9304328 Frances The project examines the dynamic surface tension and adsorption behavior of surfactants, lipids, and proteins at the air/water interface. Dynamic adsorption is important in foam-based separations of toxic or useful chemicals from dilute solutions. It is also important in coasting flows, pesticide spray efficiency, downstream bioprocessing of hydrophobic molecules, and in lung surfactant formulations for treating the respiratory distress syndrome of premature infants. The objectives are to study how different kinds of molecular interactions of various surfactants and proteins affect the competitive adsorption behavior. Dynamic surface tensions area measured either at constant area or at pulsating area conditions. Surface adsorption densities are estimated from surface electrical potential measurements, from using radiotracers, and from sampling the surface monolayers by the use of Langmuir-Blodgett deposition method. Moreover, an apparatus is being built for probing dynamic concentration profiles. The results are correlated with transport- adsorption description models and are used in interpreting foam - concentration and foam fractionation experiments of octanol, sodium dodecylsulfate, bovine serum albumin, lysozyme, and other molecules. Finally, hexadecanol, dipalmitoylphosphatidylcholine, tyloxapol, and SP-A, SP-B, and SP-C (lung specific proteins) are studied for their importance in lung surfactant formulations.
