Conformational behavior of polymer chains of different architectures in strongly endothermic solvent mixtures: specific solvation effects

摘要

Preferential solvation of polymer chains by the thermodynamically better component in mixed solvent is a general phenomenon which has been amply studied in systems of miscible solvent components. In strongly endothermic mixtures of partially miscible solvent components, it provokes transient contraction of polymer chains and can lead to cononsolvency, which consists in the fact that a mixture of two good solvents becomes a poor solvent. It has been studied for a few polymers and solvent mixtures, but so far, there is not a consensus concerning the principles of this behavior at the molecular level. We performed a series of coarse-grained dissipative particle dynamic simulations aimed at broadening the knowledge of preferential solvation in endothermic mixtures. The study shows that the cononsolvency can be partially explained by general thermodynamic arguments at coarse-grained the mean-field level, but the model ignoring specific interactions fails to describe all details correctly.