Self-Assembling Branched and Hyperbranched Nanostructures of Poly(3-hexylthiophene) by a Solution Process

As a typical linear conjugated polymer, poly (3-hexylthiophene) (P3HT) has been successfully used in organic electronic and optoelectronic devices. Strong anisotropic pi-pi interactions between planar molecular backbones and weak van der Waals interactions between their alkyl side groups make P3HT favorable for the formation of long nanowires, Herein, we propose a facile solution strategy to prepare branched and hyperbranched P3HT nanostructures. A P3HT nanowire was first generated as the trunk, and then branches formed by a heterogeneous nucleation process. The process was realized by a slow evaporation of P3HT in a blend solvent, in which 1,2-dichlorobenzene acted as a good solvent and trimethanolamine acted as a poor solvent. Interestingly, the hyperbranched P3HT nanostructures can be produced using the same principle by changing the evaporation conditions. The molecular direction of P3HT in the trunks and branches was determined dearly by selected area electron diffraction. Due to its good crystallinity and unique morphology, branched and hyperbranched nanostructures might have potential opportunities for organic electronic and optoelectronic devices.