558 results about "Graphene nanoribbons" patented technology

Provided in this invention is a process for producing chemically functionalized nano graphene materials, known as nano graphene platelets (NGPs), graphene nano sheets, or graphene nano ribbons. Subsequently, a polymer can be grafted to a functional group of the resulting functionalized NGPs. In one preferred embodiment, the process comprises (A) dispersing a pristine graphite material and an azide or bi-radical compound in a liquid medium comprising to form a suspension; and (B) subjecting the suspension to direct ultrasonication with to ultrasonic waves of a desired intensity or power level for a length of time sufficient to produce nano graphene platelets and to enable a chemical reaction to occur between the nano graphene platelets and the azide or bi-radical compound to produce the functionalized nano graphene material. Concurrent production and functionalization of NGPs directly from pristine graphitic materials can be achieved in one step and in the same reactor.

The invention relates to a layer-by-layer self-assembling oxidized graphene nano-filtration membrane and a preparation method of the layer-by-layer self-assembling oxidized graphene nano-filtration membrane, which belongs to the technical field of the preparation of a nano-filtration membrane. The layer-by-layer self-assembling oxidized graphene nano-filtration membrane comprises a supporting layer and a functional layer, wherein the functional layer is in a layered structure which is different from the compact structure of the traditional nano-filtration membrane functional layer. The preparation method comprises the following steps of (I) preparing an oxidized graphene solution through a hummers method; and (II) preparing an oxidized graphne nano-filtration membrane through a layer-by-layer self-assembling method. The oxidized graphene nano-filtration membrane is prepared through the layer-by-layer self-assembling method, a water passage is formed between the oxidized graphene lamellas, the distance of the oxidized graphene layer has a good interception effect for ions, the hydrophilia can be improved through the oxygen-containing functional groups on the surface of the oxidized graphene layer, so that the membrane is good in permeability and interception property. By utilizing the layer-by-layer self-assembling method, the high requirement of the traditional nano-filtration membrane preparation process on the condition can be avoided, the process is simple, the condition is easily controlled, and the application prospect is wide.

A novel method for fabrication of hybrid semiconductor-graphene nanostructures in large scale by floating graphene sheets on the surface of a solution is provided. Using this approach, crystalline ZnO nano/micro-rod bundles on graphene fabricated using chemical vapor deposition were prepared. UV detectors fabricated using the as-prepared hybrid ZnO-graphene nano-structure with graphene being one of the two electrodes show high sensitivity to ultraviolet light, suggesting the graphene remained intact during the ZnO growth. This growth process provides a low-cost and robust scheme for large-scale fabrication of semiconductor nanostructures on graphene and may be applied for synthesis of a variety of hybrid semiconductor-graphene nano-structures demanded for optoelectronic applications including photovoltaics, photodetection, and photocatalysis.

Provided is a surface Raman and infrared spectroscopy double-enhanced detecting method based on graphene and nanogold compounding.According to the method, light sources, a lens, a graphene nanobelt and gold nanoparticle composite substrate, an infrared Fourier spectrograph and a Raman spectrometer are included.Infrared light waves and visible light waves emitted by the infrared light source and the laser light source respectively pass through a beam combiner and then irradiate the graphene nanobelt and gold nanoparticle composite substrate, after the light waves and trace molecules adsorbed on the substrate interact, reflected light is gathered by the focusing lens to enter the infrared Fourier spectrograph, and meanwhile scattered light is gathered into the Raman spectrometer.Raman scattering signals of the trace molecules can be enhanced through the local area plasma effect of the gold nanoparticles, and meanwhile infrared absorption spectrum signals of the trace molecules can be dynamically enhanced through the graphene surface plasma effect within the broadband range.According to the method, double enhancement of surface Raman and broadband infrared spectroscopy signals is achieved on the same substrate, and the advantages of being wide in enhancement wave band, high in detecting sensitivity, wide in detected matter variety range, good in stability and the like are achieved.

