Interfacial Phenomena Near Critical Points

本实验研究项目涉及在许多物理、化学和生物过程中起重要作用的表面吸附和润湿现象。这项研究是基于最近开发的椭偏显微镜。该仪器由PI实验室开发，将用于在实验条件下确定液滴的大小和形状。这些数据将与适当的理论模型进行比较。这项研究将增强我们对均匀润湿层如何通过液滴生长和聚结形成的理解，溶液中的离子如何影响润湿和吸附现象，并将阐明在临界离子混合物表面取向顺序是否重要。由于表面的相互作用在界面处产生了吸附层或湿润层，溶液表面的组成常常与体中的组成不同。这些表面效应在许多过程中是重要的，如润滑、催化和流体流动，通过生物膜和多孔介质。这项工作将使用椭圆显微镜来研究当湿润液滴结合在临界非离子二元液体混合物表面形成均匀湿润膜时的聚结和生长动力学。随着温度的变化，动力学将被研究。离子的影响也将被研究。这项工作将增强我们对体积临界现象和表面过程之间复杂相互作用的理解，在溶液中存在和不存在离子的情况下。* * *

w:\awards\awards96\*.doc 9631133 Law This experimental research project is concerned with surface phenomena of adsorption and wetting, which play an important role in many physical, chemical, and biological processes. The research is based on a recently developed ellipsometric microscope. This instrument, developed in the PI's laboratory, will be used to determine size and shape of droplets under experimental conditions. The data will be compared with appropriate theoretical models. This study will enhance our understanding of how uniform wetting layers form via droplet growth and coalescence, how ions in the solution influence the phenomena of wetting and adsorption, and will clarify whether or not orientational order is important at the surfaces of critical ionic mixtures. %%% The composition at the surface of a solution frequently differs from that in the bulk because surface interactions create an adsorbed layer or a wetting layer at the interface. These surface effects are important in many processes such as lubrication, catalysis, and fluid flow, through biological membranes and porous media. The work will use an ellipsometric microscope to study the dynamics of coalescence and growth as wetting droplets combine to form a uniform wetting film at the surface of a critical non-ionic binary liquid mixture. The dynamics will be studied as the temperature is varied. The influence of ions will also be studied. This work will enhance our understanding of the complex interplay between bulk critical phenomena and surface processes, in the presence and absence of ions in solution. ***