A polymer / nanoporous copper composite material and a preparation method thereof

Abstract

The application discloses a method for preparing a polymer / nanoporous copper composite material, and belongs to the technical field of metal materials. The method comprises the following steps: proportionally preparing pure copper and pure manganese and smelting to obtain a Mn-Cu binary alloy; uniformly annealing the obtained alloy to form a gamma single-phase alloy; recrystallizing the gamma single-phase alloy and performing aging heat treatment to cause alpha phase to precipitate, thereby generating an alpha / gamma dual-phase alloy as a precursor material; placing the alpha / gamma dual-phase alloy into an acid solution containing sufficient acid, removing the alpha phase through selective phase corrosion to form a macroporous structure; vacuum-impregnating and solidifying the macroporous structure by using a polymer material; subsequently placing the material into a stronger acid solution, and causing the gamma phase to dealloy through free corrosion or electrochemical corrosion to generate nanopores, thereby obtaining the polymer / nanoporous copper composite material. The composite material can realize wide adjustment of the proportion of the nanoporous copper and the polymer material while maintaining a large surface area and excellent toughness.

Description

Technical Field

[0001] This invention relates to the field of metal materials technology, specifically to a polymer / nanoporous copper composite material and its preparation method. Background Technology

[0002] Nanoporous metals, due to their extremely high surface area, have significant application value in catalysis, actuation, sensing, and battery current collectors. Among them, hierarchical nanoporous copper has attracted widespread attention due to its simple preparation process and relatively low raw material prices.

[0003] However, existing hierarchical nanoporous copper has a significant problem: its intrinsic brittleness. Because the pore edges in nanoporous metals are uniformly sized, the fracture of any pore edge during loading leads to stress concentration on adjacent pore edges. If this stress concentration exceeds the strength of the strongest pore edge, it can cause catastrophic failure of the entire material. During tensile fracture, the elongation at break is often less than 1%. Existing methods to improve this brittleness by reducing sample size or increasing pore edge size are not very effective, and even if some improvement is achieved, it comes at the cost of sacrificing the extremely large surface area of ​​the nanoporous metal. A large specific surface area is one of the most important and essential characteristics of nanoporous metals.

[0004] With the advancement of science and technology and the development of production processes, higher requirements have been placed on the mechanical stability of nanoporous copper. How to prepare nanoporous copper or nanoporous copper composite materials with good toughness and a large surface area is an urgent problem to be solved. Therefore, the search for a simple preparation process that is easy to operate, produces stable and reliable samples, and can yield hierarchical nanoporous copper or composite materials with good toughness, large specific surface area, and controllable shape and size requires continuous exploration and research. Summary of the Invention

[0005] To address the challenge of maintaining a large surface area while ensuring excellent toughness in currently prepared nanoporous copper, this invention aims to provide a method for preparing polymer / nanoporous copper composite materials. The method described in this invention is simple, convenient, and relatively inexpensive. The finished product exhibits adjustable size and shape, good toughness, and a large specific surface area, making it significant for the preparation, theoretical research, and application of nanoporous metals.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing a polymer / nanoporous copper composite material, the method comprising the following steps:

[0008] (1) Prepare a certain proportion of pure copper and pure manganese, and smelt them to prepare a Mn-Cu binary alloy;

[0009] (2) The Mn-Cu alloy prepared by melting is subjected to homogenization annealing to obtain γ single-phase alloy, and then rolled.

[0010] (3) Recrystallization annealing of γ single-phase alloy;

[0011] (4) After recrystallization annealing, the γ single-phase alloy is subjected to aging treatment to precipitate the α phase and obtain the α / γ dual-phase alloy.

[0012] (5) The Mn-Cu alloy with α / γ dual-phase structure is placed in a weakly acidic aqueous solution containing sufficient amounts of acetic acid, ascorbic acid, ammonium sulfate, and ammonium chloride for selective phase corrosion. The α phase is completely corroded to form macropores, while the γ phase is retained to form porous γ-Mn(Cu).

[0013] (6) Using the impregnation method, a uniform mixture of a certain proportion of polymer and curing agent is introduced into the porous γ-Mn(Cu). After the polymer material is cured, a two-phase composite material of polymer / γ-Mn(Cu) is formed.

