CN104640808B

CN104640808B - Composition comprising graphene

Info

Publication number: CN104640808B
Application number: CN201280067001.7A
Authority: CN
Inventors: K.雷德蒙; D.谢菲尔
Original assignee: Vorbeck Materials Corp
Current assignee: Vorbeck Materials Corp
Priority date: 2011-11-14
Filing date: 2012-11-14
Publication date: 2020-10-02
Anticipated expiration: 2032-11-14
Also published as: EP2780282A4; WO2013074710A1; EP2780282A1; EP2780281A4; CN104640808A; CN104220369A; WO2013074712A1; EP2780281A1; WO2013074709A1

Abstract

A composition comprising graphene sheets and at least one acid. The composition may optionally comprise a polymer. They may be in the form of inks or coatings. The acid may be an organic acid or an inorganic acid. The acid preferably has a pKa in water of less than about 4, or more preferably less than about 3, or even more preferably less than about 2.5. The pKa in water may be less than about 2, or less than about 1, or less than about 0. Examples of the inorganic acid include sulfuric acid, hydrochloric acid, nitric acid, nitrous acid, phosphoric acid, boric acid, hydrobromic acid, perchloric acid, and the like. Examples of acids include sulfur-based acids such as sulfonic acids, polysulfonic acids, sulfinic acids, including monomeric and polymeric organic sulfonic acids such as aromatic sulfonic acids such as benzenesulfonic acid, alkylbenzene sulfonic acids, alkyl and aliphatic sulfonic acids, toluene sulfonic acid, and naphthalene sulfonic acids.

Description

Composition comprising graphene

Reference to related applications

This application claims priority from: united states provisional application 61/559715 filed on day 11/14 of 2011, 61/596216 filed on day 2/7 of 2012, 61/596220 filed on day 2/7 of 2012, and 61/596224 filed on day 8 of 2012, the entire contents of which are incorporated herein by reference.

Technical Field

The present invention relates to a composition comprising graphene and at least one acid.

Statement regarding federally sponsored research and development

The invention was accomplished with government support under license numbers IIP-1152700 and IIP-1046880 provided by NSF. The government has certain rights in the invention.

Background

Due to its many excellent properties, graphene is increasingly used for many practical applications: conductive inks and coatings, polymer composites, sensors (e.g., gas sensors, biosensors, etc.), electrodes, thermal transfer applications, energy storage devices (e.g., batteries and supercapacitors), solar cells, and the like. In some cases, graphene is used in combination with other components (e.g., polymeric binders, which may improve the mechanical properties of the composition, among other advantages). Even though successful graphene has many such applications, it is desirable to obtain graphene compositions with enhanced properties (e.g., electrical conductivity, thermal conductivity, mechanical properties, etc.).

Summary of The Invention

Disclosed and claimed herein are compositions comprising graphene sheets and at least one acid. The composition may further comprise one or more binders. Also disclosed and claimed herein are inks and coatings comprising compositions comprising graphene sheets and at least one acid.

Detailed Description

The composition comprises graphene sheets and at least one acid. They may optionally comprise at least one polymer.

The composition may further comprise one or more acid catalysts. The acid may be an organic acid or an inorganic acid. The acid preferably has a pKa in water of less than about 4, or more preferably less than about 3, or even more preferably less than about 2.5. The pKa in water may be less than about 2, or less than about 1, or less than about 0. The acid may be in blocked form. In such cases, the pKa is based on the unblocked acid. The acid may be a curing catalyst.

Examples of the inorganic acid include sulfuric acid, hydrochloric acid, nitric acid, nitrous acid, phosphoric acid, boric acid, hydrobromic acid, perchloric acid, and the like.

Examples of acids include sulfur-based acids such as sulfonic acids, polysulfonic acids (e.g., disulfonic acids), sulfinic acids, including monomeric and polymeric organic sulfonic acids, such as aromatic sulfonic acids such as benzenesulfonic acids, alkylbenzenesulfonic acids, alkyl and aliphatic sulfonic acids, toluenesulfonic acids, and naphthalenesulfonic acids. Examples of sulfonic acids include monomeric sulfonic acids such as p-toluenesulfonic acid, benzenesulfonic acid, cresolsulfonic acid, 4-ethylbenzenesulfonic acid, xylenesulfonic acid, dimethylbenzenesulfonic acid, oxybenzenesulfonic acid, dinonylnaphthalenesulfonic acid (DNNSA), dinonylnaphthalenedisulfonic acid (DNNDSA), dodecylbenzenesulfonic acid (DDBSA), methanesulfonic acid, and the like. Examples also include sulfonic acid resins such as poly (styrenesulfonic acid), sulfonated fluoropolymers such as sulfonated tetrafluoroethylene (e.g., Nafion @)^®) Etc.).

The acid may be a phosphorus-based acid such as phosphoric acid and its derivatives, phosphorous acid and its derivatives, an organic phosphorus-and phosphate-based acid such as alkyl and dialkyl acid phosphates, and the like. Examples include amyl acid phosphate, dipentyl acid phosphate, butyl acid phosphate, dibutyl acid phosphate, ethyl acid phosphate, diethyl acid phosphate, octyl acid phosphate, dioctyl acid phosphate, and the like. They may be metal salts of phosphorus-based acids, such as metal salts of phosphoric acid and phosphoric esters.

In some cases, the acid may be present in the following weight ratios relative to the graphene sheets: from about 0.1:99.9 to about 75:25, or from about 0.5:99.5 to about 50:50, or from about 0.5:99.5 to about 25:75, or from about 0.5:99.5 to about 15:85, or from about 0.5:99.5 to about 10:90, or from about 0.5:99.5 to about 5:95, or from about 1:99 to about 75:25, or from about 1:99 to about 50:50, or from about 1:99 to about 25:75, or from about 1:99 to about 15:85, or from about 1:99 to about 10:90, or from about 1:99 to about 5:95, or from about 2:98 to about 75:25, or from about 2:98 to about 50:50, or from about 2:98 to about 25:75, or from about 2:98 to about 15:85, or from about 2:98 to about 90, or from about 2: 98: 95 to about 5:95, about 5:95 to about 25:75, about 10:90 to about 75:25, about 10:90 to about 50:50, about 10:90 to about 25: 75.

The graphene sheets preferably have a thickness of about 100 to about 2630m²Graphite flake per gram of surface area. In some embodiments, the graphene sheets comprise predominantly, almost entirely, or entirely, whole sheets of exfoliated graphite (these are approximately ≦ 1nm thick and are commonly referred to as "graphene"), while in other embodiments, at least a portion of the graphene sheets may comprise partially exfoliated graphite sheets, wherein two or more graphite sheets are not exfoliated with respect to each other. The graphene sheets may comprise a mixture of completely and partially exfoliated graphite sheets. Graphene sheets are distinct from carbon nanotubes. The graphene sheets may have a "sheet (e.g., two-dimensional) structure and not have an acicular form of carbon nanotubes. The two longest dimensions of the graphene sheets may each be at least about 10 times greater, or at least about 50 times greater, or at least about 100 times greater, or at least about 1000 times greater, or at least about 5000 times greater, or at least about 10,000 times greater than the shortest dimension (i.e., thickness) of the sheet.

