Estimation of diffusion coefficients in acetone-cellulose acetate solutions

The mutual and the self-diffusion coefficients of the acetone-cellulose ace tate system are determined by using established gravimetric measurements of the acetone evaporation rate. The process is studied as a one-dimensional numerical experiment utilizing the Galerkin finite element method. The nume rical technique provides simultaneous solution of the model equations and y ields by comparison with gravimetric data the diffusion coefficients of ace tone in cellulose acetate for a wide range of temperatures and compositions . The estimated diffusion coefficients based on free volume theory are in s atisfactory agreement with the available experimental data. It-is believed that this method can be applied to other systems of interest.