Preparation method of copper powder with adjustable particle size
By using a low-temperature synthesis process of functionalized ionic liquids and reducing agents, copper powder with controllable particle size was prepared, solving the problems of uneven particle size, poor dispersibility, and low crystallinity in existing copper powder technologies. This enabled the green and environmentally friendly production of high-performance copper powder and improved conductivity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HENAN UNIV OF SCI & TECH
- Filing Date
- 2023-06-27
- Publication Date
- 2026-06-26
AI Technical Summary
Existing technologies struggle to produce copper powder with uniform particle size, good dispersibility, and high crystallinity. Furthermore, the preparation process may generate toxic gases or corrode equipment, affecting the performance and environmental safety of the copper powder.
Copper powder is synthesized at low temperature using functionalized ionic liquids and reducing agents. By controlling the type, concentration and reaction temperature of the ionic liquid, spherical or polyhedral copper powder with a controllable particle size between 200 nm and 5.2 μm is prepared using green and environmentally friendly solvents and low-temperature reaction processes.
This method achieves uniform particle size distribution, good dispersibility, high crystallinity, and strong oxidation resistance in copper powder, reducing production costs and improving conductivity. It is suitable for the preparation of Cu@Ag metal powder with tightly coated silver.
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Figure CN116604012B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of metal powder preparation technology, specifically relating to a method for preparing copper powder with adjustable particle size. Background Technology
[0002] Copper powder has significant application prospects in conductive pastes, printed circuits, and ceramic components. The morphology, particle size, crystallinity, dispersibility, and uniformity of copper powder are closely related to its properties. Therefore, researchers have been exploring different synthesis methods to prepare high-performance copper powder.
[0003] Currently, various methods can be used to prepare copper powder, such as electrolysis, atomization, ball milling, plasma methods, vapor-phase evaporation, radiation irradiation, and wet chemical methods. Chinese invention patent CN 1686645A uses a sulfuric acid system to synthesize copper powder, but this process generates toxic SO2 gas during the electrified state, posing a health hazard and environmental risk. Chinese invention patent CN 102978667B uses electrodeposition to deposit 50-100 nm nano-copper powder on a cathode stainless steel plate in an acidic environment. However, the acidic solution used corrodes the equipment, and post-processing is troublesome.
[0004] In recent years, silver powder has shown broad application potential in many fields such as novel solar photovoltaics, flexible optoelectronic devices, 5G communication, strain sensors, electromagnetic shielding, printed circuits, and photoelectrocatalysis. However, some shortcomings have been found in its application, such as the relatively high cost of pure silver powder and its susceptibility to electron migration. Meanwhile, copper (with a resistivity of 1.68 × 10⁻¹⁰) offers advantages over other materials. -6 (Ω·cm) has the same resistivity as silver (1.59 × 10⁻¹⁰). -6 Copper has similar conductivity (Ω·cm) to copper powder, is abundant, and relatively inexpensive. However, copper is chemically reactive and easily oxidizes to copper oxide and cuprous oxide in air and at high temperatures, thus increasing its resistance. Therefore, preparing Cu@Ag metal powder with a tight silver coating not only reduces production costs but also combines the excellent physicochemical properties of copper powder with the good conductivity and oxidation resistance of silver powder, thus opening up broader development prospects.
[0005] The primary key challenge in preparing high-performance Cu@Ag metal powders is to obtain spherical or near-spherical copper powders with uniform morphology and particle size, good dispersibility, and high crystallinity. This is essential for achieving Cu@Ag metal powders with excellent conductivity, uniform Ag coating, and high oxidation resistance. Furthermore, the average particle size of the Cu powder has a significant impact on the subsequent Ag powder coating, performance, and applications. Therefore, exploring new and simple synthesis techniques to prepare Cu powders with controllable particle size, good dispersibility, and high oxidation resistance is particularly important. Summary of the Invention
[0006] This invention provides a method for preparing copper powder with adjustable particle size. The purpose is to prepare Cu powder with adjustable particle size, good dispersibility, high crystallinity, and good oxidation resistance using a simple process. The method of this invention is green and environmentally friendly, easy to scale up, and the prepared copper powder has a uniform particle size distribution with an adjustable particle size between 200nm and 5.2μm. The copper powder is polyhedral, spherical, or near-spherical in shape.