Disclosed is a method for making graphene nanoribbons (GNRs) by controlled unzipping of structures such as carbon nanotubes (CNTs) by etching (e.g., argon plasma etching) of nanotubes partly embedded in a polymer film. The GNRs have smooth edges and a narrow width distribution (2-20 nm). Raman spectroscopy and electrical transport measurements reveal the high quality of the GNRs. Such a method of unzipping CNTs with well-defined structures in an array will allow the production of GNRs with controlled widths, edge structures, placement and alignment in a scalable fashion for device integration. GNRs may be formed from nanostructures in a controlled array to form arrays of parallel or overlapping structures. Also disclosed is a method in which the CNTs are in a predetermined pattern that is carried over and transferred to a substrate for forming into a semiconductor device.

Ultraviolet (UV), Terahertz (THZ) and Infrared (IR) radiation detecting and sensing systems using graphene nanoribbons and methods to making the same. In an illustrative embodiment, the detector includes a substrate, single or multiple layers of graphene nanoribbons, and first and second conducting interconnects each in electrical communication with the graphene layers. Graphene layers are tuned to increase the temperature coefficient of resistance to increase sensitivity to IR radiation. Absorption over a wide wavelength range of 200 nm to 1 mm are possible based on the two alternative devices structures described within. These two device types are a microbolometer based graphene film where the TCR of the layer is enhanced with selected functionalization molecules. The second device structure consists of a graphene nanoribbon layers with a source and drain metal interconnect and a deposited metal of SiO2 gate which modulates the current flow across the phototransistor detector.

The invention discloses a lithium ion battery electrode made of graphene/ MoS2 and amorphous carbon and a preparation method thereof. The lithium ion battery electrode is characterized in that the active material of the electrode is a composite nano-material of graphene nano-sheets/ MoS2 graphene nano-sheets and amorphous carbon, and the balance is acetylene black and polyvinylidene fluoride; the mass percentage of each component is: 75-85% of active material of composite nano-material, 5-10%of acetylene black and 10-15% of polyvinylidene fluoride, wherein in the composite nano-material, the mass percentage of the graphene nano-sheets is 4.2-15%, the mass percentage of the MoS2 graphene nano-sheets is 44-65%, and the balance is the amorphous carbon, wherein the mass ratio of the graphene nano-sheets and the MoS2 graphene nano-sheets is 1 to 1-4 to 1. The preparation method of the electrode comprises the following steps of: using graphite as a raw material to prepare graphite oxide nano-sheets with a method of chemical oxidation; in the presence of the graphite oxide nano-sheets, compounding to obtain the composite nano-material of the graphene nano-sheets/ MoS2 graphene nano-sheets and the amorphous carbon in a hydro-thermal way; and finally using the composite nano-material of the graphene nano-sheets/ MoS2 graphene nano-sheets and the amorphous carbon as an electrochemical active material to prepare the electrode. The electrode has high electrochemical lithium intercalating reversible capacity and good stable circulation property and is widely applied to the new generation of lithium ion batteries.

A graphene nanomesh includes a sheet of graphene having a plurality of periodically arranged apertures, wherein the plurality of apertures have a substantially uniform periodicity and substantially uniform neck width. The graphene nanomesh can open up a large band gap in a sheet of graphene to create a semiconducting thin film. The periodicity and neck width of the apertures formed in the graphene nanomesh may be tuned to alter the electrical properties of the graphene nanomesh. The graphene nanomesh is prepared with block copolymer lithography. Graphene nanomesh field-effect transistors (FETs) can support currents nearly 100 times greater than individual graphene nanoribbon devices and the on-off ratio, which is comparable with values achieved in nanoribbon devices, can be tuned by varying the neck width. The graphene nanomesh may also be incorporated into FET-type sensor devices.

Radiation detecting and sensing systems using graphene and methods of making the same are provided; including a substrate, a single or multiple layers of graphene nanoribbons, first and second conducting interconnects each in electrical communication with the graphene layers. Graphene layers are tuned to increase the temperature coefficient of resistance, increasing sensitivity to IR radiation. Absorption over a wide wavelength range (200 nm to 1 mm) is possible based on the three alternative devices structures described within. Devices can variously include (a) a microbolometer based graphene film where the TCR of the layer is enhanced with selected functionalization molecules, (b) graphene layers with a source and drain metal interconnect and a deposited metal of SiO2 gate which modulates the current flow across the phototransistor detector, and/or (c) tuned graphene layers layered on top of each other where a p-type layer and a n-type layer is created using a combination of oxidation and doping.

