EFFECT OF THE POLAR HEAD IN THE MICELLIZATION OF 2-(DECYLDIMETHYLAMMONIO)ALKANOL BROMIDES IN AQUEOUS-SOLUTIONS

The micellization of two heteropolar surfactants, 2-(decyldimethylammonio)ethanol bromide and 2-(decyldimethylammonio)butanol bromide, in aqueous solutions has been detected by conductometry and light scattering. The latter technique was used to characterize the size, the mass, and hence the aggregation number of the micelles formed. The comparison between micelles formed from two amphiphile molecules containing differently incorporated alcohols in the polar head shows a steric hindrance effect of the alcohol on the critical micellar concentration (cmc), the aggregation number, and the shape of the micelles. Furthermore, the comparison between the present study and a previous study of decyltrimethylammonium bromide shows that the alcohol function has effects on the micellization similar to those obtained when alcohols are simply added to other surfactant solutions in order to form mixed micelles. © 1990 American Chemical Society.