  In this paper, diffusion in polymer solutions undergoing evaporation of
solvent is modeled as a coupled heat and mass transfer problem with moving
boundary condition within the framework of nonequilibrium thermodynamics. The
proposed governing equations derived from the fundamental equation of classical
thermodynamics using the local equilibrium hypothesis display more complex
connection between heat and non-convective mass fluxes than what has been
presented in the previous research works. Numerical computations, performed
using an explicit finite difference scheme, indicate that the model is able to
capture the effect of thermal diffusion in polymer solutions. This effect
manifests itself as an increase in local concentration of solvent near warm
substrates during solution casting process.
