Interfacial Transport Processes at Oil-Surfactant-Water Interfaces

该项目涉及一个非常重要的主题，在许多 工业分离和纯化操作，即，的 物质通过表面负载界面的传输 分离两个宏观流体相。 在胶体 水平，了解动态过程， 微乳液体系受界面 表面活性剂层的结构可以导致更好的 机械描述的这种不同的现象，例如， 相变、乳液稳定性、细胞内转运和 反胶束模拟膜介质与生物催化 系统. 为了更好地了解这些影响因素， 和其他界面传输过程，PI计划（i） 研究可压缩和不可压缩的作用 表面活性剂层在延缓溶质跨膜转运中的作用 分离两个体相的界面，（ii）检查 反胶束形成和聚结动力学. （3）实验研究这些接口的速率， 探针分子与它们的运输通过的缔合， 油包水中高度弯曲的表面活性剂界面 微乳液，（iv）开发一个理论模型， 溶质分子与表面活性剂界面的相互作用， 胶束的形成和破坏速率 接口. 的热松弛和结构松弛行为 还将涉及微乳液体系。 为此， 研究所将采用两种互补的实验技术。 设计了一种独特的扩散池， 引入浓度的阶跃变化， 将溶质转移到非常接近界面的位置， 引起界面本身的任何干扰。 碘激光温度跃变（ILTJ）方法， 技术，将用于识别和量化 界面扩散时间尺度特征 微乳液体系

The project deals with a topic of great importance in many industrial separation and purification operations, i.e., the transport of materials across surfactant-laden interfaces separating two macroscopic fluid phases. At the colloidal level, an understanding of the dynamic processes in microemulsions systems as affected by the interfacial structure of the surfactant layer can lead to better mechanistic descriptions of such diverse phenomena as e.g., phase transitions, emulsion stability, transport in cells and membrane mimetic media, and biocatalysis in reversed micellar systems. To better understand the factors influencing these and other interfacial transport processes, the PIs plan to (i) investigate the role of compressible and incompressible surfactant layers in retarding the transport of solutes across interfaces separating two bulk phase, (ii) examine the kinetics of formation and coalescence of reversed micelles at such interfaces, and (iii) study experimentally the rate of association of probe molecules with their transport through, highly curved surfactant interfaces in water-in-oil microemulsion, (iv) develop a theoretical model for the interaction of solute molecules with the surfactant interface, and of the formation and destruction rates of micelles at the interface. The thermal and structural relaxation behavior of microemulsion systems will also be addressed. To these ends, the PIs will employ two complementary experimental techniques. A unique diffusion cell has been designed which enables the introduction of a step change in concentration of the transferring solute very close to the interface without causing any disturbance of the interface itself. The Iodine Laser Temperature Jump (ILTJ) method, a relaxation technique, will be used to identify and quantify the interfacial diffusion time scales characteristic of the microemulsion systems.