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论文类型：期刊论文

发表时间：2010-10-01

发表刊物：JOURNAL OF SOLUTION CHEMISTRY

收录刊物：SCIE、Scopus

卷号：39

期号：10

页面范围：1501-1508

ISSN号：0095-9782

关键字：Thermodynamic properties; Critical micelle concentration; CTAC; EG

摘要：To understand the thermodynamic characteristics of cationic surfactants in binary mixtures, the aggregation behavior of hexadecyltrimethylammonium chloride (CTAC) has been investigated in ethylene glycol (EG) + water solvent mixtures at different temperatures and EG to water ratios. The critical micelle concentration (CMC) and degree of counter ion bonding (beta) were calculated from electrical conductivity measurements. An equilibrium model for micelle formation was applied to obtain the thermodynamic parameters for micellization, including the standard Gibbs energies of micellization (Delta G degrees(mic)), standard enthalpies of micelle formation (Delta H degrees(mic)) and standard entropies of micellization (Delta S degrees(mic)). Our results show that Delta G degrees(mic) is always negative and slightly dependent on temperature. The process of micellization is entropy driven in pure water, whereas in EG + water mixtures the micellization is enthalpy driven.