LAUSR

Fuzzy nanofibers and single crystals developed using poly(3-hexylthiophene) (P3HT)-block-coily oligomers were compared. Based on grazing wide angle X-ray scattering and selected area electron diffraction patterns, grown crystalline structures were mainly edge-on. P3HT fuzzy nanofibers and single crystals were covered by the dielectric coily blocks of polystyrene, poly(methyl methacrylate), and poly(ethylene glycol), leading to brush-like regions on surface of crystals in longitude of P3HT backbones. The atomic force microscopy demonstrated that the single crystals grown by self-seeding method were significantly longer (26–181 µm) and thicker (59 nm–1.4 µm) than the corresponding nanofibers (0.8–21 µm in length and 1.5–23 nm in thickness). P3HT backbones were also more intimately stacked in single crystals in both hexyl side chains and π–π stacking directions, particularly in toluene (13.42–14.63 and 3.30–3.47 Ǻ) than in nanofibers (15.03–16.17 and 3.51–3.67 Ǻ). End coily blocks resulted in slightly higher layer spacings in both nanofibers and single crystals. Shorter P3HT chains were laminated on each other in single crystals; however, they were mostly extended in the nanofibers. Poorer solvents, lower crystallization temperatures, and shorter P3HT chains increased the backbone lamination in single crystals.