[0014] (7) The prepared polymer material / γ-Mn(Cu) biphase composite material is placed in an acidic aqueous solution containing sufficient amounts of hydrochloric acid, sulfuric acid, phosphoric acid, oxalic acid, etc., and subjected to electrochemical corrosion or free chemical corrosion without potential application. The Mn element in the γ-Mn(Cu) phase is corroded to a content of less than 2 at.%, forming nanoscale pores.

[0015] In step (1) above, the Mn content in the precursor Mn-Cu alloy is 70%-90% (atomic ratio).

[0016] In step (2) above, the annealing temperature range is 700-900℃.

[0017] In step (3) above, the annealing temperature is 700-900℃.

[0018] In step (4) above, the aging temperature range is 500-750℃.

[0019] In step (5) above, the selective phase corrosion temperature is 10-50℃.

[0020] In step (6) above, the polymer material is in a liquid state during impregnation and becomes solid after curing. The curing time varies slightly depending on the type of polymer material, and the impregnation temperature is 10-50℃.

[0021] In step (7) above, the dealloying temperature is 0-80℃.

[0022] The polymer / nanoporous copper composite material prepared by the above method possesses both good toughness and extremely high specific surface area. This composite material allows for wide adjustment of the ratio of nanoporous copper to polymer materials while maintaining a large surface area and excellent toughness.

[0023] The design mechanism of this invention is as follows:

[0024] 1. By changing the ratio of pure copper and pure manganese in step (1), the ratio of polymer phase and nanoporous copper phase in the composite material can be changed.

[0025] 2. After the time-sensitive processing in step (3), as shown in the attached document. Figure 1 As shown, in Mn-Cu alloys with an α / γ dual-phase structure, the α-phase Mn content is >98 at.%, allowing for complete corrosion in acidic aqueous solutions to form macropores with pore diameters equal to the α-phase particle size. When the Mn content in the γ-phase is 40-70 at.%, it cannot be completely or only partially removed by dealloying in weakly acidic aqueous solutions. Therefore, porous γ-Mn(Cu) can be obtained from Mn-Cu alloys with an α / γ dual-phase structure through free corrosion or electrochemical corrosion.

[0026] 3. By changing the type of polymer material in step (6), the properties of the composite material can be changed.

[0027] 4. By changing the aging treatment temperature and time in steps (3) and (4), the content and size of the α phase in the alloy, i.e., porous γ-Mn(Cu), can be controlled respectively, which is the size and proportion of the polymer phase in the final polymer / nanoporous copper composite material. By changing the dealloying corrosion temperature in step (6), the pore size of the pores in the nanoporous copper phase can be controlled.

[0028] 5. Since the last step in the preparation is dealloying to form nanopores, it can ensure that the sample has a very large specific surface area.

[0029] The advantages and beneficial effects of this invention are as follows:

[0030] (1) Low preparation cost. Compared with the previous powder sintering method, the cost of preparing precursor alloys by melting and heat treatment is lower.

[0031] (2) Large sample size. Melting can produce large-sized samples.

[0032] (3) The properties of composite materials are controllable. By changing the types of polymer materials in the composite material, the mechanical and other properties of the composite material can be significantly altered, such as... Figure 5 As shown, excellent deformability is achieved when the composite material is impregnated with a flexible polymer. Excellent lubrication and hydrophobicity are achieved when the composite material is impregnated with polytetrafluoroethylene (PTFE).

[0033] (4) The ratio of polymer materials to nanoporous copper in the composite material can be controlled. By changing the composition of the master alloy and the temperature and time of the aging treatment, the content and size of the α phase in the alloy, i.e., the ratio and size of polymer materials in the final composite material, can be controlled. By changing the dealloying corrosion temperature, the pore size of the pores in the nanoporous copper phase can be controlled. Attached Figure Description

[0034] Figure 1 In the Cu-Mn equilibrium phase diagram, (Cu,γ-Mn) represents the γ phase, and α(Mn) represents the α phase.

