Beyond geometric constraint: dynamic fluid-lattice-activated topochemical polymerization.

Topochemical polymerization affords lattice-directed polymers with high structural fidelity, but its scope is limited by the need for precise, static preorganization of reactive groups-an intrinsically fragile outcome of subtle intermolecular packing. Here we introduce dynamical fluid lattices into topochemical design to circumvent these geometric constraints, achieving near-quantitative monomer conversion even without ideal preorganization. Employing core-shell columnar liquid crystals, rapid molecular fluctuations within the fluid lattices enable temporary proximity of reactive sites that activate topochemical reactions. Meanwhile, the anisotropic columnar architecture directs chain growth into well-defined linear helical polymers. Despite their covalent backbones, the resulting polymers undergo temperature-dependent, dissipative depolymerization that enables complete monomer regeneration. We integrate fluid-lattice-activated topochemical polymerization into skin-attachable films, demonstrating temporary information encryption via fluorescence imaging at body temperature. This strategy expands the design space of topochemical synthesis and suggests opportunities in regenerable polymers and flexible wearable technologies.