The graphene sheets may be fabricated using any suitable method. For example, they may be obtained from graphite, graphite oxide, expandable graphite, expanded graphite, and the like. They can be obtained by physical exfoliation of graphite, by, for example, exfoliating, grinding or milling graphene sheets. They may be made from inorganic precursors such as silicon carbide. They can be produced by chemical vapor deposition (e.g., by reaction of methane and hydrogen on a metal surface). They can be made by reduction of an alcohol, such as ethanol, with a metal (e.g. an alkali metal such as sodium), and subsequent pyrolysis of the alkoxide product (Nature Nanotechnology (2009), 4, 30-33 reports this approach). They can be made by exfoliation of graphite in a dispersion or exfoliation of graphite oxide in a dispersion and subsequent reduction of the exfoliated graphite oxide. Graphene sheets can be made by: exfoliated graphite is exfoliated and then intercalated, and sonicated or other means of separating the intercalated flakes (see, e.g., Nature Nanotechnology (2008), 3, 538-. They can be produced by intercalation of graphite and subsequent thermal exfoliation of the product in suspension, etc.

Graphene sheets can be made from graphite oxide (also known as graphite acid or graphene oxide). The graphite may be treated with an oxidizing agent and/or an intercalating agent and exfoliated. Graphite may also be treated with an intercalant and electrochemically oxidized and exfoliated. Graphene sheets may be formed by ultrasonically exfoliating a suspension of graphite and/or graphite oxide in a liquid (which may include a surfactant and/or an intercalating agent). The dispersion or suspension of exfoliated graphite oxide may then be reduced to graphene sheets. Graphene sheets may also be formed by mechanical treatment (e.g., milling or grinding) of exfoliated graphite or graphite oxide (which is subsequently reduced to graphene sheets).

The reduction of graphite oxide to graphene can be done by means of chemical reduction and can be done on graphite oxide in dry form in a dispersion or the like. Examples of useful chemical reducing agents include, but are not limited to, hydrazine (e.g., hydrazine, N-dimethylhydrazine, etc.), sodium borohydride, citric acid, hydroquinone, isocyanates (e.g., phenyl isocyanate), hydrogen plasma, and the like. A dispersion or suspension of exfoliated graphite oxide in a carrier (e.g., water, an organic solvent, or a mixture of solvents) can be made (e.g., sonicated and/or mechanically milled or milled) and reduced to graphene sheets using any suitable method.

The graphite oxide may be produced by any method known in the art, for example by a method comprising oxidizing graphite using one or more chemical oxidizing agents and optionally an intercalant such as sulfuric acid. Examples of oxidizing agents include nitric acid, nitrates (e.g., potassium nitrate and sodium nitrate), perchlorates, potassium chlorate, sodium chlorate, chromic acid, potassium chromate, sodium chromate, potassium dichromate, sodium dichromate, hydrogen peroxide, sodium permanganate and potassium permanganate, phosphoric acid (H)₃PO₄) Phosphorus pentoxide, bisulfite and the like. Preferred oxidizing agentsComprising KClO₄、HNO₃And KClO₃；KMnO₄And/or NaMnO₄；KMnO₄And NaNO₃；K₂S₂O₈And P₂O₅And KMnO₄；KMnO₄And HNO₃(ii) a And HNO₃. A preferred intercalating agent comprises sulfuric acid. Graphite may also be treated with an intercalant and electrochemically oxidized. Examples of methods of making graphite oxide include those described by Staudenmaier (be. stsch. chem. ges. (1898), 31, 1481) and Hummers (j.am. chem. soc. (1958), 80, 1339).

One example of a method of preparing graphene sheets is to oxidize graphite to graphite oxide and then thermally flake it to form graphene sheets (also known as thermally exfoliated graphite oxide), as described in US 2007/0092432, the disclosure of which is incorporated herein by reference. The graphene sheets so formed may exhibit little or no signal corresponding to graphite or graphite oxide in their X-ray diffraction patterns.

The thermal flaking may be performed in a continuous, semi-continuous batch, or like process.

Heating may be carried out in a batch process or a continuous process and may be carried out in different atmospheres, including inert and reducing atmospheres (e.g., nitrogen, argon, and/or hydrogen atmospheres). The heating time may vary from a few seconds or less or hours or more depending on the temperature used and the characteristics desired in the final hot exfoliated graphite oxide. Heating may be performed in any suitable vessel, such as fused quartz, mineral, metal, carbon (e.g., graphite), ceramic, and the like. Heating may be performed using a flash lamp or microwave. The graphite oxide may be contained in a substantially constant position within a single batch reaction vessel during heating, or may be transported through one or more vessels during the reaction in a continuous or batch-wise manner. Heating may be performed using any suitable means, including using an oven and an infrared heater.

Examples of temperatures at which the thermal exfoliation and/or reduction of the graphite oxide can be carried out are at least about 150 ℃, at least about 200 ℃, at least about 300 ℃, at least about 400 ℃, at least about 450 ℃, at least about 500 ℃, at least about 600 ℃, at least about 700 ℃, at least about 750 ℃, at least about 800 ℃, at least about 850 ℃, at least about 900 ℃, at least about 950 ℃, at least about 1000 ℃, at least about 1100 ℃, at least about 1500 ℃, at least about 2000 ℃, and at least about 2500 ℃. Preferred ranges include from about 750 ℃ to about 3000 ℃, from about 850 ℃ to 2500 ℃, from about 950 ℃ to about 1500 ℃, from about 750 ℃ to about 3100 ℃, from about 850 ℃ to 2500 ℃, or from about 950 ℃ to about 2500 ℃.

The heating time may be from less than one second to many minutes. For example, the heating time may be less than about 0.5 seconds, less than about 1 second, less than about 5 seconds, less than about 10 seconds, less than about 20 seconds, less than about 30 seconds, or less than about 1 minute. The heating time may be at least about 1 minute, at least about 2 minutes, at least about 5 minutes, at least about 15 minutes, at least about 30 minutes, at least about 45 minutes, at least about 60 minutes, at least about 90 minutes, at least about 120 minutes, at least about 150 minutes, at least about 240 minutes, from about 0.01 seconds to about 240 minutes, from about 0.5 seconds to about 240 minutes, from about 1 second to about 240 minutes, from about 1 minute to about 240 minutes, from about 0.01 seconds to about 60 minutes, from about 0.5 seconds to about 60 minutes, from about 1 second to about 60 minutes, from about 0.01 seconds to about 10 minutes, from about 0.5 seconds to about 10 minutes, from about 1 second to about 10 minutes, from about 1 minute, from about 0.01 seconds to about 1 minute, from about 0.5 seconds to about 1 minute, from about 1 second to about 1 minute, no more than about 600 minutes, No more than about 450 minutes, no more than about 300 minutes, no more than about 180 minutes, no more than about 120 minutes, no more than about 90 minutes, no more than about 60 minutes, no more than about 30 minutes, no more than about 15 minutes, no more than about 10 minutes, no more than about 5 minutes, no more than about 1 minute, no more than about 30 seconds, no more than about 10 seconds, or no more than about 1 second. During the heating process, the temperature may change.

Examples of heating rates include at least about 120 ℃/minute, at least about 200 ℃/minute, at least about 300 ℃/minute, at least about 400 ℃/minute, at least about 600 ℃/minute, about 800 ℃/minute, at least about 1000 ℃/minute, at least about 1200 ℃/minute, at least about 1500 ℃/minute, at least about 1800 ℃/minute, and at least about 2000 ℃/minute.

