Fusion-Induced Coil-to-Globule Transition in Polymeric Solvents: A Hysteresis Process

We develop a theory to describe the two-chain interaction by considering the conformational change during fusion and fission. A fusion-induced coil-to-globule transition in the polymeric solvent is well-discovered by this proposed theory. By evaluating the second virial coefficient from the potential of mean force (PMF), we find that two coils show effective attraction, indicating that phase separation can take place by the aggregation of coils without going through the coil-to-globule (C–G) transition. This is different from the phase separation of the polymer solution, where phase separation usually takes place after the C–G transition. Finally, we study the reverse process─fission, where a globule-to-coil (G–C) transition is triggered by the fission. Interestingly, the fusion and fission show a hysteresis process in the long-solvent chain due to the first-order nature of the C–G transition.