1184 results about "Functionalized graphene" patented technology

The invention discloses a method for grafting a polymer ona surface of graphene. The method comprises the following steps: adding 1 part by weight of graphene or graphene oxide, 10-1000 parts by weight of solvent and 10-1000 parts by weight of vinyl monomer, and adding 0.01-10 parts by weight of initiator under introduction of nitrogen; heating to 55-90 DEG C, and carrying out reaction for 1.5-60hours; and precipitating, centrifugating, washing, and drying, thus obtaining a product of polymer-grafted graphene. The method is convenient and simple in process, can be used for the large-scale production, is the universal method and ensures that a variety of polymers can be grated onto the graphene. The obtained functionalized graphene has good solubility and good solution processability, is conducive and has extensive application value in micro-nano electronics, machinery, chemical industry, high-performance materials and other fields.

Provided are methods for forming graphene or functionalized graphene thin films. Also provided are graphene and functionalized graphene thin films formed by the methods. For example, electrophoretic deposition methods and stamping methods are used. Defect-free thin films can be formed. Patterned films can be formed. The methods can provide conformal coatings on non-planar substrates.

The invention provides a conducting paint which comprises 1-8 wt% of graphene, 0.1-1 wt% of functionalized graphene, 15-30 wt% of epoxy resin and curing agent, 0.2-1.5 wt% of wetting dispersant, 0.1-0.5 wt% of defoaming agent, 0-30 wt% of conducting filler and the balance of solvent. The functionalized graphene is amino-containing functionalized graphene or sulfhydryl-containing functionalized graphene. The functionalized graphene contains amino or sulfhydryl group, and therefore, can be better dispersed in the system, and the amino or sulfhydryl group can react with epoxy group in the epoxy resin, thereby enhancing the binding force of the coating; and besides, the graphene has a flake structure and a large radius-thickness ratio and is arranged as a plurality of layers in the coated film in parallel, and therefore, the conducting paint has favorable conductivity and adhesiveness.

The invention relates to the technical field of polymer-based nanocomposites, and provides a preparation method of a functionalized graphene oxide / epoxy resin nanocomposite in order to effectively solve the problems of dispersion and interface of graphene in epoxy resin. The method comprises the steps of performing ultrasonic treatment on the silane coupling agent modified graphene oxide (f-GO) for 20-40 minutes, and dispersing in an organic solvent; adding epoxy resin, and mixing to obtain master batch; removing the organic solvent under a vacuum condition; adding a curing agent and mixing; performing high-temperature curing to obtain the functionalized graphene oxide / epoxy resin nanocomposite. The graphene oxide / epoxy resin nanocomposite prepared by the method provided by the invention can effectively improve the mechanical and thermal properties of epoxy resin, including strength, rigidity, toughness and thermal stability.

The invention provides a preparation method of dispersible silane functionalized graphene. The method comprises the steps of: conducting ultrasonic dispersion to graphene oxide in absolute ethyl alcohol so as to form a uniform graphene oxide dispersion solution, then adjusting the pH value to 3-4, or under the protection of an inert atmosphere, adding silane into the dispersing solution for modification, with silane and graphene oxide in a mass ratio of 0.1:1-5:1, continuing the reaction for 12h-48h at a temperature ranging from normal temperature to 78DEG C, carrying out centrifugation, then adding hydrazine hydrate to the obtained solid, performing heating reduction, and filtering the reaction solution, then washing and drying the filter cake, thus obtaining dispersible silane functionalized grapheme. The method of the invention is simple and practicable, and the obtained silane functionalized grapheme has good dispersibility in solvents like absolute ethyl alcohol, acetone, toluene, ethyl acetate, butyl acetate, and tetrahydrofuran (THF), etc.

The invention discloses a graphene chemical modification method. The graphene chemical modification method comprises the following steps that graphene oxide and compound with primary amine radicals are mixed and are added to water or mixed solution of organic solvent and water to obtain reaction solution, and reacting is carried out under alkaline conditions to direct obtain functional graphene materials. According to the method, micromolecules and macromolecules with amino groups can be connected to graphene in a bonding mode through further chemical reactions to prepare a plurality of graphene functional materials. The method is easy, universal and efficient.