The graphene sheets can be calcined or reduced to graphene sheets having a higher carbon to oxygen ratio by heating under reducing atmosphere conditions (e.g., in a system purged with an inert gas or hydrogen). The reduction/annealing temperature is preferably at least about 300 deg.C, or at least about 350 deg.C, or at least about 400 deg.C, or at least about 500 deg.C, or at least about 600 deg.C, or at least about 750 deg.C, or at least about 850 deg.C, or at least about 950 deg.C, or at least about 1000 deg.C. The temperature used may be, for example, from about 750 to about 3000 deg.C, or from about 850 deg.C to 2500 deg.C, or from about 950 deg.C to about 2500 deg.C.

The heating time may be, for example, at least about 1 second, or at least about 10 seconds, or at least about 1 minute, or at least about 2 minutes, or at least about 5 minutes. In some embodiments, the heating time is at least about 15 minutes, or about 30 minutes, or about 45 minutes, or about 60 minutes, or about 90 minutes, or about 120 minutes, or about 150 minutes. The temperature may vary within these ranges during the annealing/reduction process.

Heating may be carried out under a variety of conditions, including in an inert atmosphere (e.g., argon or nitrogen) or a reducing atmosphere, such as hydrogen (including hydrogen diluted in an inert gas such as argon or nitrogen), or under vacuum. Heating may be carried out in any suitable vessel, such as a fused quartz or mineral or ceramic vessel or a metal vessel. The heated material (including any starting materials and any products or intermediates) may be contained in a single batch reactor vessel at a substantially constant location, or may be transported through one or more vessels during the reaction in a continuous or batch reaction. Heating may be performed using any suitable means, including the use of ovens and infrared heaters.

The graphene sheets preferably have the following surface areas: at least about 100m²G to or at least about 200m²Per g, or at least about 300m²Per gram, or at least about 350m²Per g, or at least about 400m²Per g, or at least about 500m²Per g, or at least about 600m²In terms of/g, or at least about 700m²Per gram, or at least about 800m²Per gram, or at least about 900m²In terms of/g, or at least about 700m²(ii) in terms of/g. The surface area may be from about 400 to about 1100m²(ii) in terms of/g. The theoretical maximum surface area can be calculated to be 2630m²(ii) in terms of/g. Surface area includes all values and sub-values in between, especially 400, 500, 600, 700, 800, 900, 1000, 1100, 1200. 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, and 2630m²/g。

The graphene sheets may have the following number average aspect ratio: from about 100 to about 100,000, or from about 100 to about 50,000, or from about 100 to about 25,000, or from about 100 to about 10,000 (where "aspect ratio" is defined as the ratio of the longest dimension to the shortest dimension of the sheet).

Surface area can be measured using the nitrogen adsorption/BET method at 77K or the Methylene Blue (MB) staining method in liquid solution.

The dyeing method was carried out as follows: a known amount of graphene sheets was added to the flask. At least 1.5g of MB per gram of graphene sheets was then added to the flask. Ethanol was added to the flask and the mixture was sonicated for about 15 minutes. The ethanol was then evaporated and a known amount of water was added to the flask to redissolve the free MB. The insoluble material is allowed to settle, preferably by centrifuging the sample. The concentration of MB in the solution is determined using a UV-Vis spectrophotometer by measuring at lambda_maxAbsorption at 298nm relative to the standard concentration absorption.

The difference between the amount of MB initially added and the amount present in the solution as determined by uv-vis spectrophotometry was considered to be the amount of MB that had adsorbed on the surface of the graphene sheet. The surface area of the graphene sheet was then covered with 2.54m per 1mg adsorbed MB²And calculating the value of the surface area.

The graphene sheets may have about 0.01 to at least about 200kg/m³The bulk density of (a). The bulk density includes all values and sub-values in between, especially including 0.05, 0.1, 0.5, 1, 5, 10, 15, 20, 25, 30, 35, 50, 75, 100, 125, 150 and 175kg/m³。

Graphene sheets can be functionalized using: such as oxygen-containing functional groups (including, for example, hydroxyl, carboxyl, and epoxy groups) and typically have an overall carbon to oxygen molar ratio (C/O ratio) of at least about 1:1, or more preferably at least about 3:2, as determined by bulk elemental analysis. Examples of carbon to oxygen ratios include: about 3:2 to about 85:15, about 3:2 to about 20:1, about 3:2 to about 30:1, about 3:2 to about 40:1, about 3:2 to about 60:1, about 3:2 to about 80:1, about 3:2 to about 100:1, about 3:2 to about 200:1, about 3:2 to about 500:1, about 3:2 to about 1000:1, about 3:2 to greater than 1000:1, about 10:1 to about 30:1, about 80:1 to about 100:1, about 20:1 to about 500:1, about 20:1 to about 1000:1, about 50:1 to about 300:1, about 50:1 to about 500:1, and about 50:1 to about 1000: 1. In some embodiments, the carbon to oxygen ratio is at least about 10:1, or at least about 15:1, or at least about 20:1, or at least about 35:1, or at least about 50:1, or at least about 75:1, or at least about 100:1, or at least about 200:1, or at least about 300:1, or at least about 400:1, or at least 500:1, or at least about 750:1, or at least about 1000:1, or at least about 1500:1, or at least about 2000: 1. The carbon to oxygen ratio also includes all values and sub-values between these ranges.

Graphene sheets may contain kinks on an atomic scale. These kinks can be caused by the presence of lattice defects in the two-dimensional hexagonal lattice structure of the graphite basal planes or by chemical functionalization.

The composition may also comprise graphite (including natural, crystalline, and synthetic, annealed, pyrolyzed, highly oriented pyrolyzed, etc. graphite). The weight ratio of graphite to graphene sheets may be from about 2:98 to about 98:2, or from about 5:95 to about 95:5, or from about 10:90 to about 90:10, or from about 20:80 to about 80:20, or from about 30:70 to 70:30, or from about 40:60 to about 90:10, or from about 50:50 to about 85:15, or from about 60:40 to about 85:15, or from about 70:30 to about 85: 15.

The graphene sheets may comprise two or more graphene powders having different particle size distributions and/or morphologies. The graphite may also comprise two or more graphite powders having different particle size distributions and/or morphologies.

The graphene sheets and acid may be combined with a polymer to make composites (including polymer composites), and the like. They may be dispersed in one or more solvents with or without a polymeric binder. They are useful in thermal transfer applications. They can be used on electrodes, such as those used for: solar cells (including dye-sensitized solar cells, organic solar cells, etc.), light emitting diodes, batteries (e.g., electrodes for rechargeable, lithium ion, lithium polymer, lithium air, etc. batteries), capacitors (including supercapacitors), and the like. The polymer composite may be used in gas barrier applications. The rubber compounds are useful in tire applications. The composition may be in the form of an adhesive.

The compositions may be in the form of inks and coatings. The terms "ink" and "coating" mean a composition in a form suitable for application to a substrate, as well as a material after it is applied to a substrate, when it is applied to a substrate, and both before and after any post-application treatment (e.g., evaporation, crosslinking, curing, etc.). The components of the ink and coating compositions may vary during these stages. The inks and coatings may optionally further comprise a polymeric binder.

