Interpretation of conductivity results from 5 to 45 degrees C on three micellar systems below and above the CMC.
Electrical conductivity has been used at different temperatures to study three micellar systems: tetradecyltrimethylammonium chloride (TTACl), dodecyltrimethylammonium chloride (DTACl), and decyltrimethylammonium chloride (DeTACl). A phenomenon of premicellization is observed for DeTACl and DTACl below the critical micellar concentration (CMC). Association constants are introduced in the MSA-transport theory to correctly reproduce experimental conductivity and also calculate the effective charge of the micelles and their degree of dissociation. Various mechanisms are considered to explain premicellization. The formation of a neutral pair followed by an association involving two monomers and a counterion appears to be the most probable first step in the premicellization process.
Laboratoire Liquides loniques et Interfaces Chargées, Université Pierre et Marie Curie-Paris 6, UMR CNRS 7612, case courrier 51, 4 place Jussieu F-75252 Paris Cedex 05, France. gaelle.roger@upmc.fr
G M
GM
Roger
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S
Durand-Vidal
O
O
Bernard
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P
Turq
T M
TM
Perger
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M
Bester-Rogac
D008823:Micelles; D013696:Temperature; D013816:Thermodynamics
D008823:Micelles