Graphene, method and apparatus for preparing graphene

Patent metadata

Field	Value
Publication number	US-2016200581-A1
Application number	US-201414907858-A
Country	US
Kind code	A1
Filing date	Aug 20, 2014
Priority date	Aug 21, 2013
Publication date	Jul 14, 2016
Grant date	—

Abstract

There are provided a graphene having an oxygen atom content in a predetermined range or less and a carbon/oxygen weight ratio in a specific range to show excellent electrical and thermal conductivity properties, and a barrier property, and a method and an apparatus for preparing the graphene having excellent electrical and thermal conductivity properties and a barrier property by using a subcritical-state fluid or a supercritical-state fluid. According to the method and the apparatus for preparing the graphene, impurities such as graphene oxide, and the like, may be effectively removed, such that uniformity of the graphene to be prepared may be increased, and therefore, the graphene which is highly applicable as materials throughout the industry may be mass-produced.

First claim

1 . A graphene having 20 wt % or less of an oxygen content and 5 or more of a carbon/oxygen weight ratio (C/O ratio).

2 . The graphene of claim 1 , wherein a primary differential curve has a peak at 600 to 850° C. in thermogravimetric analysis (TGA).

3 . The graphene of claim 1 , wherein a primary differential curve does not have a peak at 100 to 300° C. in thermogravimetric analysis (TGA).

4 . The graphene of claim 1 , wherein a weight loss rate at 900° C. is 90% or more in thermogravimetric analysis (TGA).

5 . The graphene of claim 1 , wherein an electrical conductivity is 20 S/cm or more.

6 . The graphene of claim 1 , wherein it is used as at least one selected from the group consisting of barrier materials, lightweight materials, energy, batteries, electronics, electrics, semiconductors, steel, displays, home electronics, mobile phones, nano-industries, biotechnologies, polymer composites, metal composites, paints, pastes, inks, water treatment, waste-water treatment, antistatic materials, electrostatic dispersion materials, conductive materials, electromagnetic wave shielding materials, electromagnetic wave absorbers, radio frequency (RF) absorbers, materials for solar cell, electrode materials for dye-sensitized-solar-cell (DSSC), electrical device materials, electronic device materials, semiconductor device materials, photoelectric device materials, notebook component materials, computer component materials, memory devices, mobile phone component materials, PDA component materials, PSP component materials, component materials for game machine, housing materials, transparent electrode materials, opaque electrode materials, field emission display (FED) materials, back light unit (BLU) materials, liquid crystal display (LCD) materials, plasma display panel (PDP) materials, light emitting diode (LED) materials, touch panel materials, electronic quotation board materials, billboard materials, display materials, heating elements, heat radiating elements, plating materials, catalysts, co-catalysts, oxidizing agents, reducing agents, automobile component materials, ship component materials, aircraft component materials, protective tape materials, adhesive materials, tray materials, clean room materials, transport component materials, flame retardant materials, antibacterial materials, metal composite materials, non-ferrous metal composite materials, materials for medical devices, building materials, flooring materials, materials for wallpaper, light source component materials, lamp materials, optical instrument component materials, materials for fabricating fibers, materials for manufacturing clothing, materials for electric products, materials for manufacturing electronic products, materials for secondary battery including cathode active materials for secondary battery, anode active materials for secondary battery and conductors for secondary battery, fuel cell materials, hydrogen storage material, and capacitor materials.

7 . A method for preparing a graphene comprising:
forming a mixed solution including a graphite oxide, a solvent, a first oxidizing agent; and a sulfur compound or a nitrogen compound; forming the graphene by reacting the mixed solution under a subcritical condition or a supercritical condition of the solvent; and recovering the graphene.

8 . The method of claim 7 , wherein the sulfur compound is represented by the following Chemical Formula 1, and the nitrogen compound is represented by the following Chemical Formula 2:
HO-A 1 -Q-A 2 -OH   [Chemical Formula 1]
in Chemical Formula 1, A 1 and A 2 are each independently linear or branched C1-C10 alkylene group or C6-C20 arylene group, and Q is a sulfur atom (—S—) or a sulfone group(—(O═S═O)—), and

in Chemical Formula 2, at least one of R 1 to R 4 is a nitro group (—NO 2 ), and the remainder is hydrogen, linear or branched C1-C7 alkyl group or C6-C20 aryl group.

