Carbon-based materials, and associated methods and articles, are generally provided. In some embodiments, a carbon-based material comprises a carbon-based portion and a functional group bonded to the carbon-based portion. The functional group may be capable of forming a reversible covalent bond with a species. Carbon may make up greater than or equal to 30 wt % of the carbon-based portion. The carbon-based portion may comprise graphene, and a ratio of a total number of functional groups in a plurality of functional groups bonded to the graphene to a total number of carbon atoms in the plurality of carbon atoms of the graphene may be greater than or equal to 1:50. The carbon-based portion may comprise graphene, and greater than or equal to 70% of the graphene sheets may be spaced apart from their nearest neighbors by a distance of greater than or equal to 10 Å. A method may comprise applying a voltage to a carbon-based material. The voltage may be applied in the presence of a combination of solvents comprising a dissolved species. The combination of solvents may comprise a solvent stable at voltages of greater than or equal to −3.15 V and less than or equal to −2.2 V and/or may comprise a solvent with a surface tension within 25% of a surface tension of the carbon-based material. The voltage may be a decreasing voltage that decreases at a rate of greater than or equal to 2 μV/s and less than or equal to 40 μV/s and has a value of greater than or equal to −2.2 V and less than or equal to −3.15 V at at least one point in time.

A method of producing an electrochemically derived graphene oxide and product produced therefrom. The method comprises locating graphite particles within an electrochemical cell having a working electrode, counter electrode, and an aqueous acid electrolyte, the working electrode being positioned within the electrolyte to contact at least a portion of the graphite particles; agitating the graphite particles within the electrolyte; and applying a potential difference between the working electrode and counter electrode, thereby resulting in electrochemical exfoliation and oxidation of the graphite particles to produce graphene oxide.

A method of producing an electrochemically derived graphene oxide and product produced therefrom. The method comprises locating graphite particles within an electrochemical cell having a working electrode, counter electrode, and an aqueous acid electrolyte, the working electrode being positioned within the electrolyte to contact at least a portion of the graphite particles; agitating the graphite particles within the electrolyte; and applying a potential difference between the working electrode and counter electrode, thereby resulting in electrochemical exfoliation and oxidation of the graphite particles to produce graphene oxide.

An apparatus and method to exfoliate a graphite grain is described. A mixture of a graphite grain and a fluid medium are transferred into a vessel. The vessel includes an agitator and a chiller. The chiller chills the mixture such that the fluid medium at least partially solidifies into an ice grain. The agitator agitates the mixture to induce a contact between the graphite grain and the ice grain. The contact between the graphite grain and the ice grain exfoliates the graphite grain.

An apparatus and method to exfoliate a graphite grain is described. A mixture of a graphite grain and a fluid medium are transferred into a vessel. The vessel includes an agitator and a chiller. The chiller chills the mixture such that the fluid medium at least partially solidifies into an ice grain. The agitator agitates the mixture to induce a contact between the graphite grain and the ice grain. The contact between the graphite grain and the ice grain exfoliates the graphite grain.

A composite sheet for shielding electromagnetic and radiating heat includes: a first layer formed of metal; and a second layer that is a graphene layer formed on one surface of the first layer and including charged chemically modified graphene such that thermal conductivity and electromagnetic shielding ability are improved while securing economic efficiency by using the second layer including the charged chemically modified graphene and the graphene flakes.

A composite sheet for shielding electromagnetic and radiating heat includes: a first layer formed of metal; and a second layer that is a graphene layer formed on one surface of the first layer and including charged chemically modified graphene such that thermal conductivity and electromagnetic shielding ability are improved while securing economic efficiency by using the second layer including the charged chemically modified graphene and the graphene flakes.

An apparatus and method to exfoliate a graphite grain is described. A mixture of a graphite grain and an ice grain are transferred into a vessel. The vessel includes an agitator. The agitator agitates the mixture to induce a contact between the graphite grain and the ice grain. The contact between the graphite grain and the ice grain exfoliates the graphite grain.

An apparatus and method to exfoliate a graphite grain is described. A mixture of a graphite grain and an ice grain are transferred into a vessel. The vessel includes an agitator. The agitator agitates the mixture to induce a contact between the graphite grain and the ice grain. The contact between the graphite grain and the ice grain exfoliates the graphite grain.

A method of producing a multi-layered functionalised graphene oxide paper, comprises the steps of providing an aqueous suspension of oxidised graphene oxide flakes, size reducing the oxidised graphene oxide flakes in the suspension to provide an aqueous suspension of particulate oxidised graphene oxide having an average particle size of less than 1 μm and drying the aqueous suspension in a vessel to provide a multi-layered graphene oxide material. The multi-layered graphene oxide material is annealed to provide a multi-layered reduced graphene oxide material, before surface grafting functional groups to the surface of the multi-layered reduced graphene oxide material by reacting the material with a functional group precursor in the presence of plasma. The use of a graphene oxide material to treat bone defects, and as an energy storage device, is also described.