751 results about "Graphene membrane" patented technology

The invention relates to a mobile phone case with a signal shielding function. The mobile phone case consists of a leather housing (1), a graphene film layer (2), a cotton liner (3), a zipper (4), and a graphene film overlapped edge (5), and is characterized in that the graphene film layer (2) is sewn in an interlayer formed by the leather housing (1) and the cotton liner (3); both ends of the leather housing (1) are sewn together by the zipper (4) and then are sewn inside the zipper (4) by the graphene film overlapped edge (5). According to the mobile phone case, all mobile phone signals from the outsides can be effectively shielded, so that a user cannot be entangled due to shutdown when using a mobile phone.

The invention discloses a method for preparing a graphene membrane. Carbon atoms are released from a solid carbon source by a method such as heat treatment, heat evaporation, sputtering, electron beam deposition, laser deposition or plasma deposition to form the graphene membrane on a catalytic layer or a substrate, wherein the solid carbon source is graphite, amorphous carbon, diamond, fullerene or carbon nano tubes. In the method for preparing the graphene membrane, the solid carbon source is used, the method is simple; and the prepared graphene membrane is easy to control in terms of thickness, structure and size, has excellent photoelectric characteristics and is suitable for preparing high-performance photoelectronic devices on a large scale.

The invention discloses an optical fiber Fabry-Perot sound pressure sensor manufacturing method based on a graphene membrane and a measuring method and device thereof. A sensor is manufactured based on the graphene membrane and the optical fiber Fabry-Perot interference optical principle. Firstly, a single mode fiber is rinsed and processed, the graphene membrane is transferred, and the graphene membrane is adsorbed to a zirconium oxide single mode inserting core; then, the zirconium oxide single mode inserting core is inserted into the processed single mode fiber from the other end. Therefore, two reflecting surfaces of Fabry-Perot interference are formed by the end face of the single mode fiber and the graphene membrane, an optical fiber-air-graphene membrane interference cavity is formed, an interference cavity length detecting device is set up, interference spectrum signals are demodulated by using a two-peak method, and the high sensitivity detection of weak sound pressure signals is achieved. The sensor has the advantages of being simple in manufacturing, high in sensitivity, small in size, resistant to electromagnetic interference and the like, the problem that a sensor is low in sensitivity due to the limitation of the reduction of the thickness of a membrane in the prior art is solved, the sensitivity of the membrane type sound pressure sensor is improved, and the sensor can be expected to be applied to the underwater sound field, the electroacoustic field, medical field, biomedical engineering filed and the like.

The invention discloses a foam metal-graphene composite material and a preparation method thereof. The composite material comprises a foam metal substrate and a graphene film layer positioned on the substrate. The foam metal-graphene composite material is prepared by means of electrophoresis. Specifically, the preparation method comprises the following steps: removing greasy dirt and oxides from the surface of a foam metal substrate, preparing graphene by the oxidation-reduction method, modifying graphene, and performing electrophoretic deposition on the graphene on the surface of the foam metal substrate. Within a certain of electromagnetic waveband, on one hand, the foam metal-graphene composite material has the structural advantages of light weight and porosity, large specific surface area and good conductivity of a foam metal, and on the other hand, the composite material integrates excellent electrical conductivity and high dielectric constant, a capacity of being more conducive to absorbing electromagnetic waves due to a large amount of defects and functional group residues of the self-made graphene, and other properties of self-made graphene. The composite material has a higher electromagnetic shielding performance and can serve as an excellent electromagnetic shielding material.

The invention provides a method for preparing a graphene wire and cable. The method comprises the following steps of: spraying or growing a graphene functional material with superior two-dimensional conduction characteristic on a substrate membrane material, and converting disordered graphene nanosheets into highly ordered two-dimensional graphene membranes through treatment of a hot pressing technology so as to prepare the graphene membrane material with the superior two-dimensional conduction characteristic; and then winding the two-dimensional graphene membrane material into the graphene wire with superior one-dimensional conduction characteristic through a winding technology. The graphene wire has the advantages of low resistance, high conduction density, superior conduction characteristic to that of metal conductors such as copper and silver, light weight, high temperature resistance and good chemical stability; and the graphene wires can be assembled and packaged to prepare a high-current graphene cable.

