화학공학소재연구정보센터
Journal of Polymer Science Part B: Polymer Physics, Vol.32, No.8, 1413-1425, 1994
An Improved Model for Mass-Transfer During the Formation of Polymeric Membranes by the Immersion-Precipitation Process
An analysis is presented, which describes the isothermal ternary diffusion process encountered in the formation of a cellulose acetate polymeric membrane by a direct immersion-precipitation of polymeric solutions in a nonsolvent bath. A material coordinate was employed to derive the mass transfer equations for the membrane solution and the convective mass transfer in the coagulation bath was taken into account by solving the hydrodynamic boundary layer equations. Diffusion coefficients were measured and used to deduce ternary phenomenological coefficients. The computed results are found to agree with the experimental precipitation time and membrane morphologies observed in scanning electron photomicrographs.