65results about "Single layer graphene" patented technology

The invention discloses a method for characterizing physical properties of a single-layer graphene / semiconductor heterojunction. The method comprises the following steps: providing a physical property model about a single-layer graphene-semiconductor heterojunction, wherein influence factors comprise the change of Fermi level of single-layer graphene after the heterojunction is formed and the influence of an interface state on a formation position of a contact potential difference; extracting heterojunction electrical characteristics by using a Kelvin probe force microscope; the interface layer spacing is obtained; and importing the heterojunction electrical characteristics and the interface interlayer spacing into a physical characteristic model, and analyzing to obtain physical characteristics. According to the new theoretical model and the method for realizing the nondestructive characterization of the physical characteristics of the heterojunction by using the Kelvin probe microscope based on the theoretical model, the influence of the change of the Fermi level of the single-layer graphene and the interface state on the formation position of the contact potential difference is fully considered; key interface physical properties, especially built-in potential and depletion region characteristics which are crucial to device performance, can be accurately analyzed.

The invention relates to the field of graphene preparation, and discloses a layer number controllable graphene material preparation process which comprises the following steps: S1, substrate selection: selecting a copper surface or nickel surface substrate, and putting the copper surface or nickel surface substrate into a chemical vapor deposition reaction chamber; s2, raw material preparation: selecting ultra-high-purity natural flaky graphite, and putting the pretreated ultra-high-purity natural flaky graphite into a reaction chamber; s3, reaction precursor: introducing hydrogen and argon into the reaction chamber, and adjusting to preset conditions; s4, reaction condition adjustment: adjusting the temperature and atmosphere to gasify the graphite and deposit the graphite into graphene; and S5, cooling and transferring: spraying a protective layer after cooling, drying, and then transferring to a target substrate. Through the technical scheme of temperature staged regulation and control and hydrogen concentration dynamic regulation, the deposition process of carbon atoms on the substrate is more controlled, the number of growth layers is more stable, the carbon dissolution and precipitation rate is effectively balanced, random accumulation of a multi-layer structure is avoided, and the application of the multi-layer structure in a high-precision electronic device is more reliable.

Provided are a 2-dimensional microporous graphene and a method for preparing the same. The 2-dimensional microporous graphene has an average pore size of about 0.1 nm to about 2 nm, interpore spacing of about 0.3 nm to about 10 nm, and a standard deviation of the interpore spacing of less than or equal to about 5 nm.

The invention belongs to the technical field of graphene preparation, and particularly discloses a graphene preparation method and device based on coupling of an ultrasonic phased array and a micro-fluidic chip, and the preparation method comprises the following steps: graphite oxide dispersion liquid enters a micro-fluidic main channel through a sample inlet of the micro-fluidic chip; in a standing wave sound field and a laminar flow state of an ultrasonic phased array, stripping the graphite oxide dispersion liquid through a micro-jet shear force generated by a cavitation effect of the standing wave sound field to obtain a graphene oxide sheet layer; graphene oxide lamellas are synchronously separated to a specified separation flow channel through fluid shear force generated by a micro-channel contraction section and an inertia focusing effect caused by curvature of an arc-shaped separation section, and non-single-layer graphene oxide lamellas are separated to a flow channel. The proportion of the single-layer graphene obtained by the preparation method provided by the invention is as high as 95%, and the problem of microchannel blockage can be relieved.

The invention belongs to the field of two-dimensional material preparation, and particularly relates to a dry transfer method of a corner two-dimensional material. On one hand, introduction of impurities is avoided by adopting a plurality of organic polymers for assistance through a splitting step mechanism; on the other hand, by means of the mechanism that the two-dimensional material slides on the h-BN interface and does not exceed the plane geometrical shape of the h-BN interface, the two-dimensional material is locked on the h-BN geometrical interface through laser cutting, the probability that the two-dimensional material wrinkles, bubbles and slides in the transfer process is remarkably reduced, meanwhile, the internal stress of a system is reduced, and the mechanical performance of the system is improved. Therefore, the accuracy of the transfer angle of the corner two-dimensional material is improved; and the phenomena of slippage, traction and the like do not occur between the corner two-dimensional materials, lattice distortion is also weakened, and the quality of the corner two-dimensional materials is further improved. According to the method, reliable technical support is provided for constructing a high-quality strong-correlation physical platform, and the method can be widely applied to the fields of novel quantum devices and the like.

