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

乳剂是由悬浮在不混相液体中的液滴组成的，例如油滴在水中。液滴为分散相，不混相为连续相。乳剂用于许多产品的生产，包括食品、营养品、药品和杀虫剂。相转化乳化（PIE）是一种通过将现有乳化液的相进行反相生成新乳化液的工艺。当用其他方法难以生成所需乳液时，PIE尤其有用。例如，施乐公司使用PIE制造乳胶颗粒，用于生产印刷和复印用的碳粉。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PIE的一种变体，称为流动诱导的PIE。在流动诱导的PIE中，通过将现有乳化液流过其横截面突变（如收缩或膨胀）的微通道，可以发生相反转。在适当的条件下，通过通道的水中的油滴乳液被倒置成油中的水滴乳液。实验将探讨通道几何形状、流速、通道表面润湿性和液相组成对相转化过程的影响。流动诱导的PIE工艺将允许产品在连续过程中生产，降低能耗，提高效率，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。来自弱势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。将进行一系列实验来确定初始乳液形态和化学以及通道几何形状对流动诱导PIE的机理和效率的影响。将确定通道表面润湿性对相转化过程的影响。流体动力学参数，如微通道中的剪切和拉伸变形也将被检查。微流控平台的使用将能够形成具有受控特性的模型乳液，并在流动过程中直接观察PIE。具有精确控制尺寸、尺寸分布和界面化学的乳状液滴将用于了解乳状液滴的形态和化学对流动诱导PIE的影响。我们还将探索可促进流动诱导PIE的其他安排，包括通过包含柱阵列的微流体装置的流动，该装置可作为模型多孔介质。

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.