Coacervate Nanoreactors: PEG Side-Chain-Assisted Compartmentalization Leads to an Oxygen-Tolerant Polymerization-Induced Electrostatic Self-Assembly

Biomimetic synthesis represents a cutting-edge topic in chemistry/materials science. Herein, we demonstrate poly(ethylene glycol) (PEG) short side-chain-assisted monomer complex coacervation and reaction-induced polyion complex compartmentalization that lead to oxygen-tolerant polymerization-induced electrostatic self-assembly (PIESA). This is achieved by the one-pot synthesis of a PEGylated anionic polyelectrolyte and heterogeneous iterative polymerization of a cationic monomer under ecofriendly ambient, in-air aqueous photo-RAFT conditions. Simultaneous reversible all-segment-participating ternary complex coacervation and Coulombic interdomain interactions lead to coacervate nanoreactors that are capable of immediate initiation and fast reversible addition-fragmentation chain transfer reactions. Approximately 2 nm monomer complex nanoclusters act as building blocks to drive liquid-liquid phase separation. Polymerization induces hierarchical self-assembly in a droplet nucleation-fusion-fission mechanism together with PEG-crowded polyion complex compartmentalization, using nanoclusters as building blocks, mechanistically similar to liquid-liquid phase separation through supramolecular polymerization. Consequently, protein-like, one-component multicompartment coacervate nanoreactors with oxygen-tolerant well-controlled fast reactions are achieved. This work provides important implications for the efficient precise synthesis of biomimetic coacervate nanodevices of increasing complexity.