Corona Chain-Controlled Transition from Ostwald Ripening-Grown Hexagonal Platelets to Screw-Dislocation Spirals in...

Ostwald ripening is ubiquitous in colloidal growth yet is rarely recognized as a dominant pathway in polymer self-assembly. Herein, we investigate the solution self-assembly of liquid-crystalline polypeptoids based on poly(N-2-ethyl-1-hexyl glycine) (PNEHG) homopolymers and their amphiphilic block copolymers. Upon supersaturation, PNEHG homopolymers form micrometer-sized, highly symmetric hexagonal platelets primarily through Ostwald ripening. This behavior arises from rod-like PNEHG chains packing into a columnar hexagonal (Col_hex) mesophase with long-range orientational order and short-range positional order, enabling continuous structural rearrangement during growth. Incorporation of a solvophilic poly(N-methyl glycine) (PNMG) block induces a morphological transition from flat platelets to hexagonal spirals with periodic screw dislocations and continuous helical ramps, which is driven by steric constraints at the core-corona interface that introduce packing frustration and redirect mesogenic growth. These findings identify Ostwald ripening as a key mechanism in mesogenic growth and establish the corona-forming block as an active regulator in liquid crystallization-driven self-assembly.