PMSE 79 |
| There has been much interest in creating microstructures in drying polymeric coatings. Typical examples include ordered phase separating morphologies, asymmetric porous layers, regular crack arrays, flow-induced surface textures and transparent, conductive particulate layers. However, these attempts have mainly focused on kinetics in liquid phase by simply assuming a quasi-steady gas phase condition. Here we report a simple class of microstructures that are tunable by periodic air blowing onto a gas/liquid interface. A switching between fast and slow air blowing allows concentration/temperature gradients in liquid to relax at a certain time scale, giving rise to inherently different structures that strongly depend on operating conditions. We built a simple diffusion model coupled with a transverse surface-tension-driven Marangoni flow to compute a transient behavior of drying-induced surface roughening of a volatile, Newtonian liquid layer. The results indicated that the periodic air blowing can level the coating surface under a properly chosen blowing condition. |
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Tess Award Symposium in Honor of L. E. (Skip) Scriven
8:00 AM-12:05 PM, Monday, August 20, 2007 Westin Boston Waterfront -- Grand Ballroom D, Oral
Division of Polymeric Materials: Science & Engineering |