GOALI: Single droplet level understanding of phase inversion emulsification to enable continuous processing

CBET-1604536PI：Lee，Dayeon乳剂是由悬浮在不相容液体中的液滴组成，如水中的油滴。液滴为分散相，不相容液体为连续相。乳状液用于许多产品的生产，包括食品、营养素、药物和杀虫剂。相转化乳化(PIE)是一种通过颠倒现有乳液的相来生成新乳液的过程。当通过其他方法很难生成所需的乳剂时，饼图尤其有用。例如，施乐使用派来制造乳胶颗粒，乳胶颗粒用于生产打印和复印用的碳粉。这个Goali项目是宾夕法尼亚大学和施乐公司的合作项目，将探索一种称为流动诱导馅饼的变体。在流动诱导PIE中，通过使现有的乳状液流过在其横截面上包含突变的变化的微通道，例如收缩或膨胀，发生相变。在适当的条件下，流经通道的水中的油滴乳状液被转化为油中水滴的乳状液。将设计实验来探索流道几何形状、流速、流道表面的润湿性和液体组成对相转化过程的影响。流动诱导馅饼工艺将允许以连续工艺生产产品，从而降低能耗、提高效率并减少对环境的影响。该项目将为不同学术水平的学生提供参与研究的机会。来自代表性不足群体的学生将被鼓励参加宾夕法尼亚大学的几个项目，包括路易斯·斯托克斯少数民族参与联盟。将进行一系列实验，以确定初始乳状液形态和化学以及通道几何形状对流动诱导派的机制和效率的影响。将确定通道的表面润湿性对反相过程的影响。还将检查微通道中的水动力学参数，如剪切和拉伸变形。微流控平台的使用将能够形成具有受控性质的模型乳状液，并可在流动过程中直接观察饼块。通过精确控制乳状液滴的大小、尺寸分布和界面化学，我们将了解乳状液的形态和化学对流动诱导派的影响。还将探索可促进流动诱导派的替代布置，包括流过包含柱子阵列的微流控装置，该装置用作模型多孔介质。

CBET - 1604536PI: Lee, DaeyeonEmulsions are composed of liquid drops that are suspended in an immiscible liquid, such as oil drops in water. The drops are the dispersed phase, and the immiscible liquid is the continuous phase. Emulsions are used in the manufacture of many products, including foodstuffs, nutrients, drugs, and pesticides. Phase inversion emulsification (PIE) is a process for generating a new emulsion by inverting the phases of an existing emulsion. PIE is especially useful when it is difficult to generate the desired emulsion by other methods. For example, Xerox uses PIE to manufacture latex particles, which are used to produce toners for printing and photocopying. This GOALI project, which is a collaborative effort between the University of Pennsylvania and Xerox, will explore a variation on PIE called flow-induced PIE. In flow-induced PIE, phase inversion takes place by flowing an existing emulsion through microchannels that contain abrupt variations in their cross-sections, such as constrictions or expansions. Under proper conditions, an emulsion of oil drops in water flowing through the channel is inverted into an emulsion of water drops in oil. Experiments will be designed to explore effects of channel geometry, flow rates, wettability of the channel surface, and composition of the liquid phases on the phase inversion process. The flow-induced PIE process will allow products to be manufactured in a continuous process with reduced energy consumption, higher efficiency, and reduced environmental impact. The project will provide opportunities for students at various academic levels to participate in research. Students from underrepresented groups will be encouraged to participate through several programs at Penn, including the Louis Stokes Alliance for Minority Participation.A series of experiments will be conducted to determine effects of initial emulsion morphology and chemistry as well as channel geometry on the mechanism and efficiency of flow-induced PIE. The effect of surface wettability of the channels on the phase inversion process will be determined. Hydrodynamic parameters such as shear and extensional deformation in the microchannels will also be examined. The use of a microfluidic platform will enable the formation of model emulsions with controlled properties and the direct observation of PIE during flow. Emulsion droplets with precisely controlled size, size distribution and interfacial chemistry will be used to understand effects of emulsion morphology and chemistry on flow-induced PIE. Alternative arrangements that can promote flow-induced PIE will also be explored, including flow through a microfluidic device containing pillar arrays, which serves as a model porous medium.