Interfacial mechanisms in the freezing of polymer solutions.

Freezing of polymer solutions plays a central role in processes such as cryopreservation, porous material synthesis, and environmental remediation. Unlike simple solutes, polymers influence solidification through chain exclusion, interfacial adsorption, and confinement effects. These interactions shape the structure and stability of the freezing front and lead to solute gradients, phase separation, or morphological instabilities. In this review, we examine the physical mechanisms that govern polymer redistribution during freezing. We describe how polymer properties affect front morphology, survey experimental approaches for tracking solute dynamics, and discuss modeling strategies that link molecular behavior to macroscopic structure. We highlight recent advances in cryo-imaging and simulation, and identify open questions at the intersection of transport, thermodynamics, and interfacial physics.