کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
592605 1453912 2014 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Kinetic study of silica dissolution in aqueous solutions of aromatic organic electrolytes
ترجمه فارسی عنوان
مطالعه سینتیکی انحلال سیلیکا در محلول های آبی الکترولیت های ارگانیک معطر
کلمات کلیدی
میزان حل شدن سیلیس، تجزیه و تحلیل سینتیک، نرخ ثابت، الکترولیت آلی، جذب
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
چکیده انگلیسی


• Rate constant in organic electrolyte solutions 18–30 times larger than in water.
• Compared with water, organic electrolytes increase the dissolution rate of silica.
• Compared with NaCl, organic electrolytes decrease the dissolution rate of silica.
• Pure organic anions decrease the dissolution rate of silica by adsorbed on surface.

To evaluate the effect of organic compounds on the dissolution rate of amorphous silica, the dissolution of amorphous silica in pure water and in organic electrolyte solutions were investigated at room temperature at pH 6. Based on the kinetic analyses, the dissolution rate constants of amorphous silica in the organic electrolyte solutions were 18–30 times larger than in pure water but less than those in the NaCl solution, which contained the same Na+ concentration as the organic electrolyte solution. The order of dissolution rate constants was NNaCl > Ntiron > Nphthalate > Nsalicylate > Nwater. In these experiments, the dried samples were analyzed by FT-IR, and the results indicated that all of the organic composition was adsorbed on the surface of the silica. Compared with pure water, the cations in the organic electrolyte solution were a dominant factor in increasing the dissolution rate of silica. However, compared with NaCl, the dissolution rate of silica decreased in the aromatic organic electrolyte solution due to the adsorption of the organic electrolytes on the surface of the silica as well as to a decrease in the exposed surface. In fact, organic anions containing in the organic electrolytes are retarding the dissolution rate of silica.

The silicic acid concentration in the organic electrolyte solution was larger than in the water, but less than in the NaCl solution. The facts suggest that organic electrolyte accelerates the dissolution rate of silica compared with water, but retard the dissolution rate of silica compared with NaCl. In fact, organic anions containing in the organic electrolytes are retarding the dissolution rate of silica. The concentration of silicic acid with time varies in the different kinds of solutions. The concentration of sodium ion in each solution is same (0.2 mol L−1).Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Colloids and Surfaces A: Physicochemical and Engineering Aspects - Volume 461, 5 November 2014, Pages 220–224
نویسندگان
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