Composition, structure and morphology evolution of Octadecylamine (ODA)-reduced graphene oxide and its dispersion stability under different reaction conditions

Octadecylamine (ODA) can solve the aggregation problem of graphene sheets in the chemical exfoliation method. However, no attempts have been made to investigate the evolution of ODA-reduced graphene oxide (ORGO) with reaction conditions and the modification mechanism, which is the core problem to realize the controllable production and practical application of graphene. In this study, we treated graphene oxide (GO) with ODA under different reaction conditions to prepare ORGO. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy, atomic force microscopy, Raman spectroscopy, thermogravimetric analysis (TGA), and UV-vis spectrophotometry were employed to analyze the composition, structure, morphology and characteristics of the as-prepared graphene sheets. The results showed that the reduction reaction could occur under mild conditions, but the edge grafting reaction could only be activated by a higher temperature. Moreover, the ORGO created at 80 °C for 5 h and 120 °C for 0.5 h exhibited the optimized properties, both excellent dispersing stability and high heat resisting property, since they had more edge grafting chains and a suitable reduction degree.