Flory–Huggins solution theory

The Flory–Huggins solution theory' is a mathematical model of the thermodynamics of polymer solutions which takes account of the great dissimilarity in molecular sizes in adapting the usual expression for the entropy of mixing. The result is an equation for the Gibbs free energy change ${\displaystyle \Delta G_{m}}$ for mixing a polymer with a solvent. Although it makes simplifying assumptions, it generates useful results for interpreting experiments.

The thermodynamic equation for the Gibbs energy change accompanying mixing at constant temperature and (external) pressure is

A change, denoted by ${\displaystyle \Delta }$, is the value of a variable for a solution or mixture minus the values for the pure components considered separately. The objective is to find explicit formulas for ${\displaystyle \Delta H_{m}}$ and ${\displaystyle \Delta S_{m}}$, the enthalpy and entropy increments associated with the mixing process.

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