Scalable production of concentrated graphene oxide dispersion from acidic graphite oxide within one system

Concentrating graphene oxide (GO) dispersion is essential to realize the macro assembly of GO for many industrial applications. However, the preparation of GO dispersion from graphite oxide is very inefficient because of three involved independent processes of purification, exfoliation, and water removal. In this work, we developed an efficient tip-sonication field-assisted continuous cross-flow filtration (CFF) system combing the functions of the above independent processes. The pow-law model was used to study the influence of operating parameters (e.g. time, volume, and velocity) on the exfoliation yield in the dynamic sonication, and the maximum production rate was optimized to 218.7 g·h⁻¹. The ultrasonic effects on the permeate flux were studied systemically by the membrane fouling analysis and calculating the permeate flux recovery and the flux increase. The sonication can effectively improve the dispersibility and stability of the GO, and the obtained GO dispersions exhibit lower viscosity and narrower size distribution.