The present invention discloses a modified chimeric antigen receptor T cell, its preparation method, and its use. The present invention prepares cells, such as chimeric antigen receptor T cells, modified with a hydrophobic two-dimensional sheet material. Compared to simple chimeric antigen receptor T cells, these cells can bind to more leukemia cells, enhancing their recognition and killing abilities. Furthermore, the nanomaterial's high specific surface area provides space for drug loading, enabling the combination of CAR T cells with other therapies.

The present application relates to graphene material and its preparation technology, specifically to a method for growing graphene on the surface of non-metallic particles on a large scale, which is suitable for large-scale preparation of graphene-coated non-metallic powder material. The present application uses a two-step method to grow graphene uniformly on the surface of a large number of non-metallic particles: first, mix a large number of non-metallic particles with a carbon source, and form a bulk composite material of non-metallic particles and carbon through low-temperature carbonization; then, pass current to the above bulk composite material using electrodes to heat it to a higher temperature, convert the carbon into graphene, until graphene-coated non-metallic particles are obtained, which are separated from each other, and the high-temperature heating process stops spontaneously. The present application can grow a graphene layer on the surface of a large number of non-metallic particles, the method is easy to scale up, and has the characteristics of good uniformity of graphene coating and high particle separation degree; at the same time, by taking advantage of the large resistance of graphene-coated non-metallic particles which are separated from each other, the high-temperature heating process stops spontaneously.

The application provides a preparation method of graphene, and belongs to the technical field of graphene. The application comprises the following steps: step 1: preparing an electrolysis environment required by an electrolysis experiment: a graphite electrode, a prepared electrolyte, and a low-temperature environment; step 2: inserting the graphite electrolysis into the electrolyte with a proper electrode spacing and connecting a direct-current power supply, and waiting for a period of time to observe the stability; step 3: placing the electrolysis device built in step 2 into a low-temperature constant-temperature tank, setting a low-temperature temperature and a constant time, taking out part of the electrolysis slurry at a time for freeze-drying and then testing XRD, judging the quality of the graphene slurry, and obtaining graphene slurry with a 1-3 layer content of more than 70%; and step 4: obtaining graphene dry material after collecting and purifying the graphene slurry in step 3, namely graphene. The application prepares graphene by a low-temperature electrolysis experiment, so that more graphene can be prepared.

The invention discloses a hydrophilic and hydrophobic modification method of laser-induced graphene, and relates to the technical field of graphene modification.The method comprises the steps that laser-induced graphene is subjected to heat treatment, and hydrophilic or hydrophobic laser-induced graphene is obtained; according to the method, tearing and separation in graphene sheet layers are caused by heat treatment energy, and the size and morphology of the graphene sheet layers are changed; carbon atoms in the graphene can obtain relatively high energy due to thermal vibration, so that the carbon atoms are shifted from original positions, different defects are formed, the wettability of the surface of the laser-induced graphene is influenced, and the hydrophilic or hydrophobic laser-induced graphene is obtained.

Upgraded coal, method of forming the same, and graphene films and quantum dots made therefrom. A method of upgrading coal includes cleaning coal to form a cleaned coal residue. The method also includes (A) reacting the cleaned coal residue with an oxidizable inorganic metallic agent, or (B) reacting the cleaned coal residue with a reducing agent, or a combination thereof, to form the upgraded coal.