In various embodiments, the present invention provides electrically conductive and radio frequency (RF) transparent films that include a graphene layer and a substrate associated with the graphene layer. In some embodiments, the graphene layer has a thickness of less than about 100 nm. In some embodiments, the graphene layer of the film is adhesively associated with the substrate. In more specific embodiments, the graphene layer includes graphene nanoribbons that are in a disordered network. Further embodiments of the present invention pertain to methods of making the aforementioned electrically conductive and RF transparent films. Such methods generally include associating a graphene composition with a substrate to form a graphene layer on a surface of the substrate.

The invention discloses an oxidized graphene nano-ribbon/polymer composite film and a preparation method thereof. The preparation method comprises the following steps: longitudinally cutting a multi-walled carbon nano-tube into oxidized graphene nano-ribbons of strip-shaped structures through oxidation; compounding the oxidized graphene nano-ribbons with a polymer to form the film. The composite film prepared according to the invention is excellent in barrier property and mechanical property, and has a certain fixed degree of transparency, thereby being widely applied to the field with higher barrier requirements. At present, mass production of multi-walled carbon nano-tubes is realized in domestic and foreign countries, so that the preparation cost of the oxidized graphene nano-ribbon is greatly reduced. The barrier property and mechanical property of the composite film can be greatly improved only with few oxidized graphene nano-ribbons. The preparation method is simple, high in operability, and is suitable for large-scale industrialized production.

An electrical conductor comprising an electrically conducting fibre comprising carbon nanotubes and/or graphene nanoribbon and a layer of insulating material coated around the electrically conducting fibre. The insulating material substantially does not penetrate the electrically conducting fibre, or penetrates the electrically conducting fibre only to a depth that leaves a continuous conductive path along a remaining part of the electrically conducting fibre.

The invention relates to a preparation method of waterborne polyurethane/graphene nano-composite emulsion, and belongs to the field of organic-inorganic nano-composite materials. According to the preparation method, graphene oxide dispersion liquid is prepared by adopting an improved Hummers method, and is compounded with waterborne polyurethane to obtain the waterborne polyurethane/graphene nano-composite emulsion. By use of the preparation method disclosed by the invention, the waterborne polyurethane/graphene nano-composite emulsion is prepared by taking oligomer polyol as a soft segment, taking an isocyanate compound as a hard segment and carrying out in-situ introduction of the graphene oxide dispersion liquid in the preparation process of the waterborne polyurethane. The mechanical property, antistatic property, conductive property, electromagnetic shielding property, thermal conductivity, chemical resistance, corrosion resistance and the like of a waterborne polyurethane film and a coating are effectively improved by introducing grapheme. The waterborne polyurethane/graphene nano-composite emulsion has a better application prospect in the fields of coating materials, adhesives, ink, surface treatment agents, elastomers, foaming materials, functional films and the like.

The invention relates to a preparation method of a graphene nano-fiber and super-capacitor application of the preparation method of the graphene nano-fiber. The preparation method of the graphene nano-fiber includes the following steps: (1) an electrostatic spinning method is utilized to prepare a polymer fiber; (2) the polymer fiber obtained by the method is conducted with stabilizing treatment in appropriate temperature and in an oxygen-bearing atmosphere; (3) the fiber after the stabilizing treatment is conducted with carbonization thermal treatment in an NH3-bearing atmosphere and in appropriate temperature. The surface of the prepared graphene nano-fiber is provided with a graphene sheet which grows along the radial direction, and the thickness of the graphene sheet is 1 to 10 atomic layers. The graphene nano-fiber integrates the advantages of graphene and carbon nanofibers, solves the problems of graphene agglomeration and recrystallization, is high in surface activity and has various application values. The graphene nano-fiber is utilized to serve as a super-capacitor of electrode material preparation. Therefore, compared with the prior art, the preparation method of the graphene nano-fiber and the super-capacitor application of the preparation method of the graphene nano-fiber have good performance. The working voltage reaches 1.8-2.2 volts; the energy density reaches 41.3 watt hour/kilogram; and the specific capacitance in acid can reach 300 F/g.