[0035] Figure 2 The following are physical images and corresponding XRD patterns of each stage in the preparation process of the polymer / nanoporous copper composite material in Example 2: (a) Physical images of each stage in the preparation process of the polymer / nanoporous copper composite material, (b) XRD patterns of each stage in the preparation process of the polymer / nanoporous copper composite material.

[0036] Figure 3 Scanning electron microscope (SEM) images of the polymer / nanoporous copper composite materials prepared in Examples 1, 2, and 3: (a) Example 1, (b) Example 2, (c) Example 3, (d) Example 2 (high magnification).

[0037] Figure 4 Scanning electron microscope images of hierarchical nanoporous copper prepared for comparison: (a) low magnification, (b) high magnification.

[0038] Figure 5 The stress-strain curves for uniaxial tensile engineering of the polymer / nanoporous copper composite materials prepared in Examples 1, 2, and 3 are shown.

[0039] Figure 6 Stress-strain curves of hierarchical nanoporous copper uniaxial tensile engineering were prepared for comparison.

[0040] Figure 7 This is a comparison of the electrochemical driving performance of the composite material in Example 3 and the hierarchical nanoporous copper in the comparative case. Detailed Implementation

[0041] This invention provides a method for preparing a polymer / nanoporous copper composite material. Several specific implementation examples and comparative examples are provided below to further illustrate this invention.

[0042] Example 1:

[0043] (1) Prepare pure copper and pure manganese (purity requirement ≥99.9%) according to the atomic ratio of Mn:Cu = 90:10 (at.%), and prepare Mn by electric arc furnace smelting.90 Cu 10 (at.%) Alloy button-shaped ingot, approximately 10 mm in diameter and 6 mm in height.

[0044] (2) The cast Mn-Cu alloy button ingot was subjected to homogenization heat treatment and then cooled to room temperature to obtain γ single-phase alloy. The heat treatment temperature was 850℃, the heat treatment time was 24h, and the cooling method was water cooling.

[0045] (3) The sample after the above homogenization heat treatment is subjected to room temperature cold rolling treatment. The total number of rolling passes is 10, the total rolling reduction is 80%, and the final plate size is approximately 18mm×5mm×1mm (length×width×thickness).

[0046] (4) After recrystallization annealing, the rolled Mn-Cu alloy was cooled to room temperature. The heat treatment temperature was 750℃ and the heat treatment time was 30min. The cooling method was water cooling. According to the scanning electron microscope, the final Mn-Cu alloy with equiaxed structure was obtained.

[0047] (5) The obtained equiaxed Mn-Cu alloy was subjected to aging heat treatment and then cooled to room temperature to obtain an α / γ dual-phase alloy. The aging temperature was 650℃, the heat treatment time was 5h, and the cooling method was water cooling. Combined with SEM observation and EDS analysis, it can be seen that the chemical composition of the α phase is Mn. 99 Cu1 (at.%), volume percentage ~78%, γ-phase chemical composition is Mn 54 Cu 46 (at.%), volume percentage ~22%.

[0048] (6) The Mn-Cu alloy after aging heat treatment was placed in 1L of 0.1mol / L ascorbic acid aqueous solution for selective phase corrosion (corrosion of the α phase) at 25℃. After 24h of corrosion, no obvious bubbles were emitted, and the phase corrosion was completed, thus obtaining micron-porous γ-Mn(Cu) with an average pore size of 4.8μm, a pore size distribution range of 0.5-10μm, and a porosity of 0.78.

[0049] (7) The micron-porous γ-Mn(Cu) obtained after phase etching was placed in a vacuum impregnation equipment (manufacturer: Shenyang Kejing Automation Equipment Co., Ltd., model: CXQ-2500) with a vacuum degree of ~100Pa. 0.1L of epoxy resin and its curing agent (manufacturer: Easy CompositesAsia Ltd, model: EF80) were prepared at a mass ratio of 2:1 and mixed evenly to obtain an epoxy resin impregnation solution. The micron-porous γ-Mn(Cu) was placed in the epoxy resin impregnation solution to impregnate the micron-porous γ-Mn(Cu) with flexible epoxy resin. After impregnation at room temperature for 2 hours, the mixture was completed and cured at room temperature for 24 hours to obtain a two-phase composite material of epoxy resin / γ-Mn(Cu).

