CN113927041B - Graphene copper-based composite material and preparation method and application thereof - Google Patents

Abstract

The present application relates to the technical field of composite materials, and provides a graphene-copper-based composite material and a preparation method and application thereof, wherein the preparation method includes the following steps: using machine learning and high-throughput screening technology to establish a graphene-copper-based composite material model Graphene, complexing agent and organic solvent are first mixed to obtain a mixed product, the mixed product is separated and processed in different centrifugal speed intervals, and then screened to obtain a graphene product modified by a complexing agent; according to graphene copper base composite material model, the soluble copper salt, the graphene product modified by the complexing agent and the organic solvent are subjected to a second mixing process to obtain a graphene-complexing agent-copper complex dispersion; a reducing agent is provided, and the graphite The graphene-complexing agent-copper complex dispersion liquid is subjected to a reduction reaction with a reducing agent to obtain a graphene-copper-based composite material. It is ensured that the graphene has a good dispersion effect in the copper matrix and a good interface composite effect, which is conducive to the wide application of composite materials.

Description

Graphene copper matrix composite material and its preparation method and application

technical field

The application belongs to the technical field of composite materials, and in particular relates to a graphene-copper-based composite material and a preparation method and application thereof.

Background technique

Railway is the main artery of the national economy, key infrastructure and major livelihood projects. It is the backbone of the comprehensive transportation system and one of the main modes of transportation. Its status and role in my country's economic and social development are crucial. At present, copper alloy contact wires are used in high-speed electrified railways all over the world. Japan initially used pure copper material on the Shinkansen with a speed of 210km/h. Due to poor wear resistance, the line had to be changed after two years of operation. After research and tests, it was decided to use copper-tin material contact lines with better wear resistance; Copper-tin material contact wires and copper-magnesium material contact wires are used on high-speed railways above and above; in Germany and Spain, copper-silver material contact wires are used at speeds of 250-300km/h, and copper-magnesium material contact wires are used at speeds above 300km/h. Since 2003, my country's independent innovation of "upward continuous extrusion cold forming technology" has been applied to the production of copper-silver alloy material contact wires. It has been promoted in electrified railways for more than 15,000 km, and can be applied to high-speed electrified railways with a speed of 250-300 km per hour; Subsequently, the copper-magnesium alloy contact wire was further developed, which has higher mechanical strength and still has a high electrical conductivity, which can be applied to high-speed electrified railways with a speed of 350km/h. With the rapid development of railway electrification, the speed of railway transportation has been increased again and again, and the performance requirements of contact wires for electrified railways have become higher and higher. It is difficult for copper alloy materials to meet the requirements of the new generation of 400km/h high-speed rail contact wires in terms of electrical conductivity, mechanical strength, wear resistance, and corrosion resistance. Therefore, the development of new high-end copper-based composite material technology has gradually become a new hot spot in the research of new copper-based materials.

The copper matrix composite material uses copper as the matrix, and breaks through the limitation of a single metal or alloy matrix by adding a suitable reinforcing phase, and has excellent thermal, electrical, mechanical properties, and wear resistance and corrosion resistance. The wrinkled surface of graphene helps to improve the bonding force and contact area between it and the matrix interface, and its unique two-dimensional structure can effectively hinder the migration of dislocations and significantly reduce the propagation of microcracks in the composite material through energy loss. Therefore, graphene is considered as an ideal reinforcement phase for copper matrix composites.

The preparation method of graphene-copper-based composite material mainly adopts the traditional ball milling method at first. This method mainly involves mixing graphene and copper powder, adding a solvent, dispersing and drying in an electromagnetic oscillator, and loading it together with grinding balls. The ball mill can grind and mix at a certain speed and time. Considering the non-wetting between copper and carbon, the traditional ball milling method is limited to mechanical mixing at the micro-nano scale, which is easy to cause problems such as low interface strength and poor comprehensive performance, and the strong impact during the grinding process will cause defects in graphene. Reduce inherent characteristics. On this basis, in order to achieve uniform mixing of graphene and copper matrix on a more microscopic scale, such as molecular level mixing method, in-situ chemical vapor deposition method and electrochemical deposition method. The above method improves the problem of reduced strengthening efficiency due to poor wettability of copper and graphene through molecular-level bonding between carbon atoms and metal atoms. However, due to process limitations, the preparation cost is high, and the content of the obtained graphene is low, which is not conducive to reflecting the excellent functional properties of graphene in a uniform configuration. Although the research direction of graphene enhancement in copper matrix is mainly focused on the preparation of bulk composites, there are also a large number of research and development reports of graphene applied to coatings. Among them, the use of electrochemical technology to deposit copper-based composite material coating is a reliable method for preparing copper-based composite materials. For the graphene-enhanced coating, graphene was dispersed in a copper ion-containing electroplating solution by ultrasonic waves, and then graphene and copper particles were co-deposited on the cathode surface. However, this method is only suitable for the preparation of foil composites, and cannot be used for the preparation of graphene-reinforced copper-based bulk composites, thus limiting the wide application of the materials.

SUMMARY OF THE INVENTION

The purpose of this application is to provide a kind of graphene-copper-based composite material and its preparation method and application, aiming to solve the problem that graphene in the copper-based matrix dispersibility, wettability and The problem of poor interface bonding.

In order to realize the above-mentioned application purpose, the technical scheme adopted in this application is as follows:

In the first aspect, the application provides a method for preparing a graphene-copper-based composite material, comprising the following steps:

Modeling of graphene-copper matrix composites using machine learning and high-throughput screening techniques;

The graphene, the complexing agent and the organic solvent are subjected to a first mixing treatment to obtain a mixed product, the mixed product is subjected to separation treatment in different centrifugal rotation speed intervals, and then screened to obtain a graphene product modified by the complexing agent;

According to the graphene-copper-based composite material model, the soluble copper salt, the graphene product modified by the complexing agent and the organic solvent are subjected to a second mixing treatment to obtain a graphene-complexing agent-copper complex dispersion;

A reducing agent is provided, and the graphene-complexing agent-copper complex dispersion liquid is subjected to a reduction reaction with the reducing agent to obtain a graphene-copper-based composite material.

