The aggregation in dodecyltrimethylammonium hydroxide aqueous solutions

Abstract

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)×10-4 mol · dm-3 the surface excess becomes zero, at CT=(1.300±0.041)×10-3 mol · dm-3 small aggregates from, which grow with concentration. At CT=(1.108±0.010)×10-2 mol · dm-3 true micelles form (CMC) and at (3.02±0.28)×10-2 mol · dm-3 the structure of micelles probably changes affecting their properties. The DTAOH micelles are highly ionized (α=0.8) at the CMC, and decreases to reach very small values when the total concentration increases. © 1995 Steinkopff Verlag.