How to process Graphene with Ultrasonic equipment

As graphene becomes more and more popular, various disciplines have gradually carried out in-depth research, and many methods for preparing graphene have been developed, such as micromechanical exfoliation, epitaxial growth, chemical vapor deposition, liquid phase exfoliation, and redox method, etc. However, the above methods have their own shortcomings to a greater or lesser extent, and the efficiency is generally low. In addition, some methods will also destroy the quantum structure of graphene, greatly affecting the electrical and thermal properties of graphene. Therefore, efficient, simple, and large-scale preparation of graphene has become a major difficulty in the relevant fields.

Ultrasonic preparation of graphene process

Assemble the ultrasonic drive power supply, reactor body, ultrasonic vibrator, material feed port, and material pump according to Figure 1. Connect the cooling circulating water inlet to the external water source, the cooling circulating water outlet to the external outlet pipe, and close the material flow regulating valve, feed control valve, discharge control valve, and sampling port control valve. Using graphite as the raw material, pre-intercalation is used to obtain low-oxidation expanded graphite, which is added to an organic solvent or water to form a graphene pretreatment liquid; then, with the help of ultrasound, heating or airflow, a well-dispersed graphene dispersion is obtained; finally, the dispersion is separated by a centrifuge or filtered by a filter press to obtain graphene microsheets.

When graphene matches the surface of the organic solvent, their interaction can balance the energy required to peel off the graphene sheets. Then, through ultrasonic treatment, the ultrasonic wave provides the peeling force and plays a peeling effect. Increasing the ultrasonic time can greatly improve the graphene yield. Adjusting the ultrasonic power of the ultrasonic power supply also has a significant effect on the graphene peeling effect. The graphene peeling effect depends on the matching degree between the ultrasonic power and the van der Waals force between the graphene layers. When the ultrasonic power is appropriately increased, the tensile stress generated on the graphene surface is greater than the van der Waals force between the graphene layers, and the peeling effect will also be significantly increased.

Experimental research has found that by thermally inserting graphite to form a graphene pretreatment solution, high-quality graphene can be easily peeled off under the action of ultrasound, and the number of graphene sheets is basically less than 10. Since the principle of ultrasonic preparation of graphene is based on "ultrasonic cavitation", it will not cause structural defects in graphene, ensuring its morphology and performance are intact, which is of great significance for large-scale mass production of graphene.