[0050] (8) The vacuum-impregnated polymer / γ-Mn(Cu) biphase composite material (as the working electrode) was placed in a three-electrode system containing 500 mL of 0.01 mol / L + 1 mol / L KCl aqueous solution for constant potential electrochemical dealloying at 25 °C and a dealloying voltage of -0.30 V. The reference electrode was an Ag / AgCl electrode, and the counter electrode was an Ag wire. The initial current was approximately 10 mA. After 12 h of dealloying, when the current was less than 10 μA, the dealloying corrosion was complete, yielding an epoxy resin / nanoporous copper composite material with a Mn content of 0.5 at.% in the metallic phase. The scanning electron microscope image is shown below. Figure 3 As shown in Figure a, the volume ratio of epoxy resin is V = 0.78, the average width of the epoxy resin phase is W = 4.8 μm, the overall porosity is P = 0.12, and the nanopore size in the nanoporous copper phase is D = 42 nm, with a pore size distribution range of 20-100 nm.

[0051] (9) Uniaxial tensile mechanical properties were tested on the obtained epoxy resin / nanoporous copper composite material (gauge length: 5mm × 2mm × 1mm (length × width × thickness), strain rate: 1 × 10⁻⁶). -4 s -1 Test equipment: Instron 5982; stress-strain curves are shown below. Figure 5 As shown, it possesses excellent toughness.

[0052] Example 2:

[0053] (1) Prepare pure copper and pure manganese (purity requirement ≥99.9%) according to the atomic ratio of Mn:Cu = 85:15 (at.%), and prepare Mn by electric arc furnace smelting. 85 Cu 15 (at.%) Alloy button-shaped ingot, approximately 10 mm in diameter and 6 mm in height.

[0054] (2) The above-mentioned cast Mn-Cu alloy button ingots were subjected to homogenization heat treatment and then cooled to room temperature to obtain a γ single-phase alloy. The heat treatment temperature was 850℃, the heat treatment time was 24h, and the cooling method was water cooling. The XRD characterization results are as follows: Figure 2 b.

[0055] (3) The homogenized heat-treated sample was subjected to room temperature cold rolling with a total of 10 rolling passes and a total reduction of 80%. The final sheet material size was approximately 18mm × 5mm × 1mm (length × width × thickness). A photograph of the actual product is shown below. Figure 2 As shown in a.

[0056] (4) After recrystallization annealing, the rolled Mn-Cu alloy was cooled to room temperature. The heat treatment temperature was 750℃ and the heat treatment time was 30min. The cooling method was water cooling. According to the scanning electron microscope, the final Mn-Cu alloy with equiaxed structure was obtained.

[0057] (5) The obtained equiaxed Mn-Cu alloy was subjected to aging heat treatment and then cooled to room temperature to obtain an α / γ dual-phase alloy. The aging temperature was 650℃, the heat treatment time was 5h, and the cooling method was water cooling. A physical image is shown below. Figure 2 As shown in figure a. Combined with SEM observation and EDS analysis, the chemical composition of the α phase is Mn. 99 Cu1 (at.%), volume percentage ~67%, γ-phase chemical composition is Mn 53 Cu 47 (at.%), volume percentage ~33%.

[0058] (6) The Mn-Cu alloy after aging heat treatment was placed in 1L of 0.1mol / L ascorbic acid aqueous solution for selective phase corrosion (corrosion of the α phase) at 25℃. After 24 hours of corrosion, no obvious bubbles escaped, indicating that the phase corrosion was complete, resulting in micron-porous γ-Mn(Cu) with an average pore size of 3.1μm, a pore size distribution range of 0.5-10μm, and a porosity of 0.67. A photograph of the actual product is shown below. Figure 2 As shown in figure a, the XRD characterization results are as follows: Figure 2 b.

