A method for manufacturing graphene-based materials includes (a) positioning graphite into an inner chamber of a rotatable housing of a rod mill. A plurality of elongate rigid rods are loosely positioned in the housing. In addition, the method includes (b) rotating the housing of the rod-mill after (a). Further, the method includes (c) rod milling the graphite with the rods during (b) to produce a first portion of the graphene-based materials and milled graphite. The first portion of the graphene-based materials include 30 layers or less of graphene and the milled graphite comprises more than 30 layers of graphene.

A method for manufacturing graphene-based materials includes (a) positioning graphite into an inner chamber of a rotatable housing of a rod mill. A plurality of elongate rigid rods are loosely positioned in the housing. In addition, the method includes (b) rotating the housing of the rod-mill after (a). Further, the method includes (c) rod milling the graphite with the rods during (b) to produce a first portion of the graphene-based materials and milled graphite. The first portion of the graphene-based materials include 30 layers or less of graphene and the milled graphite comprises more than 30 layers of graphene.

A process for exfoliating graphene, includes a step of irradiating a first substrate comprising graphene on its surface, with a helium or hydrogen plasma containing ions of energy comprised between 10 and 60 eV. A process for fabricating graphene on the surface of a second substrate, comprising the exfoliating process.

A process for exfoliating graphene, includes a step of irradiating a first substrate comprising graphene on its surface, with a helium or hydrogen plasma containing ions of energy comprised between 10 and 60 eV. A process for fabricating graphene on the surface of a second substrate, comprising the exfoliating process.

The invention described herein provides a dry graphene powder composition comprising pristine graphene flakes, wherein the pristine graphene flakes are non-covalently functionalised with polymeric amphiphilic molecules and wherein the dry graphene powder composition is capable of forming a stable homogeneous dispersion in aqueous or alcoholic media, in the absence of free dispersants or stabilizers, as well as methods for producing same, and the use thereof in graphene inks, for 2D and 3D printing, for production of flexible circuits, electrodes, electrocatalysts, for fabrication of nanocomposites and for wet-spinning of pristine graphene fibers.

A method of producing a graphene suspension, comprising: (a) mixing multiple particles of a graphitic material and multiple particles of a solid carrier material to form a mixture in an impacting chamber of an energy impacting apparatus; (b) operating the energy impacting apparatus with a frequency and an intensity for a length of time sufficient for peeling off graphene sheets from the graphitic material and transferring the graphene sheets to surfaces of the carrier material particles to produce graphene-coated carrier particles inside the impacting chamber; and (c) dispersing the graphene-coated carrier particles in a liquid medium and separating the graphene sheets from the carrier material particles using ultrasonication or mechanical shearing means and removing the carrier material from the liquid medium to produce the graphene suspension. The process is fast (1-4 hours as opposed to 5-120 hours of conventional processes), environmentally benign, cost effective, and highly scalable.

A method of producing a graphene suspension, comprising: (a) mixing multiple particles of a graphitic material and multiple particles of a solid carrier material to form a mixture in an impacting chamber of an energy impacting apparatus; (b) operating the energy impacting apparatus with a frequency and an intensity for a length of time sufficient for peeling off graphene sheets from the graphitic material and transferring the graphene sheets to surfaces of the carrier material particles to produce graphene-coated carrier particles inside the impacting chamber; and (c) dispersing the graphene-coated carrier particles in a liquid medium and separating the graphene sheets from the carrier material particles using ultrasonication or mechanical shearing means and removing the carrier material from the liquid medium to produce the graphene suspension. The process is fast (1-4 hours as opposed to 5-120 hours of conventional processes), environmentally benign, cost effective, and highly scalable.

A graphene preparing apparatus for exfoliating graphite includes a high-pressure water pump for generating a high-pressure flow of water, a waterjet nozzle for receiving the water and for generating a pulsed or cavitating waterjet, a graphite supply vessel having a supply duct for supplying graphite powder, an exfoliation chamber that has a first inlet for receiving the waterjet and a second inlet for receiving the graphite powder, an outlet through which a graphite slurry is expelled from the exfoliation chamber, a filtering unit downstream of the exfoliation chamber for separating graphene from the slurry and a graphene collection tank for collecting the graphene.

Compositions comprising hydrogenated and dehydrogenated graphite comprising a plurality of flakes. At least one flake in ten has a size in excess of ten square micrometers. For example, the flakes can have an average thickness of 10 atomic layers or less.

Compositions comprising hydrogenated and dehydrogenated graphite comprising a plurality of flakes. At least one flake in ten has a size in excess of ten square micrometers. For example, the flakes can have an average thickness of 10 atomic layers or less.