Surface-modified polyether-ether-ketone, preparation method thereof and metal coating substrate

Abstract

The invention relates to the technical field of surface engineering, and discloses surface-modified polyether-ether-ketone, a preparation method thereof and a metal coating base material. The preparation method comprises the following steps: firstly, forming holes in the surface of polyether-ether-ketone by adopting a non-solvent induced phase separation method; then putting polyether-ether-ketone into a dopamine solution to be treated to obtain polyether-ether-ketone coated with polydopamine; and finally, putting the polyether-ether-ketone into a mixed solution of the carbon nitride loaded silver supramolecules / carbon nitride loaded iron supramolecules and silver nitrate, so that uniformly attached silver / iron particles are formed on the surface of the polyether-ether-ketone. According to the supramolecular self-adsorption treatment method for the silver active particles on the surface of the polyether-ether-ketone, the surface of the polyether-ether-ketone is uniformly coated with a layer of silver / iron active particles with good binding force through supramolecular preparation, dopamine and silver / iron active particle surface modification and other treatments, and the silver / iron active particles serve as a catalytic activity center of chemical plating; and uniform, compact and high-binding-force attachment of the surface coating of the polyether-ether-ketone is realized.

Description

Technical Field

[0001] The present application relates to the technical field of surface engineering, and particularly relates to a surface-modified polyetheretherketone, a preparation method thereof, and a metal-coated substrate. Background Art

[0002] Polyetheretherketone (PEEK) is a semi-crystalline aromatic thermoplastic engineering resin. The macromolecular chain contains a large number of rigid benzene rings, flexible ether bonds, and carbonyl groups that enhance intermolecular forces, endowing it with many excellent properties. For example, excellent high-temperature resistance and chemical corrosion resistance, good mechanical properties, radiation resistance, and self-lubricating and friction-resistant properties, etc. This makes the PEEK material have broad application prospects in the fields of aerospace, electronics, and electrical engineering. However, due to its non-conductive surface, it cannot be used to replace metal materials to achieve functional requirements such as conductivity and welding, and surface metallization treatment is required. Due to the extremely high chemical inertness and hydrophobicity of the PEEK material surface, roughening and activation treatments are required before electroless plating. When using the traditional chromic acid-sulfuric acid solution for chemical roughening and palladium activation treatment, the surface roughening and activation of the PEEK material are uneven, resulting in poor densification and bonding strength of the metal layer after electroless plating. Moreover, due to the difference in the thermal expansion coefficients of the PEEK material and the metal layer material, higher requirements are placed on the interfacial bonding strength between the PEEK material and the metal layer to meet the thermal stability requirements during application. Therefore, it is necessary to find a surface modification method for the PEEK material to improve the bonding strength between the PEEK and the surface coating. Summary of the Invention

[0003] In view of this, the purpose of the present application is to provide a surface-modified polyetheretherketone and a preparation method thereof, so that the bonding strength between the polyetheretherketone and the surface coating is significantly improved and it can withstand high and low temperature environments;

[0004] Another purpose of the present application is to provide a metal-coated substrate based on the above surface-modified polyetheretherketone.

[0005] In order to solve the above technical problems / achieve the above purposes or at least partially solve the above technical problems / achieve the above purposes, as the first aspect of the present application, a preparation method of a surface-modified polyetheretherketone is provided, including:

[0006] S1. Form pores on the surface of polyetheretherketone by non-solvent induced phase separation method;

[0007] S2. Treat the polyetheretherketone in S1 in a dopamine solution to obtain polyetheretherketone coated with polydopamine;

[0008] S3. Provide silver-loaded carbon nitride supramolecules, mix them with a silver nitrate solution to obtain a mixed solution, and place the polyetheretherketone in S2 into the mixed solution to form uniformly attached silver particles on the surface of the polyetheretherketone; or

[0009] Provide iron-loaded carbon nitride supramolecules, mix them with an iron nitrate solution to obtain a mixed solution, and place the polyetheretherketone in S2 into the mixed solution to form uniformly attached iron particles on the surface of the polyetheretherketone.