[0059] (7) The micron-porous γ-Mn(Cu) obtained after phase etching was placed in a vacuum impregnation device (manufacturer: Shenyang Kejing Automation Equipment Co., Ltd., model: CXQ-2500) with a vacuum degree of ~100Pa. 0.1L of epoxy resin and its curing agent (manufacturer: Easy CompositesAsia Ltd, model: EF80) were prepared at a mass ratio of 2:1 and mixed evenly to obtain an epoxy resin impregnation solution. The micron-porous γ-Mn(Cu) was then placed in the epoxy resin impregnation solution to impregnate it with flexible epoxy resin. After impregnation at room temperature for 2 hours, the mixture was cured at room temperature for 24 hours to obtain a two-phase composite material of epoxy resin / γ-Mn(Cu). A physical image is shown below. Figure 2 As shown in figure a, the XRD characterization results are as follows: Figure 2 b.

[0060] (8) The vacuum-impregnated polymer / γ-Mn(Cu) biphase composite material (as the working electrode) was placed in a three-electrode system containing 500 mL of 0.01 mol / L + 1 mol / L KCl aqueous solution for constant potential electrochemical dealloying at 25 °C and a dealloying voltage of -0.30 V. The reference electrode was an Ag / AgCl electrode, and the counter electrode was an Ag wire. The initial current was approximately 10 mA. After 12 h of dealloying, when the current was less than 10 μA, the dealloying corrosion was complete, yielding an epoxy resin / nanoporous copper composite material with a Mn content of 0.5 at.% in the metallic phase. The scanning electron microscope image is shown below. Figure 3 As shown in b, the volume ratio of epoxy resin is V = 0.67, the average width of the epoxy resin phase is W = 3.1 μm, the overall porosity is P = 0.18, and the nanopore size in the nanoporous copper phase is D = 43 nm, with a pore size distribution range of 20-100 nm.

[0061] (9) Uniaxial tensile mechanical properties were tested on the obtained epoxy resin / nanoporous copper composite material (gauge length: 5mm × 2mm × 1mm (length × width × thickness), strain rate: 1 × 10⁻⁶). -4 s -1 Test equipment: Instron 5982; stress-strain curves are shown below. Figure 5 As shown, it possesses excellent toughness.

[0062] Example 3:

[0063] (1) Prepare pure copper and pure manganese (purity requirement ≥99.9%) according to the atomic ratio of Mn:Cu = 80:20 (at.%), and prepare Mn by electric arc furnace smelting. 80 Cu 20 (at.%) Alloy button-shaped ingot, approximately 10 mm in diameter and 6 mm in height.

[0064] (2) The cast Mn-Cu alloy button ingot was subjected to homogenization heat treatment and then cooled to room temperature to obtain γ single-phase alloy. The heat treatment temperature was 850℃, the heat treatment time was 24h, and the cooling method was water cooling.

[0065] (3) The sample after the above homogenization heat treatment is subjected to room temperature cold rolling treatment. The total number of rolling passes is 10, the total rolling reduction is 80%, and the final plate size is approximately 18mm×5mm×1mm (length×width×thickness).

[0066] (4) After recrystallization annealing, the rolled Mn-Cu alloy was cooled to room temperature. The heat treatment temperature was 720℃ and the heat treatment time was 30min. The cooling method was water cooling. According to the scanning electron microscope, the final Mn-Cu alloy with equiaxed structure was obtained.

[0067] (5) The obtained equiaxed Mn-Cu alloy was subjected to aging heat treatment and then cooled to room temperature to obtain an α / γ dual-phase alloy. The aging temperature was 650℃, the heat treatment time was 5h, and the cooling method was water cooling. Combined with SEM observation and EDS analysis, it can be seen that the chemical composition of the α phase is Mn. 99 Cu1 (at.%), volume percentage ~59%, γ-phase chemical composition is Mn 51 Cu 49 (at.%), volume percentage ~41%.

[0068] (6) The Mn-Cu alloy after aging heat treatment was placed in 1L of 0.1mol / L ascorbic acid aqueous solution for selective phase corrosion (corrosion of the α phase) at 25℃. After 24h of corrosion, no obvious bubbles were emitted, and the phase corrosion was completed, thus obtaining micron-porous γ-Mn(Cu) with an average pore size of 2.1μm, a pore size distribution range of 0.5-10μm, and a porosity of 0.59.

