PRE Scientist Supplement: Molecular Interactions in Binary Mixtures of Surfactants

研究综述：这是对两种表面活性剂混合物表现出协同作用的条件的研究，即表现出比单独使用的表面活性剂更好的性能。研究的重点有三个方面：(1)协同作用是动态表面张力。在这里，首席调查员正在调查表面张力降低的速度。(2)负协同效应。这是最近观察到的一种新现象，在类似条件下，混合物表现出的界面性质比单独的表面活性剂要小得多。(3)计算作为协同作用基础的分子相互作用参数的新方程。通过测量单个表面活性剂及其混合物的各种界面性质(表面和界面张力、接触角、发泡)来研究协同作用。动态表面张力将用他们的新装置进行研究。意义重大。表面活性剂用于大量的工业过程和消费品，通常是含有至少两种表面活性成分的混合物。这项研究将为选择能够优化其在这些产品和工艺中的性能的表面活性剂对提供指导。根据单个表面活性剂本身的相关性质和一个易于测量的相互作用参数的值，这种处理方法允许人们预测：(1)当两种表面活性剂混合时，是否会发生协同作用，如果是，(2)将显示出最大协同作用的两种表面活性剂的比例，以及(3)该点上体系的性质。这意味着我们现在有了一种强大的新工具，可以在许多工业流程和产品中提高性能。

Research Summary: This is an investigation of conditions under which mixtures of two surfactants exhibit synergism, i.e., show properties that are better than those of the individual surfactants by themselves. There are three foci of the research: (1) Synergism is dynamic surface tension. Here the principal investigator is investigating the rate at which surface tensions are reduced. (2) Negative synergism. This is a novel phenomenon recently observed where the mixture demonstrates an interfacial property to a smaller extent than the individual surfactants by themselves under similar conditions. (3) New equations for calculating the molecular interaction parameters that are the basis for synergism. Synergism is investigated by measuring various interfacial properties (surface and interfacial tension, contact angle, foaming) of the individual surfactants and their mixtures. Dynamic surface tension will be investigated with their new apparatus. Significance. Surfactants, which are used in a vast number of industrial processes and consumer items, are generally mixtures containing at least two surface-active components. This research will provide guidelines for the selection of surfactant pairs that can optimize their performance in those products and processes. From the relevant properties of the individual surfactants by themselves and the value of an easily-measured interaction parameter, this treatment allows one to predict: (1) whether a synergistic interaction will occur when two surfactants are mixed and, if so, (2) the ratio of the two that will show maximum synergism, and (3) the properties of the system at that point. This means that we now have a powerful, new tool for improving performance in a multitude of industrial processes and products.