Phase separation of polymers

An example of a homogeneous phase is a solution of a dissolved substance in pure water. But natural as well as manufactured materials often consist of a mixture of separated phases. An example is porous materials formed by mixing polymers and ethanol. When ethanol evaporates, the two polymers become immiscible and separate into phases (domains). When put in water, one of the polymers leaks out and a porous material is formed.

For porous materials, the pore diameter and the pore tortuosity are two impartant parameters. Using Cahn-Hilliard modelling of phase separation, the formation of pores can be modelled as function of for instance temperature.