[0069] (7) The micron-porous γ-Mn(Cu) obtained after phase etching was placed in a vacuum impregnation equipment (manufacturer: Shenyang Kejing Automation Equipment Co., Ltd., model: CXQ-2500) with a vacuum degree of ~100Pa. 0.1L of epoxy resin and its curing agent (manufacturer: Easy CompositesAsia Ltd, model: EF80) were prepared at a mass ratio of 2:1 and mixed evenly to obtain an epoxy resin impregnation solution. The micron-porous γ-Mn(Cu) was placed in the epoxy resin impregnation solution to impregnate the micron-porous γ-Mn(Cu) with flexible epoxy resin. After impregnation at room temperature for 2 hours, the mixture was completed and cured at room temperature for 24 hours to obtain a two-phase composite material of epoxy resin / γ-Mn(Cu).

[0070] (8) The vacuum-impregnated polymer / γ-Mn(Cu) biphase composite material (as the working electrode) was placed in a three-electrode system containing 500 mL of 0.01 mol / L + 1 mol / L KCl aqueous solution for constant potential electrochemical dealloying at 25 °C and a dealloying voltage of -0.30 V. The reference electrode was an Ag / AgCl electrode, and the counter electrode was an Ag wire. The initial current was approximately 10 mA. After 12 h of dealloying, when the current was less than 10 μA, the dealloying corrosion was complete, yielding an epoxy resin / nanoporous copper composite material with a Mn content of 0.5 at.% in the metallic phase. The scanning electron microscope image is shown below. Figure 3 As shown in c, the volume ratio of epoxy resin is V = 0.59, the average width of the epoxy resin phase is W = 2.1 μm, the overall porosity is P = 0.21, and the nanopore size in the nanoporous copper phase is D = 42 nm, with a pore size distribution range of 20-100 nm.

[0071] (9) Uniaxial tensile mechanical properties were tested on the obtained epoxy resin / nanoporous copper composite material (gauge length: 5mm × 2mm × 1mm (length × width × thickness), strain rate: 1 × 10⁻⁶). -4 s -1 Test equipment: Instron 5982; stress-strain curves are shown below. Figure 5 As shown, it possesses excellent toughness.

[0072] Comparative example:

[0073] (1) Prepare pure copper and pure manganese (purity requirement ≥99.9%) according to the atomic ratio of Mn:Cu = 80:20 (at.%), and prepare Mn by electric arc furnace smelting. 80 Cu 20 (at.%) Alloy button-shaped ingot, approximately 10 mm in diameter and 6 mm in height.

[0074] (2) The cast Mn-Cu alloy button ingot was subjected to homogenization heat treatment and then cooled to room temperature to obtain γ single-phase alloy. The heat treatment temperature was 850℃, the heat treatment time was 24h, and the cooling method was water cooling.

[0075] (3) The sample after the above homogenization heat treatment is subjected to room temperature cold rolling treatment. The total number of rolling passes is 10, the total rolling reduction is 80%, and the final plate size is approximately 18mm×5mm×1mm (length×width×thickness).

[0076] (4) After recrystallization annealing, the rolled Mn-Cu alloy was cooled to room temperature. The heat treatment temperature was 720℃ and the heat treatment time was 30min. The cooling method was water cooling. According to the scanning electron microscope, the final Mn-Cu alloy with equiaxed structure was obtained.

[0077] (5) The obtained equiaxed Mn-Cu alloy was subjected to aging heat treatment and then cooled to room temperature to obtain an α / γ dual-phase alloy. The aging temperature was 650℃, the heat treatment time was 5h, and the cooling method was water cooling. Combined with SEM observation and EDS analysis, it can be seen that the chemical composition of the α phase is Mn. 99 Cu1 (at.%), volume percentage ~59%, γ-phase chemical composition is Mn 51 Cu 49 (at.%), volume percentage ~41%.

[0078] (6) The aged Mn-Cu alloy was placed in a 1L volume of 0.1mol / L HCl aqueous solution for free corrosion dealloying at 40℃. After 12 hours of corrosion, no obvious bubbles were observed, indicating that dealloying was complete, yielding a hierarchical nanoporous copper alloy, such as... Figure 4 As shown, the volume ratio of macropores is V = 0.59, the macropore diameter is L(W) = 2.1 μm, the pore diameter distribution range is 0.5-10 μm, the micropore diameter is D = 45 nm, the pore diameter range is 20-100 nm, and the overall porosity is P = 0.80.

