THERMODYNAMIC STUDY ON THE ADSORPTION AND MICELLE FORMATION OF LONG-CHAIN ALKYLTRIMETHYLAMMONIUM CHLORIDES

The surface tension of aqueous solutions of tetradecyl-trimethylammoni um chloride (TTAC) and decyltrimethylammonium chloride (DeTAC) were me asured as a function of temperature at concentrations below and above the critical micelle concentration under atmospheric pressure. The ent ropy and energy of adsorption from the monomeric state and from the mi cellar state and also the entropy and energy of micelle formation for TTAC were evaluated and compared with those of dodecyltrimethylammoniu m chloride (DTAC). The values of Delta(W)(M)s and Delta(W)(M)u for TTA C and DTAC systems show that the micelle formation is driven by the en tropy at low temperatures and by the energy at high temperatures.