کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
613310 880719 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Counterion specificity in the phase behavior of tetradecyldimethylamine oxides at different degrees of protonation
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Counterion specificity in the phase behavior of tetradecyldimethylamine oxides at different degrees of protonation
چکیده انگلیسی

Effects of counterion species on the aggregate structure of tetradecyldimethylamine oxide (C14DMAO) accompanying the protonation were examined by viscoelastic properties and phase behavior observations. Different extents of the synergetic behavior between protonated and non-protonated amine oxides were observed depending on the counterion species, which follow the Hofmeister, or the lyotropic, series. The efficacy of monovalent anions with respect to the increasing the surfactant packing parameter was as follows: salicylate > perchlorate > nitrate > bromide > chloride, formate. Vesicle formation was found in the case of salicylate and perchlorate anions and elongation of rodlike micelles was observed for nitrate, bromide, sulfate, tartronate and tartrate anions but little effects in the case of chloride and formate anions. The observed ionic specificity is well correlated with the free energy of hydration of counterions.

Note that a 20% protonation with HCl on a 100 mM C14DMAO solution leads to a decrease of the viscosity while the same protonation with HSCN leads to an increase of the viscosity by almost a factor of 1000.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Colloid and Interface Science - Volume 299, Issue 1, 1 July 2006, Pages 388–395
نویسندگان
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