[0079] (7) Uniaxial tensile mechanical properties were tested on the obtained hierarchical nanoporous copper (sample gauge length: 5mm × 2mm × 1mm (length × width × thickness), strain rate: 1 × 10⁻⁶). -4 s -1 Test equipment: Instron 5982, such as Figure 6 As shown, it exhibits extreme brittleness and fractures at a tensile strain of 0.3%.

[0080] The porous structure parameters and tensile mechanical properties of all the above cases are summarized in Table 1. Comparing Examples 1, 2, and 3, it can be seen that the proportion of polymer materials in the final composite material sample can be controlled by adjusting the precursor alloy composition, thereby affecting its mechanical properties. Comparing Examples 1, 2, and 3 with the comparative cases, it can be seen that the final composite material sample has a greater tensile elongation at break than pure nanoporous copper, indicating better toughness.

[0081] Table 1 Summary of porous structure parameters and tensile mechanical properties in the case studies

[0082]

[0083] Due to their extremely high specific surface area and porous structure, nanoporous metals have significant application value in lithium batteries, electrocatalytic hydrogen production, and driving applications. The polymeric nanoporous copper composite material prepared in this invention is based on hierarchical nanoporous copper, with macropores filled with polymers to improve its tensile plasticity and toughness. Simultaneously, the micropores retain their open-pore structure, and the specific surface area of ​​the structure remains essentially unchanged, having no impact on the application of nanoporous metals in electrocatalytic hydrogen production and driving applications. Referring to the experimental protocol of Q. Bai, et al. Electrochemistry Communications 124(2021)106940, this invention conducted electrochemical driving experiments on the composite material in Example 3 and the hierarchical nanoporous copper in the comparative example, with driving sample sizes of 1×2×2 mm. 3 (As the working electrode), the experiment was conducted in a three-electrode system (Ag / AgCl electrode as the reference electrode, Ag wire as the counter electrode) of an AUTOLAB PASTAT. The electrolyte was 200 mL of 1 mol / L NaOH aqueous solution, and the voltage was varied between 0 and 0.5 V. The results are as follows: Figure 7 As shown, when the voltage cyclically changes within the 0-0.5V range, both the composite material in Example 3 and the hierarchical nanoporous copper in the comparative example can achieve length variations between +0.02% and -0.07%, with a driving amplitude of 0.09%. This demonstrates that the filling of macropores with polymer does not diminish the driving performance of the nanoporous copper. Furthermore, the increased plasticity is beneficial for the application of nanoporous structures in the driving field.

Claims

1. A method for preparing a polymer / nanoporous copper composite material, characterized in that: The method includes the following steps: (1) Prepare a Mn-Cu binary alloy, or prepare copper and manganese and smelt them to prepare a Mn-Cu binary alloy; (2) The Mn-Cu alloy was subjected to homogenization annealing heat treatment to obtain a γ single-phase alloy, and then rolled with a rolling reduction of 50%-99%; (3) The γ single-phase alloy is subjected to recrystallization annealing heat treatment at a temperature of 700-900℃ for a time of 2-60 min; (4) After recrystallization annealing, the γ single-phase alloy is subjected to aging heat treatment to precipitate the α phase and obtain the α / γ dual-phase alloy. (5) The Mn-Cu alloy with α / γ dual-phase structure was placed in a weakly acidic aqueous solution for selective phase corrosion. The α phase was completely corroded to form macropores, while the γ phase was retained to form porous γ-Mn(Cu). (6) Using the vacuum impregnation method, liquid polymer material is immersed in porous γ-Mn(Cu), and after the polymer material is cured, a polymer / γ-Mn(Cu) biphase composite material is formed; (7) The prepared polymer / γ-Mn(Cu) biphase composite material is placed in an acidic aqueous solution for electrochemical corrosion or free chemical corrosion until the Mn element content in the metal phase is less than or equal to 2 at.%, forming nanoscale pores.