Further, the method for predicting the graphene-copper matrix composite material model using machine learning and high-throughput screening technology includes the following steps:

Through DFT theoretical calculation, build a copper crystal model;

Combining DFT theoretical calculation with machine learning, adding graphene on the surface of the copper crystal model, establishing graphene-copper crystal models at different scales, and analyzing the intrinsic structure, defects, morphology, and graphene-copper interface of graphene. Form for model optimization;

Based on the Sabatier principle, the graphene-copper crystal model was screened by high-throughput DFT calculation, and the graphene-copper matrix composite model was established.

Further, the mass ratio of graphene and complexing agent is 1:0.2-1.5.

Further, the complexing agent is selected from at least one of methylamine, ethylenediamine, isopropylamine, isobutylamine, cyclopropylamine, sec-butylamine, tert-butylamine, hexylamine, dodecylamine, hexadecylamine, octadecylamine .

Further, the first mixing treatment is selected from any one of ball milling treatment, stirring treatment, grinding treatment, mechanical mixing treatment, and ultrasonic treatment.

Further, in the step of separating the mixed product in different centrifugal speed intervals, the different centrifugal speed intervals are respectively selected from: 0-2000r/min; 2000-6000r/min; 6000-9000r/min; 9000-13000r/min.

Further, after the mixed product is subjected to separation treatment in different centrifugal rotation speed intervals, sedimentation treatment, separation treatment and washing treatment are carried out in sequence.

Further, the mass ratio of the soluble copper salt and the graphene product modified by the complexing agent is 0.01-3:1.

Further, the molar ratio of the soluble copper salt and the reducing agent is 1:0.5-3.

Further, the soluble copper salt is selected from at least one of copper sulfate, copper nitrate, copper acetate, copper chloride, copper isooctanoate, and copper tartrate.

Further, the reducing agent is selected from at least one of hydrazine hydrate, hydrogen, sodium borohydride, formaldehyde, acetaldehyde, and propionaldehyde.

Further, in the step of carrying out the second mixing treatment with the soluble copper salt, the graphene product modified by the complexing agent and the organic solvent, the mixing is carried out by means of stirring, wherein the stirring speed is 200～1000rpm, and the stirring time is 5 ~30 minutes.

Further, in the step of performing the reduction reaction between the graphene-complexing agent-copper complex dispersion and the reducing agent, the temperature of the reduction reaction is 25-75° C., and the time of the reduction reaction is 5-30 minutes.

In a second aspect, the present application provides a graphene-copper-based composite material, and the graphene-copper-based composite material is prepared by a preparation method.

In a third aspect, the present application provides a high-speed rail contact wire, wherein the high-speed rail contact wire is selected from a graphene-copper-based composite material, and the graphene-copper-based composite material is a graphene-copper-based composite material.

The first aspect of the present application provides a method for preparing a graphene-copper-based composite material. The preparation method first uses machine learning and high-throughput screening technology to achieve accurate prediction of a high-strength and high-conductivity graphene-copper-based composite material model. It is then used to know the preparation of subsequent materials, and then provide a complexing agent to react with graphene to obtain a graphene product with a surface-modified complexing agent, and then react with copper salt materials to precisely control the deposition of copper atoms on the surface of graphene through copper mirror reaction On the one hand, graphene can be uniformly dispersed into the organic system through the surface modification complexing agent, and on the other hand, the graphene surface complexing agent is complexed with copper ions to form a graphene-complexing agent-copper ion complex dispersion system , which improves the dispersibility of graphene in the copper matrix; further, in the reduction process, the deposition process of copper atoms on the surface of graphene is precisely regulated by changing the type and quantity of complexing agents on the surface of graphene, and graphite is achieved at the molecular atomic level. Good interfacial recombination between alkene and copper. On this basis, the interfacial cross-scale recombination mechanism of graphene in the crystallization process of copper crystal is further revealed, the coupling process route of graphene to copper crystal crystallization process is established, and a large-scale stable preparation technology of graphene-copper matrix composites is provided. , to break through the technical problem of uniform implantation of graphene-copper-based composite materials in industrialized preparation, which is conducive to promoting the high-end development of the copper-based material industry.

In the graphene-copper-based composite material provided in the second aspect of the present application, the graphene-copper-based composite material is prepared by a preparation method, and the above-mentioned method is used for preparation, and the preparation efficiency is high, and the strength of the obtained graphene-copper-based composite material is not less than 600MPa, The electrical conductivity is not less than 110IACS%, the elongation is not less than 3.0%, the properties are excellent, the dispersion effect is good, and the interface bonding is strong, which can meet the extensive needs of the market.

In the high-speed rail contact wire provided by the third aspect of the present application, the high-speed rail contact wire is selected from graphene-copper-based composite materials, and the graphene-copper-based composite material is a graphene-copper-based composite material. Based on the provided graphene-copper-based composite material, the obtained The high-speed rail contact line has high strength, and has high mechanical properties and electrical conductivity, ensuring that the product quality is superior to the level of similar foreign products, ensuring that it can occupy an obvious advantage in the high-speed rail market, and has huge economic benefits.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clear, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

In this application, the term "and/or", which describes the relationship between related objects, means that there can be three relationships, for example, A and/or B, which can mean that A exists alone, A and B exist at the same time, and B exists alone Happening. where A and B can be singular or plural. The character "/" generally indicates that the associated objects are an "or" relationship.

