Collaborative Research: The Role of Monolayer Structure on Interfacial Hydrodynamics

项目编号：CTS-0340768和0340736研究人员：Amir H.Hirsa和Juan M.Lopezinsttion：伦斯勒理工学院/亚利桑那州立大学单层结构对界面水力的作用这项研究计划的目的是促进对表面活性剂单层流体动力学的基本了解。单层流体力学的应用很多。技术方面的例子包括材料和食品加工、液体雾化和涂层系统。以单分子层流体力学为主的自然系统的一个例子是肺。在没有表面活性物质单分子膜的情况下，覆盖在肺组织上的水膜的表面张力将关闭通道，使呼吸无法进行。这项研究旨在通过发展新的理论、数值和实验技术来检验这些理论，从而为界面流体动力学的本质提供基本的见解。特别是，将阐明单层中尺度结构在界面传输过程中的作用，以及流动对单层结构的影响。过去用简单的本构关系来解释实验数据，得到的结论是许多单分子膜具有明显的负表面膨胀粘度。这在物理上不符合热力学第二定律。在这个项目中，将考虑非平衡单分子膜浓度和相形态的贡献，这可能为观察到的表观负表面膨胀粘度之谜提供解释。这一问题具有基本意义，并将对广泛的领域产生广泛的影响，因为小型化的驱动导致了小型开放式流体系统，在该系统中，对界面应力的粘性贡献超过了弹性贡献。更好地理解单分子膜预计将对从事设计型表面活性剂单分子膜工作的工业和生物医学界产生重大影响。此外，该项目的多学科性质将为研究生和本科生提供一个在科学和工程方面进行教育的绝佳机会。*由流体动力学与液压、界面、运输和热力学项目以及数学科学优先领域共同资助。

ABSTRACTPROPOSAL NO.: CTS-0340768 AND 0340736PRINCIPAL INVESTIGATORS: AMIR H. HIRSA AND JUAN M. LOPEZINSTITUTION: RENSSELAER POLYTECHNIC INST./ARIZONA STATE UNIVERSITY THE ROLE OF MONOLAYER STRUCTURE ON INTERFACIAL HYDRODYNAMICSThe goal of this research program is to advance fundamental understanding of surfactant monolayer hydrodynamics. Applications of monolayer hydrodynamics are numerous. Technology examples include material and food processing, liquid atomization, and coating systems. An example of a natural system dominated by monolayer hydrodynamics is the lung. In the absence of surfactant monolayers, the surface tension of the aqueous film covering the lung tissue would close the passages and make respiration impossible. This research is intended to provide fundamental insight into the nature of interfacial hydrodynamics by developing new theories, and numerical and experimental techniques to test these theories. In particular, the role of monolayer mesoscale structure on interfacial transport processes will be elucidated, as will the effect of flow on the monolayer structure. Use of simple constitutive relations in interpreting experimental data in the past has led to the conclusion that many monolayers have an apparent negative surface dilatational viscosity. This is not physically consistent with the second law of thermodynamics. In this project, contributions from non-equilibrium monolayer concentration and phase morphology will be considered, and these may provide an explanation for the observed enigma of apparent negative surface dilatational viscosity. This issue is of fundamental significance and will have a broad impact on a wide range of fields as the drive to miniaturization leads to small-scale open fluidic systems in which the viscous contributions to the interfacial stresses dominate over the elastic contributions. Better understanding of monolayers is expected to have a significant impact on the industrial and biomedical communities working on designer surfactant monolayers. Also, the multidisciplinary nature of this project will provide an excellent opportunity to educate graduate and undergraduate students in both science and engineering.*co-funded jointly by the Fluid Dynamics & Hydraulics, and Interfacial, Transport and Thermodynamics programs, and Math Sciences Priority Area.