46results 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.

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 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.

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.

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.

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 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.

Amorphous two-dimensional graphene-like carbon films provide benefits to a variety of applications due to advantageous electrical, mechanical, and chemical properties. Methods are provided to efficiently and cheaply create high-quality amorphous two-dimensional carbon films with embedded graphene-like nanocrystallites using coal as a precursor. These methods employ solution-phase deposition of coal-derived graphene-containing quantum dots followed by relatively low-temperature annealing / crosslinking of the quantum dots to form a single two-dimensional layer of carbon that includes a plurality of randomly-oriented discrete graphene domains connected to each other via amorphous carbon regions. Multi-layer films can be easily created by repeating the deposition and annealing processes. Two-dimensional carbon films formed in this manner exhibit improved properties when compared to crystalline graphene sheets and have properties especially suited to use as the storage medium of memristors. Further processing can result in large free-standing two-dimensional graphene-like carbon thin films that can be used as membranes or for other applications.

The invention discloses a graphene preparation method based on interlayer stress resonance. Macroscopic mechanical rotation energy is converted into high-frequency and directional stress energy capable of accurately acting on Van der Waals force between graphite layers through a series of well-designed physical processes. Under a specific rotation condition, an unstable vortex structure (such as Taylor vortex) can be generated in a limited fluid, and when a stress wave formed by the vortex in a viscoelastic fluid is coupled with an intrinsic vibration frequency between graphite layers, a resonance phenomenon can be caused. The resonance can amplify the strain energy between the graphite layers, so that the Van der Waals' force between the layers is efficiently and selectively overcome under the energy input condition far lower than the in-plane fracture threshold of the carbon-carbon bond, the graphene is delaminated, and the large-piece and few-layer graphene is obtained.

The present invention resides in a method for directly depositing graphene or graphene oxide onto a target substrate from a gaseous source of at least one carbon precursor using plasma enhanced chemical vapor deposition. The present invention also relates to a device for carrying out the method.

Disclosed are a single-layer edge-oxidized graphene and a preparation method therefor, which belong to the technical field of graphene materials. A single-layer graphene is used as a raw material and electrolyzed by applying an ultra-low-frequency alternating current with a low current density to prepare the single-layer edge-oxidized graphene. The number of oxygen free radicals generated from an electrolyte is regulated and controlled by adjusting the current intensity and frequency of the applied alternating current, a small number of oxygen free radicals are reacted at the sites having more active binding energy of the edge of the single-layer graphene, and the low current intensity and the short current time result in insufficient invasion of generated oxygen radicals into the plane of the single-layer graphene, thereby constructing the single-layer edge-oxidized graphene. The polarity of the prepared single-layer edge-oxidized graphene is increased on the basis of retaining the excellent physical and chemical properties of graphene, thereby greatly improving the dispersing capability of the graphene in polar solvents.

The present invention pertains to a process for direct deposition of graphene oxide onto a substrate of interest from a gaseous source of at least one carbon precursor, using a plasma-enhanced chemical vapor deposition method. It is also directed to a device for implementing this process.

The application provides a preparation method of a graphene oxide semiconductor film with adjustable band gap, the graphene oxide semiconductor film and application thereof. The preparation method comprises the following steps: graphene oxide solution is sprayed onto the surface of a substrate by using an ultrasonic atomization spraying method, and heat treatment is simultaneously performed to obtain the graphene oxide semiconductor film with adjustable band gap; wherein the temperature of the heat treatment is 120-340 DEG C. The preparation method of the graphene oxide semiconductor film adopts the method of ultrasonic atomization spraying and simultaneous heat treatment. Through continuously stacking graphene oxide layers and adjusting the band gap of the graphene oxide while stacking the layers, the graphene oxide semiconductor film with the following characteristics can be finally obtained: complete structure, good uniformity, controllable band gap, excellent conductive performance, and the thickness is in the range of hundreds of nanometers to microns.