High-Quality Nano/Micro Hairy Single Crystals Developed from Poly(3-hexylthiophene)-Based Conductive-Dielectric Block Copolymers Having Flat-on and Edge-on Orientations.

Highly uniform and conductive single crystals of poly(3-hexylthiophene) (P3HT)-based homo and block copolymers with the end coily blocks of polystyrene, poly(methyl methacrylate), and poly(ethylene glycol) are developed using self-seeding method from varied quality solvents. Edge-on and flat-on orientations are detected depending on the thickness and width of single crystals. Coily blocks are excluded from the P3HT crystalline structures, leading to brush-like or hairy regions on surface of grown single crystals in the longitude of P3HT chains. The larger single crystals possessing flat-on orientation are obtained from weaker solvents at higher seeding temperatures. The longer P3HT chains are folded, however, the shorter backbones are laminated on each other. The highest backbone lamination occurs for homo-P3HT7150 ( Mn of P3HT = 7150 g mol−1) single crystals grown at 20 °C from anisole, the weakest employed solvent. In contract, highly ordered and folded hairy single crystals are acquired from better solvents and high molecular weight P3HTs. In these conditions, the crystallographic features of the hairy block copolymer single crystals are similar to those of nonhairy homo-P3HT ones. The coily brush-covered P3HT48 800 single crystals have more foldings compared to the homo-P3HT48 800 ones, whereas only two laminated backbones in shorter P3HT blocks are detected. [ABSTRACT FROM AUTHOR]