The invention discloses an integrated hydrogen sensor made from mixed graphene film, noble metal particles and metallic oxide materials and a preparation method of the integrated hydrogen sensor. The sensor comprises a substrate, a heating electrode, a heat-conducting insulation layer and a detection electrode; the heating electrode is placed on the substrate; the heat-conducting insulation layer is placed between the heating electrode and the detection electrode and further the sensor further comprises a metallic oxide film deposited on the detection electrode, the noble metal particles deposited on the metallic oxide film, and the graphene film covers the metallic oxide film on which the noble metal particles are deposited. The noble metal particles covering the metallic oxide film are single atoms, wherein the covering rate is 0.05-100 percent, the particle size is 0.2-0.4 nanometers, and the noble metal particles are randomly and uniformly arranged. The metallic oxide film is 10 nanometers to 2 micrometers in thickness. The graphene film is 0.5-1.2 nanometers in thickness. By adopting the integrated hydrogen sensor provided by the invention, high-sensitivity and high-selectivity detection and monitoring for hydrogen can be simultaneously achieved.

The invention relates to a graphene based transparent electric heating film and a production method thereof. The graphene based transparent electric heating film comprises a transparent flexible substrate, a graphene film is arranged on the transparent flexible substrate, a conductive connection mesh film is arranged on the graphene film and provided with electrodes which are electrically connected with the conductive connection mesh film and the graphene film. The electrodes are provided with protective layers covering the electrodes as well as covering the graphene film and the conductive connection mesh film. The graphene transparent electric heating film is suitable for large-scale production, labor cost is greatly reduced, and meanwhile, product stability is improved and the graphene based transparent electric heating film has the advantages of uniformity in heating, high transparency, good flexibility, low cost and good stability. Besides, heating power of the transparent electric heating film can be designed according to practical needs, heating curves can be designed according to service needs, and the heating film is guaranteed to have demisting and defrosting functions. Simultaneously, brittle cracking of glass due to sudden change of temperature is avoided. The graphene based transparent electric heating film is wide in application range, stable and reliable.

The invention discloses a device for measuring object stress by utilizing a graphene membrane, and a preparation method and a testing method of the device. The testing method is characterized in that graphene is arranged on a flexible stretchable substrate by utilizing a growth and transfer technology of the graphene and is tightly adhered to the surface of a to-be-measured object or a single crystal silicon substrate which is provided with a through hole, a characteristic peak of a Raman spectrum of the graphene can be subjected to shifting and splitting when the to-be-measured object is subjected to deformation or gas pressure difference exists between the internal part and the external part of the through hole, and sensing on strain or gas pressure can be realized basing on shifting and splitting amount of the characteristic peak. According to the device, the preparation method and the testing method, disclosed by the invention, the technical design is simple, the performance is stable, non-contact with the to-be-measured object is realized, and the complexity of an electrical measurement method which is in need of arranging leading wires can be avoided; the strain loading range is large, and the stress measurement accuracy degree is high.

The invention relates to a preparation method of a porous-ceramic-supported graphene film. An inorganic ceramic material serves as a support body, and one side of a silane-modified inorganic ceramic support body is coated with a graphene film-forming material. The preparation method can be applied to removal of water in an organic solvent through a pervaporation method and separation of organic systems in other fields of industrial production. A composite film has the unique properties of a graphene material and the own advantages of a ceramic material. The inherent limitations of common organic and inorganic materials are overcome. The preparation method is simple and economic in process, and wide in application range.

The invention aims to provide a nanocellulose-assisted preparation method of a high-content graphene flexible conductive composite membrane. The preparation method is characterized in that a low-content nanocellulose waterborne suspension is used to help disperse a graphene powder so as to obtain a uniform stable graphene/nanocellulose dispersion, and a flexible graphene composite membrane with graphene content up to 98 wt% and controllable mechanical property and conductivity can be prepared by a solvent evaporation method. The method is simple and low-cost, requires no complex equipment and is environmentally friendly. By the method, problems such as poor film-forming property of graphene, low strength, environmental pollution and the like existing in the prior art can be solved. In comparison with the prior art, the graphene membrane obtained by the method has advantages of good strength, controllable size and high conductivity.

The invention discloses an independent self-support wrinkled graphene film in nano thickness and a preparation method thereof. The independent self-support wrinkled graphene film in nano thickness isobtained through film formation by suction filtration of oxidized graphene prior to chemical reduction and high-temperature treatment. The independent self-support wrinkled graphene film in nano thickness is formed by single-layer graphene through physical crosslinking, wherein the graphene is complete in base structure without obvious defects and rich in wrinkles, and the content of turbostraticstructures among lamellas exceed 30%. Since the independent self-support wrinkled graphene film in nano thickness is extremely thin in thickness (16-130 nm) with a great quantity of superficial wrinkles, thereby being highly flexible.

