▎ 摘　　要

NOVELTY - Preparing a dispersion of graphene particles or sheets in a liquid medium (6), comprises: (a) providing a bar or block (5) of solid material made of graphite; (b) scraping the material surface (2) of a substrate to create a trace of scraping of the material on the surface of the substrate; and (c) dipping the substrate in a liquid medium and subjecting the liquid medium to ultrasound, where the steps (b) and (c) are performed at least in part, simultaneously. USE - The dispersion of graphene particles or sheets is useful in the manufacture of polymer composites, composite materials, final composite and electronic circuits. ADVANTAGE - The process: provides a dispersion of graphene particles or sheets with high yield; and is inexpensive and suitable for industrial scale preparation. The process avoids external heating or addition of toxic chemicals. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a device for carrying out the process comprising an arm (3) capable of holding the bar or block (5) in bulk material, a substrate provided with a surface (2) contacting the bar or block in bulk material, a means of shifting to generate a relative displacement between the solid material and the substrate, a means of regulating and/or controlling the force of pressure for regulating, consistently maintaining and/or measuring the pressure between the solid material and surface of the substrate during the relative movement, a liquid reservoir for immersing at least partially the surface in a liquid medium (6), an ultrasound generator (7) for subjecting the liquid to the ultrasound effect. DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of a device for preparing dispersion of graphene particles or sheets. Surface (2) Arm (3) Bar or Block (5) Liquid phase (6) Ultrasound generator. (7)