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 π–π 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(ε-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.