CN118561273A - Method for preparing graphene by mechanical stripping method and application of method in preparation of graphene composite material - Google Patents

Abstract

The invention relates to the technical field of graphene preparation, in particular to a method for preparing graphene by a mechanical stripping method and application of the method in preparation of a graphene composite material, and the method comprises the following steps: step one: taking graphite powder, adding sugar, and pouring into a pulverizer to pulverize, so as to form a powder semi-finished product; step two: pouring a proper amount of powder semi-finished product into a marshmallow machine, heating, rotating and throwing out to a dust-free space to form a mixture; step three: collecting the mixture, and pulverizing in a pulverizer; step four: repeatedly circulating the crushed powder for multiple times, adding water to prepare slurry, and filtering the slurry to prepare sugar-containing concentrated liquid; step five: adding water into the filtered sugar-containing concentrated liquid, and pouring the filtered sugar-containing concentrated liquid into a cavity of an ultrasonic cleaner for vibration cleaning for a preset time; step six: oscillating the cleaned liquid, and filtering to form graphene liquid; step seven: spraying graphene liquid on a glass plane, and drying water to enable graphene to adhere to the glass surface.

Description

Method for preparing graphene by mechanical stripping method and application of method in preparation of graphene composite material

Technical Field

The invention relates to the technical field of graphene preparation, in particular to a method for preparing graphene by a mechanical stripping method and application of the method in preparation of a graphene composite material.

Background

Graphene is known as a 21 st century strategic emerging material. The excellent material performance of the graphene on one hand stimulates scientific research enthusiasm in academia and on the other hand also lifts the tide of application development and industrialization. The carbon material family is becoming more complete as graphene is found, and this family currently includes zero-dimensional fullerenes, one-dimensional carbon nanotubes, two-dimensional graphene, and three-dimensional graphite and diamond. Graphene is not only a single layer of carbon atom material, but also belongs to the basic unit of carbon family to form carbon materials with other dimensions. Graphene is also a very young material, and presents bottlenecks and challenges in many respects. How to realize controllable, massive and high-quality preparation of graphene, how to develop the functions of graphene and expand the application field is a bottom problem faced by the current graphene industry development. The breakthrough of graphene productivity, key preparation technology and process technology is needed to be solved. According to the macroscopic morphology of graphene, the graphene can be roughly classified into two types, namely powder and film, wherein the graphene powder refers to disordered aggregates of graphene sheets with nanometer and micrometer sizes. Currently, the preparation of graphene can be roughly classified into two types of technical paths, one is a top-down method, i.e., graphene is obtained from graphite itself (also referred to as a graphite path), and the other is a bottom-up method, i.e., graphene is prepared from carbon-containing compounds (also referred to as a carbon atom path). The basic processing method of the graphite path is as follows:

1) The liquid phase stripping method is to disperse graphite in an organic solvent or a specific surfactant, strip single-layer or multi-layer graphene from the surface of the graphite by means of ultrasonic waves and the like, obtain graphene dispersion liquid by centrifugal separation, and finally deposit the graphene on different matrixes. The method is one of the main methods for preparing the graphene powder at low cost, but has the problems of poor product quality and large process lifting space;

2) The oxidation-reduction method uses strong acid such as sulfuric acid, nitric acid, potassium permanganate, hydrogen peroxide and the like and a strong oxidant to oxidize natural graphite to obtain graphite oxide, then disperses the graphite oxide in a physical stripping and high-temperature expansion mode and the like to obtain graphene oxide, and finally reduces the graphene oxide to obtain reduced graphene oxide. The method is also one of the main methods for preparing the domestic graphene powder, has simple operation and high yield, but has the problems of high product defect, serious environmental pollution and unclear industrialization prospect in the long term;

3) The mechanical stripping method is used for extracting single-layer graphene from graphite in a tape tearing mode, the graphene prepared by the method has excellent electrical, optical, thermodynamic and mechanical properties, the method is simple to operate and is easy to realize in a laboratory, but the defect is that the method has poor control capability on the size and shape of the graphene, cannot be used for large-scale production and cannot be used for industrial mass production.