In this application, "at least one" means one or more, and "plurality" means two or more. "At least one item(s) below" or similar expressions thereof refer to any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one (one) of a, b, or c", or, "at least one (one) of a, b, and c", can mean: a,b,c,a-b( That is, a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple respectively.

It should be understood that, in various embodiments of the present application, the size of the sequence numbers of the above-mentioned processes does not imply the sequence of execution, some or all of the steps may be executed in parallel or sequentially, and the execution sequence of each process should be based on its functions and It is determined by the internal logic and should not constitute any limitation on the implementation process of the embodiments of the present application.

The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. As used in the embodiments of this application and the appended claims, the singular forms "a," "" and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

The weight of the relevant components mentioned in the description of the examples of this application can not only refer to the specific content of each component, but also can represent the proportional relationship between the weights of the components. It is within the scope disclosed in the description of the embodiments of the present application that the content of the ingredients is scaled up or down. Specifically, the mass in the description of the embodiments of the present application may be μg, mg, g, kg and other mass units known in the chemical industry.

The terms "first" and "second" are only used for descriptive purposes to distinguish objects such as substances from each other, and cannot be understood as indicating or implying relative importance or implying the number of indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX may also be referred to as the second XX, and similarly, the second XX may also be referred to as the first XX. Thus, a feature defined as "first", "second" may expressly or implicitly include one or more of that feature.

A first aspect of the embodiments of the present application provides a method for preparing a graphene-copper-based composite material, comprising the following steps:

S01. Use machine learning and high-throughput screening technology to establish a graphene-copper matrix composite model;

S02. Graphene, a complexing agent and an organic solvent are carried out first mixing treatment to obtain a mixed product, and the mixed product is subjected to separation treatment in different centrifugal rotation speed intervals, and then screened to obtain a graphene product modified by a complexing agent;

S03. According to the graphene-copper-based composite material model, the soluble copper salt, the modified graphene product of the complexing agent and the organic solvent are carried out a second mixing process to obtain a graphene-complexing agent-copper complex dispersion;

S04. A reducing agent is provided, and the graphene-complexing agent-copper complex dispersion liquid is subjected to a reduction reaction with the reducing agent to obtain a graphene-copper-based composite material. Graphene-complexing agent-copper complex Graphene-complexing agent-copper complex.

The first aspect of the present application provides a method for preparing a graphene-copper-based composite material. The preparation method first uses machine learning and high-throughput screening technology to achieve accurate prediction of a high-strength and high-conductivity graphene-copper-based composite material model. It is then used to know the preparation of subsequent materials, and then provide a complexing agent to react with graphene to obtain a graphene product with a surface-modified complexing agent, and then react with copper salt materials to precisely control the deposition of copper atoms on the surface of graphene through copper mirror reaction On the one hand, graphene can be uniformly dispersed into the organic system through the surface modification complexing agent, and on the other hand, the graphene surface complexing agent is complexed with copper ions to form a graphene-complexing agent-copper ion complex dispersion system , which improves the dispersibility of graphene in the copper matrix; further, in the reduction process, the deposition process of copper atoms on the surface of graphene is precisely regulated by changing the type and quantity of complexing agents on the surface of graphene, and graphite is achieved at the molecular atomic level. Good interfacial recombination between alkene and copper. On this basis, the interfacial cross-scale recombination mechanism of graphene in the crystallization process of copper crystal is further revealed, the coupling process route of graphene to copper crystal crystallization process is established, and a large-scale stable preparation technology of graphene-copper matrix composites is provided. , to break through the technical problem of uniform implantation of graphene-copper-based composite materials in industrialized preparation, which is conducive to promoting the high-end development of the copper-based material industry.

In step S01, a graphene-copper-based composite material model is established by using machine learning and high-throughput screening technology, and the multi-factor coupling mechanism in the crystallization process of multi-scale graphene on copper crystal materials can be used to realize high-strength and high-conductivity. The accurate prediction of the graphene-copper matrix composite material model provides theoretical guidance for the laboratory preparation of high-strength and high-conductivity graphene-copper matrix composite materials.

In some embodiments, the method of using machine learning and high-throughput screening technology to establish a graphene-copper matrix composite model includes the following steps:

S011. Construct a copper crystal model through DFT theoretical calculation;

S012. Combine DFT theoretical calculation with machine learning, add graphene on the surface of the copper crystal model, establish graphene-copper crystal models at different scales, and analyze the intrinsic structure, defects, morphology, graphene-copper The model is optimized in the form of interface;

S013. Based on Sabatier principle, high-throughput screening of graphene-copper crystal model is performed by high-throughput DFT calculation, and a graphene-copper matrix composite material model is established.

In step S011, a copper crystal model is constructed through DFT theoretical calculation.

In some embodiments, the constructed copper crystal model is controlled to have high conductivity, so as to ensure that the resulting composite material has better conductivity. To construct a copper crystal model, it is necessary to fully consider the influence mechanisms of the crystal orientation, different exposed crystal planes, and crystal defect density on the conductivity of the crystal model, so as to achieve accurate prediction of the copper crystal model with ultra-high conductivity.

In step S012, combining DFT theoretical calculation and machine learning, adding graphene on the surface of the copper crystal model, establishing graphene-copper crystal models at different scales, and analyzing the intrinsic structure, defects, morphology, and graphene of graphene. -Model optimization in the form of copper interface.

In some embodiments, adding graphene on the surface of the copper crystal model to establish graphene-copper crystal models at different scales includes modeling the added content, size, distribution, orientation, and the like of graphene.

In some embodiments, by performing model optimization on the intrinsic structure, defects, morphology, and the form of graphene-copper interface of graphene, and through optimization of the model, it is revealed that the introduction of graphene has an effect on the electrical conductivity, strength of copper matrix composites , hardness and wear resistance and other influencing mechanisms, and then guide the subsequent screening.

