Versatile Polymer Nanocapsules via Redox Competition

Polymer nanocapsules have demonstrated significant value in materials science and biomedical technology, but require complicated and time‐consuming synthetic steps. We report here the facile synthesis of monodisperse polymer nanocapsules via a redox‐mediated kinetic strategy from two simple molecules: dopamine and benzene‐1,4‐dithiol (BDT). Specifically, BDT forms core templates and modulates the oxidation kinetics of dopamine into polydopamine (PDA) shells. These uniform nanoparticles can be tuned between ≈70 and 200 nm because the core diameter directly depends on BDT while the shell thickness depends on dopamine. The supramolecular core can then rapidly disassemble in organic solvents to produce PDA nanocapsules. Such nanocapsules exhibit enhanced physicochemical performance (e.g., loading capacity, photothermal transduction, and anti‐oxidation) versus their solid counterparts. Particularly, this method enables a straightforward encapsulation of functional nanoparticles providing opportunities for designing complex nanostructures such as yolk–shell nanoparticles. Monodisperse and tunable polymer nanocapsules are synthesized via a redox‐mediated kinetic strategy from two simple molecules, dopamine and benzene‐1,4‐dithiol. This streamlined method not only provides functional nanocapsules, but also enables the facile accommodation of functional cores for yolk–shell nanostructures, expediting the development of multifunctional nanosystems.