Disclosure of Invention

The invention aims to provide a method for preparing graphene by a mechanical stripping method and application of the method in preparation of a graphene composite material, so as to solve the problems in the background art.

In order to achieve the above purpose, the present invention provides the following technical solutions:

a method for preparing graphene by a mechanical exfoliation method, comprising the following steps:

step one: taking a proper amount of graphite powder, adding a proper amount of sugar, pouring into a pulverizer, mixing and pulverizing to form a powder semi-finished product;

Step two: pouring a proper amount of powder semi-finished product into a marshmallow machine, heating, rotating and throwing out to a dust-free space to form a mixture;

Step three: collecting the mixture subjected to gathering and drying, putting the mixture into a pulverizer for pulverization, and repeating the steps two and three for a plurality of times;

step four: repeatedly circulating the crushed powder for multiple times, adding water to prepare slurry, filtering the slurry to prepare sugar-containing concentrated liquid, and returning residues which cannot be filtered to the second step after drying;

Step five: adding a proper amount of water into the filtered sugar-containing concentrated liquid to dilute the liquid into a preset proportion, and pouring the liquid into a cavity of an ultrasonic cleaner to shake and clean for a preset time;

Step six: vibrating the cleaned liquid, filtering in a precise filtering device below 0.1 micrometer to form graphene liquid suspended in water, and drying residues which cannot be filtered and returning to the second step;

Step seven: spraying the graphene liquid filtered by the precise filtering device on a glass plane, rapidly drying water, enabling graphene to adhere to the glass surface, and observing the graphene from a simple electron microscope to the opposite surface adhering to the glass surface.

As a further scheme of the invention: in the mixing and crushing process of the first step and the third step, sugar is mixed with graphite powder, the cohesion of the graphite powder is reduced, and the proportion of the sugar is larger than that of graphite.

As still further aspects of the invention: the crushing process in the first step and the third step comprises four stages of shearing, tearing, stamping and grinding, and powder flowability is followed.

As still further aspects of the invention: and the design of sugar doping and technology is combined with mechanical powder processing and ultrasonic liquid phase stripping assistance to form graphene powder on the glass plane base.

As still further aspects of the invention: when the graphite powder and the sugar are crushed in the first step and the third step, the graphene powder can escape from the crusher.

As still further aspects of the invention: in the second step, the solid and the fluid are mutually converted, and the graphite is fixed around the sugar molecules in two physical states.

As still further aspects of the invention: the cotton candy machine is heated and rotated to be thrown out, so that the drying time is shortened, and the water is saved.

The application of the method for preparing the graphene by the mechanical stripping method in preparation of the graphene composite material is provided.

Compared with the prior art, the invention has the beneficial effects that:

The glass of the graphene is peeled off by adding sugar to achieve the level of mechanization, the chemical property of the sugar is stable, the price is low, the van der Waals force of the graphite powder is overcome by utilizing the viscosity of the sugar (in the process of mixing and crushing, the viscosity is mixed with powdery substances, and the cohesive force of the powdery substances is reduced), the high-quality graphene can be recycled, a platform foundation is built for the subsequent operation by a mechanical method, the unit bearing capacity of the graphene in a dispersion liquid is improved by the existence of the sugar, the time of a suspension state in the graphene in water is prolonged by liquid phase peeling, and the high quality of liquid phase peeling is brought about by a high starting point of the mechanical peeling;

Compared with a liquid phase stripping method, the mechanical tearing and crushing high-quality materials are carried forward under the action of ultrasonic waves, the process of the liquid phase stripping method is improved, the pollution-free condition is improved compared with a redox reaction method, the strong redox waste liquid is eliminated, the original functions and crystal lattices of graphite are perfectly reserved, the method is environment-friendly, the problems of the defects of a redox graphite path processing method are overcome, and the method changes and improves the physical properties of graphite, such as electric conduction, heat conduction, transparency and the like through mixing and crushing graphite powder and sugar and liquid phase stripping and glass base generation.

