Gibbs Free Energy Expression for the System Polystyrene in Methylcyclohexane and Its Application to Microencapsulation

A semiempirical equation of Gibbs free energy of mixing ΔG for the system polystyrene in methylcyclohexane has been determined based on the Flory−Huggins equation by using a series of coexistence curve data. The functional form of the interaction parameter g with respect to chain length of the polymer was determined so as to express the critical universality. The resultant equation of ΔG was used to prepare microcapsules of controlled size distribution by means of coacervation in the spinodal region.