The invention discloses a method for preparing few-layer graphene through supercritical CO2 stripping, and belongs to the technical field of graphene preparation. The preparation method comprises the following steps: mechanically crushing natural crystalline flake graphite, and carrying out airflow classification purification to obtain graphite powder with the particle size of 50-100 mu m; the method comprises the following steps: mixing graphite powder and a bio-based anionic surfactant, adding the mixture into a supercritical reaction kettle, and introducing CO2 to replace air; carrying out constant-temperature and constant-pressure pretreatment under the conditions that the temperature of the reaction kettle is 40-60 DEG C and the pressure is 2-4MPa, increasing the pressure to 15-20MPa, and carrying out stirring reaction for 2-3h; and after the reaction is finished, slowly releasing the pressure to normal pressure, carrying out centrifugal classification on the product, washing to be neutral, and carrying out vacuum freeze drying to obtain the few-layer graphene. The problems that an existing supercritical CO2 stripping process is poor in environmental protection property, products are prone to agglomeration and low in efficiency are effectively solved, the number of layers of the products is 1-5, the proportion of 1-3 layers is larger than or equal to 75%, the sheet diameter is 0.8-2.0 micrometers, and the method has the advantages of being high in crystallinity and low in defect density; in addition, according to the method, the CO2 recycling rate is larger than or equal to 95%, the stripping efficiency reaches 85% or above, cost is low, and the method is suitable for large-scale industrial production.

Upgraded coal, method of forming the same, and graphene films and quantum dots made therefrom. A method of upgrading coal includes cleaning coal to form a cleaned coal residue. The method also includes (A) reacting the cleaned coal residue with an oxidizable inorganic metallic agent, or (B) reacting the cleaned coal residue with a reducing agent, or a combination thereof, to form the upgraded coal.

The invention discloses an optimization method of a graphene nanobelt edge structure, and belongs to the technical field of material preparation. Joule heat generated by bias voltage is used for driving edge atom migration and interlayer sublimation, in single-layer GNR treatment, edge recrystallization is achieved through constant bias voltage, the edge structure is improved, and a foundation is laid for subsequent conductivity optimization and width reduction; the step bias strategy further regulates the width and the conductivity in a coordinated mode, the performance is gradually improved by accurately controlling the change and the holding time of the bias, and a new thought is provided for preparation of high-performance nano electronic devices.

Provided is a highly crystalline heteroelement-containing graphene including carbon (C) and, as a heteroelement (X), at least one element selected from the group consisting of nitrogen (N), phosphorus (P), arsenic (As), sulfur (S), boron (B), and silicon (Si). Also, spots belonging to either the orthorhombic system or the hexagonal system and having the symmetry of a single crystal are observed in the selected area electron diffraction.

The invention relates to a method for preparing high-quality graphene based on bubbling transfer, which comprises the following steps: S1, spin-coating PMMA (Polymethyl Methacrylate) on the surface of a graphene film on a metal substrate, and attaching PDMS (Polydimethylsiloxane) to form a PDMS / PMMA / graphene / metal substrate sample; s2, respectively connecting the sample in the step S1 and the conductive material with an electrode, enabling the electrode to be in contact with a sugar / salt mixed solution, turning on a power supply to generate bubbles on the sample until graphene is separated from a metal substrate, and cleaning to obtain a PDMS / PMMA / graphene sample; s3, transferring the sample in the step S2 to a target substrate, and drying to form a PDMS / PMMA / graphene / target substrate sample; and S4, heating the sample in the step S3, stripping the PDMS, and removing the PMMA to obtain the high-quality graphene attached to the target substrate. The method provided by the invention is simple and easy to implement, has good repeatability, can improve the quality of graphene subjected to bubbling transfer, and realizes large-area graphene film transfer.

The present application relates to graphene material and its chemical vapor deposition (CVD) preparation technology, specifically to a method for low-temperature growth of graphene on non-metal substrate surface, which is suitable for preparation of single-layer and multi-layer graphene without using metal catalyst and high-temperature condition. The method uses organic matter containing delocalized bond as an additive of carbon source, and utilizes the delocalized bond to promote the reconfiguration of carbon source on the non-metal surface to form graphene. By adding the organic matter containing delocalized bond, the nucleation and growth of graphene on the non-metal substrate surface under lower temperature condition can be effectively promoted without using metal catalyst and high temperature. By using the method described in the present application, high-quality graphene can be grown on the non-metal substrate at low temperature, thereby avoiding the adverse effects of conventional transfer process on the performance of graphene devices.