Drawings

Fig. 1 is a schematic diagram of separation of graphene using tape in one embodiment of a method for preparing graphene by mechanical exfoliation.

In the figure: 1. an adhesive tape; 2. graphite; 3. fluid glue; 4. the sliding distance plus the tearing distance.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In addition, an element in the present disclosure may be referred to as being "fixed" or "disposed" on another element or being directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

In the embodiment of the invention, the method for preparing graphene by a mechanical stripping method comprises the following steps:

Step one: taking a proper amount of graphite powder, adding a proper amount of sugar, pouring into a pulverizer, mixing and pulverizing to form a powder semi-finished product, wherein the purity of the graphite powder is more than 60%;

Step two: pouring a proper amount of powder semi-finished product into a marshmallow machine, heating, rotating and throwing out to a dust-free space to form a mixture;

Step three: collecting the mixture subjected to gathering and drying, putting the mixture into a pulverizer for pulverization, and repeating the steps two and three for a plurality of times, wherein the pulverizing fineness of the pulverizer is more than 400 meshes;

step four: repeatedly circulating the crushed powder for multiple times, adding water to prepare slurry, filtering the slurry to prepare sugar-containing concentrated liquid, and returning residues which cannot be filtered to the second step after drying;

Step five: adding a proper amount of water into the filtered sugar-containing concentrated liquid to dilute the liquid into a preset proportion, and pouring the liquid into a cavity of an ultrasonic cleaner to shake and clean for a preset time, wherein the water is purified water;

Step six: vibrating the cleaned liquid, filtering in a precise filtering device below 0.1 micrometer to form graphene liquid suspended in water, and drying residues which cannot be filtered and returning to the second step;

Step seven: spraying the graphene liquid filtered by the precise filtering device on a glass plane, rapidly drying water, enabling graphene to adhere to the glass surface, and observing the graphene from a simple electron microscope to the opposite surface adhering to the glass surface.

In order to realize the purpose of macro and high-quality graphite deep processing, a technician can quickly understand and master the technological process method, and the steps are specifically described:

Step one: the sugar is introduced to realize the aim of mutually adhering and mixing together, in the crushing process, sugar molecules adhere to graphite particles, and under the impact of the shearing force of a crusher, the sugar is broken into fine particles, the particles are larger sugar molecule particles, and the outside is mainly adhered to the graphite particles. The characteristics of sugar are large viscosity, brittle crystal, good shaping, small molecular weight, excellent water solubility, good dispersibility in water, a certain degree of hardness after drying, and the like, and the characteristics of sugar are fully utilized. And because the particle size of the sugar molecules is larger than that of the graphite molecules, the sugar molecules and the graphite molecules drive the powder to rotate at a high speed by the pulverizer under the action of high-speed shearing impact force, and the powder collides with each other and is adhered and falls off.

Step two and step three: after the sugar is heated and rotated by a cotton candy machine and thrown out, a specific viscous condition can be generated, so that the fluid is converted into solid, the crystallization hardness of sugar molecules is increased, meanwhile, the heat dissipation is increased, and the drying time is shortened by utilizing the contact area of air. The solid is not a non-viscous liquid because the solid and the liquid are in a physical state, but the molecular arrangement and the movement mode of the solid are different, the molecular arrangement of the solid is compact, the arrangement is ordered, the interaction force between the molecules is large, and therefore, the solid has no fluidity and deformability, and has certain hardness and shape stability. The liquid has loose molecular arrangement and weak interaction force between molecules, so that the liquid has fluidity and deformability.

Furthermore, the fine powder is favorably produced by a buffer crushing mode of mixing and crushing, the mixing and the crushing are synchronously carried out, the specific condition that the fluidity of the powder is sticky is that the fine powder smaller than 10 microns produces tackiness, and larger particles are automatically adhered to the sugar.

Further, the physical properties, chemical properties and the like of the solid and the liquid are greatly different, for example, the solid has the characteristics of crystallinity, small thermal expansion coefficient and the like, and the liquid has the characteristics of fluidity, surface tension and the like.

