Estimating polymer/solvent diffusion coefficient by optimization procedure

Solvent diffusion in polymer solutions is one of the main parameters that d etermine the drying kinetics of polymer films, especially in the concentrat ed domain. As is well known for polymer/solvent solutions, solvent diffusio n coefficients decrease by several orders of magnitude when the solvent con centration decreases. Direct measurements of these coefficients are complex and time-consuming, and most often dedicated to well-characterized "model" systems. In this study, another approach is developed that is based on sim ple gravimetric experiments coupled with the modelization of the drying kin etics and an optimization iterative procedure. The sensitivity of tire meth od to various errors (measurement errors and uncertainties on a priori know n parameters) is thoroughly investigated. The method accurately estimates d iffusion coefficients on a large concentration domain, provided a suitable experimental strategy is used.