Dynamics of elastic surfactants

薄而柔韧的物体漂浮在流体表面的自然例子包括树叶、纤维和昆虫。该奖项旨在了解围绕将这些柔性细丝和薄片附着到液体界面的过程的现象。除了推进这些无处不在的自然过程背后的基本物理之外，这种理解还将为使用薄片和细丝作为表面屏障奠定基础，从而允许两种液体的分离。虽然这种表面活性剂功能传统上是通过部署适当的分子或纳米颗粒在工艺过程中实现的，但使用薄片包裹和保护液体货物，或将有毒液滴与周围环境隔离，提供了显著的优势。将为初中和高中的科学教师组织一个关于流体和柔性弹性材料中图案形成的年度研讨会，这是一个与该奖项的主题密切相关的主题。这是一项联合实验和理论研究，旨在探索高度柔性的固体薄片在流体-流体界面上的吸附动力学。这项拟议的研究研究了弹性毛细现象的新的动力学方面，涉及与弹性薄片或细丝吸附到粘性界面的动力学相关的动力学。解决与这一基本动力学步骤相关的难题暴露了柔性元件界面动力学的一些基本问题。虽然以前对流体-结构相互作用的研究集中在通过柔性元件内的弯矩来平衡剪切力和毛细管力的区域，但此次获奖将涉及重要但未被探索的高度弯曲物体区域，在这些区域中，流体产生的力自然远大于弯曲刚度。研究生和本科生都将参与这项研究，并受益于理论和实验工作。此外，将通过组织有针对性的暑期学校，对研究生和本科生进行相关科学主题的培训。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Natural examples of thin, flexible objects floating at the surface of a fluid include leaves, fibers, and insects. This award seeks to understand the phenomena surrounding the process of attachment of these flexible filaments and sheets to the liquid interface. Apart from advancing the fundamental physics behind these ubiquitous natural processes, this understanding will lay a foundation for the use of sheets and filaments as surface barriers that allow the separation of two liquids. While this surfactant function is traditionally achieved in technological processes by deploying appropriate molecules or nanoparticles, using sheets to wrap and protect a liquid cargo, or sequester a toxic droplet from its surroundings, offers significant advantages. An annual workshop on pattern formation in fluids and flexible elastic materials, a topic closely aligned with the themes of this award, will be organized for middle- and high-school science teachers.This is a joint experimental and theoretical research to explore dynamics of the adsorption of highly flexible solid sheets at fluid-fluid interfaces. The proposed research study novel dynamical aspects of elasto-capillary phenomena on the dynamics associated with the adsorption of an elastic sheet or filament to a viscous interface. Addressing the puzzles associated with this essential kinetic step lay bare some fundamental issues in interfacial dynamics of flexible elements. While previous studies of fluid-structure interaction have focused on regimes where shear and capillary forces are balanced by bending moments within a flexible element, this award will address the important, but unexplored regime of highly bendable objects where fluid-generated forces are naturally much larger than the bending rigidity. Both graduate and undergraduate students will participate in the research and have the benefit of exposure to theoretical and experimental efforts. In addition, outreach efforts to train both graduate and undergraduate students in the associated science topics will be conducted by organizing targeted summer schools.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.