ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 38, Number 8
JKCSEZ 38(8)
April 20, 1994 

The critical micelle concentration(CMC) and the counterion binding constant(β) at the CMC of cetyltrimethylammonium bromide(CTAB) in a series of aqueous solutions containing medium chain-length n-alcohols(Propanol, Butanol, Pentanol and Hexanol) have been determined from the concentration dependence of electrical conductance at serveral temperature from 17℃ to 41℃. Thermodynamic parameters (△Gom, △Hom, △Som, △Cp) associated with micelle formation of CTAB have been also estimated from the temperature dependence of CMC and β values, and the significance of these parameters and their relation to the theory of micelle formation have been considered. The results show that an enthalpy-entropy compensation effect is usually observed for the micellization of CTAB. The effects of n-alcohols on the micellar properties (CMC and β) of CTAB solutions have been also investigated. The addition of n-alcohol to the CTAB solution in a small quantity decreases the CMC value and the counterion binding constant (β) at the CMC, but the addition of n-alcohol in an excessive quantity increases the CMC values on the conterary. These results have been explained in terms of the effect of the micelle-solubilized alcohol on the micellar surface charge density.