"The Effects of Finite Concentration and Surfactants on the Coalescence of Drops in Flow"

摘要提案编号：CTS-0624446主要制造商：加里L. LEALINSTITUTION：加州大学圣塔芭芭拉分校有限浓度和表面活性剂对液滴在流动中聚结的影响这一资助将有助于研究液滴在4辊磨机的微型版本中流动诱导聚结的过程，该过程允许控制一对液滴在流动中碰撞时的位置和方向（低至5-10微米范围）。该装置允许独特的实验，可用于探索在单个液滴的水平上的聚结过程，这导致了许多意想不到的结果，这些结果证明了用于预测混合和共混装置中的液滴尺寸分布的当前缩放类型理论中的重大缺陷。这项研究最初的动机是需要更好地了解在表面活性剂存在下粘性流体的共混或乳化过程。目前的研究考虑两个重要的扩展以前的工作：（1）一个是考虑在非稀释浓度的液滴的聚结与其他周围的液滴的相互作用预计将发挥重要作用;（2）第二个是扩展目前的理论计算，包括表面活性剂的影响，从而寻求了解最近获得的数据，这个问题。表面活性剂效应的理论模拟和实验之间的比较不仅有助于更好地理解表面活性剂所发挥的作用，但也将提供一个测试的共聚物表面活性剂的小分子模型的适用性。这项工作的预期的实际意义是最终一个更好的基础预测的结果的共混过程中，以及它将如何被修改的变化，在本体和界面性能，两个本体流体的相对量，特别是如何优化的过程中的可控参数的增容剂。该项目的理论方面将与UCSB科学计算IGERT计划的“复杂流体”小组合作进行。PI还将利用UCSB MSRC的全国知名的推广计划，每年夏天至少邀请一名本科生参与拟议的实验研究。一般而言，在粘性流体中进行混合或乳化的有效模型将在理解、优化和开发新的多组分聚合物材料方面发挥重要作用。

ABSTRACTPROPOSAL NO.: CTS-0624446PRINCIPAL INVESTIGATOR: GARY L. LEALINSTITUTION: UNIVERSITY OF CAL- SANTA BARBARAThe Effects of Finite Concentration and Surfactants on the Coalescence of Drops in FlowThis grant will facilitate a study of the process of flow-induced coalescence of drops in a miniature version of the 4-roll mill, that allows control of the position and orientation of a pair of drops (down to the 5-10 micron range) while they are colliding in a flow. This device allows unique experiments that can be used to explore the coalescence process at the level of the individual drops, and this has led to a number of unexpected results, which demonstrate significant flaws in current scaling type theories that are used for the prediction of drop size distribution in mixing and blending devices. This study was originally motivated by the need for a better understanding of the process of blending or emulsification processes for viscous fluids in the presence of a surfactant. The present studies consider two important extensions of previous work: (1) one is to consider the coalescence of drops at non-dilute concentrations where interactions with other surrounding drops are expected to play an important role; (2) the second is to extend current theoretical calculations to include surfactant effects, and thus seek to understand recently obtained data for this problem. Comparisons between theoretical simulations of surfactant effects and experiments will not only help to better understand the role played by surfactant, but will also provide a test of the applicability of the small molecule model for copolymer surfactants. The expected practical significance of this work is ultimately a better basis for predicting the outcome of a blending process, and how it will be modified by changes in the bulk and interface properties, the relative quantities of the two bulk fluids, and particularly how to optimize the process in terms of the controllable parameters of the compatibilizer. The theoretical aspects of this project will be carried out with the collaboration of the "complex fluids" group of the IGERT program at UCSB on scientific computing. The PI will also utilize the nationally well-known outreach program of the MSERC at UCSB to engage at least one undergraduate student each summer, to be involved in experimental studies that are proposed. In general terms, effective models for blending or emulsification in viscous fluids will play a major role in understanding, optimizing and developing new multi-component polymeric materials.