Improved dispersibility of graphene oxide in o-dichlorobenzene by adding a poly(3-alkylthiophene)

The dispersibility of graphene oxide (GO) in o-dichlorobenzene was improved by adding poly(3-hexylthiophene) (P3HT). The resulting GO dispersion was stable for up to one week. Transmission electron microscopy, UV-Vis spectroscopy, Raman spectroscopy and photoluminescence spectroscopy indicated that the crystallization of P3HT molecules on the GO surface prevented GO sheets from strong pi-pi interactions, and thus greatly increased the dispersibility of GO in organic solvent. The crystallization of P3HT molecules is a physical and reversible process, and it is time and temperature dependent. The crystallization process becomes remarkable with prolonged aging time and decreasing temperature. Other conjugated polymers, including poly(3-butylthiophene) and poly(3-hexylthiophene)-b-poly(epsilon-caprolactone), were further examined by the same method, and similar phenomena were also observed, indicating that the simple method of using a poly(3-alkylthiophene) to improve GO dispersibility in organic solvent is universal. (C) 2012 Elsevier Ltd. All rights reserved.