Preparation method of monodisperse high-crystalline copper powder

Abstract

The application discloses a preparation method of monodisperse high-crystalline copper powder and belongs to the technical field of metal powder preparation. The application is used for solving the technical problem of how to control the process of synthesizing cuprous oxide powder and copper powder in the prior art, so as to improve the dispersity and crystallinity of the synthesized copper powder. The preparation method of the monodisperse high-crystalline copper powder comprises the following steps: mixing cuprous oxide powder in deionized water to obtain a cuprous oxide mixture; mixing ascorbic acid and chelating resin in deionized water to obtain a complexing solution; and mixing the cuprous oxide mixture and the complexing solution, then performing a post-heating reaction and filtering to obtain copper powder particles. The preparation method of the cuprous oxide powder is that copper nitrate, gelatin and cetyltrimethylammonium bromide are reacted. The copper powder with regular morphology, high crystallinity and uniform dispersion is prepared through adsorption of a template agent and chelating resin.

Description

Technical Field

[0001] This invention relates to the field of metal powder preparation technology, and specifically to a method for preparing monodisperse, highly crystalline copper powder. Background Technology

[0002] Copper powder preparation methods can be broadly categorized into physical and chemical methods based on whether a chemical reaction occurs during the preparation process. Physical methods mainly include atomization, ball milling, and physical vapor deposition, which do not involve changes in chemical composition. Chemical methods, on the other hand, operate at the atomic or molecular level, allowing for simple and effective control of the copper crystallization process. By adjusting the chemical reaction conditions, precise control over the particle size, morphology, and purity of the copper powder can be achieved. Therefore, chemical methods have demonstrated great potential and advantages in the preparation of ultrafine copper powder; by optimizing reaction conditions, high-performance ultrafine copper powder can be easily obtained.

[0003] In chemical methods, copper powder obtained by direct reduction with strong reducing agents is relatively loose and has an uneven particle size distribution. After copper ions are rapidly reduced, the growth process of copper crystals is very rapid, easily forming a large number of crystal nuclei in a short time. Under these conditions, aggregation and growth are very significant, easily forming loose and porous particles. Patent application CN102941351A discloses a method for preparing ultrafine copper powder. An ferrous carboxylate complex solution is added to cuprous oxide, and ultrafine copper powder is prepared without the need for a dispersant. Alternatively, a glucose aqueous solution is added to a copper salt aqueous solution, and after reduction, cuprous oxide powder is synthesized. However, the particle size morphology of cuprous oxide powder has a crucial influence on the morphology, dispersibility, and crystallinity of the synthesized copper powder. How to control the particle size morphology of the two reduction products is of great significance for preparing copper powder with high crystallinity and high dispersibility.

[0004] To address this technical deficiency, a solution is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing monodisperse, highly crystalline copper powder, which solves the technical problem of how to control the process of synthesizing cuprous oxide powder and copper powder in the existing copper powder synthesis process, thereby improving the dispersibility and crystallinity of the synthesized copper powder.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for preparing monodisperse highly crystalline copper powder includes the following steps:

[0008] S1. Add cuprous oxide powder to deionized water and mix well to obtain a cuprous oxide mixture;

[0009] S2, ascorbic acid and chelating resin are added to deionized water to prepare a complexing solution; the cuprous oxide mixture is mixed with the complexing solution, then heated to 55-65℃ and kept at that temperature for 2-3 hours, and then filtered to obtain monodisperse highly crystalline copper powder.

[0010] Using ascorbic acid as a weak reducing agent, cuprous oxide powder was adsorbed and uniformly dispersed by chelating resin to prepare uniformly dispersed copper powder particles.

[0011] Furthermore, the method for preparing the chelating resin includes the following steps:

[0012] A1. Solvent, chloroacetyl polystyrene resin and ethyl chloroacetate were mixed to obtain a reaction system; NaOH solution was added dropwise to the reaction system, and the reaction was carried out at 25-30℃ for 5-6 hours. After filtration, washing and drying were performed to constant weight to synthesize a β-diketone chelating resin.

[0013] NaOH solution is added dropwise to methanol solvent to form sodium methoxide; sodium methoxide can be used as a base reagent to deprotonate the hydrogen atom at the α-position of aromatic ketone to generate a stable enol anion, which then undergoes nucleophilic addition to the acyl carbon in ethyl chloroacetate to form an intermediate; subsequently, the intermediate loses the ethanol molecule and undergoes intramolecular rearrangement to synthesize the product, namely the chelating resin containing the β-diketone structure.