The graphene sheets and acid may be combined with the polymer using any suitable method, including melt processing (using, for example, single or twin screw extruders, blenders, kneaders, banbury mixers, etc.) and solution/dispersion blending. The polymer may be used as a binder. When used, the polymer may be a thermoset, thermoplastic, non-melt processible polymer, or the like. The polymer may also comprise monomers, which may be polymerized before, during, or after the coating is applied to the substrate. The polymeric binder may be crosslinked or cured after the coating has been applied to the substrate. Examples of polymers include, but are not limited to, polyolefins (e.g., polyethylene, Linear Low Density Polyethylene (LLDPE), Low Density Polyethylene (LDPE), high density polyethylene, polypropylene, and olefin copolymers), styrene/butadiene rubber (SBR), styrene/ethylene/butadiene/styrene copolymers (SEBS), butyl rubber, ethylene/propylene copolymers (EPR), ethylene/propylene/diene monomer copolymers (EPDM), polystyrene (including high impact polystyrene), poly (vinyl acetate), ethylene/vinyl acetate copolymers (EVA), poly (vinyl alcohol), ethylene/vinyl alcohol copolymers (EVOH), poly (vinyl butyral) (PVB), poly (vinyl formal), poly (methyl methacrylate), and other acrylate polymers and copolymers (e.g., methyl methacrylate polymers, poly (vinyl acetate) s, poly (vinyl alcohol) s, poly (vinyl butyral) s, poly (methyl methacrylate) s, poly (vinyl acetate) s, Methacrylate copolymers, polymers derived from one or more acrylates, methacrylates, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, glycidyl acrylate, methacrylates, and the like), olefin and styrene copolymers, acrylonitrile/butadiene/styrene (ABS), styrene/acrylonitrile polymers (SAN), styrene/maleicAnhydride copolymers, isobutylene/maleic anhydride copolymers, ethylene/acrylic acid copolymers, poly (acrylonitrile), poly (vinyl acetate) and poly (vinyl acetate) copolymers, poly (vinyl pyrrolidone) and poly (vinyl pyrrolidone) copolymers, vinyl acetate and vinyl pyrrolidone copolymers, Polycarbonates (PC), polyamides, polyesters, Liquid Crystal Polymers (LCP), poly (lactic acid) (PLA), poly (phenylene oxide) (PPO), PPO-polyamide alloys, Polysulfones (PSU), polysulfides, Polyetherketones (PEK), Polyetheretherketones (PEEK), polyimides, Polyoxymethylene (POM) homopolymers and copolymers, polyetherimides, fluorinated ethylene propylene polymers (FEP), poly (vinyl fluoride), poly (vinylidene chloride), poly (vinyl chloride) (PVC), Polyurethanes (thermoplastic and thermoset (including cross-linked polyurethanes such as those cross-linked amines, etc.), aramids (e.g., Kevlar @)^®And Nomex^®) Polysulfides, Polytetrafluoroethylene (PTFE), polysiloxanes (including polydimethyisiloxanes, dimethylsiloxane/vinylmethylsiloxane copolymers, vinyldimethylsiloxane-terminated poly (dimethylsiloxane), and the like), elastomers, epoxy polymers (including crosslinked epoxy polymers such as those crosslinked with polysulfones, amines, and the like), polyureas, alkyds, cellulosic polymers (such as nitrocellulose, ethylcellulose, ethylhydroxyethylcellulose, carboxymethylcellulose, cellulose acetate propionate, and cellulose acetate butyrate), polyethers (such as poly (ethylene oxide), poly (propylene glycol), oxide/propylene oxide copolymers, and the like), acrylic latex polymers, polyester acrylate oligomers and polymers, polyester glycol diacrylate polymers, poly (ethylene glycol) copolymers, poly (, Ultraviolet hardening resin, and the like.

Examples of elastomers include, but are not limited to: polyurethanes, copolyetheresters, rubbers (including butyl rubber and natural rubber), styrene/butadiene copolymers, styrene/ethylene/butadiene/styrene copolymers (SEBS), polyisoprene, ethylene/propylene copolymers (EPR), ethylene/propylene/diene monomer copolymers (EPDM), polysiloxanes, and polyethers (e.g., poly (ethylene oxide), poly (propylene oxide), and copolymers thereof).

Examples of polyamides include, but are not limited to, aliphatic polyamides (e.g., polyamide 4, 6; polyamide 6, 6; polyamide 11; polyamide 12; polyamide 6, 9; polyamide 6, 10; polyamide 6, 12; polyamide 10, 10; polyamide 10, 12; and polyamide 12,12), alicyclic polyamides and aromatic polyamides (e.g., poly (m-xylylene adipamide) (polyamide MXD,6)) and polyterephthalamides such as poly (dodecamethylene terephthalamide) (polyamide 12, T), poly (decamethylene terephthalamide) (polyamide 10, T), poly (nonamethylene terephthalamide) (polyamide 9, T), polyamides of hexamethylene terephthalamide and hexamethylene adipamide, polyamides of hexamethylene terephthalamide and 2-methylpentamethylene terephthalamide, and the like. The polyamides can be polymers and copolymers having melting points of about 120-255 ℃ (i.e., polyamides having at least two different repeat units) including aliphatic copolyamides having a melting point of about 230 ℃ or less, aliphatic copolyamides having a melting point of about 210 ℃ or less, aliphatic copolyamides having a melting point of about 200 ℃ or less, aliphatic copolyamides having a melting point of about 180 ℃ or less, and the like. Examples of these include those sold by Henkel under the trade name Macromelt and by Cognis under the name Versamid.

Examples of acrylate polymers include those made by the polymerization of one or more acrylic acids (including acrylic acid, methacrylic acid, and the like) and their derivatives (e.g., esters). Examples include methyl acrylate polymers, methyl methacrylate polymers, and methacrylate copolymers. Examples include polymers derived from: one or more acrylates, methacrylates, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, glycidyl acrylate, glycidyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, hydroxyethyl acrylate, hydroxyethyl (meth) acrylate, acrylonitrile, and the like. The polymer may comprise repeating units derived from other monomers, such as olefins (e.g., ethylene, propylene, etc.), vinyl acetate, vinyl alcohol, vinyl pyrrolidone, and the like. They may include partially neutralized acrylate polymers and copolymers (e.g., ionomer resins).

Examples of polymers include Elvacite supplied by Lucite International, Inc^®Polymers, including Elvacite^®2009. 2010, 2013, 2014, 2016, 2028, 2042, 2045, 2046, 2550, 2552, 2614, 2669, 2697, 2776, 2823, 2895, 2927, 3001, 3003, 3004, 4018, 4021, 4026, 4028, 4044, 4059, 4400, 4075, 4060, 4102 and the like. Other polymer classes include Bynel^®Polymer (e.g. Bynel from DuPont)^®2022) And Joncryl^®Polymer (e.g. Joncryl^®678 and 682).

Examples of polyesters include, but are not limited to, poly (butylene terephthalate) (PBT), poly (ethylene terephthalate) (PET), poly (1, 3-propylene terephthalate) (PPT), poly (ethylene terephthalate) (PEN), poly (cyclohexanedimethanol terephthalate) (PCT)), and the like.

In some embodiments, the polymer has the following acid number: at least about 5, or at least about 10, or at least about 15, or at least about 20.

In some embodiments, the glass transition temperature of the at least one polymer is not greater than about 100 ℃, 90 ℃, or not greater than about 80 ℃, or not greater than about 70 ℃, or not greater than about 60 ℃, or not greater than about 50 ℃, or not greater than about 40 ℃.

