PSEUDOPHASE SEPARATION MODEL FOR SURFACTANT ADSORPTION - ISOMERICALLY PURE SURFACTANTS
PSEUDOPHASE SEPARATION MODEL FOR SURFACTANT ADSORPTION - ISOMERICALLY PURE SURFACTANTS
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DOI：
10.1021/la00062a013
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发表时间：
1985-01-01
期刊：
影响因子：
3.9
通讯作者：
WADE, WH
中科院分区：
文献类型：
--
作者：
HARWELL, JH;HOSKINS, JC;WADE, WH
提出了一种新的表面活性剂吸附模型，它综合了疏水效应、表面活性剂表面聚集、表面非均匀性和表面活性剂浓度的贡献。新模型的基本假设是，表面活性剂聚集体形成在固/溶液界面上形成的局部surfacedbecause表面的异质性，这些局部聚集体，这被描绘为双层，并被称为admicelles，可以被视为一个假相，一种方法，已成功地应用于胶束形成的现象，虽然众所周知的和公认的局限性。该模型的发展包括一个相当详细的处理静电吸附的表面活性剂聚集体，包括所谓的离散电荷效应。在详细模型的开发之后，将简化模型应用于实验数据。结果表明，可调参数假设物理上可接受的值，这反过来表明，估计的分子参数，表面活性剂的分子结构的特性，代表合理的值。所得的表面电荷密度的累积分布实际上表征了在一定温度、pH和添加的电解质下的表面。
A new model of surfactant adsorption is presented which incorporates the contributions of the hydrophobic effect, surfactant surface aggregation, surface heterogeneities, and counterion concentrations. The basic assumptions of the new model are that surfactant aggregates forming at the solid/solution interface form locally on the surfacebecause of surface heterogeneity and that these local aggregates, which are pictured as bilayered and are called admicelles, can be treated as a pseudophase, an approach that has been applied successfully to the phenomenon of micelle formation, though with well-known and acknowledged limitations. Development of the model includes a rather detailed treatment of the electrostaticsof adsorbed surfactant aggregates including so-called discreteness of charge effects. After development of a detailed model, a simplified model is applied to experimental data. It is shown that the adjustable parameters assume physically acceptable values which in turn indicates that the estimated molecular parameters, characteristic of the molecularstructure of the surfactant, represent reasonable values. The resulting cumulative distribution of the surface charge density in effect characterizes the surface at a certain temperature, pH, and added elebtrolyte.