ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 43, Number 6
JKCSEZ 43(6)
December 20, 1999 

The critical micelle concentration (CMC) and the counterion binding constant ( β) at the CMC of the mixtures of Dodecylpyridinium chloride (DPC) and Tetradecyltrimethylammonium bromide (TTAB) have been determined from the concentration dependence of electrical conductance at various temperatures from 4 ℃ to 36 ℃. Thermodynamic parameters (△Cp, △Gm, △Hm, and △Sm), associated with the micelle formation of DPC/TTAB mixtures, have been estimated from the temperature dependence of CMC and βvalues. The measured values of △Cp and △Gm are negative but the values of △Sm, are positive in the whole measured temperature region. The values of △Hm are positive at low temperature region and negative at high temperature region. The results show that all of the thermodynamic parameters are dependent on temperature and mole fraction of DPC(αDPC).