In some cases, when a binder is used, it may be present in the following amounts relative to the graphene sheets and graphite (when used): from about 1 to about 99 wt.%, or from about 1 to about 50 wt.%, or from about 1 to about 30 wt.%, or from about 1 to about 20 wt.%, or from about 5 to about 80 wt.%, or from about 5 to about 60 wt.%, or from about 5 to about 30 wt.%, or from about 15 to about 85 wt.%, or from about 15 to about 60 wt.%, or from about 15 to about 30 wt.%, or from about 25 to about 80 wt.%, or from about 25 to about 50 wt.%, or from about 40 to about 90 wt.%, or from about 50 to about 90 wt.%, or from about 70 to about 95 wt.%, based on the total weight of the binder and graphene plus graphite (when present).

Examples of solvents in which the graphene sheets and acid may be dispersed include water, distilled or synthetic isoparaffins (e.g., Isopar @)^®And Norpar^®(both manufactured by Exxon) and Downol^®(manufactured by Dow), citrus terpenes and mixtures comprising citrus terpenes (e.g., Purogen, Electron and Positron (all manufactured by Ecolink)), terpenes and terpene alcohols (including terpineol, including α -terpineol), limonene, aliphatic petroleum fractions, alcohols (e.g., methanol, ethanol, N-propanol, isopropanol, N-butanol, isobutanol, sec-butanol, tert-butanol, pentanol, isopentanol, hexanol, heptanol, octanol, diacetone alcohol, butyl glycol, etc.), ketones (e.g., acetone, methyl ethyl ketone, cyclohexanone, isobutyl ketone, 2,6,8, trimethyl-4-nonanone, etc.), esters (e.g., methyl acetate, ethyl acetate, N-propyl acetate, isopropyl acetate, N-butyl acetate, isobutyl acetate, tert-butyl acetate, carbitol acetate, etc.), glycol ethers, esters and alcohols (e.g., 2- (2-ethoxyethoxy) ethanol, propylene glycol monomethyl ether and other propylene glycol ethers; ethylene glycol monobutyl ether, 2-methoxy ethyl ether (diethylene glycol dimethyl ether), Propylene Glycol Monomethyl Ether (PGME), propylene glycol ether acetate and propylene glycol acetate, propylene glycol ether acetate, 2- (2-ethoxyethoxy) ethanol, propylene glycol monomethyl ether, dimethyl ether acetate, dimethyl ether, dimethyl pyrrolidone, dimethyl ether acetate, dimethyl ether-2-dimethyl pyrrolidone, dimethyl ether-2-dimethyl pyrrolidone, dimethyl-2-isopropyl pyrrolidone, dimethyl ether-2-isopropyl ether-dimethyl ether-2-dimethyl-2-N-isopropyl ether-N-isopropyl pyrrolidone, dimethyl-2-isopropyl ether-2-isopropyl ether-isopropyl-4-isopropyl ether-dimethyl-isopropyl ether-methyl pyrrolidone, dimethyl-2-isopropyl ether-&P naphtha) and mixtures of two or more of the above, and mixtures of one or more of the above with other carriers. The solvent can be a low VOC or VOC-free solvent, a non-hazardous air polluting solvent and a non-halogenated solvent.

The composition may comprise the following additives: such as dispersing aids (including surfactants, emulsifiers, and wetting aids), adhesion aids, thickeners (including clays), defoamers and foam inhibitors, biocides, additional fillers, flow enhancers, stabilizers, crosslinking and curing agents, conductive additives, and the like.

Examples of dispersing aids include glycol ethers (e.g. poly (ethylene oxide), block copolymers derived from ethylene oxide and propylene oxide (e.g. by BASF as Pluronic)^®Those sold under the trade name of the trademark), acetylenic diols (e.g., 2,5,8, 11-tetramethyl-6-dodecyne-5, 8-diol ethoxylate and Surfynol under the trade name by Air Products)^®And Dynol^®Others sold), carboxylic acid salts (including alkali metal and ammonium salts), and polysiloxanes.

Examples of grinding aids include stearates (e.g., Al, Ca, Mg, and Zn stearates) and acetylenic diols (e.g., Surfynol, a trade name given by Air Products^®And Dynol^®Those sold).

Examples of adhesion promoters include titanium chelates and other titanium compounds such as titanium phosphate complexes (including titanium butyl phosphate), titanates, titanium diisopropoxide bis (ethyl-3-oxybutyrate ester, titanium isopropoxide acetylacetonate, and others sold under the trademark Vertec by Johnson-Matthey Catalysts.

Examples of thickeners include glycol ethers (e.g. poly (ethylene oxide), block copolymers derived from ethylene oxide and propylene oxide (e.g. by BASF under the trade name Pluronic^®Those sold under the name Minex by uni Specialty Minerals), long chain carboxylates (e.g., stearates, oleates, palmitates, etc. of aluminum, calcium, zinc, etc.), aluminosilicates (e.g., by the name Minex by uni Specialty Minerals)^®And by Evonik Degussa as Aerosil^®9200), fumed silica, natural and synthetic zeolites, and the like.

The composition may optionally comprise at least one "multi-chain lipid", which term refers to a naturally occurring or synthetic lipid having a polar head group and at least two non-polar tail groups attached thereto. Examples of polar head groups include oxygen, sulfur and halogen containing, phosphate esters, amides, ammonium groups, amino acids (including alpha-amino acids), sugars, polysaccharides, esters (including glycerides), zwitterionic groups, and the like.

The end groups may be the same or different. Examples of tail groups include alkanes, alkenes, alkynes, aromatics, and the like. They may be hydrocarbons, functionalized hydrocarbons, and the like. The tail group may be saturated or unsaturated. They may be linear or branched. The tail group can be derived from fatty acids such as oleic acid, palmitic acid, stearic acid, arachidic acid, erucic acid, arachidonic acid, linoleic acid, linolenic acid, oleic acid, and the like.

Examples of multi-chain lipids include, but are not limited to, lecithin and other phospholipids (e.g., phosphatidylcholine, phosphoglycerides (including phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine (cephalin), and phosphatidylglycerol), and sphingomyelin); glycolipids (e.g., glucosyl-cerebroside); glycolipids; sphingolipids (e.g., ceramides, diglycerides, and triglycerides, phosphosphingolipids, and glycosphingolipids); and the like. They may be amphoteric, including zwitterionic.

The composition may optionally include electrically and/or thermally conductive components such as metals (including metal alloys), conductive metal oxides, conductive carbons, polymers, metal coating materials, and the like. These components may take a variety of forms including granules, powders, flakes, foils, needles, and the like.

Examples of metals include, but are not limited to, silver, copper, aluminum, platinum, palladium, nickel, chromium, gold, zinc, tin, iron, gold, lead, steel, stainless steel, rhodium, titanium, tungsten, magnesium, brass, bronze, colloidal metals, and the like. Examples of the metal oxide include antimony tin oxide and indium tin oxide and materials such as a filler coated with a metal oxide. Metal and metal oxide coated materials include, but are not limited to, metal coated carbon and graphite fibers, metal coated glass beads, metal coated ceramic materials (e.g., beads), and the like. These materials may be coated with a variety of metals, including nickel.

Examples of conductive polymers include, but are not limited to, polyacetylene, polyethylene dioxythiophene (PEDOT), poly (styrene sulfonate) (PSS), PEDOT: PSS copolymers, polythiophenes and polythiophenes, poly (3-alkylthiophene), poly (2, 5-bis (3-tetradecylthiophene-2-yl) thieno [3, 2-b: (meth) acrylic acid), poly (meth) acrylates]Thiophene) (PBTTT), poly (phenylene vinylene), polypyrene, polycarbazole, polyazulene, polyazazepine

Polyfluorene, polynaphthalene, polyisonaphthalene, polyaniline, polypyrrole, poly (phenylene sulfide), polycarbazole (polybenzazole), polyindole, polyphenylene, a copolymer of one or more of the foregoing, and the like, as well as derivatives and copolymers thereof. The conductive polymer may be doped or undoped. They may be doped with boron, phosphorus, iodine, etc.

