pH‐Modulated 1D Hierarchical Self‐Assembly of a Brush‐Like Poly‐Para‐Phenylene Homopolymer

Abstract The controllable self‐assembly of conjugated homopolymers, especially homopolymers without other segments (a prerequisite for phase separation), which can afford chances to achieve tunable optical/electronic properties, remains a great challenge due to their poor solubility and has remained rarely documented. Herein, a conjugated homopolymer (DPPP‐COOH) is synthesized, which has a unique brush‐like structure with a conjugated dendritic poly‐para‐phenylene (DPPP) backbone and alkyl‐carboxyl side chains at both edges of the backbone. The introduction of carboxyl makes the brush‐like homopolymer exhibit pH‐modulated 1D hierarchical self‐assembly behavior in dilute solution, and allows for flexible morphological regulation of the assemblies, forming some uncommon superstructures including ultralong nanowires (at pH 7), superhelices (at pH 10) and “single‐wall” nanotubes (at pH 13), respectively. Furthermore, the good aqueous dispersibility and 1D feature endow the superstructures formed in a high‐concentration neutral solution with high broad‐spectrum antibacterial performance superior to that of many conventional 1D materials.