Mass transfer kinetics of graphene oxide prepared by chemical oxidation intercalationg assisted ultrasonic field

Abstract

The key step of the control reaction for the preparation of graphene oxide (GO) by chemical oxidation of KMnO4/ concentrated H2SO4 oxidation system is the intercalation mass transfer process of oxidizer in graphite. Ultrasonic field can promote the intercalation mass transfer process, but the mass transfer kinetics remains unclear. In this paper, the kinetic model of mass transfer coefficient of graphene oxide sheet intercalated by Mn2O7 oxidizer in ultrasonic field was established. The Mn2O7 intercalation process after the intervention of the ultrasonic was simulated by COMSOL Multiphysics 5.5 simulation software. The results show that the ultrasonic field makes the Mn2O7 solution inside and outside the graphite layer turbulent, and the ultrasonic intervening time has little influence on the concentration distribution and diffusion rate of the solution outside the graphite layer, while it has great influence on the concentration distribution and little influence on the diffusion rate change inside the graphite layer. These results contribute to the improvement of the mass transfer theory for the preparation of GO by ultrasonic assisted chemical oxidation.

Keywords

• Graphene oxide
• Intercalation oxidation
• Ultrasonic field
• Mass transfer modeling
• Numerical simulation