International Research Fellowship Program: Surface Forces Between Two Oil Drops in Aqueous Solutions: Measurements and Interpretation Using Atomic Force Microscopy

0202675达加斯汀国际研究奖学金计划使美国科学家和工程师能够在国外进行三到二十四个月的研究。 该计划的奖项提供了联合研究的机会，以及使用独特或互补的设施，专业知识和国外的实验条件。Dagastine将与澳大利亚维多利亚帕克维尔的墨尔本大学微粒流体处理中心的Franz Grieser博士合作。该项目的目标是定量研究在各种不同类型的乳化剂和表面活性添加剂存在下两个油滴之间的力。 PI将开发一种实验方法来直接使用原子力显微镜（AFM）测量这些力，并为这些测量结果的解释提供理论框架。 该方法建立在他对单个油滴与刚性探针相互作用之间的测量结果的解释上。 工业过程中常见的添加剂和乳化剂通常是两亲分子，其在油-水界面中分配自身。 吸附到界面可以是竞争性的或合作性的，并且这些被吸附物质的增加的移动性可以提供与在固-液界面处被吸附的相同物质不同的力行为。 这项工作将提供添加剂和乳化剂之间的相关性，在油-水乳液和液滴之间的颗粒间，从而洞察配方，乳液稳定性和加工。 了解液-液界面之间的相互作用力，液滴之间的吸引力会导致乳液中的聚结和相分离，对于预测和模拟加工和储存情况下的乳液稳定性至关重要。颗粒流体处理中心是墨尔本大学建立的胶体和界面科学研究领域世界领先计划的一部分，该计划已超过20年。 Grieser博士是在液-液界面进行AFM测量的领导者。

0202675DagastineThe International Research Fellowship Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four month research fellowship by Dr. Raymond R. Dagastine to work with Dr. Franz Grieser at the Particulate Fluids Processing Center at the University of Melbourne in Parkville, Victoria, Australia.The goal of this project is to quantitatively study forces between two oil drops in the presence of a variety of different types of emulsifiers and surface-active additives. The PI will develop an experimental approach to measure these forces directly using atomic force microscopy (AFM) and a theoretical framework for interpretation of these measurements. The approach builds on his work on the interpretation of measurements between a single oil drop interacting with a rigid probe. The additives and emulsifiers that are common in industrial processes are commonly amphiphilic molecules, which partition themselves in the oil-water interface. Adsorption to the interface can be competitive or cooperative and the increased mobility of these absorbed species can provide different force behavior than that of the same species absorbed at solid-liquid interfaces. This work will provide correlation between additives and emulsifiers in oil-water emulsions and the interparticle between drops, leading to insight in formulation, emulsion stability, and processing. Understanding of the interaction forces between liquid-liquid interfaces, where attraction between droplets can lead to coalesce and phase separation in emulsions, is vital to predict and model emulsion stability in processing and storage situations.The Particulate Fluids Processing Center is part of the world-leading program in colloidal and interfacial science research that has been established at the University of Melbourne for more than twenty years. Dr. Grieser is a leader in making AFM measurements at liquid-liquid interfaces.