Polymerization-Induced Self-Assembly with Assistance of Aromatic Interactions Facilitates the Formation of Polymeric Nanotubes

• Published in: Macromolecules Vol. 56; no. 9; pp. 3296 - 3303
• Main Authors: Zhu, Ren-Man, Chang, Zi-Xuan, Zhang, Wen-Jian, Hong, Chun-Yan
• Format: Journal Article
• Language: English
• Published: American Chemical Society 09.05.2023
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/acs.macromol.3c00302

Polymerization-induced self-assembly (PISA) has been demonstrated to be a powerful strategy for producing polymeric nano-objects. Polymeric nanotubes with hollow and anisotropic structures have attracted great interest in materials science. However, according to the theoretical prediction of the packing parameter, polymeric nanotubes are hard to be produced by the self-assembly of block copolymers, which may be due to the lack of directionality of solvophobic interactions. Herein, we demonstrate that aromatic interactions between the solvophobic blocks facilitate the formation of polymeric nanotubes. Polymeric nanotubes with a remarkable length (>11 μm) are generated in the reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization of the aromatic monomer 2-(methacryloyloxy) ethyl anthracene-9-carboxylate (MAEAC) using poly­(ethylene glycol) as the macro RAFT agent (PEG45-CPADB). When the aromatic interactions of the membrane-forming blocks are weakened by high temperature or copolymerization of MAEAC with a weakly aromatic monomer 2-(methacryloyloxy)­ethyl benzoate (MAEB), spherical nano-objects instead of nanotubes tend to be produced. The concentration of polymer chains also plays a vital role in the formation of polymeric nanotubes. The aspect ratio of the polymeric nanotubes can be adjusted by controlling the polymer concentration without varying the polymer composition, and polymeric nanotubes with a larger aspect ratio tend to be generated at higher concentrations of block copolymers. The formation of polymersomes with different aspect ratios for a given polymer provides significant opportunities to investigate the shape-determined performances of the polymersomes while eliminating the influence of polymer composition.