Levich Institute Seminar Announcement, 12/15/2015
Steinman Hall, Room #312
(Chemical Engineering Conference Room)
Professor Carlos Colosqui
Stony Brook University
Department of Mechanical Engineering
"From Capillary-driven to Thermally-Driven Wetting Dynamics in Microscale Systems"
Dynamic wetting phenomena such as spreading of droplets, wicking of fibrous materials, or imbibition and drainage of capillaries and pores are commonly considered to be governed by the interplay between hydrodynamic and capillary forces. Through the use of differential geometry, conventional continuum-based models for wetting dynamics describe solid-fluid interfaces as smooth surfaces. Moreover, surface energies are usually assumed to be constant or to exhibit smooth spatial variation. In recent years, experimental observations have revealed significant limitations of these conventional wetting models in describing the final approach to thermodynamic equilibrium. The final approach to equilibrium appears to be governed by the interplay between Brownian motion and surface energy fluctuations caused by physical or chemical heterogeneities of the solid surfaces. This talk will present recent experimental, theoretical, and computational analyses of systems with microscale dimensions that exhibit a remarkable transition from dynamics dominated by hydrodynamic and capillary forces to a different regime governed by thermally-activated processes. These results indicate specific ways in which combinations of microscale geometry and nanoscale surface structure can dramatically modify the time scales of dynamic wetting processes.
BRIEF ACADEMIC/EMPLOYMENT HISTORY
RECENT RESEARCH INTERESTS
Colloidal systems, wetting and interfacial hydrodynamics, nanostructured surfaces