The invention provides methods functionalizing a planar surface of a graphene layer, a graphite surface, or microelectronic structure. The graphene layer, graphite surface, or planar microelectronic structure surface is exposed to at least one vapor including at least one functionalization species that non-covalently bonds to the graphene layer, a graphite surface, or planar microelectronic surface while providing a functionalization layer of chemically functional groups, to produce a functionalized graphene layer, graphite surface, or planar microelectronic surface.

A process for producing a highly oriented graphitic film, consisting of (a) preparing a dispersion having graphene oxide (GO) or chemically functionalized graphene (CFG) dispersed in a liquid to form a liquid crystal phase (but not in a GO gel state); (b) depositing the dispersion onto a supporting substrate to form a layer of GO or CFG under an orientation-inducing stress; (c) removing the liquid to form a dried GO or CFG layer having an inter-plane spacing d002 of 0.4 nm to 1.2 nm; (d) thermally reducing the dried layer at a first temperature higher than 100° C. to produce a porous layer of reduced GO or CFG; (e) further heat-treating the porous layer at a second temperature to produce a porous graphitic film having an inter-plane spacing d002 less than 0.4 nm; and (f) compressing the porous graphitic film to produce the highly oriented graphitic film.

A graphene-based saturable absorber device suitable for use in a ring-cavity fiber laser or a linear-cavity fiber laser is disclosed. The saturable absorber device includes an optical element and a graphene-based saturable absorber material supported by the optical element and comprising at least one of graphene, a graphene derivative and functionalized graphene. An examplary optical element is an optical fiber having an end facet that supports the saturable absorber material. Various forms of the graphene-based saturable absorber materials and methods of forming same are also disclosed.

A gas separation membrane including a porous layered support; and a gas separating active layer which is disposed on the porous layered support and includes a functionalized graphene.

The invention provides a preparation method of a graphene modified polyurethane film-forming agent. The method includes: reacting polyether diols or polyether polyol with isocyanate modified graphene or functional graphene to generate an isocyanate-terminated prepolymer, then subjecting the prepolymer to chain extension with diol amine or triol amine, finally performing end-capping with alkylamine, a hydroxyl compound or dialkyl alcohol amine compound, then carrying out acidizing neutralization, and adding water to conduct emulsification, removing the organic solvent by vaporization so as to obtain the graphene modified polyurethane film-forming agent. The method provided by the invention has the characteristics of low reaction temperature, simple process, and recyclability of solvent, and is atom economic reaction without ''three wastes''. The obtained film-forming agent can be used as conductive paint and film-forming agent to prepare glass fiber drawing impregnating agents, fabric sizing agents, leather finishing agents, carbon fiber sizing agents, adhesives or paint, etc. The film-forming agent can effectively reduce the material surface resistance, and can be used in the antistatic or electromagnetic shielding material field.

Fuel system components comprising polymer compositions containing functionalized graphene sheets. The components are formed from the polymer compositions or are coated with the polymer composition.

A ceramic capacitor comprising at least a dielectric ceramic layer and at least a graphene electrode layer deposited on the ceramic layer, wherein the graphene electrode layer has a thickness no less than 2 nm and consists of a graphene material or a graphene composite material containing at least 0.1% by weight of a graphene material dispersed in a matrix material or bonded by a binder material, wherein the graphene material is selected from (a) a plurality of single-layer or multi-layer pristine graphene sheets having less than 0.01% by weight of non-carbon elements, or (b) one or a plurality of a non-pristine graphene material having at least 0.01% by weight of non-carbon elements, wherein the non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, doped graphene, chemically functionalized graphene, or a combination thereof.

The invention discloses a high-solubility multi-fold dry-state graphene oxide microsphere and a preparation method thereof. According to the dry-state graphene oxide microsphere, firstly graphene oxide dispersion liquid is prepared through an organic solvent dilution Hummers method, and then atomized drying is performed so that the dry-state graphene oxide microsphere can be obtained. The dry-state graphene oxide microsphere obtained through the preparation method is good in solubility, the solubility in water and common organic solvents is 20-30 mg / g, and the dry-state graphene oxide microsphere can be stably dispersed for a long time in the mode of a single-layer graphene oxide sheet; good solubility can still be kept after the dry-state graphene oxide microsphere is compressed into high-density blocks; the preparation method is simple, convenient and fast, low in energy consumption and suitable for large-scale industrial production. The problem that the solubility of graphene oxide obtained through an existing drying method is poor is solved, transportation, storage and use of the dry-state graphene oxide microsphere are facilitated because of high density, the dry-state graphene oxide microsphere can be used in the fields of graphene macroscopic assembly materials, functional graphene materials, graphene composite materials and the like.

