Functionalization of Graphene Oxide by Two‐Step Alkylation

Abstract A new reaction sequence for the chemical functionalization of graphene oxide (GO) consisting of the nucleophilic addition of n‐butyllithium (n‐BuLi) to the GO sheets and a subsequent coupling and etherification reaction of the intermediates (Bu‐GO)n−Lin+ and 2‐ethylhexyl bromide leading to functionalized GO is developed. The reaction is investigated. The results show that the n‐Bu and 2‐ethylhexyl are covalently attached to the GO sheets and many sp3 carbons are formed by addition reaction of n‐BuLi to the plane of GO. After functionalization, the dispersibility of functionalized GO in ortho‐dichlorobenzene (ODCB) increases significantly to 0.4 mg mL−1 and the structural integrity of the graphene sheets remained. Good electronic conductivity of the film prepared from functionlized GO (i‐Octyl‐Bu‐GO) in ODCB is obtained after high temperature annealing.