Provided is a 2D nanomaterial fiber. The 2D nanomaterial fiber includes plate-type fibrous cross sections formed by orienting a 2D nanomaterial in a longitudinal direction and stacking the oriented 2D nanomaterial.

Provided is a laminated graphitic layer as an elastic heat spreader, the layer comprising: (A) a plurality of graphitic or graphene films prepared from (i) graphitization of a polymer film or pitch film, (ii) aggregation or bonding of graphene sheets, or (iii) a combination of (i) and (ii), wherein the graphitic or graphene film has a thermal conductivity of at least 200 W/mK, an electrical conductivity no less than 3,000 S/cm, and a physical density from 1.5 to 2.25 g/cm.sup.3; and (B) a conducting polymer network adhesive that bonds together the graphitic or graphene films to form the laminated graphitic layer; wherein the conductive polymer network adhesive is in an amount from 0.001% to 30% by weight and wherein the laminated graphitic layer preferably has a fully recoverable tensile elastic strain from 1% to 50% and an in-plane thermal conductivity from 100 W/mK to 1,750 W/mK.

There are provided a composite plated product, which has little uneven appearance, a low contact resistance and good wear resistance, and a method for producing the same without the need of any silver-plating solutions containing cyanides and any silver-plating solutions containing silver nitrate as a silver salt. After carbon particles are caused to be suspended in water, an oxidizing agent is added thereto for carrying out a wet oxidation treatment of the carbon particles, and a silver-plating solution, which contains at least one sulfonic acid and the carbon particles treated by the wet oxidation treatment, is used for electroplating a base material to form a coating film of a composite material, which contains the carbon particles in a silver layer, on the base material to produce a composite plated product.

There are provided a composite plated product, which has little uneven appearance, a low contact resistance and good wear resistance, and a method for producing the same without the need of any silver-plating solutions containing cyanides and any silver-plating solutions containing silver nitrate as a silver salt. After carbon particles are caused to be suspended in water, an oxidizing agent is added thereto for carrying out a wet oxidation treatment of the carbon particles, and a silver-plating solution, which contains at least one sulfonic acid and the carbon particles treated by the wet oxidation treatment, is used for electroplating a base material to form a coating film of a composite material, which contains the carbon particles in a silver layer, on the base material to produce a composite plated product.

A heat dissipation sheet is provided. The heat dissipation sheet has a plurality of graphene oxide particle layers including first graphene oxide particles having an average diameter of a first size and second graphene oxide particles having an average diameter of a second size, and a fine crease structure including pores with a thickness of less than 2 μm between the plurality of graphene oxide particle layers. Additionally, a manufacturing method for the heat dissipation sheet and a mobile communication device comprising the heat dissipation sheet are provided.

A heat dissipation sheet is provided. The heat dissipation sheet has a plurality of graphene oxide particle layers including first graphene oxide particles having an average diameter of a first size and second graphene oxide particles having an average diameter of a second size, and a fine crease structure including pores with a thickness of less than 2 μm between the plurality of graphene oxide particle layers. Additionally, a manufacturing method for the heat dissipation sheet and a mobile communication device comprising the heat dissipation sheet are provided.

To provide a manufacturing method of graphene oxide that allows mass production through a relatively simple process, at low costs, and with safety and efficiency. A hydrogen peroxide solution, sulfuric acid, and flake graphite are put in a reaction container, and the mixture is stirred to obtain expansion graphite. The synthesized expansion graphite is washed not with pure water but with a saturated aqueous solution of magnesium sulfate (MgSO.sub.4) or an organic solvent, whereby a large amount of sulfuric acid is contained between graphite layers. The expansion graphite is subjected to heat treatment or microwave irradiation to form expanded graphite, and a graphite layer is peeled by ultrasonic treatment and then oxidized to form a graphene compound.

To provide a manufacturing method of graphene oxide that allows mass production through a relatively simple process, at low costs, and with safety and efficiency. A hydrogen peroxide solution, sulfuric acid, and flake graphite are put in a reaction container, and the mixture is stirred to obtain expansion graphite. The synthesized expansion graphite is washed not with pure water but with a saturated aqueous solution of magnesium sulfate (MgSO.sub.4) or an organic solvent, whereby a large amount of sulfuric acid is contained between graphite layers. The expansion graphite is subjected to heat treatment or microwave irradiation to form expanded graphite, and a graphite layer is peeled by ultrasonic treatment and then oxidized to form a graphene compound.

A supercapacitor electrode comprises a mixture of graphene sheets and humic acid. The humic acid occupies 0.1% to 99% by weight of the mixture and the graphene sheets are selected from a pristine graphene material having essentially zero % of non-carbon elements, or a non-pristine graphene material having 0.001% to 5% by weight of non-carbon elements. The non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, chemically functionalized graphene, or a combination thereof. The mixture has a specific surface area greater than 500 m.sup.2/g.

A supercapacitor electrode comprises a mixture of graphene sheets and humic acid. The humic acid occupies 0.1% to 99% by weight of the mixture and the graphene sheets are selected from a pristine graphene material having essentially zero % of non-carbon elements, or a non-pristine graphene material having 0.001% to 5% by weight of non-carbon elements. The non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, chemically functionalized graphene, or a combination thereof. The mixture has a specific surface area greater than 500 m.sup.2/g.