POLYDISPERSITY EFFECTS IN EVAPORATION OF PERFLUOROPOLYETHER THIN FILMS

摘要

The evaporation rates of bulk liquid and thin films of an alcohol-derivatized perfluoropolyether have been studied experimentally and computationally. We find that the time dependence of the evaporation rate in both cases is dominated by the polydispersity, and can be described very well by a model that incorporates the molecular weight distribution, molecular-weight-dependent Arrhenius parameters of evaporation, and Raoult's law of vapor pressures. Minor corrections to the model that account for surface interactions are necessary in the case of thin film evaporation.