Accueil > Séminaires > Précédents séminaires > Particles and Droplets at Nanostructured Interfaces : Metastability and Thermally Activated Dynamics

Particles and Droplets at Nanostructured Interfaces : Metastability and Thermally Activated Dynamics

Carlos E. Colosqui Mechanical Engineering Dept., Stony Brook University

Our fundamental understanding of wetting, adsorption, and imbibition phenomena is embodied in classical mathematical descriptions (e.g., Young-Dupre, Young-Laplace, and Lucas-Washburn equations) that are derived under the assumption that interfaces are ideally smooth surfaces (e.g., planes, spheres, differentiable surfaces) separating perfectly homogeneous phases. Such idealization leads to the prediction of stable thermodynamic equilibrium states and neglects the presence of metastable states induced by diverse physicochemical heterogeneities. An increasing volume of experimental evidence indicates that the interplay between thermal motion and metastable states induced by nanoscale heterogeneities of solid/liquid interfaces can dominate the near-equilibrium dynamics of diverse colloidal and multiphase systems. In particular, this presentation will discuss recent experimental, theoretical, and computational studies of nano/microparticle adsorption at liquid interfaces, spontaneous droplet spreading, and nano/microcapillary imbibition. These systems exhibit a transition from dynamic regimes, dominated by hydrodynamic and capillary forces, to “kinetic” regimes governed by thermally activated transitions between metastable states. The presented results and proposed models suggest specific mechanisms by which combination of “system-level” geometry and nanoscale surface structure can alter the evolution of colloidal and multiphase systems.

Short Bio
Carlos Colosqui is an assistant professor in The Department of Mechanical Engineering and affiliated faculty in The Applied Mathematics and Statistics Department of Stony Brook University. He previously held postdoctoral positions at The Levich Institute for Physicochemical Hydrodynamics at CCNY-City University of New York and the Chemical and Biomolecular Engineering Department of Princeton University. His group currently performs theoretical, computational, and experimental research on wetting and interfacial phenomena in micro/nanoscale systems with support from the U.S. National Science Foundation and Office of Naval Research.