Adosrption and Surface Tension of Surfactant/Lipid/Protein Mixtures: Direct Probing of Surface Layers & Theoretical Modeling

CTS-9615649 Elias Frances Purdue University 研究了几种表面活性剂和表面活性剂/蛋白质混合物的水溶液体系的表面张力，以了解不同尺寸、表面活性或分子特征的组分如何竞争空气/水表面。 提出了混合物平衡吸附和动态吸附的新模型。 为了测试模型，使用了几种光学和光谱工具来获得成分和微观结构信息：空气/水表面单层的外反射红外光谱（IR）;固体基底上转移的单层（LB膜）的ATR-IR（全反射）光谱;几种波长的椭圆偏振法;和放射性示踪剂方法。 目标是制定定量的指导方针，如何混合物的组成和组分的分子结构可以定制，以控制动态表面张力行为。 微溶颗粒表面活性剂的分散体及其平衡和动态吸附用于使泡沫稳定性和泡沫中的表面活性剂浓度如何与散装组合物和基于泡沫的分离合理化。 该项目也有一个生物医学工程的重点：几个特定的表面活性剂和脂质的应用或潜在的应用作为肺表面活性剂替代药物进行检查，以描绘实现非常低的10 mNm非平衡表面张力（脉动条件下）所需的适当肺泡功能的最佳条件。

CTS-9615649 Elias Frances Purdue University The surface tension of several aqueous systems of surfactant and surfactant/protein mixtures is examined, to find out how components of different size, surface activity, or molecular character compete for the air/water surface. New models for both equilibrium and dynamic adsorption of mixtures are developed. To test the models, several optical and spectroscopic tools are used to obtain compositional and microstructural information: external-reflection infrared spectroscopy (IR) from air/water surface monolayers; ATR-IR (total reflection) spectroscopy from monolayers (LB films) transferred on solid substrates; ellipsometry at several wavelengths; and radiotracer methods. The objectives are to develop quantitative guidelines on how the mixture composition and the molecular structures of the components can be tailored to control the dynamic surface tension behavior. Dispersions of sparingly soluble particulate surfactants and their equilibrium and dynamic adsorption are used to rationalize how foam stability and surfactant concentrations in the foamate are related to bulk composition, and to foam-based separations. The project also has a biomedical engineering focus: several specific surfactants and lipids with applications or potential applications as lung surfactant replacement drugs are examined to delineate the best conditions for achieving the very low 10 mNm nonequilibrium surface tensions (under pulsating are conditions) required for proper alveoli function.