Reverse Sequence Polymerization‐Induced Self‐Assembly in Aqueous Media

We report a new aqueous polymerization-induced self-assembly (PISA) formulation that enables the hydrophobic block to be prepared first when targeting diblock copolymer nano-objects. This counter-intuitive reverse sequence approach uses an ionic reversible addition–fragmentation chain transfer (RAFT) agent for RAFT dispersion polymerization of 2-hydroxypropyl methacrylate (HPMA) produce charge-stabilized latex particles. Chain extension using water-soluble methacrylic, acrylic or acrylamide comonomer then produces sterically stabilized nanoparticles in one-pot formulation. In each case, monomer diffuses into PHPMA particles, which act as locus polymerization. A remarkable change morphology occurs ≈600 nm is converted much smaller nanoparticles, exhibit thermoresponsive behavior. Such PISA formulations enable efficient synthesis functional nanoparticles.