A strategy for preparing porous polymeric micro-/nanomaterials via polymerization-induced self-assembly with process conditions modulated by macromolecular chain transfer agents.

A strategy for the fabrication of porous polymeric micro-/nanomaterials via reversible addition-fragmentation chain transfer (RAFT) polymerization-induced self-assembly (PISA) has been proposed. The process is regulated by tuning the stepwise addition strategy of the macromolecular chain transfer agent (macro-CTA). A systematic study was carried out on three types of polymerization-induced self-assembly (PISA) systems, including redox-initiated and photo-initiated aqueous emulsion polymerization of glycidyl methacrylate (GlyMA), as well as thermally initiated dispersion polymerization of styrene (St) in methanol. All systems were mediated by the same poly(ethylene glycol) methacrylate (PPEGMA) macro-CTA. Experimental results show that all three polymerization-induced self-assembly systems can successfully prepare porous polymer micro-/nanomaterials with regular morphology, tunable pore size, and abundant pores, namely PPEGMA9.1-b-PGlyMAn and PPEGMA9.1-b-PSn. It should be noted that the redox and thermal systems are comprehensively characterized by kinetic and GPC tests, while the photoinitiated system only acts as a supporting demonstration based on TEM images in the supplementary information. Moreover, the process conditions for achieving porous morphologies were explored by adjusting the molar ratio of the macro-CTA added in batches, the time intervals between additions, and the monomer concentration.