[0014] The reaction formula for synthesizing a chelating resin with a β-diketone structure by reacting chloroacetyl polystyrene resin and ethyl chloroacetate is as follows:

[0015]

[0016] A2. A β-diketone chelating resin is mixed with nitric acid, and then 85-90 wt% concentrated sulfuric acid is added dropwise. The mixture is reacted at 70-80℃ and then filtered to synthesize a nitrated β-diketone chelating resin. The nitrated β-diketone chelating resin is mixed with ethanol and stannous chloride and reacted at room temperature for 2-3 hours to generate an intermediate. The intermediate is added to sodium hydroxide solution, mixed, and filtered to obtain the product. The product is washed and dried to prepare the chelating resin.

[0017] The above reaction cannot proceed completely, resulting in a considerable number of unreacted benzene rings and benzene-like chain segments remaining in the resin. The β-diketone chelating resin is then subjected to nitration and nitro reduction reactions to ultimately prepare an amino-grafted chelating resin. Concentrated sulfuric acid is used as a sulfonating agent to graft nitro groups onto the β-diketone chelating resin, stannous chloride is used as a reducing agent, and sodium hydroxide solution is added to promote phase transfer, thereby preparing a solid chelating resin.

[0018] Furthermore, in step A1, the ratio of solvent, chloroacetyl polystyrene resin, and ethyl chloroacetate is 200mL:30-50g:15-25g, and the drying temperature is 65-70℃.

[0019] Further, in step A2, the ratio of the amount of β-diketone chelating resin, nitric acid, and concentrated sulfuric acid is 10-20g:50mL:3-10mL; the ratio of the amount of nitrated β-diketone chelating resin, ethanol, and stannous chloride is 5-15g:50mL:0.3-0.5g; and the mass ratio of the intermediate to the sodium hydroxide solution is 1:1.

[0020] Furthermore, the method for preparing the cuprous oxide powder includes the following steps:

[0021] B1. Ethanol and water are mixed to obtain a solvent; the solvent, copper nitrate, gelatin and hexadecyltrimethylammonium bromide are added to a reaction vessel, the temperature of the reaction vessel is set to 50-60℃ and the reaction time is 1-2h to obtain the product;

[0022] B2. Add 0.15-0.2 g / mL NaOH solution to the product and react at 55-65℃ for 10-20 min. Then add hydrazine hydrate and continue the reaction. After the reaction is complete, the product is obtained. Centrifuge the product to obtain the reduced product. Wash the reduced product and vacuum dry it to prepare cuprous oxide powder.

[0023] Cuprous oxide powder was synthesized by using the surfactant cetyltrimethylammonium bromide as a template agent and gelatin as a reducing agent after the reaction.

[0024] Further, in step B1, the mass ratio of ethanol to water is 1:2-3, and the volume ratio of solvent, copper nitrate, gelatin, and hexadecyltrimethylammonium bromide is 100mL:2-5g:2.5-4.5g:1.5-2.5g; in step B2, the volume ratio of product, NaOH solution, and hydrazine hydrate is 105-110mL:3-6mL:100-120μL; the centrifugation speed is 2000-3000r / min, and the centrifugation time is 15-20min.

[0025] Furthermore, in step S1, the ratio of cuprous oxide powder to deionized water is 10-20g:150-200mL.

[0026] Further, in step S2, the ratio of ascorbic acid, chelating resin and deionized water is 5-10g:3-8g:150-200mL; the ratio of cuprous oxide mixture and complexing solution is 150-200mL:160-210mL.

[0027] The present invention has the following beneficial effects:

[0028] 1. This invention employs a two-step reduction method to synthesize copper powder. Gelatin is used as a reducing agent, and hexadecyltrimethylammonium bromide is used as a template agent to reduce copper nitrate to cuprous oxide powder. The addition of surfactants provides steric hindrance and electrostatic repulsion, thereby preventing the agglomeration of cuprous oxide particles and controlling the particle size of the synthesized cuprous oxide powder. Hexadecyltrimethylammonium bromide aggregates and arranges itself into an ordered microstructure in solution, preventing the agglomeration of cuprous oxide powder and forming fine cuprous oxide powder with a specific structure. The size of the cuprous oxide particles is significantly reduced, and the uniformity is good.