Examples of conductive carbons include, but are not limited to, graphite (including natural, crystalline and synthetic, annealed, pyrolyzed, highly oriented pyrolyzed, etc. graphite), graphitized carbon, carbon black, mesoporous carbon, carbon fibers and fibrils, carbon whiskers, vapor grown carbon nanofibers, metal coated carbon fibers, carbon nanotubes (including single and multi-walled nanotubes), fullerenes, activated carbon, carbon fibers, expanded graphite, expandable graphite, graphite oxide, hollow carbon spheres, carbon foams, and the like.

Inks and coatings can be formed by blending graphene sheets and an acid with at least one solvent and/or binder and optionally other additives. Blending can be accomplished using one or more of the methods previously described. The compositions may be prepared using any suitable method, including wet or dry methods and batch, semi-continuous and continuous methods. Dispersions, suspensions, solutions, etc. of graphene sheets and one or more aliphatic compounds, including ink and coating formulations, can be made or processed (e.g., milled/ground, blended, dispersed, suspended, etc.) using suitable mixing, dispersing, and/or compounding techniques.

For example, one or more of the components of the composition, such as the graphene sheets, acids, graphite (if used), binder, carrier, and/or other components, may be processed (e.g., milled/ground, blended, etc., by suitable mixing, dispersing, and/or compounding techniques and equipment, including ultrasonic equipment, high shear mixers, ball mills, grinding equipment, sand mills, two-roll mills, three-roll mills, freeze mill crushers, extruders, kneaders, double planetary mixers, three planetary mixers, high pressure homogenizers, horizontal and vertical wet mill mills, etc.). The treatment (including grinding) techniques may be wet or dry and may be continuous or discontinuous. Suitable materials for use as the grinding media include metals, carbon steel, stainless steel, ceramics, stabilized ceramic media (e.g., cerium yttrium stabilized zirconia), PTFE, glass, tungsten carbide, and the like. Methods such as these can be used to alter the particle size and/or morphology of graphite, graphene sheets, other components and blends, or two or more components.

The components may be treated together or separately and may be subjected to multiple treatment (including mixing/blending) stages, each involving one or more components (including blends).

The manner in which the graphene sheets, graphite (if used), and other components are treated and combined is not particularly limited. For example, graphene sheets and/or graphite may be processed separately into a given particle size distribution and/or morphology and then combined for further processing, with or without additional components. Untreated graphene sheets and/or graphite may be combined with treated graphene sheets and/or graphite and further treated with or without additional components. The treated and/or untreated graphene sheets and/or treated and/or untreated graphite may be combined with other components, such as one or more binders, and then combined with the treated and/or untreated graphene sheets and/or treated and/or untreated graphite. Two or more combinations of treated and/or untreated graphene sheets and/or treated and/or untreated graphite that have been combined with other components may be further combined or treated.

In one embodiment, if a multi-chain lipid is used, it may be added to the graphene sheets (and/or graphite, if present) prior to processing.

After the blending and/or grinding step, additional components may be added to the composition, including but not limited to thickeners, viscosity modifiers, binders, and the like. The composition may also be diluted by adding more carrier.

Inks and coatings can be applied to a wide variety of substrates, including but not limited to: flexible and/or stretchable materials, silicone and other elastomers and other polymeric materials, metals (e.g., aluminum, copper, steel, stainless steel, etc.), adhesives, heat seal materials (e.g., cellulose, biaxially oriented polypropylene (BOPP), poly (lactic acid), polyurethane, etc.), fabrics (including cloth) and textiles (e.g., cotton, wool, polyester, rayon, etc.), cloth, glass and other minerals, ceramics, silicon surfaces, wood, paper, cardboard, cellulose-based materials, cellophane, labels, silicon and other semiconductors, laminates, corrugated materials, concrete, bricks, and other building materials, and the like. The substrate may be in the form of: films, paper, wafers, larger three-dimensional objects, and the like.

The substrate may be treated with other coatings (e.g., paints) or similar materials prior to application of the ink and coating. Examples include substrates coated with indium tin oxide, antimony tin oxide, and the like (e.g., PET). They may be woven, non-woven, in the form of a web, and the like. They may be woven, non-woven, in the form of a web, and the like.

The substrate may typically be a paper-based material (including paper, paperboard, cardboard, cellophane, etc.). The paper-based material may be surface treated. Examples of surface treatments include coatings such as polymeric coatings, which may include PET, polyethylene, polypropylene, acetate, nitrocellulose, and the like. The coating may be an adhesive. The paper-based material may be sized selectively.

Examples of polymeric materials include, but are not limited to, those of the following: it comprises thermoplastics and thermosets including elastomers and rubbers including thermoplastics and thermosets, silicones, fluorinated polysiloxanes, natural rubber, butyl rubber, chlorosulfonated polyethylene, chlorinated polyethylene, styrene/butadiene copolymers (SBR), styrene/ethylene/butadiene/styrene copolymers (SEBS), styrene/ethylene/butadiene/styrene copolymers grafted with maleic anhydride, styrene/isoprene/styrene copolymers (SIS), polyisoprene, nitrile rubber, hydrogenated nitrile rubber, neoprene, ethylene/propylene copolymers (EPR), ethylene/propylene/diene copolymers (EPDM), ethylene/vinyl acetate copolymers (EVA), hexafluoropropylene/vinylidene fluoride/tetrafluoroethylene copolymers, ethylene/vinyl acetate copolymers (EVA), ethylene/vinylidene fluoride/tetrafluoroethylene copolymers, styrene/butadiene copolymers (sbc), styrene/styrene copolymers (abs), styrene/styrene copolymers (styrene/butadiene), tetrafluoroethylene/propylene copolymers, fluoroelastomers, polyesters (e.g., poly (ethylene terephthalate), poly (butylene terephthalate), poly (ethylene terephthalate), liquid crystal polyesters, poly (lactic acid), etc.); polystyrene; polyamides (including poly-p-phenylenebenzoic acid)Formamide); polyimides (e.g. Kapton)^®) (ii) a Aramids (e.g. Kevlar @)^®And Nomex^®) (ii) a Fluoropolymers (e.g., Fluorinated Ethylene Propylene (FEP), Polytetrafluoroethylene (PTFE), poly (vinyl fluoride), poly (vinylidene fluoride), etc.); a polyetherimide; poly (vinyl chloride); poly (vinylidene chloride); polyurethanes (e.g., Thermoplastic Polyurethane (TPU); spandex, cellulosic polymers (e.g., nitrocellulose, cellulose acetate, etc.), styrene/acrylonitrile polymers (SAN); acrylonitrile/butadiene/styrene polymers (ABS), polycarbonates, polyacrylates, poly (methyl methacrylate), ethylene/vinyl acetate copolymers, thermoset epoxies and polyurethanes, polyolefins (e.g., polyethylene (including low density polyethylene, high density polyethylene, ultra high molecular weight polyethylene, etc.), polypropylene (e.g., biaxially oriented polypropylene, etc.), Mylar (Mylar); etc.. they can be nonwoven materials, such as DuPont Tyvek^®. They may be adhesive materials or back adhesive materials (e.g. back adhesive paper or paper substitutes). They may be paper substitutes based on minerals, such as Teslin from PPG Industries^®. The substrate may be a transparent or translucent or optical material such as glass, quartz, a polymer such as polycarbonate or poly (meth) acrylate (e.g. poly (methyl methacrylate)).

