Influence of Hydrophile Topology on the Formation of Polymer Cubosomes by Polymerization-Induced Self-Assembly

Polymer cubosomes (PCs) have attracted considerable attention in nanomaterials research due to their high specific surface areas. Polymerization-induced self-assembly (PISA) provides an efficient and versatile route for preparing such structures. However, the critical role of hydrophilic stabilizers with tailored architectures in PC fabrication has remained incompletely understood. Herein, we investigate the effect of stabilizers containing poly (ethylene glycol) (PEG) oligomeric side-chains with elaborate adjustment of position and content on the formation of PCs via PISA. The stabilizers include poly(poly (ethylene glycol) methyl ether methacrylate (oE), poly(hydroxypropyl methacrylate (H), and their block copolymers (oE-b-H and H-b-oE), and the core-forming monomer is styrene (St). Compared with the homopolymer-type stabilizers, a high feeding ratio of St to stabilizers is needed to form PCs for block copolymer-type stabilizers. This is attributed to impeded morphological fusion resulting from incompatibility between oE and H segments. Additionally, increasing the oE content in H-b-oE-type stabilizers leads to a more substantial St amount for preparing PCs than in oE-b-H-type stabilizers. We propose that excess St acts as a plasticizer, mitigating the strong steric hindrance imposed by PEG side-chains near the hydrophobic/hydrophilic interface. We believe that this work will enrich the fundamental research for PISA-mediated PC preparation through stabilizer engineering.