[0007] This invention is specifically achieved through the following technical solution: a method for preparing copper powder with adjustable particle size according to this invention includes the following steps:
[0008] (1) Weigh a certain amount of copper sulfate and functionalized ionic liquid, add them to a certain volume of solvent I, stir until completely dissolved, and obtain solution A for later use;
[0009] The concentrations of copper sulfate and functionalized ionic liquid in solution A are 30-100 mmol / L and 80-300 mmol / L, respectively; the cation of the functionalized ionic liquid is carboxymethyl imidazolium cation, and the anion of the functionalized ionic liquid is one of oxalate, formate, acetate, citrate, methyl sulfate, and glycinate.
[0010] (2) Weigh a certain amount of reducing agent and add it to a certain volume of solvent II. Stir until completely dissolved to obtain solution B, which is then set aside. The concentration of the reducing agent in solution B is 100-500 mmol / L.
[0011] (3) Mix solution A and solution B and stir the mixture at 70-90℃ for 2 hours; then centrifuge the mixture, wash the precipitate with anhydrous ethanol and dry it under vacuum at 40℃ to obtain copper powder.
[0012] Solvent I and Solvent II are the same, both selected from one or more of distilled water, ethylene glycol, propylene glycol, and glycerol.
[0013] Preferably, the volumes of solvent I and solvent II are equal.
[0014] In the aforementioned method for preparing copper powder with adjustable particle size, solvent I and solvent II can both be a mixture of distilled water and ethylene glycol.
[0015] Furthermore, the volume ratio of distilled water to ethylene glycol in the mixture of distilled water and ethylene glycol is 1:(0.25-9).
[0016] Preferably, the functionalized ionic liquid is selected from one of 1-carboxymethyl-3-methylimidazolium acetate, 1-carboxymethyl-3-methylimidazolium methyl sulfate, 1-carboxymethyl-3-methylimidazolium carboxylate, and 1-carboxymethyl-3-methylimidazolium oxalate.
[0017] Further, the concentration of 1-carboxymethyl-3-methylimidazolium acetate in solution A is 80-90 mmol / L, the concentration of 1-carboxymethyl-3-methylimidazolium methyl sulfate in solution A is 100-150 mmol / L, the concentration of 1-carboxymethyl-3-methylimidazolium carboxylate in solution A is 150-280 mmol / L, and the concentration of 1-carboxymethyl-3-methylimidazolium oxalate in solution A is 200-240 mmol / L.
[0018] Preferably, the reducing agent can be selected from vitamin C, glucose, and hydroxylamine.
[0019] The aforementioned method for preparing copper powder with tunable particle size allows for adjustment of the copper powder particle size by changing the type, concentration, and reaction temperature of the functionalized ionic liquid. The particle size of the prepared copper powder is tunable between 200 nm and 5.2 μm.
[0020] Furthermore, the prepared copper powder has a polyhedral, spherical, or near-spherical morphology.
[0021] Compared with existing technologies, this invention has significant advantages and beneficial effects. Through the above technical solution, this invention achieves considerable technological advancement and practicality, and has broad application value, possessing at least the following advantages:
[0022] (1) The process of this invention is simple, environmentally friendly, and easy to scale up. The prepared copper powder is spherical, near-spherical or polyhedral in shape, with good dispersibility, high crystallinity, good oxidation resistance, uniform particle size distribution, and the particle size can be adjusted in the range of 200nm-5.2μm.
[0023] (2) The present invention uses carboxyl-functionalized ionic liquid in the preparation process, and the use of carboxyl-functionalized ionic liquid improves the antioxidant properties of copper powder.
[0024] (3) Traditional dispersants such as polyvinylpyrrolidone (PVP) and polyethylene oxide-propylene oxide-ethylene oxide triblock copolymer (P123) are non-conductive and often difficult to clean completely during post-processing, with residual parts severely reducing the conductivity of copper powder. In contrast, this invention uses carboxyl-functionalized ionic liquids, which are conductive. Even if some residue remains, the impact on the conductivity of copper powder is relatively small, thus improving the conductivity of copper powder.