The inks and coatings may be applied to the substrate using any suitable method, including but not limited to: painting, pouring, spin casting, solution casting, dip coating, powder coating, by syringe or pipette, spray coating, curtain coating, lamination, coextrusion, electrospray deposition, inkjet printing, spin coating, thermal transfer (including laser transfer) methods, doctor blade printing, screen printing, rotary screen printing, gravure printing, lithography, gravure printing, digital printing, capillary printing, offset printing, Electrohydrodynamic (EHD) printing (methods described in WO 2007/053621, which is herein incorporated by reference), microprinting, gravure transfer printing, pad printing, stencil printing, wire rod coating, tracing, flexographic printing, stamping, electrostatic printing, micro-contact printing, dip-pen nanoimprinting, laser printing, via a pen or similar hand segment, and the like. The composition may be applied in multiple layers.

After they have been applied to the substrate, the inks and coatings may be cured using any suitable technique, including drying and oven drying (in air or another inert or reactive atmosphere), ultraviolet curing, infrared curing, drying, crosslinking, thermal curing, laser curing, infrared curing, microwave curing or drying, sintering, and the like.

The cured ink and coating may have different thicknesses. For example, they may optionally have a thickness of at least about 2nm or at least about 5 nm. In various embodiments, the coating may optionally have the following thicknesses: about 2nm to 2mm, about 5nm to 1mm, about 2nm to about 100nm, about 2nm to about 200nm, about 2nm to about 500nm, about 2nm to about 1 micron, about 5nm to about 200nm, about 5nm to about 500nm, about 5nm to about 1 micron, about 5nm to about 50 microns, about 5nm to about 200 microns, about 10nm to about 200nm, about 50nm to about 500nm, about 50nm to about 1 micron, about 100nm to about 10 microns, about 1 micron to about 2mm, about 1 micron to about 1mm, about 1 micron to about 500 microns, about 1 micron to about 200 microns, about 1 micron to about 100 microns, about 50 microns to about 1mm, about 100 microns to about 2mm, about 100 microns to about 1mm, about 100 microns to about 750 microns, about 2 microns to about 1mm, about 100 microns to about 750 microns, From about 100 microns to about 500 microns, from about 500 microns to about 2mm, or from about 500 microns to about 1 mm.

The inks and coatings may have different forms when applied to a substrate. They may be provided as films or lines, patterns, letters, numbers, lines, logos, identification tags, and other shapes and forms. The inks and coatings may be completely or partially covered by additional materials, such as covercoats, varnishes, polymers, fabrics, and the like.

Inks and coatings can be applied to the same substrate at varying thicknesses at different points and can be used to build three-dimensional structures on the substrate.

Inks and coatings can be used for passivation of surfaces, such as metal (e.g., steel, aluminum, etc.) surfaces, including exterior structures such as bridges and buildings. Examples of other uses for inks and coatings include: uv radiation resistant durable coatings, abrasion resistant coatings, coatings having permeation resistance to liquids (e.g., hydrocarbons, alcohols, water, etc.) and/or gases, conductive coatings, static dissipative coatings, and blast and impact resistant coatings. They are useful for preparing fabrics having electrical conductivity. Inks and coatings can be used in solar cell applications; solar energy capture applications; logo, flat panel display; flexible displays including light emitting diode, organic light emitting diode, and polymer light emitting diode displays; a backplane and a front panel display; and lighting, including electroluminescent and OLED lighting. Displays may be used as components of portable electronic devices such as computers, cellular telephones, game consoles, GPS receivers, personal digital assistants, music players, game consoles, calculators, artificial "paper" and reading devices, and the like.

They can be used for packaging and/or for the preparation of labels. They are useful in inventory control and anti-counterfeiting applications (e.g., pharmaceuticals), including packaging labels. They can be used to make smart packaging and labels (e.g., for marketing and advertising, information gathering, inventory control, information display, etc.). They can be used to form faraday cages in packaging, for example for electronic components.

Inks and coatings can be used in electrical and electronic devices and components, such as housings and the like, to provide EMI shielding properties. They are manufactured for use in microdevices, such as micro-electromechanical systems (MEMS) devices, including for providing antistatic coatings.

They may be used to make housings, antennas, and other components of portable electronic devices such as computers, cellular telephones, game consoles, navigation systems, personal digital assistants, music players, game consoles, calculators, radios, artificial "paper" and reading devices, and the like.

The inks and coatings can be used to form thermally conductive channels on a substrate or to form films with desired flow properties and porosity. These materials may have highly variable and tunable porosity and may form a porosity gradient. Inks and coatings can be used to form articles having anisotropic thermal and/or electrical conductivity. The coating can be used to form a prototype for three-dimensional printing.

Inks and coatings can be used to prepare printed electronic devices (also referred to as "printed electronics") which can be in the form of finished devices, portions or sub-components of devices, electronic components, and the like.

Printed electronics can be prepared by applying inks and coatings to a substrate, using a pattern containing conductive pathways designed to achieve the desired electronic device. The channels may be solid, mostly solid, liquid or gel form, etc.

Printed electronics can take a wide variety of forms and be used in a wide variety of applications. They may comprise many layers of electronic components (e.g., circuitry) and/or substrates. All or a portion of the printed layer may be covered or coated with another material, such as an over coat, varnish, overlay, coverlay, dielectric coating, electrolyte and other conductive materials, and the like. There may also be one or more materials between the substrate and the printed circuit. The layers may include semiconductors, metal foils, dielectric materials, and the like.

The printed electronics may further include additional elements such as processors, memory chips, other microchips, batteries, resistors, diodes, capacitors, transistors, and the like.

Other applications include, but are not limited to: passive and active devices and components; power and electronics, integrated circuits; a flexible printed circuit board; a transistor; a field effect transistor; a micro-electromechanical systems (MEMS) device; a microwave circuit; an antenna; a diffraction grating; an indicator; chipless tags (e.g., for preventing theft of stores, libraries, etc.); security and anti-theft devices for retail, library and other environments; a keyboard; a smart card; sensors (including gas and biosensors); liquid Crystal Displays (LCDs); identifying; illuminating; a flat panel display; flexible displays including light emitting diode, organic light emitting diode, and polymer light emitting diode displays; a back panel and a front panel for a display; electroluminescent and OLED lighting; a photovoltaic device comprising a backsheet; product identification chips and equipment; membrane switches, batteries, including thin film batteries; an electrode; an indicator; printed circuits in portable electronic devices (e.g., cellular telephones, computers, personal digital assistants, global positioning system devices, music players, game players, calculators, etc.); an electronic connector fabricated through a hinge or other movable/bendable connection in an electronic device, such as a cellular phone, portable computer, folding keyboard, etc.); a wearable electronic article; and circuitry within vehicles, medical instruments, diagnostic equipment, instruments, and the like.

The electronic equipment may be Radio Frequency Identification (RFID) devices and/or their components and/or radio frequency communication devices. Examples include, but are not limited to, RFID tags, chips, and antennas. The RFID device may be an ultra high frequency RFID device, which typically operates at a frequency of about 868 to about 928 MHz. Examples of RFID uses are tracking containers, products in stores, products in transit, and parts used in manufacturing processes; a passport; barcode replacement applications; an inventory control application; identifying the pet; controlling livestock; a contactless smart card; automobile key ring, etc.

