Controlling Poly(3-Hexylthiophene) Crystal Dimension: Nanowhiskers And Nanoribbons

A study was conducted to investigate crystallization of regioregular poly(3-hexylthiophene) (P3HT) by changing the polymer molecular weight (M n), crystallization temperature, and polymer concentration. It was observed that polymer chains changed from extending to folding in nanowhiskers when the Mn was above a critical value. The fold length was controlled by changing the crystallization temperature. These observations provided the first evidence of P3HT chain folding when it crystallized from solutions. It was also observed that one dimensional (ID) nanowhiskers composed of extended P3HT chains were grown into highly ordered two-dimensional (2D) nanoribbons from more concentrated P3HT solutions, generating a new class of large P3HT crystals. The increased concentration of folded-chain and extended-chain P3HT samples resulted in the formation of gels