Direct Probing and Modeling of Adsorbed Layers of Surfactant/Lipid/Protein Mixtures atT Air/Water Interfaces

本文的主要目的是定量和定性地了解表面活性剂、脂肪和蛋白质在空气/水界面上的吸附情况。通过单独或竞争吸附，表面活性分子改变了平衡和动态表面张力、表面电荷、起泡行为和蛋白质变性行为。这些现象在生物和生化分散体的生物处理、药物溶液的喷雾干燥、农用化学品在树叶中的传播、泡沫稳定性以及表面活性剂和蛋白质稀溶液的泡沫分离、矿物浮选和去污剂等方面有着重要的应用。一个主要的焦点是肺表面活性物质的替代治疗，它是一种脂类和蛋白质的混合物，负责稳定肺泡和控制呼吸。平衡和动态吸附不仅用间接表面张力方法，而且用直接光学(椭圆偏振法，EL)和红外反射吸收光谱(IRRAS)来探测。IRRAS主要用于确定单个组件的范围、速率和机制。红外光谱与电致发光和表面张力法相结合，已被证明是定量探测复杂工业或生物混合物的有价值的工具。这些结果被用于开发技术有效、成本效益高、对生物或环境友好的配方；以及开发新的、潜在有效的肺表面活性物质配方。所考察的体系是牛血清白蛋白、纤维蛋白原、各种脂类和肥皂，以及模型离子表面活性剂。这些数据用于指导表面活性剂、脂类和蛋白质从整体溶液或分散到界面的扩散/吸附过程的定量模拟。这些模型用于帮助设计新的改进配方，并预测配方如何在不同的溶液和不同的几何形状中发挥作用。

AbstractCTS-0135317Franses, Elias IPurdue University"Direct Probing and Modeling of Adsorbed Layers of Surfactant/Lipid/Protein Mixtures at Air/Water Interfaces" The main objectives are to understand quantitatively and qualitatively how surfactants, lipids, and proteins adsorb at air/water interfaces. By adsorbing, alone or in competition, surface active molecules modify the equilibrium and dynamic surface tension, the surface charges, the foaming behavior, and the protein denaturation behavior. These phenomena have important applications in bioprocessing of biological andbiochemical dispersions, spray drying of pharmaceutical solutions, spreading of agricultural chemical in leaves; also in foaming stability, and foam-based separations of dilute solutions of surfactants and proteins, mineral ore flotation, and detergency. A major focus is the area of replacement therapy of lung surfactant, which is a mixture of lipids and proteins responsible for stabilizing the lung alveoli and controlling breathing.The equilibrium and dynamic adsorption is probed not only with indirect surface tension methods but with direct optical (ellipsometry, EL) and infrared reflection absorption spectroscopy (IRRAS). IRRAS is used primarily to determine the extent, rates, and mechanisms of individual components. IRRAS, in combination with EL and surface tensiometry, has proven to be a valuable tool for quantitative probing of complexindustrial or biological mixtures. The results are used to develop formulations which are technically effective, cost-effective, and biologically or environmentally friendly; and to develop new, potentially effective lung surfactant formulations. The systems examined are bovine serum albumin, fibrinogen, various lipids and soaps, and model ionic surfactants. The data are used to guide quantitative modeling of diffusion/adsorption processes of surfactants, lipids, and proteins from the bulk solution or dispersion to the interface. The models are used to help design new improved formulations, and to predict how formulations may function in different solutions and different geometries.