And the cohesive semi-finished product and the powder semi-finished product are mixed and crushed, so that the cohesive force of the powder semi-finished product is reduced, the acting force for adhering and fixing the graphite powder is large after viscous crystallization, and the fine powder is easily discharged by adopting a mixed crushing buffering mode.

Step four: the powder after repeated crushing is added with pure water to prepare slurry, the concentrated solution filtered out by the filter cloth is mixed liquid with a large amount of sugar molecules, the dissolution amount of the graphene carried by water in unit volume is small, and the dissolution amount of the graphene can be greatly improved by the action of the sugar molecules.

Step five: the concentrated liquid filtered by the filter cloth is diluted by adding water and poured into an ultrasonic cleaner, and the added water quantity is required to meet the cleaning requirement and is diluted as much as possible (according to the situation). The vibration cleaning function separates graphene molecules from sugar molecules and has liquid phase stripping. The adhesion of sugar molecules and graphene molecules is a physical phenomenon, and is easy to separate rapidly under the vibration action of an ultrasonic cleaner. The separated graphene molecules form agglomeration superposition or grow along the edges in water by means of electron attraction and self lattice requirements due to damage caused in the crushing process, and the hybridized orbit is repaired into a regular hexagonal structure. The water serves to provide an environment for repair and reorganization (and continues to step six), and no human intervention is currently possible, and this repair action is an ad hoc manner. Water and graphene are the essential components. It is seen that the agglomeration and superposition of graphite are carried out for a period of time (which is also one reason why graphene is difficult to find in nature), and water is a powerful and cheap substance for repairing the breakage of graphene.

Step six: spraying the liquid after fine filtration on the plane glass, spraying as thin as possible and drying rapidly. There are three ways of drying. Firstly, preheating glass, secondly, blowing hot air, and thirdly, mixing the first two. The purpose is to lose moisture rapidly, hot air can blow the glass plane, so that liquid is dispersed in the glass plane thinner and more uniform, single-layer graphene is overlapped or agglomerated into graphite and multi-layer graphene as little as possible after water loss, the graphene has extremely strong adhesion to the glass plane, can be adsorbed on the glass surface rapidly, and brown yellow fine powder or flakes below 1 square centimeter are scraped from the glass surface, so that the graphite color is changed into a brown yellow and micro-transparent form. Spraying a scraping (the scraping process takes care of local airtight dust prevention) on the glass, which is similar to a pencil and a rubber, continuously writing and continuously wiping, and enabling the glass plane to be as large as possible. The powder obtained from the glass plane is put into the water with the same volume again, and still returns to the state before being sprayed on the glass surface, and is completely dissolved without sedimentation in a certain time.

Step seven: the method has the advantages that the mechanical damage to the graphene during the crushing process can be repaired by water, the graphene can pass through the filter membrane during the filtering process, the graphene suspension is a condition and a method for selecting graphene and graphite, the graphite is insoluble in water, and the graphene is subjected to static precipitation and is sunk in water to be not suspended. Graphene suspension is a necessary condition for manufacturing graphene powder.

The proportion of sugar in the first step is larger than that of graphite powder, the sugar is mixed with the graphite powder, the cohesion of the graphite powder is reduced, the crushing process in the second step comprises four stages of shearing, tearing, stamping and grinding, powder flowability is followed, and the crushing time can be reduced by the processing of a crusher in consideration of the slow grinding degree of the ball mill.

And the design of sugar doping and technology is combined with mechanical powder processing and ultrasonic liquid phase stripping assistance to form graphene powder on the glass plane base.

In the second step, the solid and the fluid are mutually converted, and the graphite is fixed around the sugar molecules in both physical states.

