Self-catalyzed synthesis of a nano-capsule and its application as a heterogeneous RCMP catalyst and nano-reactor

A novel polymeric nano-capsule bearing quaternary ammonium iodide (QAI) groups on both the outer and inner surfaces of the shell was synthesized via self-catalyzed polymerization-induced self-assembly (PISA). Because QAI works as a catalyst of reversible complexation mediated living radical polymerization (RCMP), the obtained nano-capsule was exploited as a dual RCMP catalyst based on the outer and inner QAI groups. Benefitting from the outer QAI groups, the nano-capsule served as a supported heterogeneous RCMP catalyst with good recyclability to generate polymers outside the nano-capsule. Benefitting from the inner QAI groups, the nano-capsule served as a nano-reactor to generate polymers inside the nano-capsule. The nano-capsule served as a substrate-sorting nano-reactor based on the selective diffusivity of small molecules and polymers through the shell by their sizes. Namely, large molecules (polymers) once generated in the nano-reactor are not permeable through the shell, enabling the entrapment of the generated polymers in the nano-capsule. A homopolymer, an amphiphilic block copolymer, and a multi-polarity and multi-elemental block copolymer were synthesized and entrapped in the nano-capsule.