The invention belongs to the technical field of a transition metal chalcogenide-carbon material, and specifically relates to a molybdenum selenide nanosheets/graphene nanoribbons composite material and its preparation method. According to the invention, graphene nanoribbons are prepared by a solution oxidization method, and then molybdenum selenide nanosheets grow in situ on the graphene nanoribbons by a solvothermal method. The prepared graphene nanoribbons have advantages of stable chemical property, high length-to-diameter ratio and the like. The prepared composite material has characteristic of controllable morphology. As molybdenum selenide nanosheets are uniformly loaded on the graphene nanoribbons, agglomeration of molybdenum selenide itself is effectively inhibited, and the particular high specific surface area and high conductivity of the graphene nanoribbons are fully utilized. The prepared molybdenum selenide nanosheets/graphene nanoribbons composite material can become an ideal high-performance electrochemical hydrogen evolution catalytic material and electrode material of new energy devices such as lithium ion battery and solar cell, etc.

The invention relates to a method for preparing graphene, a method for carrying out graphene surface modification by taking one or more than two of pyrene, pyrene derivatives, naphthalene and naphthalene derivatives as a modifying agent as well as a method for manufacturing TiO2-graphene nano-composite material by utilizing the reaction of the surface-modified graphene and a titanium-containing compound and a product thereof. The method for preparing graphene comprises the steps of (a1) reducing dispersive graphite oxide in inert solvent by using a reducing agent to form a graphene-containing reaction mixture, wherein the reducing agent comprises sodium borohydride, vitamin C or combination thereof; and (a2) isolating graphene from the reaction mixture. The obtained graphene is flocculent and the TiO2-graphene nano-composite material has efficient photocatalytic performance.

The invention discloses a waterborne polyurethane/dopamine modified graphene nano-composite emulsion preparation method and belongs to the field of organic-inorganic nano-composite materials. According to the preparation method, an improved Hummers method is utilized to prepare graphene oxide dispersion liquid at first, and then dopamine is utilized to surface modify the graphene oxide and compounded with waterborne polyurethane to prepare a waterborne polyurethane/dopamine modified graphene nano-composite emulsion. According to the preparation method disclosed by the invention, low polymer polyalcohol is utilized as a soft segment, isocyanate compound is utilized as a hard segment, and the dopamine modified graphene oxide dispersion liquid is guided into a waterborne polyurethane preparation process in site to prepare the waterborne polyurethane/dopamine modified graphene nano-composite emulsion. As the dopamine modified graphene is guided into, mechanical property, static resistance,conductivity, electromagnetic shielding, thermal conductivity, chemical resistance, corrosion resistance and the like of waterborne polyurethane membranes and coatings are effectively improved. The waterborne polyurethane/dopamine modified graphene nano-composite emulsion and rubber powder have a better application prospect in the fields of coatings, adhesives, printing ink, surface treating agents, elastomer, foam materials, functional films and the like.

The invention belongs to the field of chemical coatings, and particularly relates to a graphene nano-silver antibacterial coating and a preparation method thereof. The graphene nano-silver antibacterial coating comprises water, cellulose, a wetting agent, an antifreezing agent, a thickening agent, a defoaming agent, titanium dioxide slurry, filler slurry, a multifunctional amine auxiliary, emulsion, a sterilizing agent, a coalescing agent, a flatting agent, a formaldehyde-resistant auxiliary, and a silver-bearing antibacterial agent, and the silver-bearing antibacterial agent is graphene nano-silver dispersion liquid. According to the graphene nano-silver antibacterial coating and the preparation method thereof, a traditional formula is improved, the specially-made graphene nano-silver dispersion liquid is added to the formula, and the antibacterial effect is achieved. Nano silver can further destroy a microorganism electron transmission system, a respiratory system and a material transfer system. When the activity of thalli is lost, the nano silver can be dissociated out of the thalli and repeatedly conducts sterilization activities, and therefore the long-acting antibacterial function of the coating can be maintained. The nano silver can exert the lasting antibacterial effect by slowly releasing Ag<+>.