Block Copolymer Nanoparticles with Surface-enriched RAFT Groups Prepared by Orthogonal RAFT-mediated Polymerization-induced Self-assembly

Abstract

Block copolymer nanoparticles prepared via reversible addition-fragmentation chain transfer (RAFT)-mediated polymerization-induced self-assembly (PISA) have attracted considerable attention because of their structural controllability, compositional diversity, and scalability. However, conventional RAFT-PISA formulations can only generate block copolymer nanoparticles with RAFT groups buried inside, which restricts subsequent surface modification and morphological control. Herein, we synthesized a multifunctional macro-RAFT agent bearing multiple poly(N,N-dimethylacrylamide) side chains enriched in RAFT reactive groups. This macro-RAFT agent enabled orthogonal RAFT-PISA of methacrylic monomers, affording block copolymer nanoparticles with a high surface density of RAFT groups. Notably, the surface-exposed RAFT moieties can be reactivated for the subsequent chain extension, allowing surface-initiated RAFT polymerization to functionalize nanoparticles and construct hierarchical vesicles with well-defined nanostructures on the surface. This work provides insights into the intrinsic origin of the different levels of control imparted by RAFT agents and offers a new design strategy for the surface modification and further functionalization of block copolymer nanoparticles.

Keywords

Polymerization-induced self-assembly / RAFT polymerization / Block copolymer nanoparticles / Surface modification / Dispersion polymerization / Photoinitiated polymerization / Orthogonal polymerization / PET-RAFT polymerization

RIGHTS & PERMISSIONS

2026 SIOC, CAS, Shanghai, & WILEY-VCH GmbH