The invention discloses conductive ink based on a graphene composite material and a preparation method thereof. The conductive ink is prepared from the following components in parts by mass: 1-30 parts of a functional graphene composite material, 1-70 parts of a resin coupling agent, 5-60 parts of a solvent and 1-40 parts of an auxiliary. According to the method, graphene is modified into a functional graphene composite material, low density and high conductivity of graphene can be maintained, the situation that graphene is easily agglomerated and difficult to disperse can be improved, and then affinity between conductive filler and a resin connecting material is improved, so that the high-conductivity conductive ink under a low-content conductive agent can be successfully prepared. The conductive ink is simple in preparation method, stable in system, good in conductivity and easy to print, has a flexible and abrasion-resistance membrane layer, can be widely applied to radio frequency tags, intelligent package, film switches, conductive circuits, sensors and other light flexible electronic products, and has a huge market prospect.

Provided is an integral 3D graphene-carbon hybrid foam composed of multiple pores and pore walls, wherein the pore walls contain single-layer or few-layer graphene sheets chemically bonded by a carbon material having a carbon material-to-graphene weight ratio from 1 / 100 to 1 / 2, wherein the few-layer graphene sheets have 2-10 layers of stacked graphene planes having an inter-plane spacing d002 from 0.3354 nm to 0.40 nm and the graphene sheets contain a pristine graphene material having essentially zero % of non-carbon elements, or a non-pristine graphene material having 0.01% to 25% by weight of non-carbon elements wherein said non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, doped graphene, chemically functionalized graphene, or a combination thereof. Also provided are a process for producing the hybrid form, products containing the hybrid foam, and its applications.

Provided is a lithium or sodium metal battery having an anode, a cathode, and a porous separator and / or an electrolyte, wherein the anode contains an integral 3D graphene-carbon hybrid foam composed of multiple pores, pore walls, and a lithium-attracting metal residing in the pores; wherein the metal is selected from Au, Ag, Mg, Zn, Ti, Na, K, Al, Fe, Mn, Co, Ni, Sn, V, Cr, or an alloy thereof and is in an amount of 0.1% to 50% of the total hybrid foam weight or volume, and the pore walls contain single-layer or few-layer graphene sheets chemically bonded by a carbon material having a carbon material-to-graphene weight ratio from 1 / 200 to 1 / 2, wherein graphene sheets contain a pristine graphene or non-pristine graphene selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, doped graphene, chemically functionalized graphene, or a combination thereof.

The invention relates to a method for functionalizing a polymer on the surface of nano graphene oxide. The method comprises the following specific steps: preparing graphene oxide from natural graphite powder by an improved Hummers method, utilizing methoxy polyethylene glycol and pyrene acids to carry out esterification to generate polyethylene glycol with pyrenyl as the terminal group, and finally grafting the polyethylene glycol with pyrenyl as the terminal group on the surface of graphene oxide through pi-pi interaction between pyrenyl and the surface of graphene oxide, thus obtaining the graphene oxide with the functionalized polymer on the surface. The solubility of the prepared graphene oxide with the functionalized polymer on the surface is greatly improved. The method has the following advantages: a main process adopted in the experiment is as follows: a polymer with a complex structure is designed and prepared in advance and then is grafted on the graphene oxide, and the grafting reaction can be carried out at normal temperature and pressure, so the whole experiment process is very simple and convenient. Therefore, the study provides a direct method for modifying the graphene oxide and preparing the functionalized graphene oxide-polymer complex to form a new inorganic-organic hybrid material, thereby promoting the development and application of graphene oxide-based materials.

The present invention is directed to a process for preparing a conductive film comprising: 1) coating a solution comprising functionalized graphene on the surface of a substrate to form a film; and 2) chemically reducing and / or calcining the film, which is loaded on the matrix material and obtained in step 1). The process can be used to prepare a conductive film on various substrates, such as steel, glass, ceramic, quartz, carbon materials, silicon materials, and organic materials.