The invention provides an industrial-scale graphene film ultrafast reel-to-reel deposition method which comprises the following steps: vacuumizing the inside of CVD (Chemical Vapor Deposition) equipment to be in a vacuum state, filling pretreatment gas, and pretreating a copper foil serving as an initial substrate; filling mixed gas of methane and inert gas into the CVD equipment, and changing the vacuum state in a cavity of the CVD equipment into a low-pressure state of 1-100 Torr; after the temperature in the CVD equipment chamber is increased to the preset temperature, the copper foil is rotated in a roll-to-roll mode at the transmission speed of 300-2000 mm / min, chemical vapor deposition is conducted on the copper foil in the CVD equipment chamber, and the graphene film is prepared on the surface of the copper foil. Compared with the prior art, the preparation rate of the graphene film can be increased by about 7 times, the length of the prepared single-layer graphene film can reach 1000 m or above, and the method is suitable for industrial-scale mass production preparation of the high-quality single-layer graphene film.

Systems and methods for cascaded compression of zero-dimensional nanostructures (0DNs) ae disclosed. The cascaded compression approach can be used to narrow the size distribution of nanopores with left skewness and ultra-small tail deviation, while keeping the density of nanopores increasing at each compression cycle. In some embodiments, a size distribution of existing nanopores can be compressed by a combination of shrinkage and expansion, with a new batch of nanopores being created, which can lead to increased nanopore density at the completion of each cycle. Moreover, cascaded compression of the 0DNs can allow for independent control of nanopore density, the mean diameter, the standard deviation, and the skewness of the size distribution.

The invention discloses a method for preparing graphene based on radio chemical mechanical stripping, and belongs to the technical field of material preparation. The method comprises the following steps: S1, preparing a stripping solution: mixing graphite powder with a mixed solution containing electrolyte to prepare the stripping solution; s2, a radio chemical mechanical stripping device is assembled, specifically, a polishing pad is pasted to the bottom of a polishing disc with the same diameter, and the polishing pad and the polishing disc are provided with the same through holes arranged in a honeycomb array; a pair of positive and negative electrodes is arranged on the bottom wall of each through hole of the polishing disc, merged into a bus line at the top of the polishing disc and connected with positive and negative electrodes of a power supply through conductive slip rings; the polishing head clings to the polishing pad; and S3, dropping a stripping solution into the through hole, and carrying out stripping treatment on the stripping solution to prepare graphene. According to the method, expensive experimental equipment and tedious steps are not needed, extreme conditions such as high temperature, high pressure and vacuum are not involved, graphene can be efficiently prepared from the graphite raw material in a large scale within a short time, and the method has the advantages of being easy to operate, practical, convenient and the like.

This invention discloses a graphene preparation apparatus and method using a high-voltage pulse power supply. The preparation apparatus includes a sliding track, a fixed outer shell and a movable outer shell disposed on the sliding track, and a four-way tube disposed between the fixed and movable outer shells. The four-way tube is fixedly disposed on the sliding track, with its upper port connected to a nitrogen source, its left port connected to a conductor, and its right port connected to another conductor. The two conductors are respectively connected to a test current source, and the positive terminal of the high-voltage pulse power supply is applied to the same side of the conductors and the positive terminal of the test current source. This invention has the advantages of stable and rapid preparation, high-quality graphene, and simple operation, and can effectively solve the problems of long preparation time and unstable graphene quality in traditional methods. At the same time, it saves energy and raw materials, improves preparation efficiency and performance indicators, and has high practical value.

