A water-based graphene dispersion is made by shear stabilization. The method of preparing the water-based graphene dispersion using shear stabilization includes adding a composition containing a graphene powder, a super wetter surfactant and a water dispersible rheology agent into water to form an aqueous mixture; and shearing the aqueous mixture under high pressures to break down the thick layers of the graphene powder to thin layers of graphene platelet particles and to form the water-based graphene dispersion with the graphene platelet particles dispersed in the water-based graphene dispersion. The water-based graphene dispersion is stable without visible phase separation after storage at room temperature for at least one year or even more than one year.

A water-based graphene dispersion is made by shear stabilization. The method of preparing the water-based graphene dispersion using shear stabilization includes adding a composition containing a graphene powder, a super wetter surfactant and a water dispersible rheology agent into water to form an aqueous mixture; and shearing the aqueous mixture under high pressures to break down the thick layers of the graphene powder to thin layers of graphene platelet particles and to form the water-based graphene dispersion with the graphene platelet particles dispersed in the water-based graphene dispersion. The water-based graphene dispersion is stable without visible phase separation after storage at room temperature for at least one year or even more than one year.

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.

Disclosed are a method for manufacturing an electrode, an electrode manufactured thereby, a membrane-electrode assembly including the electrode, and a fuel cell containing the membrane-electrode assembly. The method includes the steps of: preparing an electrode forming composition by mixing a catalyst with an ionomer; applying a low-frequency acoustic energy to the electrode forming composition to perform resonant vibratory mixing so as to coat the ionomer on the surface of the catalyst; and coating the electrode forming composition to manufacture an electrode.

Disclosed are a method for manufacturing an electrode, an electrode manufactured thereby, a membrane-electrode assembly including the electrode, and a fuel cell containing the membrane-electrode assembly. The method includes the steps of: preparing an electrode forming composition by mixing a catalyst with an ionomer; applying a low-frequency acoustic energy to the electrode forming composition to perform resonant vibratory mixing so as to coat the ionomer on the surface of the catalyst; and coating the electrode forming composition to manufacture an electrode.

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.

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.