کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
644312 884433 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Changes in the electrochemical characteristics of a bipolar membrane immersed in high concentration of alkaline solutions
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی تصفیه و جداسازی
پیش نمایش صفحه اول مقاله
Changes in the electrochemical characteristics of a bipolar membrane immersed in high concentration of alkaline solutions
چکیده انگلیسی

The chemical stability of a commercial bipolar membrane (Neosepta BP-1, Tokuyama Co.) was examined after immersing it in concentrated NaOH solution at different temperatures, for various periods of time. The physical and electrochemical changes in the alkali-treated membranes were measured and the effects on membrane performance were investigated thoroughly by analyzing FTIR spectra, water-splitting capabilities, and current–voltage curves. The FTIR spectra showed that the quaternary ammonium groups in the anion-exchange layer (AEL) of the BP-1 membrane decomposed via the Hofmann reaction when the membranes were immersed in 5.0 M NaOH at over 40 °C, and in 2.5 M NaOH at 50 °C. In addition, the water-splitting capability of the membranes that had undergone structural change decreased. This was attributed to decreased Donnan exclusion resulting from the decomposition of functional groups in the AEL of the BP-1 membrane. The results of the current–voltage experiments were similar to those of FTIR and water-splitting capability studies. The electric resistance for water dissociation increased when the structure of the AEL changed in concentrated alkaline solution, and at high temperature. We concluded that a more stable bipolar membrane anion-exchange layer is required for use in concentrated alkaline solutions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Separation and Purification Technology - Volume 48, Issue 1, February 2006, Pages 16–23
نویسندگان
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