Morphology modeling for polymer monolith obtained by non-solvent-induced phase separation

Abstract Polymer monoliths had wide application possibilities due to their unique porous structures. Non-solvent induced phase separation (NIPS) method was a convenient and simple method to fabricate polymer monolith. In this study, the modeling work of the thermodynamics and dynamics for the polymer/solvent/non-solvent ternary system was carried out. The Flory-Huggins theory was employed to the thermodynamics of the mixed polymer/solvent/non-solvent ternary system, by which the predicted phase diagram was obtained and compared with the experimental results. Cahn-Hilliard model was used to describe the dynamics of the ternary system. The modeling results exhibited a correct type of morphology and pore/skeleton size in dependence on the initial polymer concentration and cooling temperature. Besides, the prediction demonstrated the pore and skeleton forming process during a monolith formation. The quantitative modeling work provided an insight into the formation of polymer monolith by NIPS method, as well as a theoretical reference for controlling the morphology of polymer monolith for practical applications.