Microscale Flows to Engineer Fluid Interfaces Containing Macromolecular and Colloidal Species

拟议的工作的目标是开发实验方法，用于控制吸附物种在移动的（流动）接口的存在。 这项工作的指导下，已经开发的界面破裂在表面活性剂的存在下的一个简化的理论模型的框架。 这项工作的智力价值是开发工具来解决涉及耦合表面活性剂动力学和流体流动的问题。我们将开发这些工具，通过详细的实验分析和建模的一个具体的例子：表面活性剂介导的tipstreaming形成的亚微米液滴。这些研究将有助于阐明控制更广泛的界面流动应用的关键机制，从而能够更好地控制关键过程。这个框架将使工程的移动的接口，我们将使用这种能力，以开发新的方法，用于定量的动力学的ad/解吸更复杂的分子（即，生物分子，大分子和胶体），并解决一个具体的应用，定量的动力学变性的蛋白质在接口。 这项工作的结果将具有广泛的技术影响，因为表面活性剂负载的多相流在乳化，喷涂和涂层等技术中的重要性，以及在新兴应用中的重要性，如新材料的喷墨打印或微流体设备中的两相流，这些应用已被用于合成单分散液滴，气泡，胶体颗粒和其他新型胶体组件。 这项工作的界面和微流体流动的特点将有广泛的教育影响，通过提供高度可视化的图像和流体动力学的例子，可以喂到两个PI的主要推广，本科研究和课程开发活动。

The goal of the proposed work is to develop experimental methods for controlling the presence of adsorbed species at mobile (flowing) interfaces. This work is guided by the framework of a simplified theoretical model that has been developed for interface breakup in the presence of surfactants. The intellectual merit of this work is the development of tools to tackle problems involving coupled surfactant dynamics and fluid flow. We will develop these tools through detailed experimental analysis and modeling of a specific example: surfactant-mediated tipstreaming for formation of submicron droplets. These studies will help elucidate the critical mechanisms controlling a broader set of interfacial flow applications, enabling greater control over key processes. This framework will enable the engineering of mobile interfaces, and we will use this capability to develop novel methods for quantifying the kinetics of ad/desorption of more complex molecules (i.e, biomolecules, macromolecules and colloids) and tackle a specific application, quantification of the kinetics of denaturation of proteins at interfaces. The results of this work will have broad technological impact because of the importance of surfactant-laden multiphase flows in technologies such as emulsification, spraying and coatings and in emerging applications such as ink-jet printing of new materials or two-phase flows in microfluidic devices, which have been exploited to synthesize monodisperse droplets, bubbles, colloidal particles, and other novel colloidal assemblies. The interfacial and microfluidic flows characterized by this work will have broad educational impact by providing highly visual images and fluid dynamics examples that can feed into the major outreach, undergraduate research, and course development activities of the two PIs.