In step S013, based on the Sabatier principle, high-throughput screening is performed on the graphene-copper crystal model by high-throughput DFT calculation, and a graphene-copper matrix composite material model is established. In some embodiments, the screening is mainly performed according to the properties of the model, which includes screening the high strength and high conductivity of the model to establish a graphene copper matrix composite material model.

In step S02, the graphene, the complexing agent and the organic solvent are subjected to a first mixing process to obtain a mixed product, and the mixed product is subjected to separation processing in different centrifugal speed ranges, and then screened to obtain a graphene product modified by the complexing agent.

In some embodiments, the mass ratio of graphene and complexing agent is 1:0.2-1.5. Controlling the mass ratio of graphene and complexing agent can better regulate the amount of complexing agent on the surface of graphene, which can then be complexed with copper ions to form complexes.

In some specific embodiments, the mass ratio of graphene and complexing agent is 1:0.2, 1:0.5, 1:1, 1:1.5.

In some specific embodiments, the graphene is selected from flake graphene materials, and providing phosphor flake graphene materials is beneficial to obtain graphene of a specific size and a specific number of layers.

In some embodiments, the complexing agent is selected from methylamine, ethylenediamine, isopropylamine, isobutylamine, cyclopropylamine, sec-butylamine, tert-butylamine, hexylamine, dodecylamine, hexadecylamine, octadecylamine at least one. The group of the provided complexing agent is modified on the surface of the graphene material, which is conducive to the combination of the graphene material with the copper base through the complexing agent to form a complex of "graphene-complexing agent-copper base", thereby improving the graphene Binding ability to copper base. Among them, providing organic amines with different C contents can control the types of organic amines on the graphene surface, thereby forming composite materials with different properties.

Further, the organic solvent is provided to dissolve the graphene and the complexing agent, and the provided organic solvent can dissolve various complexing agents, and can also have good wettability with the graphene, so as to improve the wetting of the graphene and the copper-based material. sex. In some embodiments, the organic solvent is selected from any one of alcohol solvents and cyclohexane.

In some embodiments, the ratio of the addition amount of graphene and the organic solvent is 1 g: (10-15) mL, and the addition amount of the organic solvent is controlled to be moderate, which is conducive to better dissolving the reactants and performing the mixing process.

In some embodiments, the first mixing treatment is selected from any one of ball milling treatment, stirring treatment, grinding treatment, mechanical mixing treatment, and ultrasonic treatment, and the first mixing treatment is used for mixing treatment to ensure the obtained mixed product. The intermediate complexing agent can modify graphene well.

In some embodiments, the first mixing treatment is selected from ball milling treatment, the rotation speed of the ball milling treatment is 200-600 r/min, and the time of the ball milling treatment is 1-10 hours. Controlling the rotational speed and time of the ball-milling treatment can ensure that the ball-milling treatment is thorough, and the graphene in the controlled product retains its surface structure, which is beneficial for subsequent use. If the rotational speed of the ball milling treatment is too low, the ball milling treatment will be incomplete, which is not conducive to the formation of products. If the rotational speed of the ball milling treatment is too high, the surface structure of graphene will be damaged, which will affect the subsequent preparation of composite materials. If the ball-milling treatment time is too short, the ball-milling treatment will be incomplete, which will affect the yield of the product; if the ball-milling treatment time is too long, graphene will be oxidized, which will affect the subsequent preparation of composite materials.

In some specific embodiments, the rotation speed of ball milling is selected from 200r/min, 250r/min, 300r/min, 350r/min, 400r/min, 450r/min, 500r/min, 550r/min, 600r/min. The rotation speed selection of the specific ball milling treatment can be determined according to the specific addition amount of the reactant.

In some specific embodiments, the time of ball milling is selected from 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours hours, 7.5 hours, 8 hours, 8.5 hours, 9 hours, 9.5 hours, 10 hours.

Further, the mixed product is subjected to separation treatment in different centrifugal speed ranges, and by performing separation treatment in different centrifugal speed ranges, graphenes of different sizes and layers can be separated, which is beneficial to the subsequent preparation of composite materials with copper salts.

In some embodiments, in the step of separating the mixed product in different centrifugal speed intervals, the different centrifugal speed intervals are respectively selected from: 0-2000r/min; 2000-6000r/min; 6000-9000r/min; 9000-13000r /min. Different layers of graphene can be separated through different centrifugal speeds, mainly by using its centrifugal force. In the low-speed centrifugation range, graphene with a larger number of layers will preferentially settle at the bottom of the centrifuge tube due to gravity or centrifugal force. As the range increases, the thin layers continue to settle, so graphene products with different layers can be obtained by adjusting the centrifugation range.

In a specific embodiment, the products with different layer numbers in the corresponding centrifugal range obtained by separation at different centrifugal speed intervals are as follows: the graphene product obtained by separation at the centrifugal speed of 0-2000r/min is 30-100 layers; The graphene product obtained by separation at the centrifugal speed of 2000-6000r/min is 10-30 layers; the graphene product obtained by separation at the centrifugal speed of 6000-9000r/min is 3-10 layers; at 9000-13000r/min The graphene product obtained by the centrifugal rotation speed separation is a single layer or within 3 layers, and by adjusting the range of the centrifugal rotation speed, the graphene product with the required number of layers can be ensured.

In some implementations, after the mixed product is subjected to separation treatment in different centrifugal rotation speed intervals, sedimentation treatment, separation treatment and washing treatment are performed in sequence. The graphene products with different layers obtained in different centrifugal rotation speed intervals are respectively subjected to sedimentation treatment, separation treatment and washing treatment, so as to obtain graphene products modified by complexing agents with higher purity.