[0025] (4) The synthesis temperature of this invention is relatively low, mainly due to the selection and use of the reducing agent, which enables the synthesis of copper powder with excellent performance, uniform particle size distribution, and high crystallinity at a relatively low temperature. By adjusting the concentration, type, and reaction temperature of the ionic liquid, copper powder with uniform particle size ranging from 200 nm to 5.2 μm can be effectively synthesized. This is beneficial for further synthesis of Cu@Ag metal powder with excellent performance and tight silver coating. The preparation of Cu@Ag metal powder can not only reduce production costs, but also combine the good physicochemical properties of copper powder with the good conductivity and oxidation resistance of silver powder, thus giving Cu@Ag metal powder a broader development space. Attached Figure Description
[0026] Figure 1 This is a 2000x magnified SEM image of the copper powder prepared in Example 1 of this invention.
[0027] Figure 2 The image shows the XRD pattern of the copper powder prepared in Example 1 of this invention.
[0028] Figure 3 This is a 2000x magnified SEM image of the copper powder prepared in Example 2 of this invention.
[0029] Figure 4 This is a 2000x magnified SEM image of the copper powder prepared in Example 3 of this invention.
[0030] Figure 5 This is a 2000x magnified SEM image of the copper powder prepared in Example 4 of this invention.
[0031] Figure 6 This is a 2000x magnified SEM image of the copper powder prepared in Example 5 of this invention.
[0032] Figure 7 This is a 2000x magnified SEM image of the copper powder prepared in Example 6 of this invention.
[0033] Figure 8 This is a 5000x magnified SEM image of the copper powder prepared in Example 7 of this invention.
[0034] Figure 9 This is a 5000x magnified SEM image of the copper powder prepared in Example 8 of this invention.
[0035] Figure 10 This is a 5000x magnified SEM image of the copper powder prepared in Example 9 of this invention.
[0036] Figure 11 The image shows the XRD pattern of the copper powder prepared in Example 9 of this invention.
[0037] Figure 12This is a 5000x magnified SEM image of the copper powder prepared in Example 10 of the present invention.
[0038] Figure 13 The image shows the XRD pattern of the copper powder prepared in Example 10 of this invention.
[0039] Figure 14 This is a 5000x magnified SEM image of the copper powder prepared in Example 11 of this invention.
[0040] Figure 15 This is a SEM image of the copper powder prepared in Example 12 of the present invention, magnified 10,000 times.
[0041] Figure 16 This is a SEM image of the copper powder prepared in Example 13 of the present invention, magnified 10,000 times. Detailed Implementation
[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, 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.
[0043] Example 1:
[0044] 1) Measure a certain amount of distilled water and ethylene glycol, mix them at a volume ratio of 1:9 and use them as a solvent for later use;
[0045] 2) Take 50 mL of the solvent from step 1), add a certain mass of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium acetate to it, stir until completely dissolved, so that the concentrations of copper sulfate and 1-carboxymethyl-3-methylimidazolium acetate are 60 mmol / L and 80 mmol / L respectively, to obtain solution A, for later use.
[0046] 3) Take another 50 mL of the solvent from step 1), add a certain mass of vitamin C to it, and after it is completely dissolved, the concentration of vitamin C is 100 mmol / L, to obtain solution B, which is ready for use.
[0047] 4) Add solutions A and B sequentially into a 200 mL three-necked round-bottom flask and stir the reaction at 70 °C for 2 h.
[0048] 5) Centrifuge the solution after the reaction in step 4), wash the precipitate with anhydrous ethanol, and then dry it under vacuum at 40°C to obtain copper powder.
[0049] The copper powder obtained in this embodiment has a polyhedral morphology and an average particle size of approximately 5.2 μm. Figure 1As shown.
[0050] Figure 2 The XRD pattern of the copper powder obtained in this embodiment shows strong diffraction peaks, indicating high crystallinity and a face-centered cubic structure; the absence of diffraction peaks for copper oxide and cuprous oxide proves its high purity.
