Vlachy, Nina and Drechsler, Markus and Verbavatz, Jean-Marc and Touraud, Didier and Kunz, Werner (2008) Role of the surfactant headgroup on the counterion specificity in the micelle-to-vesicle transition through salt addition. JOURNAL OF COLLOID AND INTERFACE SCIENCE, 319 (2). pp. 542-548. ISSN 0021-9797,
Full text not available from this repository. (Request a copy)Abstract
A transition from micelles to vesicles is reported when salts are added to a catanionic micellar solution composed of sodium dodecylcarboxylate (SL) and dodecyltrimethylammonium bromide (DTAB), with an excess of SL. The counterion binding and increase in aggregate size was monitored by mass spectrometry, rheology and dynamic light scattering measurements, whereas the vesicles were characterized by freeze-fracture and cryo-transmission microscopy experiments. The effect of counterions on the formation of vesicles was studied and compared to a previously studied catanionic system with a sulfate head group, SDS/DTAB. As in the latter case, no anion specificity was found, while large differences in the hydrodynamic radii of the formed objects were observed, when the cation of the added salt was varied. A classification of the cations could be made according to their ability to increase the measured hydrodynamic radii. It is observed that, if the sulfate headgroup of the anionic surfactant is replaced by a carboxylic group, the order of the ions is reversed, i.e. it follows the reversed Hofmeister series. Different morphologies are observed as the ionic strength of the system is increased. The aggregates are analogous to those found in the SDS/DTAB system. (C) 2007 Elsevier Inc. All rights reserved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | CONVERGENT FUNCTIONAL-GROUPS; ALKALI METAL CATIONS; DODECYL-SULFATE; SODIUM IODATE; ION-BINDING; HYDRATION; ACID; CARBOXYLATE; SELECTIVITY; INTERFACES; specific-ion effects; micelle-to-vesicle transition; catanionic surfactant mixtures |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry VI - Physical Chemistry (Solution Chemistry) > Prof. Dr. Werner Kunz |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 05 Nov 2020 11:12 |
| Last Modified: | 05 Nov 2020 11:12 |
| URI: | https://pred.uni-regensburg.de/id/eprint/31176 |
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