In some embodiments, sedimentation treatment is performed first, mainly to sediment the product to the bottom to facilitate separation. And then carry out separation treatment, including centrifugal separation treatment, by which the sediment and solution can be separated to the maximum extent. Finally, the washing process is carried out, and water, ethanol or cyclohexane can be used to wash away the organic solvent or excess alcohol, so as to reduce the pollution caused.

Further, screening is performed to obtain a graphene product modified by a complexing agent. Among them, in the process of screening, follow-up research is carried out on the graphene product modified by the complexing agent with the least number of layers obtained by the maximum centrifugal speed.

In step S03, according to the graphene-copper-based composite material model, the soluble copper salt, the graphene product modified by the complexing agent and the organic solvent are mixed to obtain a graphene-complexing agent-copper complex dispersion; The excellent properties of the graphene-copper matrix composite material model, determine the addition amount of each reactant to prepare the composite material.

In some embodiments, the mass ratio of the soluble copper salt and the complexing agent-modified graphene product is 0.01-3:1. Controlling the mass ratio of the soluble copper salt and the graphene product modified by the complexing agent can ensure that the conductive effect of graphene can be fully exerted. By facilitating the good combination of graphene and soluble copper salt, if there are too many graphene products, it will affect the Conductivity and strength of composites.

In some specific embodiments, the mass ratio of the soluble copper salt and the complexing agent-modified graphene product is 0.01:1, 0.05:1, 0.1:1, 0.5:1, 1:1, 1.5:1, 2:1 , 2.5:1, 3:1.

In some embodiments, the soluble copper salt is selected from at least one of copper sulfate, copper nitrate, copper acetate, copper chloride, copper isooctanoate, and copper tartrate.

In some embodiments, in the step of performing the second mixing treatment with the soluble copper salt, the graphene product modified by the complexing agent and the organic solvent, the step includes: dispersing the graphene product modified by the complexing agent into the organic solvent to obtain complexation The graphene product dispersion liquid modified by the agent is prepared, the soluble copper salt is dispersed in an organic solvent to obtain a copper salt dispersion liquid, and then the graphene product dispersion liquid and the copper salt dispersion liquid are mixed. Dispersing the soluble copper salt and the graphene product modified by the complexing agent to obtain a dispersion and then mixing is conducive to a more complete reaction between the two reactants and a better effect. Wherein, in the step of dispersing the soluble copper salt into the organic solvent to obtain the copper salt dispersion liquid, the molar concentration of the soluble copper salt in the organic solvent is controlled to be 0.01-2 mol/L, and the amount of the soluble copper salt in the solution is controlled. Too much salt will lead to oversaturation, which will affect the dissolution and is not conducive to the experiment. In some specific embodiments, the molar concentration of the soluble copper salt in the alcohol solvent is 0.01 mol/L, 0.5 mol/L, 1 mol/L, 1.5 mol/L, 2 mol/L.

In some embodiments, in the step of performing the second mixing treatment with the soluble copper salt, the graphene product modified by the complexing agent and the organic solvent, the mixing is performed by means of stirring, wherein the stirring speed is 200-1000 rpm, and the stirring speed is 200-1000 rpm. The time is 5 to 30 minutes. The method of stirring is used for mixing, and the speed and time of stirring are controlled, which can ensure that the complexing agent modified on the graphene surface is complexed with copper ions to form a highly uniform and stable graphene-complexing agent-copper complex dispersion.

In some specific implementations, the stirring speed is selected from 200rpm, 300rpm, 400rpm, 500rpm, 600rpm, 700rpm, 800rpm, 900rpm, 1000rpm; the stirring time is selected from 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes minute.

In step S04, a reducing agent is provided, and the graphene-complexing agent-copper complex dispersion liquid is subjected to a reduction reaction with the reducing agent to obtain a graphene-copper-based composite material.

In some embodiments, the reducing agent is selected from at least one of hydrazine hydrate, sodium borohydride, hydrogen, formaldehyde, acetaldehyde, and propionaldehyde, and the reducing agent is provided to ensure the formation of reduction.

In some embodiments, the molar ratio of the soluble copper salt to the reducing agent is 1:0.5-3. Controlling the molar ratio of the reducing agent to the soluble copper salt is conducive to precise control of the reduction reaction and ensures that the graphene-copper-based composite material is obtained. In some specific embodiments, the molar ratio of soluble copper salt and reducing agent is selected from 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5, 1:3.

In some embodiments, in the step of performing the reduction reaction between the graphene-complexing agent-copper complex dispersion and the reducing agent, the temperature of the reduction reaction is 25-75° C., and the time of the reduction reaction is 5-30 minutes. Through the reduction reaction, the graphene-copper-based composite material is obtained.

In some embodiments, during the reduction reaction, by changing the number and types of organic amines on the graphene surface, the reduction reaction rate can be precisely regulated. In specific embodiments, the number of organic amines on the graphene surface is increased or the The chain length can effectively reduce the reduction reaction rate.

In some embodiments, the product obtained by the reduction reaction further includes: separation treatment and washing treatment, so as to ensure that the obtained graphene-copper-based composite material has high purity and no doping impurities.

A second aspect of the embodiments of the present application provides a graphene-copper-based composite material, and the graphene-copper-based composite material is prepared by a preparation method.

In the graphene-copper-based composite material provided in the second aspect of the present application, the graphene-copper-based composite material is prepared by a preparation method, and the above-mentioned method is used for preparation, and the preparation efficiency is high, and the strength of the obtained graphene-copper-based composite material is not less than 600MPa, The electrical conductivity is not less than 110IACS%, the elongation is not less than 3.0%, the properties are excellent, the dispersion effect is good, and the interface bonding is strong, which can meet the extensive needs of the market.

In some embodiments, the obtained graphene copper-based composite material has a strength of not less than 600 MPa, an electrical conductivity of not less than 110 IACS%, an elongation of not less than 3.0%, and excellent properties.

