Self-aggregation of alkyltrimethylammonium bromides (C10-, C12-, C14-, and C16TAB) and their binary mixtures in aqueous medium: a critical and comprehensive assessment of interfacial behavior and bulk properties with reference to two types of micelle form
Self-aggregation of alkyltrimethylammonium bromides (C10-, C12-, C14-, and C16TAB) and their binary mixtures in aqueous medium: a critical and comprehensive assessment of interfacial behavior and bulk properties with reference to two types of micelle form
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DOI：
10.1021/la051509g
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发表时间：
2005-10
期刊：
影响因子：
--
通讯作者：
G. Ray;I. Chakraborty;S. Ghosh;S. P. Moulik;R. Palepu
中科院分区：
文献类型：
--
作者：
G. Ray;I. Chakraborty;S. Ghosh;S. P. Moulik;R. Palepu
使用张力测定、电导测定、荧光测定、粘度测定和量热测定方法研究了纯和混合烷基三甲基溴化铵（ATAB：C10-、C12-、C14- 和 C16TAB）的详细界面吸附和胶束化行为。测定了临界胶束浓度（CMC）、吸附和胶束化的热力学、抗衡离子结合、聚集数和胶束极性。据观察，所研究的 C10-C12TAB、C10-C14TAB 和 C10-C16TAB 的 1:1 摩尔混合物以及不同摩尔比的 C12-C14TAB 和 C12-C16TAB 混合物产生了两种 CMC，并得到电导法、量热法和粘度法的支持。与第一个胶束相比，第二个胶束凝聚了更多的抗衡离子并产生了更高的聚集数，但它们的内部极性状态相同。评估并比较了表面过量、CMC 处 ATAB 的最小面积和吉布斯吸附自由能。根据 Clint 和 Rubingh 的形式主义测试了溶液中形成的混合胶束的理想/非理想状态；发现混合系统经历中度至弱的协同相互作用。破译并讨论了末端甲基、中间亚甲基和亲水性四甲基铵基团对胶束化过程的标准吉布斯自由能、焓和熵的贡献。
The detailed interfacial adsorption and micellization behavior of pure and mixed alkyltrimethylammonium bromides (ATABs: C10-, C12-, C14-, and C16TAB) were studied using tensiometric, conductometric, fluorimetric, viscometric, and calorimetric methods. The critical micellar concentration (CMC), thermodynamics of adsorption and micellization, counterion binding, aggregation number, and micellar polarity were determined. It was observed that the studied 1:1 molar mixtures of C10-C12TAB, C10-C14TAB, and C10-C16TAB, and the mixtures C12-C14TAB and C12-C16TAB at different mole ratios produced two CMCs that were supported by the conductometric, calorimetric and viscometric methods. Compared to the first micelle, the second micelle condensed more counterions and produced a higher aggregation number, but their interior polarity states were the same. The surface excess, area minimum of the ATABs at the CMC and Gibbs free energy of adsorption were evaluated and compared. The ideality/nonideality states of the mixed micelles formed in solution were tested in the light of Clint and Rubingh's formalisms; the mixed systems were found to undergo moderate to weak synergistic interaction. The contributions of the terminal methyl group, the intermediate methylene groups, and the hydrophilic tetramethylammonium group toward the standard Gibbs free energy, enthalpy, and entropy of the micellization processes were deciphered and discussed.