Resumen
Large-scale production in a single step and at room temperature of material composed of few graphene sheets with a high degree of defects by means of high-energy oscillatory dry mechanical milling. The present invention falls within the manufacturing of graphene-based materials in powder form with industrial scalability. The particles obtained are mesoporous, they are composed of few layers of graphene with a high degree of defects with great chemical stability and can be used in multidisciplinary technological fields such as catalysis, selective gas sensors and materials that absorb electromagnetic radiation in the microwave region. (Machine-translation by Google Translate, not legally binding)
Reivindicaciones
1. Method of large-scale production of few-layers graphene (FLG) with high degree of defects from graphite by grinding of high-energy balls by dry oscillating motion characterized by: - the precursor is graphite in the form of flakes with a length comprised between 2 and 50 µm and a thickness of less than 100 nm, and the grinding is carried out in a metal container coated with a material possessing a Knoop hardness greater than 1.000 kg/mm<2> in presence of balls of the same material, with a frequency of oscillation between 1.000 and 1.500 rpm and a mass ratio between the ball or balls and the graphite used between 1:20 and 1:30. 2. Method of large-scale production of few-layers graphene (FLG), according to claim 1, because the grinding process is carried out at room temperature and ambient pressure, in an inert atmosphere and without additives nor subsequent processing treatments. 3. Method of large-scale production of few-layers graphene (FLG), according to claim 1, wherein the graphite flakes are monocrystalline. 4. Method of large-scale production of few-layers graphene (FLG), according to claim 1, wherein the mass ratio between the graphite and the ball or balls used is preferably 1:25. 5. Method of large-scale production of few-layers graphene (FLG), according to previous claims, wherein the material that coats the metal container and forms the balls is tungsten carbide. 6. Method of large-scale production of few-layers graphene (FLG), according to claim 5, wherein grinding is conducted with a single ball of tungsten carbide. 7. Method of large-scale production of few-layers graphene (FLG), according to claim 6, wherein the ball possesses a volume ratio between 0,8:1 and 1,2:1, preferably 1:1 with respect to the graphite used and the volume between 1:48 and 1:52, preferably 1:50 with respect to the container's container. 8. Method of large-scale production of few-layers graphene (FLG), according to previous claims, wherein the grinding time varies between 20 and 300 minutes to obtain mesoporous structures. 9. Method of large-scale production of few-layers graphene (FLG), according to claim 8, wherein the grinding time varies between 20 and 100 minutes to obtain distributions of different sizes corresponding to the starting graphite and FLG. 10. Method of large-scale production of few-layers graphene (FLG), according to claim 8, wherein the grinding time varies between 120 and 300 minutes to obtain distributions of homogeneous size corresponding to FLG. 11. Method of large-scale production of few-layers graphene (FLG), according to claim 8, wherein FLG is obtained with a thickness comprised between 3 and 10 layers of graphene according to the grinding time so that the number of layers decreases as the grinding time increases.