[0051] Example 2:
[0052] 1) Measure a certain amount of distilled water and ethylene glycol, mix them in a volume ratio of 2:8 and use them as a solvent for later use;
[0053] 2) Take 50 mL of the solvent from step 1), add a certain mass of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium acetate to it, stir until completely dissolved, so that the concentrations of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium acetate are 50 mmol / L and 80 mmol / L respectively, to obtain solution A, for later use.
[0054] 3) Take another 50 mL of the solvent from step 1), add a certain mass of glucose to it, and after it is completely dissolved, make the glucose concentration 110 mmol / L to obtain solution B, which is ready for use.
[0055] 4) Add solutions A and B sequentially into a 200mL three-necked round-bottom flask and stir the reaction at 80℃ for 2 hours.
[0056] 5) Centrifuge the solution after the reaction in step 4), wash the precipitate with anhydrous ethanol, and then vacuum dry at 40°C to obtain copper powder. The obtained copper powder consists of spherical particles with an average particle size of approximately 4.3 μm. Figure 3 As shown.
[0057] Example 3:
[0058] 1) Measure a certain amount of distilled water and ethylene glycol, mix them at a volume ratio of 1:9 and use them as a solvent for later use;
[0059] 2) Take 50 mL of the solvent from step 1), add a certain mass of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium acetate, stir until completely dissolved, so that the concentrations of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium acetate are 30 mmol / L and 90 mmol / L respectively, to obtain solution A, for later use.
[0060] 3) Take another 50 mL of the solvent from step 1), add a certain mass of hydroxylamine to it, and after complete dissolution, the concentration of hydroxylamine is 100 mmol / L, to obtain solution B, which is ready for use.
[0061] 4) Add solutions A and B sequentially into a 200mL three-necked round-bottom flask and stir the reaction at 80℃ for 2 hours.
[0062] 5) Centrifuge the solution after the reaction in step 4), wash the precipitate with anhydrous ethanol, and then vacuum dry it at 40°C to obtain copper powder. The obtained copper powder is polyhedral in shape, with an average particle size of approximately 3.5 μm. Figure 4 As shown.
[0063] Example 4:
[0064] 1) Measure a certain amount of distilled water and ethylene glycol, mix them in a volume ratio of 2:8 and use them as a solvent for later use;
[0065] 2) Take 50 mL of the solvent from step 1), add a certain mass of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium methyl sulfate to it, stir until completely dissolved, so that the concentrations of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium methyl sulfate are 50 mmol / L and 100 mmol / L respectively, to obtain solution A, for later use.
[0066] 3) Take another 50 mL of the solvent from step 1), add a certain mass of hydroxylamine to it, and after complete dissolution, the concentration of hydroxylamine is 150 mmol / L, to obtain solution B, which is ready for use.
[0067] 4) Add solutions A and B sequentially into a 200mL three-necked round-bottom flask and stir the reaction at 70℃ for 2 hours.
[0068] 5) Centrifuge the solution after the reaction in step 4), wash the precipitate with anhydrous ethanol, and then vacuum dry at 40°C to obtain copper powder. The obtained copper powder is polyhedral in shape, with an average particle size of approximately 3.2 μm. Figure 5 As shown.
[0069] Example 5:
[0070] 1) Measure a certain amount of distilled water and ethylene glycol, mix them in a volume ratio of 2:8 and use them as a solvent for later use;
[0071] 2) Take 50 mL of the solvent from step 1), add a certain mass of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium methyl sulfate to it, stir until completely dissolved, so that the concentrations of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium methyl sulfate are 70 mmol / L and 120 mmol / L respectively, to obtain solution A, for later use.
[0072] 3) Take another 50 mL of the solvent from step 1), add a certain mass of hydroxylamine to it, and after complete dissolution, the concentration of hydroxylamine is 220 mmol / L, to obtain solution B, which is ready for use.
[0073] 4) Add solutions A and B sequentially into a 200mL three-necked round-bottom flask and stir the reaction at 80℃ for 2 hours.
