文献类型：期刊文献

英文题名：Densities, Conductivities, and Aggregation Numbers of Aqueous Solutions of Quaternary Ammonium Surfactants with Hydroxyethyl Substituents in the Headgroups

作者：Zhang, Zhiguo[1];Wang, Huanhuan[1];Shen, Weiguo[1,2]

机构：[1]E China Univ Sci & Technol, Sch Chem & Mol Engn, Shanghai 200237, Peoples R China;[2]Lanzhou Univ, Dept Chem, Lanzhou 730000, Gansu, Peoples R China

年份：2013

卷号：58

期号：8

起止页码：2326

外文期刊名：JOURNAL OF CHEMICAL AND ENGINEERING DATA

收录：;EI(收录号：20133416633295);WOS:【SCI-EXPANDED(收录号:WOS:000323081900027)】；

基金：This work was supported by the National Natural Science Foundation of China (Projects 20973061 and 21173080).

语种：英文

外文关键词：Fluorescence quenching - Critical micelle concentration - Micelles - Cationic surfactants - Volumetric analysis - Dyes - Solutions

摘要：The aggregation behaviors of two cationic surfactants, namely, N-dodecyl-N-2-hydroxyethyl-N,N-dimethyl ammonium bromide (C(12)HDAB) and N-dodecyl-N,N-2-dihydroxyethyl-N-methyl ammonium bromide (C(12)DHAB), were studied by measurements of density, conductivity, and steady-state fluorescence quenching. The aggregation number, the volumetric properties, and the standard Gibbs energy (Delta G(mic)(0)) of micellization were obtained, and the surface area (A(mic)) of the surfactant headgroups and the radius (r) of the micelles were estimated. It was found that substituting the methyl group with the hydroxyethyl group in the head of the surfactant led to the increase of the volume change of micellization and the decreases of the critical micelle concentration, association degree of the counterion, and the value of Delta G(mic)(0), while the aggregation number of those surfactants in aqueous solutions was little affected by introducing the hydroxyethyl group. It was also found that the values of A(mic) and r increase with the hydroxyethyl group.