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Philip Hodge investigated ring-opening metathesis polymerization of macrocycles. In a 2015 study with Abdel Chakiri, he prepared functionalized polymers from macrocyclic olefins derived from deoxycholic acid. The primary manuscript reports film formation and discusses potential materials applications.^[ref]

The work illustrates an alternative to explaining every ring-opening reaction solely by release of strain in a small ring. For sufficiently large rings, the balance between rings and chains can depend strongly on entropy and concentration. The thermodynamic question is the change in Gibbs free energy,for a specified reaction and state, including the relevant activities.

For an original numerical illustration, a stipulated reaction with $\Delta H=0$ and $\Delta S=20\mathrm{J}\mathrm{mo}{\mathrm{l}}^{-1}{\mathrm{K}}^{-1}$ at $298\mathrm{K}$ has $\Delta G=-5.96\mathrm{kJ}\mathrm{mo}{\mathrm{l}}^{-1}$. This demonstrates how a favorable entropy contribution can supply the free-energy decrease without a negative enthalpy change. It does not assign those values to Hodge's experimental macrocycles.

Functional groups retained in the resulting material provide another design variable beyond chain formation. Film formation, mechanical performance and suitability for contact with cells are separate tests: a transparent film is not by itself proof of a biological effect. The example connects molecular architecture, thermodynamics and material characterization without promoting a proposed use to an established result.