Intramolecular association in flexible hard chain molecules

摘要

Due to the flexibility of associating polymer and protein molecules, intramolecular association can have a significant affect on the thermodynamic properties and structure of associating polymer and protein solutions. The equilibrium state is determined by the minimization of the appropriate free energy with respect to intermolecular association between like and unlike species and intramolecular association. As a first step to understanding this competition between intramolecular and intermolecular hydrogen bonding, we have conducted a molecular simulation study of flexible hard chain molecules that intramolecularly associate in the absence of intermolecular association. To explain the simulation results, we have developed a new simple and accurate theory of intramolecular association. By considering the limit of total bonding, we have also developed an accurate equation of state for hard rings. The theory is in good agreement with new molecular simulation results for intramolecularly associating hard chains, rigid hard rings, and bent triatomics.