Drainage and Dewetting of Stratified Liquid Films

PI: Fuller, Gerald G.提案号：1435683提议研究的目标是探索曲面上薄层液体的润湿和排水。这个主要是实验性的项目将同时测量一种密度较低的上层液体在另一种密度较大的也在排水的液体上的层厚。这种系统的一个例子是从曲面上排水的油和水系统。在涉及分层液体膜排水和脱湿的环境中发生的一个重要事件是水面浮油与水生生物的相互作用。了解这个例子很重要，因为水基植物、鸟类、哺乳动物和鱼类的涂层是这种泄漏的不幸结果。在教育和推广方面，PI将开发和传播教学模块，通过涵盖流体力学和界面科学的新发展和挑战，升级和补充现有的核心化学工程课程。从弯曲表面（例如，将检查半球）的分层液体层的排水和脱湿预计将受到两种液体的粘度比的强烈影响。根据粘度比的不同，排水动力学将经历许多转变。例如，在上层液体变得更粘稠的极限下，它的排水将从雷诺数排水响应转变为指数衰减，在雷诺数排水响应中，上层膜的变薄以代数方式减少。所提出的实验旨在测量当排水进行到足够长的时间时所产生的表面覆盖模式的形态。这时，弯曲的基材就会发生脱湿。该项目将研究这些过程作为两种不混溶液体的粘度比和基材表面能的函数。此外，还研究了液/液界面粘弹性的影响。

PI: Fuller, Gerald G. Proposal Number: 1435683The goal of the proposed research is to explore the wetting and drainage of thin layers of liquid from curved surfaces. This largely experimental program will provide simultaneous measurements of the layer thicknesses of an upper, less dense liquid draining atop a second, more dense liquid that is also undergoing drainage. An example of such a system is an oil and water system that drains from a curved surface. An important event that occurring in the environment involving the drainage and dewetting of stratified liquid films is the interaction of oil slicks at the surface of water with aquatic life. It is important to understand this example since the coating of water-based plants, birds, mammals and fish is an unfortunate result of such spillage. In terms of education and outreach, the PI will develop and disseminate teaching modules that upgrade and complement existing core chemical engineering classes by covering new developments and challenges in fluid mechanics and interface science.The drainage and dewetting of stratified liquid layers from curved surfaces (e.g., hemispheres will be examined) is expected to be strongly affected by the viscosity ratio of the two liquids. It is expected that the drainage dynamics will undergo a number of transitions, depending on the viscosity ratio. For example, in the limit that the upper liquid becomes much more viscous, its drainage will transition from a Reynolds draining response where the thinning of the upper film decreases algebraically to an exponential decay. The experiments proposed are designed to measure the morphology of the resulting surface coverage patterns when drainage has proceeded to sufficiently long times. That is when dewetting of the curved substrate will ensue. The project will examine these processes as a function of the viscosity ratio of the two immiscible liquids and the surface energy of the substrate. In addition, the influence of interfacial viscoelasticity of the liquid/liquid interface will be examined.