The phase inversion process generally involves two main steps: the formation of a homogeneous polymer solution and the subsequent phase separation. This can be achieved through different methods, such as solvent evaporation, temperature change, and non-solvent induced phase separation (NIPS). In NIPS, for example, a polymer solution is cast into a film and then immersed in a non-solvent bath. The solvent diffuses out while the non-solvent diffuses in, causing the polymer to precipitate and form a porous structure.