2. The preparation method according to claim 1, characterized in that: The rolling reduction in step (2) is 60-98%; the temperature in step (3) is 700-750℃ and the heat treatment time is 10-40min.

3. The preparation method according to claim 1, characterized in that: In step (1), the atomic percentage of Mn content in the Mn-Cu binary alloy is 70%-90%.

4. The preparation method according to claim 3, characterized in that: In step (1), the atomic percentage of Mn content in the Mn-Cu binary alloy is 80%-85%.

5. The preparation method according to claim 1, characterized in that: In step (2), the heat treatment is followed by cooling to room temperature. The heat treatment temperature is 700-900℃, the heat treatment time is 1-100h, and the cooling method is water cooling. A γ single-phase alloy is obtained and rolled. The rolling passes are 5-50 times, and a plate material with a thickness of 0.1mm-10mm is formed after rolling.

6. The preparation method according to claim 5, characterized in that: In step (2), the heat treatment is followed by cooling to room temperature. The heat treatment temperature is 800-900℃, the heat treatment time is 10-50h, and the cooling method is water cooling. A γ single-phase alloy is obtained and rolled. The rolling passes are 10-20 times, and a plate material with a thickness of 0.5-5mm is formed after rolling.

7. The preparation method according to claim 1, characterized in that: In step (3), the γ single-phase alloy undergoes recrystallization annealing, and is then cooled to room temperature by water cooling.

8. The preparation method according to claim 1, characterized in that: In step (4), the γ single-phase alloy after recrystallization annealing is aged and heat-treated to form an α / γ dual-phase structure. The aging heat treatment temperature range is 500-750℃ and the heat treatment time is 0.5-100h. After heat treatment, it is cooled to room temperature by water cooling.

9. The preparation method according to claim 8, characterized in that: In step (4), the aging heat treatment temperature range is 650-700℃, and the heat treatment time is 1-20h.

10. The preparation method according to claim 1 or 8, characterized in that: In step (4), the recrystallized annealed γ single-phase alloy is aged and heat-treated to form an α / γ dual-phase structure. The percentage content of Mn atoms in the α phase is 98%-100%, and the percentage content of Mn atoms in the γ phase is 40%-70%.

11. The preparation method according to claim 1, characterized in that: In step (5), during the selective phase corrosion process, the α phase is completely corroded, while the γ phase is completely preserved or only less than or equal to 20% of the Mn element is lost in the γ phase. The Mn-Cu alloy with α / γ dual-phase structure is placed in a weakly acidic aqueous solution of acetic acid, ascorbic acid, ammonium sulfate, or ammonium chloride at a volume greater than 100 times its volume, with a solution concentration of 0.001-1 mol / L, for selective phase corrosion at a corrosion temperature of 10-50℃ and a corrosion time of 1-200h.

12. The preparation method according to claim 1, characterized in that: In step (6), the liquid polymer material used for impregnation is liquid before curing and solid after curing; The liquid polymer material is a homogeneous mixture of one or more of phenolic resin, epoxy resin, polycarbonate, and polytetrafluoroethylene and their curing agents. The impregnation process has a vacuum degree of 0.01-100Pa, an impregnation temperature of 10-50℃, an impregnation time of 0.5-2h, a curing temperature of 10-380℃, and a curing time of 1-24h.

13. The method for preparing the polymer / nanoporous copper composite material according to claim 1, characterized in that: In step (7), the prepared polymer / γ-Mn(Cu) biphase composite material is placed in an acidic aqueous solution containing one or more of the following: hydrochloric acid, sulfuric acid, phosphoric acid, and oxalic acid, with a solution concentration of 0.001-5 mol / L. Free chemical corrosion or electrochemical corrosion is then performed to remove the alloy until the Mn element content in the metal phase is less than or equal to 2 at.%. The free chemical corrosion temperature is 0℃-80℃, the electrochemical corrosion temperature is 0℃-80℃, and the electrochemical corrosion applied potential is -1V to +0.3V standard electrode potential.

14. A polymer / nanoporous copper composite material prepared by any one of the preparation methods according to claims 1-13, characterized in that: The width of the polymer phase ranges from 0.5 to 10 μm, while the pore diameter of the nanoporous Cu phase ranges from 20 to 100 nm.

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