(633f) Diffusion And Relaxation Behavior Of Polymer Ultra-Thin Films: A Progress Report

Diffusion of penetrants through polymer thin films is important in a variety of applications ranging from microelectronics to gas separations. Recent experiments have shown that the transport behavior of water vapor in polymer ultra-thin films appears to follow a two stage anomalous diffusion behavior that can be described as being made up of both a Fickian diffusion and non-Fickian relaxation component. The behavior of both components of the diffusion behavior has been studied as a function of polymer type, polymer molecular weight, film thickness, and film age. Quartz crystal microbalance techniques have been used to performa sorption and desorption experiments for films over a period of time up to five months. This presentation will provide a summary of these recent experiments and the insight they provide on the possible origins of the anomalous diffusion behavior in such systems.