric potential. Reverse and continuous changes of up to one order of magnitude on the transversal ionic conductivity are obtained when the membrane is in stationary oxidation states attained by polarisations at a constant potential in the range between â0.6 V and +0.4 V, respectively. A prevalent conductivity of anions (tâ = 0.94) was obtained from Donnan potential measurements. The experimental results indicate that the oxidised film behaves as a nanoporous membrane highly permeable to nitrate ions, while the rejection of these ions is very high in the reduced film. The free-standing polypyrrole film works then as a smart membrane selective to nitrate ions under concentration gradient.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Membrane Science - Volume 290, Issues 1â2, 1 March 2007, Pages 241-249
Journal: Journal of Membrane Science - Volume 290, Issues 1â2, 1 March 2007, Pages 241-249
نویسندگان
MarÃa J. Ariza, Toribio F. Otero,