The invention discloses a graphene film for light efficient electromagnetic shielding and a preparation method thereof. An oversized graphene oxide sheet is used for forming the film and by virtue of an annealing mode under high temperature, the graphene defect is perfectly repaired, the edge defect is reduced to the lowest to form a perfect large conjugate structure, and the smoothness of a head conducting path of the graphene is guaranteed; furthermore, through three steps of independent warming processes, a functional group is separated from the surface of the graphene step by step, a pore-foaming agent included between the graphene sheets is slowly decomposed, and the functional group and the pore-forming agent are released step by step in a gas mode; and meanwhile, the graphitization process is gradually developed to form a graphene micro airbag; in the forming process of the micro gasbag, the most stable functional group on the surface of the graphene falls off, thereby producing the graphene structure formed by 1-4 layers of graphene sheets with the gas expansion under high temperature; the successful introduction of the graphene few-layer structure greatly promotes the conductivity performance of the material. The micro gasbag structure is assisted by good conductivity performance so that the graphene of the invention has strong electromagnetic shielding performance.

The invention belongs to the field of heat-conducting materials, and particularly relates to a preparation method of a novel high-heat-conductivity graphene film/carbon fiber heat-radiating plate. A graphene-carbon fiber resin matrix composite material is prepared from a graphene layer, a carbon fiber woven mesh layer and a vertical alignment carbon fiber reinforced layer. The graphene film is punched in advance through a stamping technology so as to obtain a meshy graphene film, and is then pre-impregnated with epoxy so as to obtain a prepreg. The graphene film and the carbon fiber sheet prepreg are sequentially laminated and paved, and then an ultrasonic impacting gun is used for driving a carbon fiber needling preform into a composite plate, or a needling method is used for vertically aligning part of carbon fiber, so that a shearing performance is improved. According to the preparation method provided by the invention, graphene powder and the carbon fiber sheet are compounded, so that the composite material has excellent heat conductivity and better machinability. The composite material plate can be used for heat radiation of a large-scale component, has a heat radiation performance similar to pure metal and other heat-radiating materials, and has cuttability and better flexibility. The material is simple in production process, energy-saving, environmental-friendly, high inapplicability, and capable of being produced in a large scale.

Technologies are generally described for perforated graphene monolayers and membranes containing perforated graphene monolayers. An example membrane may include a graphene monolayer having a plurality of discrete pores that may be chemically perforated into the graphene monolayer. The discrete pores may be of substantially uniform pore size. The pore size may be characterized by one or more carbon vacancy defects in the graphene monolayer. The graphene monolayer may have substantially uniform pore sizes throughout. In some examples, the membrane may include a permeable substrate that contacts the graphene monolayer and which may support the graphene monolayer. Such perforated graphene monolayers, and membranes comprising such perforated graphene monolayers may exhibit improved properties compared to conventional polymeric membranes for gas separations, e.g., greater selectivity, greater gas permeation rates, or the like.

The invention relates to a boron nitride-graphene composite material which sequentially comprises a boron nitride film (8), a graphene film (9) and the boron nitride film (10). By using the composite material, under the condition that a carrier density is not increased, conductivity of the grapheme can be substantially increased. In addition, the invention also relates to a preparation method of the composite material and a purpose of preparing a transparent electrode.

The invention discloses a preparation method of a flexible self-supported paper graphene membrane and a composite membrane thereof. The preparation method comprises the following steps of: preparing a graphene oxide aqueous solution with concentration of 1.5mg/mL-12mg/mL by using graphite as the material according to an improved Hummers method; pouring the graphene oxide aqueous solution and functionalized carbon nano tube mixed aqueous solution to the bottom of 0.2mg/mL-11mg/mL of hydroxylamine alcohol solution or a hydroxylamine hydrochloride hydroxylamine alcohol solution, stewing and condensing; heating up at a low temperature, and evaporating alcohol solvent to obtain N-doped flexible self-supported paper graphene membrane and the composite membrane thereof. The product prepared by the preparation method disclosed by the invention is controllable in thickness, good in flexibility, high in electrical conductivity and thermal conductivity, and can be used for a capacitor electrode material, a mechanical driver and a heat conducting material. The preparation method is simple to operate, capable of completing the whole preparation process by one step and capable of realizing mass production of the N-doped flexible self-supported paper graphene membrane and the composite membrane thereof.