Thomas R K, Penfold J
Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK.
Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK; ISIS Facility, Rutherford Appleton Laboratory, STFC, Chilton, Didcot, UK.
Adv Colloid Interface Sci. 2023 Sep;319:102984. doi: 10.1016/j.cis.2023.102984. Epub 2023 Aug 18.
The nature of surfactant mixing at interfaces and in bulk solution is key to understanding and optimising the diverse industrial, technological, biological and domestic applications of surfactants. The use of neutron reflectivity, NR, and small angle neutron scattering, SANS, in combination with isotopic substitution, has transformed the ability to quantify and understand the nature of surfactant mixing at the air-water interface and in self-assembled aggregates or micelles in solution. The accuracy and scope of the compositional data from NR, the application of recent developments in the pseudo phase approximation, PPA, and the availability of complementary critical micelle concentration, cmc, and micelle composition data, enables a detailed thermodynamical quantification of the mixing properties to be made. The NR data in particular, and the SANS data to a lesser extent, provides constraints on the thermodynamical analysis which reveals important properties and trends about the bulk phase which are not available from the analysis of data such as the variation in the cmc alone. The importance and impact of this approach is illustrated with an overview of a range of mixed surfactant examples from the recent literature, and which encompass mixtures with different degrees of departure from ideality.
表面活性剂在界面和本体溶液中的混合性质是理解和优化表面活性剂在各种工业、技术、生物及家庭应用中的关键。将中子反射率（NR）和小角中子散射（SANS）与同位素取代相结合，已改变了定量和理解表面活性剂在气-水界面以及溶液中自组装聚集体或胶束内混合性质的能力。NR所得组成数据的准确性和范围、伪相近似（PPA）近期发展的应用以及互补的临界胶束浓度（cmc）和胶束组成数据的可得性，使得能够对混合性质进行详细的热力学定量分析。特别是NR数据，以及在较小程度上的SANS数据，为热力学分析提供了限制条件，揭示了关于本体相的重要性质和趋势，而这些是仅通过分析诸如cmc变化等数据无法获得的。通过对近期文献中一系列混合表面活性剂实例的概述来说明这种方法的重要性和影响，这些实例涵盖了与理想情况有不同程度偏差的混合物。
