Document Type: Research Paper
Chemical Engineering Department, Faculty of Engineering, Azarbaijan Shahid Madani University, Tabriz, Iran
Faculty of Polymer Engineering and Institute of Polymeric Materials, Sahand University of Technology, Tabriz, Iran
The multi-walled carbon nanotubes (CNTs) and reduced graphene oxide (rGO) nanosheets were functionalized with 2-hydroxymethyl thiophene (CNT-f-COOTh) and 2-thiophene acetic acid (rGO-f-TAA) and grafted with poly(3-dodecylthiophene) (CNT-g-PDDT and rGO-g-PDDT) to manipulate the orientation and patterning of crystallized regioregular poly(3-hexylthiophene) (P3HT). Distinct nano-hybrid structures including double-fibrillar (5.11−5.18 S/cm), shish-kebab (2.19−2.28 S/cm), and stem-leaf (6.96−7.51 S/cm) were developed using modified CNTs and P3HT. The most effective parameter on morphology of donor-acceptor supramolecules was the surface functionalization and grafting. The electrical conductivities of supramolecules based on P3HT and rGO, rGO-f-TAA, and rGO-g-PDDT ranged in 3.81−3.87, 3.91−3.95, and 10.67−10.70 S/cm, respectively. P3HT chains preferred to interact with their thiophene rings with bared rGO and CNT surfaces, resulting in a conventional face-on orientation. In P3HT/rGO-f-TAA and P3HT/CNT-f-COOTh supramolecular nanostructures patterned with P3HT, the orientation of P3HT chains changed from face-on to edge-on, originating from the strong interactions between the hexyl side chains of P3HTs and functional groups. Nano-hybrids based on grafted rGO demonstrated a patched-like morphology composed of flat-on P3HTs with main backbones perpendicular to the substrate. Based on the ultraviolet-visible and photoluminescence analyses, the flat-on orientation was the best for P3HT chains assembled onto CNT and rGO, which was acquired for CNT-g-PDDT and rGO-g-PDDT nano-hybrids.