The present invention belongs to the technical field of inorganic nanomaterials, and particularly relates to a preparation method of magnetic fluorescent graphene. Magnetic grinding is carried out on flake graphite and stainless steel needles to obtain magnetic graphene; magnetic graphene, concentrated nitric acid and concentrated sulfuric acid are subjected to an oxidation reaction to obtain a mixed solution; the mixed solution is subjected to ultrasonic treatment and calcination to obtain magnetic graphene oxide; the magnetic graphene oxide is dissolved in deionized water, filtered by suction and dialyzed to obtain a magnetic fluorescent graphene solution; the magnetic fluorescent graphene solution is freeze-dried to obtain magnetic fluorescent graphene. The preparation process of the present invention is simple, does not generate too much waste acid, and has less environmental pollution; in the process of obtaining magnetism, no magnetic material reaction needs to be added, and no fluorescent material needs to be added to make it fluorescent.

This invention belongs to the field of two-dimensional graphene oxide nanomaterial technology. This invention provides a method for separating the size of monolayer graphene oxide, comprising the following steps: mixing water and an organic solvent and allowing the mixture to stand to obtain an oil / water two-phase system containing an oil phase and an aqueous phase; adding a surfactant and an aqueous solution of monolayer graphene oxide to the oil phase and the aqueous phase respectively, allowing the mixture to stand, repeatedly collecting the oil-water interface layer solution, and sequentially washing and centrifuging the interface layer solution to obtain large-sized monolayer graphene oxide; centrifuging the remaining aqueous phase solution to obtain small-sized monolayer graphene oxide. The method for separating the size of monolayer graphene oxide of this invention has good separation accuracy; and compared with ultrasonic methods, centrifugation methods, and membrane filtration methods, it has milder reaction conditions, lower energy consumption, and does not cause changes in the structure and size of graphene oxide; compared with precipitation methods and liquid crystal methods, the reaction time is shorter; and compared with electrophoresis methods, it does not change the structure of graphene oxide.

The application relates to a method for preparing fluorinated graphene, and belongs to the graphene material field. The preparation method comprises the following steps: mixing and dispersing waste lithium battery recovery graphite powder, an intercalation agent and a dispersing agent in water to form a slurry, keeping the slurry at 40-60 DEG C for 4-8 hours, then spraying the slurry through a high-pressure device to form high-speed jets, and realizing graphite layer peeling through the cross impact of multiple jet beams, then adding a fluorination agent, keeping the slurry at 150-200 DEG C for 6-12 hours, centrifugally separating upper clear liquid, filtering and washing, vacuum drying, and obtaining fluorinated graphene. The application realizes graphite layer peeling through liquid cross impact, has high production efficiency, the obtained graphene sheet layer is regular and neat, has few structural defects, and the performance of the graphene is improved; the peeling strength can be adjusted by adjusting the jet speed, different layer number graphene products can be obtained, and the production is continuous, and the efficiency is relatively high; the raw material is waste lithium battery recovery graphite, the cost is low, the obtained graphene contains oxygen-containing functional groups, and has good water solubility.

The application discloses a graphene preparation method based on interlayer stress resonance. Macroscopic mechanical rotation energy is converted into high-frequency and directional stress energy which can precisely act on the van der Waals force between graphite layers through a series of carefully designed physical processes. Under specific rotation conditions, unstable vortex structures (such as Taylor vortex flow) are generated in the confined fluid. When the stress wave formed by the vortex in the viscoelastic fluid is coupled with the intrinsic vibration frequency between the graphite layers, resonance phenomenon is triggered. The resonance can amplify the strain energy between the graphite layers, so that the interlayer van der Waals force is efficiently and selectively overcome under the condition of energy input far lower than the in-plane fracture threshold of carbon-carbon bond, and the graphene is exfoliated to obtain large and few-layer graphene.

An object of the present invention is to provide a highly crystalline heteroelement-containing graphene. A heteroelement-containing graphene disclosed herein includes carbon (C) and, as a heteroelement (X), at least one element selected from the group consisting of nitrogen (N), phosphorus (P), arsenic (As), sulfur (S), boron (B), and silicon (Si). Also, spots belonging to either the orthorhombic system or the hexagonal system and having the symmetry of a single crystal are observed in the selected area electron diffraction.