[0029] 2. Cuprous oxide powder is further reduced using ascorbic acid, a weak reducing agent, to prepare copper powder. This invention uses a self-made chelating resin to disperse and adsorb cuprous oxide powder; the cuprous oxide powder is directly reduced to copper powder in a specific in-situ environment, resulting in copper powder with high dispersibility and high crystallinity. Using chloroacetyl polystyrene resin and ethyl chloroacetate as monomers, a chelating resin with a β-diketone-like structure is synthesized. Then, the benzene ring of the above chelating resin undergoes a specific nitration and reduction reaction, thereby grafting amino functional groups onto the synthesized chelating resin, achieving specific adsorption and reduction of cuprous oxide by multiple functional groups.

[0030] 3. This invention employs a two-step weak reduction method instead of a single strong reduction. By controlling the reaction process of synthesizing cuprous oxide powder and copper powder, it avoids the excessively rapid growth of copper crystals caused by strong reduction, which would lead to the formation of a large number of crystal nuclei in a short period of time. The copper powder prepared by this invention has a uniform particle size distribution and small particle size. SEM images show that the prepared copper powder has a regular morphology, clear grain boundaries, and high crystallinity. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 Electron micrograph of the monodisperse highly crystalline copper powder prepared in Example 9 of this invention;

[0033] Figure 2 Electron micrograph of the monodisperse highly crystalline copper powder prepared in Comparative Example 1 of this invention;

[0034] Figure 3 Electron micrograph of the monodisperse highly crystalline copper powder prepared in Comparative Example 2 of this invention;

[0035] Figure 4 This is an electron micrograph of the monodisperse highly crystalline copper powder prepared in Comparative Example 3 of this invention. Detailed Implementation

[0036] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] The chloroacetylated polystyrene resin used in Examples 1-3 of this invention was purchased from Nanjing Macfali High-Efficiency Separation Carrier Co., Ltd., with a crosslinking degree of 10% and a particle size of 200 μm; the gelatin used in Examples 4-6 of this invention was purchased from Jiangsu Yanke Bioengineering Co., Ltd., with product number 101 and CAS number 9000-70-8.

[0038] Example 1

[0039] This embodiment provides a method for preparing a chelating resin for monodisperse highly crystalline copper powder, comprising the following steps:

[0040] A1. Select a 500mL three-necked flask, add 200mL of methanol solvent, 30g of chloroacetyl polystyrene resin, and 15g of ethyl chloroacetate, mix well to obtain the reaction system. Add 5mL of 0.1mol / L NaOH solution dropwise to the reaction system, heat the three-necked flask to 25℃, react for 5h, filter, wash three times with deionized water, and dry at 65℃ to constant weight to synthesize a β-diketone chelating resin.

[0041] A2. 10g of a β-diketone chelating resin and 50mL of 0.1mol / L nitric acid were added to a 250mL three-necked flask. 15mL of 85wt% concentrated sulfuric acid was added dropwise to the flask. The mixture was reacted at 70℃ for 3 hours, then filtered to synthesize a nitrated β-diketone chelating resin. 5g of the nitrated β-diketone chelating resin and 50mL of ethanol were added to a 250mL three-necked flask, followed by the addition of 0.3g of stannous chloride catalyst. The mixture was reacted at room temperature for 2 hours to generate an intermediate. The intermediate was mixed with 0.1mol / L sodium hydroxide solution at a mass ratio of 1:1, and then filtered to obtain the product. The product was washed with deionized water and dried to constant weight to synthesize the chelating resin.

[0042] Example 2

[0043] This embodiment provides a method for preparing a chelating resin for monodisperse highly crystalline copper powder, comprising the following steps:

[0044] A1. Select a 500mL three-necked flask, add 200mL of methanol solvent, 40g of chloroacetyl polystyrene resin, and 20g of ethyl chloroacetate, mix well to obtain the reaction system. Add 8mL of 0.1mol / L NaOH solution dropwise to the reaction system, then heat the three-necked flask to 26℃ and react for 5.5h. After filtration, wash three times with deionized water, and dry at 66℃ to constant weight to synthesize a β-diketone chelating resin.

[0045] A2. 15g of a β-diketone chelating resin and 50mL of 0.1mol / L nitric acid were added to a 250mL three-necked flask. 6mL of 88wt% concentrated sulfuric acid was added dropwise to the flask. The mixture was reacted at 65℃ for 5h, then filtered to synthesize a nitrated β-diketone chelating resin. 10g of the nitrated β-diketone chelating resin and 50mL of ethanol were added to a 250mL three-necked flask, followed by 0.4g of stannous chloride catalyst. The mixture was reacted at room temperature for 2.5h to generate an intermediate. The intermediate was mixed with 0.1mol / L sodium hydroxide solution at a mass ratio of 1:1 at 150r / min for 1.5h, then filtered to obtain the product. The product was washed with deionized water and dried at 62℃ to constant weight to synthesize the chelating resin.