The electronic device may also be an elastomeric (e.g., silicone) touch pad and keypad. These devices may be used in portable electronic devices such as calculators, cellular telephones, GPS devices, keyboards, music players, game consoles, and the like. They may also be used in many other electronic applications such as remote controls, touch screens, car buttons and switches, etc.

Compositions, including those in the form of polymer composites, dispersions, inks, coatings, and the like, can be electrically and/or thermally conductive. In some embodiments, the composition may have at least about 10^-8Conductivity of S/m. It may have a thickness of about 10^-6S/m to about 10⁵S/m, or about 10^-5S/m to about 10⁵Conductivity of S/m. In other embodiments of the invention, the coating has the following electrical conductivity: at least about 0.001S/m, at least about 0.01S/m, at least about 0.1S/m, at least about 1S/m, at least about 10S/m, at least about 100S/m, at least about 1000S/m, or at least about 10,000S/m, or at least about 20,000S/m, or at least about 30,000S/m, or at least about 40,000S/m, or at least about 50,000S/m, or at least about 60,000S/m, or at least about 75,000S/m, or at least about 10S/m⁵S/m, or at least about 10⁶S/m。

In some embodiments, the surface resistivity of the composition (including the polymer composite, cured inks and coatings, etc.) may be no greater than about 10000 Ω/square/mil, or no greater than about 5000 Ω/square/mil, or no greater than about 1000 Ω/square/mil, or no greater than about 700 Ω/square/mil, or no greater than about 500 Ω/square/mil, or no greater than about 350 Ω/square/mil, or no greater than about 200 Ω/square/mil, or no greater than about 150 Ω/square/mil, or no greater than about 100 Ω/square/mil, or no greater than about 75 Ω/square/mil, or no greater than about 50 Ω/square/mil, or no greater than about 30 Ω/square/mil, or, Or not greater than about 20 Ω/square/mil, or not greater than about 10 Ω/square/mil, or not greater than about 5 Ω/square/mil, or not greater than about 1 Ω/square/mil, or not greater than about 0.1 Ω/square/mil, or not greater than about 0.01 Ω/square/mil, or not greater than about 0.001 Ω/square/mil.

In some embodiments, the composition may have the following thermal conductivities: about 0.1 to about 50W/mK, or about 0.5 to about 30W/mK, or about 0.1 to about 0.5W/mK, or about 0.1 to about 1W/mK, or about 0.1 to about 5W/mK, or about 0.5 to about 2W/mK, or about 1 to about 5W/mK, or about 0.1 to about 0.5W/mK, or about 0.1 to about 50W/mK, or about 1 to about 30W/mK, or about 1 to about 20W/mK, or about 1 to about 10W/mK, or about 1 to about 5W/mK, or about 2 to about 25W/mK, or about 5 to about 25W/mK, or at least about 0.7W/mK, or at least 1W/mK, Or at least 1.5W/mK, or at least 3W/mK, or at least 5W/mK, or at least 7W/mK, or at least 10W/mK, or at least 15W/mK.

Examples

Comparative example 1 and examples 1 to 7

The ink formulations of examples 1-7 and comparative examples 1 and 2 were prepared by mixing: graphene sheets, graphite, methyl methacrylate copolymers, isopropanol, N-butyl acetate, N-methylpyrrolidone, and γ -butyrolactone. P-toluenesulfonic acid (TsOH) was added to each formulation in the amount shown in table 1 (given as the weight% of p-toluenesulfonic acid relative to the total weight of binder and acid).

Comparative example 2 and example 7

In the case of comparative example 2, pigments (graphene sheets and graphite) were dispersed in a solvent system of hexanol and N-methylpyrrolidone to form a coating. In the case of example 7, the pigments (graphene sheets and graphite) and p-toluenesulfonic acid were combined in a solvent system of hexanol and N-methylpyrrolidone to form a coating. The non-volatile components comprise about 2.5% by weight of the coating. The solid components are present in the amounts given in table 2 relative to each other by weight.

Comparative example 3 and example 8

In the case of comparative example 3, pigments (graphene sheets and graphite) were dispersed in a solvent system of hexanol and N-methylpyrrolidone to form a coating. In the case of example 8, pigments (graphene sheets and graphite) and p-toluenesulfonic acid were combined in a solvent system of hexanol and N-methylpyrrolidone to form a coating. The non-volatile components comprise about 10% by weight of the coating. The solid components are present in the amounts given in table 2 relative to each other by weight.

Printing and measuring

The coating was applied to the PET film using a #28 wire wound rod. Each coating was applied in two layers and cured at 130 ℃ between coats and after the second coat.

The surface resistivity of the resulting cured print was measured using a four-probe. The results are given in tables 1-3.

The adhesion (pull) of the print was measured by: a piece of 3M Scotch is put^®The #810 tape was firmly applied to the print surface and quickly pulled away from the surface using a pulling motion perpendicular to the print surface. The adhesion of the print was rated on a scale of 1-5 (with 1 being the best) based on the appearance of the tape after pulling. A grade 1 is given for samples with little ink transferred to the tape. A grade of 5 is given for samples where the tape is completely dark after being pulled from the print. The results are given in table 3.

The adhesion (peel) of the prints was measured by: a piece of 3M Scotch is put^®The #810 tape was firmly applied to the surface of the print and gently pulled away in a direction parallel to the print surface. The surface resistivity of the print was measured before the tape was applied and again after the tape was pulled off. The percent increase in resistivity after pulling the tape is given in table 2.

TABLE 1

TABLE 2

The amounts of ingredients are in weight percent based on the total weight of the ingredients given.

TABLE 3

Claims

1. A composition comprising graphene sheets and at least one acid, wherein the graphene sheets have at least 100m²Surface area per gram, wherein the acid is p-toluenesulfonic acid.

2. The composition of claim 1, further comprising at least one polymer.

3. The composition of claim 2, wherein the polymer is selected from the group consisting of poly (vinyl butyral), poly (vinyl formal), and polyacrylates.

4. The composition of claim 1, wherein the graphene sheets have at least 300m²Surface area in g.

5. The composition of claim 1, wherein the graphene sheets have at least 400m²Surface area in g.

6. The composition of claim 1, wherein the graphene sheets have a molecular weight of at least 25: 1 carbon to oxygen molar ratio.

7. The composition of claim 1, wherein the graphene sheets have a molecular weight of at least 75:1 carbon to oxygen molar ratio.

8. The composition of claim 1, further comprising graphite.

9. An ink or coating comprising a composition comprising graphene sheets and at least one acid, wherein the graphene sheets have at least 100m²Surface area per gram, wherein the acid is p-toluenesulfonic acid.

10. The ink or coating of claim 9, further comprising at least one polymer.

11. The ink or coating of claim 10, wherein the polymer is selected from the group consisting of poly (vinyl butyral), poly (vinyl formal), and polyacrylates.

12. The ink or coating of claim 9, wherein the graphene sheets have at least 300m²Surface area in g.

13. The ink or coating of claim 9, wherein the graphene sheets have at least 400m²Surface area in g.

14. The ink or coating of claim 9, wherein the graphene sheets have a molecular weight of at least 25: 1 carbon to oxygen molar ratio.

15. The ink or coating of claim 9, wherein the graphene sheets have a molecular weight of at least 75:1 carbon to oxygen molar ratio.

16. An article coated with the ink or coating of claim 9.