Design of an Ultrafast and Controlled Visible Light-Mediated Photoiniferter RAFT Polymerization for Polymerization-Induced Self-Assembly (PISA)

In this contribution, we designed a new xanthate RAFT agent by introducing (5,6,7,8-tetrahydro-2-naphthalenyl)oxy (TNO) as the Z group, namely 2-[(((5,6,7,8-Tetrahydro-2-naphthalenyl)oxycarbonothioyl)thio)ethyl propanoate] (TNXEP). Due to the presence of the TNO group, TNXEP enabled highly controlled and ultrafast photoiniferter RAFT polymerization under violet (λ=405 nm) and blue (λ=450 nm) light. This approach was effectively extended to aqueous media for polymerization-induced self-assembly (PISA), facilitating the synthesis of polymeric nanoparticles. Leveraging the rapid photolysis and extended absorption of TNXEP, we demonstrated the first photoiniferter PISA system realizing ultrafast polymerization (>90 % monomer conversion in minutes) under visible light irradiation. Enhanced visible light penetration improved photopolymerization uniformity, enabling rapid and scalable production of polymeric nanoparticles at a 30 g scale in just 10 minutes, with tunable morphologies, including spheres, worms, and vesicles.