[0046] Example 3

[0047] This embodiment provides a method for preparing a chelating resin for monodisperse highly crystalline copper powder, comprising the following steps:

[0048] A1. Select a 500mL three-necked flask, add 200mL of methanol solvent, 50g of chloroacetyl polystyrene resin, and 25g of ethyl chloroacetate, mix well to obtain the reaction system. Add 10mL of 0.1mol / L NaOH solution dropwise to the reaction system, heat the three-necked flask to 30℃, react for 6h, then filter, wash three times with deionized water, and dry at 70℃ to constant weight to synthesize a β-diketone chelating resin.

[0049] A2. 20g of a β-diketone chelating resin and 50mL of 0.1mol / L nitric acid were added to a 250mL three-necked flask. 25mL of 90wt% concentrated sulfuric acid was added dropwise to the flask, and the mixture was reacted at 80℃ for 6 hours. The reaction was then filtered to synthesize a nitrated β-diketone chelating resin. 15g of the nitrated β-diketone chelating resin and 50mL of ethanol were added to a 250mL three-necked flask, followed by the addition of 0.5g of stannous chloride catalyst. The mixture was reacted at room temperature for 3 hours to generate an intermediate. The intermediate was mixed with 0.1mol / L sodium hydroxide solution at a mass ratio of 1:1, and then filtered to obtain the product. The product was washed with deionized water and dried at 70℃ to constant weight to synthesize the chelating resin.

[0050] Example 4

[0051] This embodiment provides a method for preparing cuprous oxide powder for monodisperse highly crystalline copper powder, including the following steps:

[0052] B1. Ethanol and water were mixed at a mass ratio of 1:2 to obtain a solvent. 100 mL of the solvent, 2 g of copper nitrate, 2.5 g of gelatin and 1.5 g of the template agent hexadecyltrimethylammonium bromide were added to the reaction vessel. The mixture was stirred evenly first, and then the temperature of the reaction vessel was set to 50 °C and the reaction time was set to 1 h to obtain the product.

[0053] B2. Add 3 mL of 0.15 g / mL NaOH solution to 105 mL of the product, react at 55 °C for 10 min, then add 100 μL of hydrazine hydrate, and continue the reaction for 5 min. After the reaction is complete, the product is obtained. Centrifuge the product at 2000 r / min for 15 min to obtain the reduced product. Wash the reduced product alternately with water and ethanol three to four times, and dry it under vacuum at 70 °C to constant weight to prepare cuprous oxide powder.

[0054] Example 5

[0055] This embodiment provides a method for preparing cuprous oxide powder for monodisperse highly crystalline copper powder, including the following steps:

[0056] B1. Ethanol and water were mixed in a mass ratio of 1:3 to obtain a solvent. 100 mL of the solvent, 3 g of copper nitrate, 3.5 g of gelatin and 2 g of the template agent hexadecyltrimethylammonium bromide were added to the reaction vessel. The mixture was stirred evenly first, and then the temperature of the reaction vessel was set to 55 °C and the reaction time was set to 1.5 h to obtain the product.

[0057] B2. Add 5 mL of 0.18 g / mL NaOH solution to 108 mL of the product, react at 60 °C for 15 min, then add 110 μL of hydrazine hydrate, and continue the reaction for 6 min. After the reaction is complete, the product is obtained. Centrifuge the product at 2500 r / min for 18 min to obtain the reduced product. Wash the reduced product alternately with water and ethanol three to four times, and dry it under vacuum at 77 °C to constant weight to prepare cuprous oxide powder.

[0058] Example 6

[0059] This embodiment provides a method for preparing cuprous oxide powder for monodisperse highly crystalline copper powder, including the following steps:

[0060] B1. Ethanol and water were mixed in a mass ratio of 1:3 to obtain a solvent. 100 mL of the solvent, 5 g of copper nitrate, 4.5 g of gelatin and 2.5 g of the template agent hexadecyltrimethylammonium bromide were added to the reaction vessel. The mixture was stirred evenly first, and then the temperature of the reaction vessel was set to 60 °C and the reaction time was set to 2 h to obtain the product.

