The Aggregation in dodecyltrimethylammonium hydroxide aqueous solutions

SCHULZ,PC, MORINI,M, MINARDI,R, PUIG,J.E

COLLOID AND POLYMER SCIENCE

Año: 1995 vol. 273 p. 959 - 966

0303-402X

The aggregation of dodecyltrimethylammonium hydroxide (DTAOH) aqueous solutions has been studied by several methods. It is stepwise and four critical points were found. At CT = (2.51 + 0.10) xl0-4 mol-dm-'3 the surface excess becomes zero, at CT = (1.300 + 0.041) x 10-3 mol-dm-3 small aggregates form, which grow with concentration. At CT = (1.108 ± 0.010) x 10-2 mol-dm-3 truc micelles form (CMC) and at  (3.02 ± 0.28) x 10 - 2 mol • dm -3 the structure of micelles probably changes affecting their properties. The DTAOH micelles are highly ionized (alfa = 0.8) at the CMC, and decreases to reach very small valúes when the total concentration increases.