The memorizing capacity of polymers.

Properties of one and the same polymer can vary greatly with the history of a sample, reflecting its memory of past events. I propose that this remarkable changeability of polymer properties can be related to the immense variability of non-equilibrium conformational states, providing polymers with capacities for responding and adapting to changes in environmental conditions and to external stimuli. By decoding the relations between properties and meta-stable conformational states, we may be able to accomplish polymer products with selectable unique properties. In support of this claim, I first present a few typical examples focusing on changes induced by varying drying, freezing, or crystallization procedures, relevant in many industrial processing strategies for polymeric systems. In these examples, deviations from equilibrium conformations are controlled by a preparation parameter and the annealing/aging time and temperature. Subsequently, I briefly discuss the possibilities for a quantitative description of chain conformations deviating from equilibrium, which allow establishing a link between changes on a molecular level and their macroscopic behavior. A comprehensive and systematic investigation of out-of-equilibrium polymer properties will widen the scope of polymer science and enlarge the range of applications of polymers based on their responsiveness and adaptability derived from their memorizing capacities.