[0061] B2. 6 mL of 0.2 g / mL NaOH solution was added dropwise to 110 mL of the product, and the mixture was reacted at 65 °C for 20 min. Then, 120 μL of hydrazine hydrate was added, and the reaction was continued for another 10 min. After the reaction was complete, the product was obtained. The product was centrifuged at 3000 r / min for 20 min to obtain the reduced product. The reduced product was washed alternately with water and ethanol three to four times, and then vacuum dried at 80 °C to constant weight to prepare cuprous oxide powder.

[0062] Example 7

[0063] This embodiment provides a method for preparing monodisperse highly crystalline copper powder, including the following steps:

[0064] S1. Add 10g of the cuprous oxide powder prepared in Example 4 to 150mL of deionized water. Stir the mixture to make the cuprous oxide powder evenly dispersed in the deionized water, thus obtaining a cuprous oxide mixture.

[0065] S2. Add 5g of ascorbic acid and 3g of the chelating resin prepared in Example 1 to 150mL of deionized water to prepare a complexing solution; mix 150mL of cuprous oxide mixture with 160mL of complexing solution, heat to 55℃ and keep warm for 2h, then filter to obtain copper powder particles.

[0066] S3. Copper powder particles were centrifuged at 2000 r / min for 5 min, washed with deionized water, and freeze-dried under vacuum at 0℃ to prepare monodisperse highly crystalline copper powder.

[0067] Example 8

[0068] This embodiment provides a method for preparing monodisperse highly crystalline copper powder, including the following steps:

[0069] S1. Add 15g of the cuprous oxide powder prepared in Example 5 to 180mL of deionized water. Stir the mixture to make the cuprous oxide powder evenly dispersed in the deionized water, thus obtaining a cuprous oxide mixture.

[0070] S2. Add 8g of ascorbic acid and 6g of the chelating resin prepared in Example 2 to 180mL of deionized water to prepare a complexing solution; mix 180mL of cuprous oxide mixture with 200mL of complexing solution, heat to 60℃ and keep warm for 2.5h, then filter to obtain copper powder particles.

[0071] S3. Copper powder particles were centrifuged at 2500 r / min for 8 min, washed with deionized water, and freeze-dried under vacuum at -2℃ to prepare monodisperse highly crystalline copper powder.

[0072] Example 9

[0073] This embodiment provides a method for preparing monodisperse highly crystalline copper powder, including the following steps:

[0074] S1. Add 20g of the cuprous oxide powder prepared in Example 6 to 200mL of deionized water. Stir the mixture to make the cuprous oxide powder evenly dispersed in the deionized water, thus obtaining a cuprous oxide mixture.

[0075] S2. Add 10g of ascorbic acid and 8g of the chelating resin prepared in Example 3 to 200mL of deionized water to prepare a complexing solution; mix 200mL of cuprous oxide mixture with 210mL of complexing solution, heat to 65℃ and keep warm for 3h, then filter to obtain copper powder particles.

[0076] S3. Copper powder particles were centrifuged at 3000 r / min for 10 min, washed with deionized water, and freeze-dried under vacuum at -2℃ to prepare monodisperse highly crystalline copper powder.

[0077] Comparative Example 1

[0078] The difference between this comparative example and Example 9 is that step A2 is omitted; and the chelating resin is replaced with an equal mass of β-diketone chelating resin.

[0079] Comparative Example 2

[0080] The difference between this comparative example and Example 9 is that, in step B1 of preparing cuprous oxide powder, the template agent hexadecyltrimethylammonium bromide was not added during the synthesis of the product.

[0081] Comparative Example 3

[0082] The difference between this comparative example and Example 9 is that, in preparing monodisperse highly crystalline copper powder, sodium borohydride of equal mass was used instead of ascorbic acid.

[0083] Performance testing:

[0084] The copper powders prepared in Examples 7-9 of this invention exhibit good dispersibility, with minimal agglomeration between particles. (Based on the appendix...) Figure 1 It can be seen that the copper powder prepared in Example 9 of the present invention has regular grain morphology, clear grain boundaries, high crystallinity, and good and relatively uniform dispersion among copper powders.

[0085] In Comparative Example 1, replacing the amino-grafted β-diketone chelating resin with the same mass of β-diketone chelating resin resulted in a decrease in the adsorption and chelation performance of cuprous oxide powder; according to the appendix... Figure 2 It can be seen that the synthesized cuprous oxide powder exhibits a small amount of agglomeration.

