کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9675891 | 1454109 | 2005 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Micellar-catalyzed alkaline hydrolysis of 2,4-dinitrochlorobenzene in a cationic gemini surfactant
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
شیمی کلوئیدی و سطحی
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چکیده انگلیسی
Micellar-catalyzed alkaline hydrolysis of 2,4-dinitrochlorobenzene (DNCB) in the presence of a conventional cationic surfactant CTAB or a cationic gemini surfactant 1,2-ethane bis(dimethyldodecylammonium bromide) (12-2-12) were studied spectrophotometrically at 25 °C. It was found that both CTAB and 12-2-12 micelles accelerated the alkaline hydrolysis of DNCB, and the binding constant of the substrate to the micelle, KS, for 12-2-12 (KS = 310 Mâ1) was larger than that for CTAB (85 Mâ1), which suggested that DNCB molecules bound with gemini micelles more easily than with CTAB. However, the second-order rate constant in micellar pseudophase (kM = 1.22 Ã 10â3 sâ1) for 12-2-12 was lower than kM for CTAB (4.01 Ã 10â3 sâ1) because the substrate may enter the interior of the 12-2-12 micelles. It was found also that 12-2-12 had a similar catalysis mechanism to CTAB when the concentration of 12-2-12 was relatively low (ca. <5 mM). However, above this concentration, higher microviscosity and significant increases in aggregation number and micelle size with increased surfactant concentration may remarkably influence the hydrolysis reaction.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Colloids and Surfaces A: Physicochemical and Engineering Aspects - Volume 260, Issues 1â3, 15 June 2005, Pages 251-254
Journal: Colloids and Surfaces A: Physicochemical and Engineering Aspects - Volume 260, Issues 1â3, 15 June 2005, Pages 251-254
نویسندگان
Ling-Guang Qiu, An-Jian Xie, Yu-Hua Shen,