Synthesis and characterisation of poly(3-hexyl thiophene)-grafted graphene oxide sheets by click chemistry

Poly(3-hexyl thiophene)-grafted graphene oxide (GO-f-P3HT) was synthesised via two kinds of click chemistry reaction owing to different synthesis methods of azide-functionalised GO, that is, azide-functionalised GO derived from 2-chloroethyl isocyanate-treated GO (GO-f-P3HT(1)) and azide-functionalised GO by direct conversion of epoxy groups in the GO to azide groups (GO-f-P3HT(2)). The successful covalent grafting of P3HT to GO in both samples of GO-f-P3HT(1) and GO-f-P3HT(2) was confirmed by Fourier transform infrared and X-ray photoelectron spectroscopies. The transmission electron microscopy (TEM) measurements showed clearly that the P3HT molecules were present on the surface of GO sheets. In addition, it was observed that more polymer chains were attached on the GO surface of GO-f-P3HT(1) owing to more favourable click chemistry reaction in GO-f-P3HT(1) than GO-P3HT(2). The click coupling in this study was found to be effective for achieving homogeneous dispersion of GO in P3HT molecules which is desired for high performance P3HT-based electronic devices.