9 . The method of claim 7 , wherein the solvent includes water, carbon dioxide, or mixtures thereof.

10 . The method of claim 7 , wherein the graphite oxide is formed by treating a graphite oxide precursor with an acid and a second oxidizing agent.

11 . The method of claim 10 , wherein the graphite oxide precursor is at least one kind selected from the group consisting of graphite, graphene, graphite nanoplatelet, graphene nanoplatelet, expanded graphite, diamond, fullerene, carbon black, activated carbon, charcoal, carbon nanoribbon, carbon nanowire, carbon nanoclay, carbon nanotube, pitch carbon fiber, carbon nanofiber, carbon glass fiber, and asphalt.

12 . The method of claim 7 , wherein the first oxidizing agent is at least one kind selected from the group consisting of oxygen, ozone, and hydrogen peroxide.

13 . The method of claim 7 , wherein the graphite oxide is included in an amount of 0.0001 to 30 parts by weight based on 100 parts by weight of the solvent.

14 . The method of claim 7 , wherein the nitrogen compound or the sulfur compound is included at 0.0001 to 1 molar ratio (M) with respect to the mixed solution.

15 . The method of claim 7 , wherein the subcritical condition or the supercritical condition has a temperature of 50 to 600° C.

16 . The method of claim 7 , wherein the subcritical condition or the supercritical condition has a pressure of 30 to 500 atm.

17 . The method of claim 7 , wherein in the forming of the graphene, the mixed solution further including a reducing adjuvant is reacted under the subcritical condition or the supercritical condition.

18 . The method of claim 17 , wherein the reducing adjuvant is at least one selected from the group consisting of an ammonia water, amine, sodium hydroxide (NaOH), potassium hydroxide (KOH), sodium hydrogen carbonate (NaHCO 3 ), sodium hydride (NaH), sodium borohydride (NaBH 4 ), lithium aluminum hydride (LiAlH 4 ), hydroquinone (HO—Ph—OH), hydrogen sulfide (HS), urea (NH 2 —CO—NH 2 ), urea sulfide (NH 2 —CS—NH 2 ), and sulfide dioxide urea (NH 2 —C(NH)—SOOH).

19 . The method of claim 7 , further comprising, after the forming of the mixed solution and before the forming of the graphene, pre-heating the mixed solution to 50 to 500° C.

20 . The method of claim 7 , further comprising, after the forming of the graphene and before the recovering of the graphene, high-pressure-filtering the graphene.

21 . The method of claim 7 , further comprising, after the forming of the graphene and before the recovering of the graphene, washing the formed graphene.

22 . An apparatus for preparing a graphene comprising:
a mixing bath forming a pre-mixed solution by mixing a graphite oxide, a solvent, and a sulfur compound or a nitrogen compound; a first oxidizing agent feeding pump supplying a first oxidizing agent; a pre-heater pre-heating the pre-mixed solution and the first oxidizing agent supplied from the mixing bath and the first oxidizing agent feeding pump, respectively; a reactor connected to a rear end of the pre-heater, and generating a reaction of a mixed solution including the pre-mixed solution and the first oxidizing agent under a subcritical condition or a supercritical condition of the solvent; a cooler connected to a rear end of the reactor and cooling a product of the reaction; and recovering baths connected to a rear end of the cooler and recovering the graphene from the product.

23 . The apparatus of claim 22 , further

Assignees

• Hanwha Chemical Corp

Inventors

• Lee Jin Seo
• Do Seung Hoe
• Jeon Seong Yun
• Kong Jung Ho

Classifications

• C01B32/198

  Graphene oxide · CPC title

• C01B2204/22

  Electronic properties · CPC title

• C01B32/184 Primary

  Preparation · CPC title

• B01J2219/00103

  in a heat exchanger separate from the reactor · CPC title

• C01B32/192

  starting from graphitic oxides · CPC title