A Versatile Platform to Generate Shell‐Cross‐Linked Uniform Π‐Conjugated Nanofibers with Controllable Length, High Morphological Stability, and Facile Surface Tailorability

Living crystallization‐driven self‐assembly (CDSA) has emerged as an efficient route to generate π‐conjugated‐polymer‐based nanofibers (CPNFs) with promising applications from photocatalysis to biomedicine. However, the lack of efficient tools to endow CPNFs with morphological stability and surface tailorability becomes a frustrating hindrance for expanding application spectrum of CPNFs. Herein, a facile strategy to fabricate length‐controllable OPV‐based (OPV = oligo(p‐phenylenevinylene)) CPNFs containing a cross‐linked shell with high morphological stability and facile surface tailorability through the combination of living CDSA and thiol–ene chemistry by using OPV5‐b‐PNAAM32 (PNAAM = poly(N‐allyl acrylamide)) as a model is reported. Uniform fiber‐like micelles with tunable length can be generated by self‐seeding of living CDSA. By taking advantage of radical thiol–ene reaction between vinyls of PNAAM corona and four‐arm thiols, the shell of micelles can be cross‐linked with negligible destruction of structure of vinylene‐containing OPV core. The resulting micelles show high morphological stability in NaCl solution and PBS buffer, even upon heating at 80 °C. The introduced extra thiol groups in the cross‐linked shell can be further employed to install extra functional moieties via convenient thiol‐Michael‐type reaction. Given the negligible cytotoxicity of resulting CPNFs, this strategy opens an avenue to fabricate various CPNFs of diverse functionalities for biomedicine. A versatile approach to generate uniform π‐conjugated‐polymer‐based nanofibers with controllable length, high morphological stability, and easy surface modification through the combination of self‐seeding strategy of living crystallization‐driven self‐assembly and thiol–ene chemistry is developed.