[0074] 5) Centrifuge the solution after the reaction in step 4), wash the precipitate with anhydrous ethanol, and then vacuum dry at 40°C to obtain copper powder. The obtained copper powder is polyhedral in shape, with an average particle size of approximately 2.5 μm. Figure 6 As shown.
[0075] Example 6:
[0076] 1) Measure a certain amount of distilled water and ethylene glycol, mix them in a volume ratio of 3:7 and use them as a solvent for later use;
[0077] 2) Take 50 mL of the solvent from step 1), add a certain mass of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium methyl sulfate to it, stir until completely dissolved, so that the concentrations of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium methyl sulfate are 80 mmol / L and 150 mmol / L respectively, to obtain solution A, for later use.
[0078] 3) Take another 50 mL of the solvent from step 1), add a certain mass of glucose to it, and after it is completely dissolved, the glucose concentration is 200 mmol / L, to obtain solution B, which is ready for use.
[0079] 4) Add solutions A and B sequentially into a 200mL three-necked round-bottom flask and stir the reaction at 80℃ for 2 hours.
[0080] 5) Centrifuge the solution after the reaction in step 4), wash the precipitate with anhydrous ethanol, and then vacuum dry at 40°C to obtain copper powder. The obtained copper powder is spherical with an average particle size of approximately 2.1 μm. Figure 7 As shown.
[0081] Example 7:
[0082] 1) Measure a certain amount of distilled water and ethylene glycol, mix them in a volume ratio of 4:6 and use them as a solvent for later use;
[0083] 2) Take 50 mL of the solvent from step 1), add a certain mass of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium carboxylate, stir until completely dissolved, so that the concentrations of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium carboxylate are 60 mmol / L and 240 mmol / L respectively, to obtain solution A, for later use.
[0084] 3) Take another 50 mL of the solvent from step 1), add a certain mass of glucose to it, and after it is completely dissolved, the glucose concentration is 200 mmol / L, to obtain solution B, which is ready for use.
[0085] 4) Add solutions A and B sequentially into a 200mL three-necked round-bottom flask and stir the reaction at 80℃ for 2 hours.
[0086] 5) Centrifuge the solution after the reaction in step 4), wash the precipitate with anhydrous ethanol, and then vacuum dry at 40°C to obtain copper powder. The obtained copper powder is spherical with an average particle size of approximately 1.8 μm. Figure 8 As shown.
[0087] Example 8:
[0088] 1) Measure a certain amount of distilled water and ethylene glycol, mix them in a volume ratio of 3:7 and use them as a solvent for later use;
[0089] 2) Take 50 mL of the solvent from step 1), add a certain mass of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium carboxylate, stir until completely dissolved, so that the concentrations of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium carboxylate are 60 mmol / L and 150 mmol / L respectively, to obtain solution A, for later use.
[0090] 3) Take another 50 mL of the solvent from step 1), add a certain mass of hydroxylamine to it, and after complete dissolution, the concentration of hydroxylamine is 300 mmol / L, to obtain solution B, which is ready for use.
[0091] 4) Add solutions A and B sequentially into a 200mL three-necked round-bottom flask and stir the reaction at 80℃ for 2 hours.
[0092] 5) Centrifuge the solution after the reaction in step 4), wash the precipitate with anhydrous ethanol, and then vacuum dry at 40°C to obtain copper powder. The obtained copper powder is polyhedral in shape, with an average particle size of approximately 1.8 μm. Figure 9 As shown.
[0093] Example 9:
[0094] 1) Measure a certain amount of distilled water and ethylene glycol, mix them in a volume ratio of 5:5 and use them as a solvent for later use;
[0095] 2) Take 50 mL of the solvent from step 1), add a certain mass of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium carboxylate, stir until completely dissolved, so that the concentrations of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium carboxylate are 100 mmol / L and 280 mmol / L respectively, to obtain solution A, for later use.
[0096] 3) Take another 50 mL of the solvent from step 1), add a certain mass of vitamin C to it, and after it is completely dissolved, the concentration of vitamin C is 400 mmol / L, to obtain solution B, which is ready for use.
