ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Micellization of [1-(Ethoxycarbonyl)pentadecyl]trimethylammonium Bromide Studied by Conductometry and Potentiometry

F. Kopecký, M. Vojteková, J. Oremusová, and O. Greksáková

Department of Physical Chemistry, Faculty of Pharmacy, Comenius University, CS-832 32 Bratislava

Abstract: Micellization of the title compound, an antimicrobially active surfactant (Septonex), was studied in aqueous solution by conductometry and potentiometry with ion-selective electrodes. The effect of temperature and concentration of bromide anions (addition of KBr) upon critical micelle concentration (CMC) of the surfactant was determined, together with the degree of association of the formed cationic micelles with bromide counterions. The concentrations of the free quaternary ammonium cations and free bromide anions were determined in the micellar solution of the surfactant in the range from CMC (0.0008 mol dm^-3) to 0.1 mol dm^-3 . The results corroborate the formation of relatively small micelles at CMC, which grow continually with the increasing concentration of the surfactant, while the concentration of its free quaternary cations de creases.

Full paper in Portable Document Format: 471a55.pdf

Chemical Papers 47 (1) 55–59 (1993)