Keywords
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Carbon nanotube; Reduced Graphene Oxide, Orientation, Grafting, Functionalization, Nano-hybrid
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Abstract
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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 donoracceptor
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.
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