The high-quality and mass production of low-cost graphene materials is a precondition for realizing the industrialization of graphene application, in order to realize preconditions, the method and the process for preparing the graphene by the mechanical stripping method specifically comprise the following steps:

One of the preconditions for graphene industrialization is high quality, and currently, the pulverizer on the market cannot directly process graphene. If the method cannot be done from the subtraction, the method and the article are wanted from the addition, and the small-particle-size graphite molecules are overlapped and adhered outside the large-particle-size sugar molecules, like rice balls. The particle size of the graphite is small, the graphite cannot be crushed by a crusher, the graphite and sugar are adhered together, the particle size is increased, thus the crushing basis is provided, the sugaring crushing is similar to the surface area increase of a split two-micro mechanical tearing fracture surface, and the efficiency is improved to a mechanized step. The sugar has stable chemical property and low price. The viscosity and crystallization of sugar are utilized to reduce and overcome van der Waals force, and the sugar can be reused. The high-quality graphene is produced by a mechanical method, and a platform foundation is built for the follow-up process. In this case, the sugar-containing mixed graphene powder smoothly enters the liquid phase exfoliation stage, as compared with the graphite powder in the liquid phase exfoliation method. Ultrasonic wave is along with sugar molecule peeling and cramping, and after a new trend is renewed, the ultrasonic wave is subjected to severe filtering test. In the liquid phase stripping stage, sugar molecules replace organic solvents, surfactants, and the like. The presence of the sugar increases the unit bearing capacity of graphene in the dispersion. The liquid phase stripping stage essentially discards the addition of chemical raw materials and prolongs the time of the suspended state of graphene in water. The high starting point of mechanical stripping results in high quality of liquid phase stripping.

The second precondition of graphene industrialization is that the graphene is mass, industrial products are not complex, and experience is natural. The process for processing graphene by a solid-liquid dispersion method is summarized according to the specification. The step two and three refers to the preparation method of caramel and marshmallow, the step four, five and six refers to the liquid phase stripping method, and the step seven simulates the method of water copying of writing brush characters. Still further, steps one, two and three are in fact flour processing and feed pellet manufacturing. The fourth step is water treatment, and the seventh step is pancake spreading. The method has the advantages of simplified reproduction and retention, cheating and retention, and integration and convergence of mature common technical processes. Sugar penetrates through the step one, two, three and four, and is actually a comprehensive auxiliary utilization process of adding sugar and removing sugar. In conclusion, the mature technological process is favorable for assembly line and automatic design, and is suitable for large-scale production organization.

The third precondition for graphene industrialization is low cost, and the cost is an important factor determining product pricing, including equipment, sites, raw materials, fuel and power, production worker wages and various manufacturing costs, and the like. The use of mature process flows and mature equipment is a cost-effective approach. The classification of products, the efficient connection of classification processing in the production organization process and the like are also important factors influencing the cost. In terms of cost, it is necessary to introduce sorting screening, because this link is also a node of high quality, large-scale, low cost. The screening process is similar to that of falling Huang Tukuai when no wind exists, dust is left in the air, and soil is left on the ground. The dust which is collected and flies to different heights is selected and collected respectively, and the waste soil is not discharged, so that the soil is well placed, and the soil is made into blocks and falls down. In the experiment, a large plastic bag is obliquely bound above a small bottle opening, the bottle is gently rocked, and flying fine objects are collected. The graphene is layered, and each layer has different purposes, and is different in the field. The deep processing technology of the graphene powder by the solid-liquid dispersion method is used for producing comprehensive graphene powder, which is similar to loess blocks and classified experience and tempering times.

In the application, the materials are graphite, sugar and water. And (3) carrying out a process in the experimental process, and finally obtaining the mixed graphene powder of about 70 ml of water with the concentration of 1 g according to the proportion of graphite to sugar, wherein the residue and sugar are recycled, and the power cannot be calculated and the data is collected. According to the large-scale requirements of graphene industrialization, the mature equipment, mature process, and existing technical operation layers and sites are transplanted and grafted for production. The method has the advantages of abundant industrial products, abundant experience, reduced cost and low price. The equipment is simplified to the market everywhere, no chemical raw material is added, the site requirement is not too high, and the protection level of common dust processing is also achieved. The lower entrance threshold itself reduces cost.