[0097] 4) Add solutions A and B sequentially into a 200mL three-necked round-bottom flask and stir the reaction at 80℃ for 2 hours.
[0098] 5) Centrifuge the solution after the reaction in step 4), wash the precipitate with anhydrous ethanol, and then vacuum dry at 40°C to obtain copper powder. The obtained copper powder is spherical with an average particle size of approximately 1.4 μm. Figure 10 As shown. Its XRD pattern ( Figure 11 The sample exhibits strong diffraction peaks, indicating high crystallinity and a face-centered cubic structure. The absence of diffraction peaks for copper oxide and cuprous oxide further confirms its high purity.
[0099] Example 10:
[0100] 1) Measure a certain amount of distilled water and ethylene glycol, mix them in a volume ratio of 8:2 and use them as a solvent for later use;
[0101] 2) Take 50 mL of the solvent from step 1), add a certain mass of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium carboxylate, stir until completely dissolved, so that the concentrations of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium carboxylate are 100 mmol / L and 180 mmol / L respectively, to obtain solution A, for later use.
[0102] 3) Take another 50 mL of the solvent from step 1), add a certain mass of glucose to it, and after it is completely dissolved, the glucose concentration is 400 mmol / L, to obtain solution B, which is ready for use.
[0103] 4) Add solutions A and B sequentially into a 200mL three-necked round-bottom flask and stir the reaction at 80℃ for 2 hours.
[0104] 5) Centrifuge the solution after the reaction in step 4), wash the precipitate with anhydrous ethanol, and then vacuum dry at 40°C to obtain copper powder. The obtained copper powder is spherical with an average particle size of approximately 1.0 μm. Figure 12 As shown.
[0105] Figure 13 The XRD pattern of the copper powder obtained in this embodiment shows strong diffraction peaks, indicating high crystallinity and a face-centered cubic structure. The absence of diffraction peaks for copper oxide and cuprous oxide indicates high purity.
[0106] Example 11:
[0107] 1) Measure a certain amount of distilled water and ethylene glycol, mix them in a volume ratio of 5:5 and use them as a solvent for later use;
[0108] 2) Take 50 mL of the solvent from step 1), add a certain mass of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium oxalate to it, stir until completely dissolved, so that the concentrations of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium oxalate are 30 mmol / L and 200 mmol / L respectively, to obtain solution A, for later use.
[0109] 3) Take another 50 mL of the solvent from step 1), add a certain mass of hydroxylamine to it, and after it is completely dissolved, make the hydroxylamine concentration 300 mmol / L to obtain solution B, which is ready for use.
[0110] 4) Add solution A and solution B sequentially into a 200mL three-necked round-bottom flask and stir the reaction at 90℃ for 2 hours.
[0111] 5) Centrifuge the solution after the reaction in step 4), wash the precipitate with anhydrous ethanol, and then vacuum dry at 40°C to obtain copper powder. The obtained copper powder is spherical with an average particle size of approximately 0.6 μm. Figure 14 As shown.
[0112] Example 12:
[0113] 1) Measure a certain amount of distilled water and ethylene glycol, mix them in a volume ratio of 5:5 and use them as a solvent for later use;
[0114] 2) Take 50 mL of the solvent from step 1), add a certain mass of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium oxalate to it, stir until completely dissolved, so that the concentrations of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium oxalate are 60 mmol / L and 240 mmol / L respectively, to obtain solution A, for later use.
[0115] 3) Take another 50 mL of the solvent from step 1), add a certain mass of glucose to it, and after complete dissolution, the glucose concentration is 360 mmol / L, to obtain solution B, which is ready for use.
[0116] 4) Add solution A and solution B sequentially into a 200mL three-necked round-bottom flask and stir the reaction at 90℃ for 2 hours.
[0117] 5) Centrifuge the solution from step 4), wash the precipitate with anhydrous ethanol, and then vacuum dry at 40°C to obtain copper powder. The obtained copper powder is spherical with an average particle size of approximately 0.36 μm. Figure 15 As shown.