A third aspect of the embodiments of the present application provides a high-speed rail contact wire, wherein the high-speed rail contact wire is selected from a graphene-copper-based composite material, and the graphene-copper-based composite material is a graphene-copper-based composite material.

In the high-speed rail contact wire provided by the third aspect of the present application, the high-speed rail contact wire is selected from graphene-copper-based composite materials, and the graphene-copper-based composite material is a graphene-copper-based composite material. Based on the provided graphene-copper-based composite material, the obtained The high-speed rail contact line has high strength, and has high mechanical properties and electrical conductivity, ensuring that the product quality is superior to the level of similar foreign products, ensuring that it can occupy an obvious advantage in the high-speed rail market, and has huge economic benefits.

In some embodiments, a graphene-copper-based composite material is prepared by the provided preparation method and applied to a high-speed rail contact wire. The provided preparation method is a pilot line of a copper contact wire for high-speed rail, and the annual production capacity is greater than 1000 tons.

In some embodiments, the provided high-speed rail contact wire is a contact wire material for high-speed rail with a speed of 400 km/h.

The following description will be given in conjunction with specific embodiments.

Example 1

A graphene-copper-based composite material, the preparation method comprising:

(1) Use machine learning and high-throughput screening technology to establish a graphene-copper matrix composite model;

Through DFT theoretical calculation, build a copper crystal model;

Combining DFT theoretical calculation with machine learning, adding graphene on the surface of the copper crystal model, establishing graphene-copper crystal models at different scales, and analyzing the intrinsic structure, defects, morphology, and graphene-copper interface of graphene. Form for model optimization;

Based on the Sabatier principle, the graphene-copper crystal model was screened by high-throughput DFT calculation, and the graphene-copper matrix composite model was established.

(2) firstly mixing graphene, complexing agent and organic solvent to obtain a mixed product, separating the mixed product in different centrifugal speed intervals, and then screening to obtain a graphene product modified by a complexing agent;

The flake graphene of 1g, the sec-butanol of 200mg dodecylamine and 10ml were weighed and put into the ball milling tank of 100ml, and the ball milling product was obtained in 10 hours with the rotating speed ball milling of 400r/min, and the ball milling product was respectively in different centrifugal intervals (0 -2000r/min, 2000-6000r/min, 6000-9000r/min, 9000～13000r/min) for centrifugation to obtain graphene products in corresponding centrifugal intervals, and then sedimentation, separation and washing of centrifugal products in different intervals , cycle 3 times, and re-disperse the dodecylamine-modified graphene product with the least number of layers obtained by centrifugal separation at a rotational speed of 9000-13000 r/min into sec-butanol for use.

(3) according to the graphene-copper-based composite material model, the soluble copper salt, the modified graphene product of the complexing agent and the organic solvent are subjected to a second mixing process to obtain a graphene-complexing agent-copper complex dispersion liquid;

Dissolve Cu(CH ₃ COO) ₂ ·H ₂ O into sec-butanol to form an organic solution of Cu(CH ₃ COO) ₂ ·H ₂ O, wherein the molar concentration of copper salt in the organic solvent is 0.05mol/L ; Then, add the graphene dispersion liquid of surface-modified dodecylamine, wherein the mass ratio of graphene and copper of surface-modified dodecylamine is 1:3, and fully stir for 10 minutes at a speed of 400 to 500 rpm to make the graphene The surface-modified dodecylamine is complexed with copper ions to form a highly uniform and stable graphene-complexing agent-copper complex dispersion.

(4) providing a reducing agent, and performing a reduction reaction between the graphene-complexing agent-copper complex dispersion and the reducing agent to obtain a graphene-copper-based composite material.

Acetaldehyde is provided as an aldehyde reducing agent, wherein the molar ratio of acetaldehyde and copper salt is 0.5:1, and the graphene-complexing agent-copper complex dispersion liquid and the aldehyde reducing agent are subjected to a reduction reaction at 25 ° C for 10 minutes , and then carry out the impurity removal treatment to obtain the graphene copper matrix composite material.

Example 2

A graphene-copper-based composite material, the preparation method comprising:

(1) Use machine learning and high-throughput screening technology to establish a graphene-copper matrix composite model;

Through DFT theoretical calculation, build a copper crystal model;

Combining DFT theoretical calculation with machine learning, adding graphene on the surface of the copper crystal model, establishing graphene-copper crystal models at different scales, and analyzing the intrinsic structure, defects, morphology, and graphene-copper interface of graphene. Form for model optimization;

Based on the Sabatier principle, the graphene-copper crystal model was screened by high-throughput DFT calculation, and the graphene-copper matrix composite model was established.

(2) firstly mixing graphene, complexing agent and organic solvent to obtain a mixed product, separating the mixed product in different centrifugal speed intervals, and then screening to obtain a graphene product modified by a complexing agent;

Weigh the Graphene of 1g, the ethanol of 500mg ethylenediamine and 10ml and put it into the ball milling tank of 100ml, and obtain the ball milling product with the rotating speed ball milling of 200r/min for 10 hours, and the ball milling product is respectively in different centrifugal intervals (0-2000r/ min, 2000-6000 r/min, 6000-9000 r/min, 9000-13000 r/min) for centrifugation to obtain graphene products in the corresponding centrifugation intervals, and then sedimentation, separation and washing of the centrifugation products in different intervals, cycle 3 Next, the ethylenediamine-modified graphene product with the least number of layers obtained by centrifugation at a rotational speed of 9000-13000 r/min is redispersed into ethanol for use.