This disclosure provides a system for detecting rare cells. The system includes a substrate, an extension coupled to the substrate and extending outwardly from the substrate, and a functionalized graphene oxide disposed on the extension. This disclosure also provides a method for detecting rare cells using the system of this disclosure. The method includes the steps of providing the system and introducing a sample of bodily fluid to the system such that the sample interacts with the functionalized graphene oxide.

The invention discloses a preparation method of a graphene oxide / amino acid composite material with an adsorption effect on heavy metal ions under acidic conditions, belonging to the technical fields of preparation and application of composite materials. The preparation method comprises the following step: reacting amino groups in amino acid with carboxy groups in graphene oxide to prepare the graphene oxide / amino acid composite material by virtue of nucleophilic reaction. Amino acid is an environment-friendly amphoteric compound; because amino acid contains the amino groups and carboxy groups which have strong complexing action on the heavy metal ions, by preparing amino acid functionalized graphene oxide, the removal efficiency of functionalized graphene oxide on heavy metals under the acidic conditions can be improved by using the specific characteristic that amino acid has acidity and alkalinity; and moreover, because amino acid is environment-friendly, secondary pollution cannot be caused in a heavy metal ion removal process. Under the condition that the pH value is 2-7, relatively good adsorption effects on Pb<2+> and Cu<2+> can be achieved, and the adsorption efficiency can reach 71-99%. The graphene oxide / amino acid composite material prepared by using the preparation method disclosed by the invention has relatively high practical application values in the adsorption effects on the heavy metal ions under the acidic conditions.

The invention discloses superhigh water-soluble functionalized graphene / oxidized graphene and a preparation method thereof. The superhigh water-soluble functionalized graphene / oxidized graphene comprises a graphene / oxidized graphene base body with a diaphragm-shaped structure, and at least sulfonic groups are distributed on and connected with the surface of the graphene / oxidized graphene base body; the solubility of the functionalized graphene / oxidized graphene in a water-phase system is more than 100 mg / ml; the functionalized graphene / oxidized graphene can be stably preserved for more than three months and has wide application prospect. The preparation method of the functionalized graphene / oxidized graphene comprises the following steps of: providing a medium which is mainly formed by uniformly mixing sulfuric anhydride and strong acid, and adding graphene / oxidized graphene to the medium so that the concentration of the graphene / oxidized graphene contained in a formed mixed reactant is 1-10 percent by weight; then reacting the mixed reactant at 60-150 DEG C for 1-10 hours; then distilling at more than 160 DEG C; cleaning residues to obtain a target product. The process disclosed by the invention has the advantages of simplicity, easiness for implementation, low cost, safety and environmental protection and is suitable for the demand of large-scale industrial production.

The present invention relates to a method of preparing a nitrogen-doped graphene comprising preparing a Edge-Functionalized Graphene by binding a graphite with a organic material having amino groups and functional groups such as carboxy acid group through an electrophilic substitution reaction, and heat treating the resultant Edge-Functionalized Graphene, and a nitrogen-doped graphene prepared thereby. According to the present invention, by a more inexpensive and simpler method, a nitrogen-doped graphene can be prepared at higher purity and higher yield. The nitrogen-doped graphene obtained by the present invention has very excellent physical and electric properties, and particularly has a superior oxygen reduction capability, compared with the platinum catalyst used at cathode of a H2 / O2 fuel cell so that it will replace the platinum to lower more the cost of a H2 / O2 fuel cell or to increase its life and further to provide a new turning point for the commercialization of a H2 / O2 fuel cell.

The present invention relates to a polyimide high dielectric composite material, wherein polyimide is adopted as a matrix phase, modified graphene and nanometer barium titanate are adopted as inorganic phases, components comprise, by mass, 0.5-3.0 w% of modified graphene, 9.6-29.8 w% of nanometer barium titanate, and 69.7-87.4 w% of polyimide, the modified graphene is p-phenylenediamine graft modified graphene, and the surface of the modified graphene contains chemically grafted polyimide. The preparation method comprises the following steps: (1) graphene oxide modification, (2) polyamic acid prepolymer preparation, and (3) composite material thermal cross-linking. According to the preparation method, the functionalized graphene and the polyimide molecules can be combined through a covalent bond form, electric conductivity of the graphene can directly affect dielectric property of the composite material, and a volume fraction of the barium titanate can be effectively reduced. In addition, the conventional solution blending technology is adopted, the preparation process is simple, operation is easy, and the method can be widely promoted and applied.