AWWA MTC64510

In this study simulations were developed to represent the solidification and drying stages leading to cellular morphologies common to membranes made via liquid-liquid (L-L) thermally induced phase separation (TIPS). Diluent-extractant exchange has been experimentally determined to have a negligible effect on membrane microstructure of the crystalline and semi-crystalline polymer systems of interest here; consequently, the results from the matrix solidification simulation are fed directly into a finite element simulation used for the drying processes. It should be noted that the drying portion of the simulation package is adaptable to solid-liquid TIPS and non-solvent induced phase separation (phase inversion) processes of membrane formation by simply changing the geometric structure in the simulations. The final simulations developed will describe the sensitivities of the post-coarsening processes and thereby allow manufacturers to relate porous structure and performance to the material formation process. Computer simulation of the processes will allow investigation into different processing conditions, diluents, and extractants without extensive and expensive laboratory research. The research will have a major impact in applications where a well-controlled structure is important for separation and selectivity. By tailoring the morphology of membranes, permeability, rejection, and selectivity can be optimized for separation applications. Includes figures.