(3) according to the graphene-copper-based composite material model, the soluble copper salt, the modified graphene product of the complexing agent and the organic solvent are subjected to a second mixing process to obtain a graphene-complexing agent-copper complex dispersion liquid;

Dissolving copper sulfate in ethanol to form an ethanol solution of copper sulfate, wherein the molar concentration of copper salt in the organic solvent is 1 mol/L; then, adding a surface-modified ethylenediamine graphene dispersion, wherein the surface-modified ethylenediamine The mass ratio of the graphene to copper of the amine is 1:0.5, and it is fully stirred for 30 minutes at a speed of 200 to 300 rpm, so that the ethylenediamine modified on the graphene surface is complexed with copper ions to form a highly uniform and stable graphene-complexed Agent-copper complex dispersion.

(4) providing a reducing agent, and performing a reduction reaction between the graphene-complexing agent-copper complex dispersion and the reducing agent to obtain a graphene-copper-based composite material.

Provide formaldehyde as an aldehyde reducing agent, wherein the molar ratio of formaldehyde and copper salt is 2:1, and the graphene-complexing agent-copper complex dispersion liquid and the aldehyde reducing agent are subjected to a reduction reaction at 40 ° C for 10 minutes, and then Carry out impurity removal treatment to obtain graphene copper matrix composite material.

Example 3

A graphene-copper-based composite material, the preparation method comprising:

(1) Use machine learning and high-throughput screening technology to establish a graphene-copper matrix composite model;

Through DFT theoretical calculation, build a copper crystal model;

Combining DFT theoretical calculation with machine learning, adding graphene on the surface of the copper crystal model, establishing graphene-copper crystal models at different scales, and analyzing the intrinsic structure, defects, morphology, and graphene-copper interface of graphene. Form for model optimization;

Based on the Sabatier principle, the graphene-copper crystal model was screened by high-throughput DFT calculation, and the graphene-copper matrix composite model was established.

(2) firstly mixing graphene, complexing agent and organic solvent to obtain a mixed product, separating the mixed product in different centrifugal speed intervals, and then screening to obtain a graphene product modified by a complexing agent;

The Graphene of 1g, the butanol of 1g of cyclopropylamine and 10ml were weighed and put into the ball-milling tank of 100ml, and the ball-milling product was obtained by ball milling at the rotating speed of 600r/min for 10 hours, and the ball-milling product was respectively in different centrifugal intervals (0-2000r/min. min, 2000-6000 r/min, 6000-9000 r/min, 9000-13000 r/min) for centrifugation to obtain graphene products in the corresponding centrifugation intervals, and then sedimentation, separation and washing of the centrifugation products in different intervals, cycle 3 Second, the cyclopropylamine-modified graphene product with the least number of layers obtained by centrifugation at a rotational speed of 9000-13000 r/min is redispersed into butanol for use.

(3) according to the graphene-copper-based composite material model, the soluble copper salt, the modified graphene product of the complexing agent and the organic solvent are subjected to a second mixing process to obtain a graphene-complexing agent-copper complex dispersion liquid;

Dissolving copper isooctanoate in butanol to form a butanol solution of copper isooctanoate, wherein the molar concentration of the copper salt in the organic solvent is 1.5 mol/L; subsequently, adding the graphene dispersion of surface-modified cyclopropylamine, wherein, The mass ratio of surface-modified cyclopropylamine to copper is 1:0.5, and fully stirred for 15 minutes at a speed of 900 to 1000 rpm, so that the graphene surface-modified cyclopropylamine is complexed with copper ions to form a highly uniform and stable graphene- Complexing agent - copper complex dispersion.

(4) providing a reducing agent, and performing a reduction reaction between the graphene-complexing agent-copper complex dispersion and the reducing agent to obtain a graphene-copper-based composite material.

Propionaldehyde is provided as an aldehyde reducing agent, wherein the molar ratio of propionaldehyde and copper salt is 2:1, and the graphene-complexing agent-copper complex dispersion liquid and the aldehyde reducing agent are subjected to a reduction reaction at 70 ° C for 5 minutes , and then carry out the impurity removal treatment to obtain the graphene copper matrix composite material.

property test

The electrical conductivity, tensile strength and elongation of the graphene-copper matrix composites obtained in Examples 1 to 3 were measured respectively, and the measuring method was as follows:

(1) Conductivity: measured by the four-terminal method of the double-arm bridge, standing at 20℃±0.5℃ for 24h, 8A current, switching the positive and negative polarities of the power supply and taking the average value (IACS).

(2) Tensile strength: The size of the tensile sample is designed to be a cuboid with a gauge length of 10 mm and a cross-section of 2 mm × 1.5 mm. The tensile test is carried out using a RG2000-20 tensile machine, and the initial tensile speed is 1 mm/min. Calculate the resistance of the material to the maximum uniform plastic deformation (MPa)

(3) Elongation: The size of the tensile sample is designed as a rectangular parallelepiped with a gauge length of 10 mm and a cross-section of 2 mm × 1.5 mm. The tensile test is carried out using a RG2000-20 tensile machine, and the initial tensile speed is 1 mm/min. After the sample breaks in tension, the percentage (%) of the ratio of the original gauge length to the original gauge length is measured.

Result analysis

The electrical conductivity, tensile strength and elongation of the graphene-copper matrix composites obtained in Examples 1-3 were measured respectively, and the results are shown in Table 1 below. It can be seen that the graphene-copper obtained in Examples 1-3 The conductivity of the matrix composite material is not less than 110IACS%, the tensile strength is not less than 600MPa, and the elongation rate is not less than 3.0%. The indicators are better than the level of similar foreign products. Its advantages can occupy obvious advantages in the high-speed railway market. huge economic benefits.

