COLL 58 |
| Ryan Leach and Tom Dickinson. Washington State University, Pullman, WA 99164-2814 |
| When a cooler surface is placed above water near the boiling point, droplets quickly nucleate and grow. The rates of nucleation, growth, and aggregation (N,G, and A) and the resulting patterns of large vs. small droplets are strongly influenced by the liquid temperature vs. time. Examples of such behavior can be seen on plastic wraps covering bowls containing water after microwave heating and on plastic tops removed from hot coffee cups. We show the evolution of these patterns using time lapse microphotography for a system that starts near the boiling point and is slowly cooling, measure the rates of N, G, and A and analyze the resulting patterns vs. time. We present results from computer simulations which input the rates of molecular impingement, sticking probabilities, and surface energies. We compare the predicted rates of N, G, and A, as well as the predicted evolution of droplet patterns with the experimentally observed behavior. |
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Symposium in Memory of Arthur W. Adamson
2:00 PM-5:40 PM, Sunday, March 28, 2004 Marriott -- Orange County 4, Oral
Division of Colloid and Surface Chemistry |