Coacervates as bio-inspired intermediates for materials processing.

Nature routinely fabricates fibers and composites with combinations of toughness, strength, gradients, and multifunctionality that remain challenging for synthetic materials. A growing body of evidence indicates that many of these materials are not processed from dilute solutions or polymer melts, but instead via concentrated, liquid-like macromolecular phases known as coacervates. In this Feature Article, we review how coacervation enables aqueous, highly controlled processing of fibers and related materials. We place recent work from our groups in the broader context of natural and synthetic coacervate research, discuss established and emerging processing strategies, and outline a perspective in which gradual, stimulus-driven changes in solubility and intermolecular interactions are exploited to guide structure formation and material properties.