In summary, the processing technology of the method for preparing the graphene by the mechanical stripping method combines the mechanical method and the liquid phase stripping method, improves the processing amount of the mechanical method, retains high quality, and eliminates the ultrasonic stripping of the liquid phase stripping method and chemical raw materials. Compared with repeated means of tape tearing (ball milling, grinding machine and the like) which are time-consuming and labor-consuming and have low working efficiency, the method greatly improves productivity and efficiency on the premise of keeping high quality, and enables scale implementation which is impossible to realize to be possible. The tape tearing method only confirms the existence of graphene, but cannot solve the problem of large-scale production and application. Compared with the liquid phase stripping method, the mechanical tearing and crushing high-quality materials are continuously and smoothly carried out under the action of ultrasonic waves, and the liquid phase stripping method process is improved. The original liquid phase stripping method is somewhat like mouthwash and toothbrush to pick teeth, and is not always as direct as toothpick. Compared with the redox reaction method, the method has no pollution, eliminates the strong redox waste liquid, perfectly retains the original function and crystal lattice of graphite, belongs to environment-friendly technology, and overcomes the defects of the redox graphite path processing method. The method changes and improves the physical properties of the graphite, such as electric conduction, heat conduction, transparency and the like through mechanical tearing and crushing of the graphite, liquid phase stripping and glass base generation.

According to the method for tearing the adhesive tape, the glass graphene is shown in fig. 1, the adhesive tape 1 is applied on the graphite 2, connection and fixation are achieved through fluid glue, F is generated through pulling, sliding and tearing actions are generated between the adhesive tape 1 and the graphite 2, and a sliding distance and a tearing distance 4 are generated, and in the process, graphite powder can be adhered on the adhesive tape 1, so that stripping is achieved.

Although the obtained product is mixed powder of multiple layers of grapheme, fewer layers, multiple layers, graphite and impurities can be separated through a simple method of free falling body separation and screening. The graphene with various specifications has respective application, and the processing and screening processes are selected according to the application. And (3) repeatedly processing and sorting the unqualified and unsatisfied products which are processed and sorted by the original equipment, repeating the steps one to six of the specification, or processing and lifting the sorted and screened high-quality products, further lifting the quality, and totally presenting spiral lifting and small steps of fast walking (compressing the existing time in water) so as to increase the processing process to lift the product quality until satisfaction.

The following experiments were performed according to the step criteria: the tool is a swinging type 1000 g domestic grinder and a domestic ultrasonic cleaner for experiments, wherein a suction filter bottle for the experiments comprises a vacuum pump, 800-mesh filter cloth, a plurality of water systems 0.1 micrometer filter films, one piece of 40 x 40 cm white glass, one piece of glass rod, one piece of stainless steel lunch box, one small plastic basin, one piece of 20 ml disposable injector, one putty knife, a plurality of art designing blades, 100 g high-purity graphite powder, 500 g white sugar, 500 ml of purified water, 3 and one electric hair drier.

100 G of sugar and graphite powder are poured into a pulverizer to be pulverized for 3 to 5 minutes, and the pulverizer is cooled still. Taking out the crushed results of the first step, pouring the crushed results into a stainless steel lunch box, adding water like dough kneading or knot, sticking, adding sugar, compacting by using a glass rod and a putty knife, and cutting into small pieces, wherein the size is free, and the electric oven baking and the like are not limited. And putting the dried materials into a pulverizer for pulverizing, and repeating the steps for 3 to 5 times. Adding water into stainless steel lunch box to thin powder like soybean milk, spreading filter cloth on plastic basin, pouring liquid into plastic basin, and lifting four corners of crossed filter cloth to leave the bottom of plastic basin to make liquid flow into plastic basin. Pumping plastic basin liquid by a disposable injector, injecting the plastic basin liquid into an ultrasonic cleaner, pouring purified water according to the description water level of the cleaner, starting up and vibrating, wherein the vibrating time is calculated according to the maximum working time of the cleaner. The disposable injector extracts the liquid after vibration cleaning, and fills the liquid into the filter cup which is clamped with the filter membrane, and the liquid is pumped and filtered by a vacuum pump, and the glass rod is stirred when the pumping and filtering are not smooth. Observing the color of the liquid in the suction filtration bottle with reference to the instruction manual, cleaning the disposable syringe, preferably with a needle, and extracting the liquid in the filtration bottle for later use. The glass plane is cleaned, the utility knife is cleaned, the electric hair drier is taken off to bake the glass plane, the liquid of the disposable injector is quickly dropped on the glass plane, the electric hair drier is opened to the minimum, the water drops are scattered to be dried into water stains, the water stains are quickly lightly scraped by the utility knife blade, the graphene powder is presented and gathered together, and the disposable injector is a little like dried meat floss. Note that it must be light, too heavy and fly too fast. The technique is skillful in cutting blade sharpness and early drying technique, and larger slices can be obtained.

