Effects of 1-Butanol on the Micellization of Dodecyltrimethylammonium Bromide at Elevated Temperatures

摘要

Enthalpies of dilution of 1-butanol (BuOH) have been measured from 323 to 448 K (50/degree/ to 175/degree/C) and the enthalpies of dilution of dodecyltrimethylammonium bromide (DDTAB) in 0.2 and 0.6 m (1.5 and 4.5% by weight) aqueous BuOH were also measured at 373 and at 448 K. The relative partial molar enthalpies of BuOH which are endothermic at lower temperatures approach zero at 400 K, where the sign reverses. This trend is interpreted as showing that there is less difference between BuOH and water at elevated temperatures. The presence of this alcohol causes the critical micelle concentration (CMC) of DDTAB to be lowered at 373 K, but has no effect on it at 448 K. The alcohol has less effect on the CMC and the sharpness of micellization than does an equal molal concentration of electrolyte. 13 refs., 7 figs., 16 tabs. (ERA citation 14:014307)