Table 1

To sum up, the present application provides a method for preparing a graphene-copper matrix composite material. The preparation method first uses machine learning and high-throughput screening technology to achieve accurate prediction of a high-strength and high-conductivity graphene-copper matrix composite material model. It is then used to know the preparation of subsequent materials, and then provide organic amines to react with graphene to obtain graphene products with surface-modified organic amines, and then react with copper salt materials to accurately control the deposition of copper atoms on the surface of graphene through copper mirror reaction. On the one hand, graphene can be uniformly dispersed into the organic system through surface modification of organic amines, and on the other hand, the graphene-organic amine-copper ion complex dispersion system is formed through the complexation of organic amines on the surface of graphene and copper ions, which improves the performance of graphene. Dispersion in the copper matrix; further, in the process of aldehyde reduction, the deposition process of copper atoms on the graphene surface is precisely regulated by changing the type and quantity of organic amines on the graphene surface, and the gap between graphene and copper is realized at the molecular atomic level. Good interface compounding. On this basis, the interfacial cross-scale recombination mechanism of graphene in the crystallization process of copper crystal is further revealed, the coupling process route of graphene to copper crystal crystallization process is established, and a large-scale stable preparation technology of graphene-copper matrix composites is provided. , to break through the technical problem of uniform implantation of graphene-copper-based composite materials in industrialized preparation, which is conducive to promoting the high-end development of the copper-based material industry.

The graphene-copper-based composite material prepared by the method has high preparation efficiency, good dispersion effect of graphene and copper-based materials, and strong interface bonding, and can meet the wide demands of the market. It has high mechanical properties and electrical conductivity, ensuring that the product quality is superior to the level of similar foreign products, ensuring that it can occupy an obvious advantage in the high-speed railway market, and has huge economic benefits.

The above descriptions are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection of the present application. within the range.

Claims (8)

1. a preparation method of graphene copper-based composite material, is characterized in that, comprises the steps: Use machine learning and high-throughput screening technology to establish a graphene-copper matrix composite model; use machine learning to learn the multi-factor coupling mechanism of multi-scale graphene in the crystallization process of copper crystal materials to achieve accurate prediction of graphene-copper matrix composite material models , to improve the theoretical guidance for the laboratory preparation of graphene-copper matrix composites; The graphene, the complexing agent and the organic solvent are subjected to a first mixing process to obtain a mixed product, the mixed product is separated and processed in different centrifugal rotation speed intervals, and then screened to obtain a graphene product modified by the complexing agent; The complexing agent is selected from at least one of methylamine, ethylenediamine, isopropylamine, isobutylamine, cyclopropylamine, sec-butylamine, tert-butylamine, hexylamine, dodecylamine, hexadecylamine, and octadecylamine; The mass ratio of the graphene and the complexing agent is 1:0.2～1.5; According to the graphene-copper-based composite material model, the soluble copper salt, the graphene product modified by the complexing agent and the organic solvent are subjected to a second mixing process to obtain a graphene-complexing agent-copper complex dispersion; A reducing agent is provided, and the graphene-complexing agent-copper complex dispersion liquid is subjected to a reduction reaction with the reducing agent to obtain a graphene-copper-based composite material; Among them, in the reduction process, the deposition process of copper atoms on the graphene surface is precisely regulated by changing the type and quantity of the graphene surface complexing agent. 2. the preparation method of graphene-copper-based composite material according to claim 1, is characterized in that, the described method utilizing machine learning and high-throughput screening technology to predict graphene-copper-based composite material model comprises the steps: Through DFT theoretical calculation, build a copper crystal model; Combining DFT theoretical calculation with machine learning, adding graphene on the surface of the copper crystal model, establishing graphene-copper crystal models at different scales, and analyzing the intrinsic structure, defects, morphology, graphene-copper The model is optimized in the form of interface; Based on the Sabatier principle, the graphene-copper crystal model is subjected to high-throughput screening by high-throughput DFT calculation, and a graphene-copper matrix composite material model is established. 3. the preparation method of graphene-copper matrix composite material according to claim 1 and 2, is characterized in that, described first mixing treatment is selected from ball milling treatment, stirring treatment, grinding treatment, mechanical mixing treatment, in ultrasonic treatment any kind. 4. the preparation method of graphene-copper-based composite material according to claim 1 and 2, is characterized in that, in the step that described mixed product is carried out separation processing in different centrifugal rotation speed intervals, described different centrifugal rotation speed intervals are selected respectively. From: 0-2000 r/min; 2000-6000 r/min; 6000-9000 r/min; 9000-13000 r/min; and/or, After the mixed product is subjected to separation treatment in different centrifugal rotation speed intervals, sedimentation treatment, separation treatment and washing treatment are carried out in sequence. 5. the preparation method of graphene-copper-based composite material according to claim 1 and 2, is characterized in that, the mass ratio of the graphene product modified by described soluble copper salt and described complexing agent is 0.01～3:1 ;and / or, The molar ratio of the soluble copper salt to the reducing agent is 1:0.5~3; and/or, The soluble copper salt is selected from at least one of copper sulfate, copper nitrate, copper acetate, copper chloride, copper isooctanoate, copper tartrate; and/or, The reducing agent is selected from at least one of hydrazine hydrate, hydrogen, sodium borohydride, formaldehyde, acetaldehyde, and propionaldehyde. 6. the preparation method of graphene-copper-based composite material according to claim 1 and 2, is characterized in that, the step that soluble copper salt, the modified graphene product of described complexing agent and organic solvent are carried out the second mixing process wherein, the stirring is carried out at a speed of 200-1000 rpm, and the stirring time is 5-30 minutes. 7. the preparation method of graphene-copper-based composite material according to claim 1 and 2, it is characterized in that, described graphene-complexing agent-copper complex dispersion liquid is carried out reduction reaction with described reducing agent In the step, the temperature of the reduction reaction is 25-75° C., and the time of the reduction reaction is 5-30 minutes. 8. The method for preparing a graphene-copper-based composite material according to claim 1 or 2, wherein the prepared graphene-copper-based composite material is used for high-speed rail contact wires.