[0118] Example 13:
[0119] 1) Measure a certain amount of distilled water and ethylene glycol, mix them at a volume ratio of 10:0 and use them as a solvent for later use;
[0120] 2) Take 50 mL of the solvent from step 1), add a certain mass of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium oxalate to it, stir until completely dissolved, so that the concentrations of copper sulfate and ionic liquid 1-carboxymethyl-3-methylimidazolium oxalate are 50 mmol / L and 200 mmol / L respectively, to obtain solution A, for later use.
[0121] 3) Take another 50 mL of the solvent from step 1), add a certain mass of glucose to it, and after it is completely dissolved, make the glucose concentration 500 mmol / L to obtain solution B, which is ready for use.
[0122] 4) Add solution A and solution B sequentially into a 200mL three-necked round-bottom flask and stir the reaction at 90℃ for 2 hours.
[0123] 5) Centrifuge the solution after the reaction in step 4), wash the precipitate with anhydrous ethanol, and then vacuum dry at 40°C to obtain copper powder. The obtained copper powder is spherical with an average particle size of approximately 0.2 μm. Figure 16 As shown.
[0124] The above description is merely an embodiment of the present invention and is not intended to limit the present invention in any way. The present invention can also have other embodiments based on the above structure and function, which will not be listed hereafter. Therefore, any simple modifications, equivalent changes, and alterations made by those skilled in the art to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.
Claims
1. A method for preparing copper powder with adjustable particle size, characterized in that... Includes the following steps: (1) Weigh a certain amount of copper sulfate and functionalized ionic liquid, add them to a certain volume of solvent I, stir until completely dissolved, and obtain solution A for later use; In solution A, the concentrations of copper sulfate and the functionalized ionic liquid are 30-100 mmol / L and 80-300 mmol / L, respectively. The functionalized ionic liquid is selected from one of 1-carboxymethyl-3-methylimidazolium acetate, 1-carboxymethyl-3-methylimidazolium methyl sulfate, 1-carboxymethyl-3-methylimidazolium carboxylate, and 1-carboxymethyl-3-methylimidazolium oxalate. The concentrations of 1-carboxymethyl-3-methylimidazolium acetate, 1-carboxymethyl-3-methylimidazolium methyl sulfate, 1-carboxymethyl-3-methylimidazolium carboxylate, and 1-carboxymethyl-3-methylimidazolium oxalate in solution A are 80-90 mmol / L, 1-carboxymethyl-3-methylimidazolium methyl sulfate, 1-carboxymethyl-3-methylimidazolium carboxylate, 150-280 mmol / L, and 1-carboxymethyl-3-methylimidazolium oxalate in solution A are 200-240 mmol / L. (2) Weigh a certain amount of reducing agent and add it to a certain volume of solvent II. Stir until completely dissolved to obtain solution B, which is then set aside. The concentration of the reducing agent in solution B is 100-500 mmol / L. Solvent II is the same as Solvent I, and is selected from one or more of distilled water, ethylene glycol, propylene glycol, and glycerol. (3) Mix solution A and solution B and stir the reaction at 70-90 °C for 2 h; then centrifuge and separate the precipitate. Wash the precipitate with anhydrous ethanol and dry it under vacuum at 40 °C to obtain copper powder with a polyhedral, spherical or near-spherical morphology. The particle size of the prepared copper powder can be controlled from 200 nm to 5.2 μm.
2. The method for preparing copper powder with adjustable particle size as described in claim 1, characterized in that... Solvent I and Solvent II have equal volumes.
3. The method for preparing copper powder with adjustable particle size as described in claim 1 or 2, characterized in that... Solvent I and Solvent II are both mixtures of distilled water and ethylene glycol.
4. The method for preparing copper powder with adjustable particle size as described in claim 3, characterized in that... The volume ratio of distilled water to ethylene glycol is 1:(0.25-9).
5. The method for preparing copper powder with adjustable particle size as described in claim 1, characterized in that... The reducing agent is selected from one of vitamin C, glucose, and hydroxylamine.
6. The method for preparing copper powder with adjustable particle size as described in claim 1, characterized in that... The particle size of copper powder can be controlled by changing the type, concentration, and reaction temperature of the functionalized ionic liquid.