[0086] In Comparative Example 2, no template agent was added to control the morphology of the synthesized product during the preparation of cuprous oxide powder; according to Appendix Figure 3It can be seen that the synthesized copper powder suffers from agglomeration and irregular shape. In Comparative Example 3, sodium borohydride, a strong reducing agent, was used instead of ascorbic acid, a weak reducing agent; cuprous oxide was rapidly reduced, and significant agglomeration and growth occurred, forming loose and porous particles; according to the attached... Figure 4 It can be seen that the copper powder prepared in Comparative Example 3 of the present invention has agglomeration in many places (the agglomeration particle size is relatively large and can be measured according to the scale), which leads to irregular shape, many defects such as holes and cracks, and low crystallinity.

[0087] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

[0088] In the description of this specification, references to terms such as "an embodiment," "example," and "specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0089] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing monodisperse highly crystalline copper powder, characterized in that, Includes the following steps: S1. Add cuprous oxide powder to deionized water and mix well to obtain a cuprous oxide mixture; the preparation method of the cuprous oxide powder includes the following steps: B1. Ethanol and water are mixed to obtain a solvent; the solvent, copper nitrate, gelatin and hexadecyltrimethylammonium bromide are added to a reaction vessel, the temperature of the reaction vessel is set to 50-60℃ and the reaction time is 1-2h to obtain the product; B2. Add 0.15-0.2 g / mL NaOH solution dropwise to the product and react at 55-65℃ for 10-20 min. Then add hydrazine hydrate and continue the reaction. After the reaction is complete, the product is obtained. Centrifuge the product to obtain the reduced product. Wash the reduced product and vacuum dry it to prepare cuprous oxide powder. S2, ascorbic acid and chelating resin were added to deionized water to prepare a complexing solution; the cuprous oxide mixture and the complexing solution were mixed together, then heated to 55-65℃ and kept at that temperature for 2-3 hours, and then filtered to obtain monodisperse highly crystalline copper powder. The method for preparing the chelating resin includes the following steps: A1. Solvent, chloroacetyl polystyrene resin and ethyl chloroacetate were mixed to obtain a reaction system; NaOH solution was added dropwise to the reaction system, and the temperature was raised to 25-30℃. The reaction was carried out for 5-6 hours, then filtered, washed and dried to constant weight to synthesize a β-diketone chelating resin. A2. A β-diketone chelating resin is mixed with nitric acid, and then 85-90 wt% concentrated sulfuric acid is added dropwise. The mixture is reacted at 70-80℃ and then filtered to synthesize a nitrated β-diketone chelating resin. The nitrated β-diketone chelating resin is mixed with ethanol and stannous chloride and reacted at room temperature for 2-3 hours to generate an intermediate. The intermediate is added with sodium hydroxide solution, mixed, and filtered to obtain the product. The product is washed and dried to prepare the chelating resin.

2. The method for preparing monodisperse highly crystalline copper powder according to claim 1, characterized in that, In step A1, the ratio of solvent, chloroacetyl polystyrene resin and ethyl chloroacetate is 200mL:30-50g:15-25g, and the drying temperature is 65-70℃.

3. The method for preparing monodisperse highly crystalline copper powder according to claim 1, characterized in that, In step A2, the ratio of β-diketone chelating resin, nitric acid, and concentrated sulfuric acid is 10-20g:50mL:3-10mL; the ratio of nitrated β-diketone chelating resin, ethanol, and stannous chloride is 5-15g:50mL:0.3-0.5g; and the mass ratio of intermediate to sodium hydroxide solution is 1:

1.

4. The method for preparing monodisperse highly crystalline copper powder according to claim 1, characterized in that, In step B1, the mass ratio of ethanol to water is 1:2-3, and the volume ratio of solvent, copper nitrate, gelatin, and hexadecyltrimethylammonium bromide is 100mL:2-5g:2.5-4.5g:1.5-2.5g. In step B2, the volume ratio of product, NaOH solution, and hydrazine hydrate is 105-110mL:3-6mL:100-120μL. The centrifugation speed is 2000-3000r / min, and the centrifugation time is 15-20min.

5. The method for preparing monodisperse highly crystalline copper powder according to claim 1, characterized in that, In step S1, the ratio of cuprous oxide powder to deionized water is 10-20g:150-200mL.

6. The method for preparing monodisperse highly crystalline copper powder according to claim 1, characterized in that, In step S2, the ratio of ascorbic acid, chelating resin and deionized water is 5-10g:3-8g:150-200mL, and the ratio of cuprous oxide mixture and complexing solution is 150-200mL:160-210mL.

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