The result can be roughly judged by observing the color of the powder or flake. The chromaticity comparisons were as follows: dark brown failed without passing. Tartary buckwheat brown and gratification. The tea color of tea which is not changed in one day is excellent. A light-colored semi-invisible semi-transparent sheet with plastic texture, and (5) fine quality.

Wherein, loss of graphene is not important for a few milligrams, and most troops of graphene are behind. Most importantly, even the result of the dark brown color of the graphene powder is higher than the grade of the carbon black filler of the battery cathode in the current market.

The application of the method for preparing the graphene by the mechanical stripping method in preparation of the graphene composite material is provided.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.

Claims (8)

1. The method for preparing the graphene by the mechanical stripping method is characterized by comprising the following steps of:

step one: taking a proper amount of graphite powder, adding a proper amount of sugar, pouring into a pulverizer, mixing and pulverizing to form a powder semi-finished product;

Step two: pouring a proper amount of powder semi-finished product into a marshmallow machine, heating, rotating and throwing out to a dust-free space to form a mixture;

Step three: collecting the mixture subjected to gathering and drying, putting the mixture into a pulverizer for pulverization, and repeating the steps two and three for a plurality of times;

step four: repeatedly circulating the crushed powder for multiple times, adding water to prepare slurry, filtering the slurry to prepare sugar-containing concentrated liquid, and returning residues which cannot be filtered to the second step after drying;

Step five: adding a proper amount of water into the filtered sugar-containing concentrated liquid to dilute the liquid into a preset proportion, and pouring the liquid into a cavity of an ultrasonic cleaner to shake and clean for a preset time;

Step six: vibrating the cleaned liquid, filtering in a precise filtering device below 0.1 micrometer to form graphene liquid suspended in water, and drying residues which cannot be filtered and returning to the second step;

Step seven: spraying the graphene liquid filtered by the precise filtering device on a glass plane, rapidly drying water, enabling graphene to adhere to the glass surface, and observing the graphene from a simple electron microscope to the opposite surface adhering to the glass surface.

2. The method for preparing graphene by mechanical exfoliation method according to claim 1, wherein in the mixing and pulverizing process of the first and third steps, sugar is mixed with graphite powder, cohesion of the graphite powder is reduced, and the proportion of sugar is greater than that of graphite.

3. The method for preparing graphene by mechanical exfoliation method according to claim 1, wherein the pulverization process in the first and third steps includes four stages of shearing, tearing, punching, and grinding, and follows the powder flowability.

4. The method for preparing graphene by mechanical exfoliation according to claim 1, wherein the design of sugar incorporation and process is combined with mechanical powder processing and ultrasonic liquid phase exfoliation assistance and a method for generating graphene powder by a glass planar base.

5. The method for preparing graphene by mechanical exfoliation according to claim 1, wherein the graphene powder escapes from the pulverizer when the graphite powder and the sugar are pulverized in the first and third steps.

6. The method for preparing graphene by mechanical exfoliation according to claim 1, wherein in the second step, the solid and the fluid are converted to each other, and the graphite is fixed around the sugar molecule in two states.

7. The method for preparing graphene by using the mechanical exfoliation method according to claim 1, wherein the graphene solution is a characteristic of preparing graphene powder, and can repair and screen graphene.

8. Use of the method for preparing graphene by the mechanical exfoliation method according to any one of claims 1 to 7 in the preparation of graphene composite materials.