The application discloses a method for preparing single-layer graphene by catalytic reduction of CO2, which comprises the following steps: introducing CO2 gas into a fluidized bed reactor through a raw gas inlet, preparing CO and CO2 containing gas under the action of a reducing agent in an oxygen-free environment at 1000-1300 DEG C, introducing the CO and CO2 containing gas and a mixture containing nano catalyst into a two-stage Venturi jet unit from a product outlet and a mixed gas tank respectively, fully mixing and uniformly distributing the mixture, and preparing single-layer graphene under the action of the nano catalyst in an electric arc discharge reaction unit; the greenhouse effect gas CO2 is selected as a carbon source, and a thermal chemical series connection plasma is used to help the graphene nucleation of the CO / CO2 mixture and maintain a high growth rate of product seeds, so that large-scale single crystals are obtained; the reaction condition is controllable, and the method can be continuously produced, thereby providing a process basis for solving the current CO2 emission and energy shortage problems.

The invention discloses a microwave-plasma synergistic stripping waste lithium battery graphite regeneration and graphene preparation method, and belongs to the field of lithium battery recovery. The preparation method comprises the following steps: discharging the waste lithium battery, crushing, magnetically separating, crushing and screening to obtain a solid mixture containing graphite, drying the solid mixture, and calcining to obtain graphite slag containing metal impurities; the method comprises the following steps: treating graphite slag and mixed acid under microwaves, dispersing the treated graphite slag and mixed acid in an ionic liquid, and carrying out ultrasonic treatment in a plasma environment to obtain a graphene dispersion liquid; and separating the graphene dispersion liquid to obtain graphene powder. According to the method, graphite is recycled through microwave-assisted acid leaching pretreatment, metal impurities and residual binders are efficiently removed, meanwhile, the integrity of an interlayer structure of the graphite is reserved, and the acid consumption and secondary pollution are reduced. In the ultrasonic stripping process, low-temperature plasma is introduced, high-energy particles are used for bombarding graphite interlayers, the Van der Waals force is further weakened, and the stripping efficiency is improved.

The application belongs to the field of optical functional nanomaterials, and particularly relates to an adjustable light-absorbing sheet based on an upright micro-nano graphene sheet and a preparation method thereof. The method is to change the micro-morphology and size of the upright micro-nano graphene sheet by adjusting the growth parameters of a radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) device, such as temperature, time, gas flow and radio frequency power, so as to realize the regulation and control of the light-absorbing performance of the light-absorbing sheet. The adjustable light-absorbing sheet has the characteristics of simple preparation process, low cost and low-temperature preparation, and does not need a catalyst. The light-absorbing rate of the adjustable light-absorbing sheet is as high as more than 99%, and the structure of the double-layer transparent substrate sandwiching the upright graphene film also protects the graphene, so that the graphene has the characteristics of scratch resistance and repeated use.

A technique that enables production of pellicle membranes that are better resistant to breakage when subjected to force exerted thereon in the thickness direction thereof and that have high transmittance to light. A pellicle membrane of the present invention includes a plurality of laminated layers, where at least one of the layers is provided with at least one hole having a width or diameter of 10 nm to 500 nm.

The application belongs to the technical field of modified graphene oxide, and provides a polysiloxane modified single-layer graphene oxide and a preparation method thereof. The method comprises the following steps: mixing single-layer graphene oxide, hydrogen-containing polysiloxane, an organic solvent and a catalyst, and performing a reaction to obtain the polysiloxane modified single-layer graphene oxide. The silicon hydrogen bond in the hydrogen-containing polysiloxane is used to perform a condensation reaction with the hydroxyl group in the single-layer graphene oxide, so that the single-layer graphene oxide is modified, and the method has the advantages of high reaction activity, short reaction time and no by-products except hydrogen. The polysiloxane modified single-layer graphene oxide prepared by the application has macromolecular polysiloxane grafted on the surface of the single-layer graphene oxide, and the single-layer graphene oxide modified by the macromolecular polysiloxane has better hydrophobicity than that modified by a small-molecule silane modifier. In addition, the application can accurately control the molecular weight of the polysiloxane grafted on the surface of the single-layer graphene oxide, and has a wide application prospect.