[0010] Optionally, step S1 includes:

[0011] Treat with concentrated sulfuric acid solution, then immerse in N,N-dimethylformamide solvent and deionized water respectively, stir ultrasonically, and then dry.

[0012] Optionally, the dopamine solution includes dopamine and tris-HCl buffer solution. Further optionally, the pH value of the dopamine solution is 7-9, including 1-3 g / L dopamine and tris-HCl buffer solution.

[0013] Optionally, the silver-loaded carbon nitride supramolecules are prepared as follows:

[0014] Place the mixed solution of citric acid and silver nitrate in an aqueous solution of cyanuric acid, mix well, then place in an aqueous solution of melamine, mix well, then collect by centrifugation and dry; after drying, place in a protective gas atmosphere for high-temperature treatment to obtain silver-loaded carbon nitride supramolecules;

[0015] The iron-loaded carbon nitride supramolecules are prepared as follows:

[0016] Place the mixed solution of citric acid and iron nitrate in an aqueous solution of cyanuric acid, mix well, then place in an aqueous solution of melamine, mix well, then collect by centrifugation and dry; after drying, place in a protective gas atmosphere for high-temperature treatment to obtain silver-loaded carbon nitride supramolecules.

[0017] Further optionally, the concentrations of citric acid and silver nitrate in the mixed solution of citric acid and silver nitrate are 1-2 mmol / L and 0.5-1 mmol / L respectively; the concentration of cyanuric acid in the aqueous solution of cyanuric acid is 20-22 mmol / L; the concentration of melamine in the aqueous solution of melamine is 20-22 mmol / L.

[0018] Optionally, step S3 includes:

[0019] Add silver-loaded carbon nitride supramolecules to a silver nitrate solution and mix, place the polyetheretherketone coated with polydopamine obtained in S2 into the mixed solution, mix well under dark conditions, then freeze-dry and dry to form uniformly attached silver particles on the surface of the polyetheretherketone.

[0020] Optionally, the polyetheretherketone includes unmodified polyetheretherketone, carbon nanotube modified polyetheretherketone, carbon fiber modified polyetheretherketone, and glass fiber modified polyetheretherketone.

[0021] As a second aspect of the present application, there is provided a surface-modified polyetheretherketone prepared by the preparation method.

[0022] As a third aspect of the present application, there is provided a metal-coated substrate, including the surface-modified polyetheretherketone of the present application and a metal coating plated on the surface of the surface-modified polyetheretherketone.

[0023] The present application provides a method for supermolecular self-adsorption treatment of silver active particles on the surface of polyetheretherketone. Through treatments such as supramolecular preparation, dopamine and silver active particle surface modification, a layer of silver active particles with good bonding force is uniformly coated on the surface of polyetheretherketone, serving as the catalytic active center for electroless plating, and realizing uniform and dense surface plating and high bonding force attachment of polyetheretherketone. Description of the Drawings

[0024] Figure 1 Shown is the network-like pore structure formed on the surface of polyetheretherketone after sulfuric acid treatment;

[0025] Figure 2 Shown are the contact angle test results of the surface of polyetheretherketone without any treatment (A) and the surface of polyetheretherketone after sulfuric acid treatment (B); the contact angle of A is 83.2°, and the contact angle of B is 115.7°;

[0026] Figure 3 Shown are the microscopic structure of the surface of polyetheretherketone coated with polydopamine and the contact angle test (contact angle 43.4°);

[0027] Figure 4 Shown is the transmission electron microscope image of silver supramolecule supported on carbon nitride;

[0028] Figure 5 Shown is the EDS spectrum of silver attached to the surface of polyetheretherketone;

[0029] Figure 6 Shown are the microscopic results of silver attached to the surface of polyetheretherketone; A: concentration of silver nitrate solution is 2 mol / L, B: concentration of silver nitrate solution is 6 mol / L;

[0030] Figure 7 Shown is the SEM image of the surface of polyetheretherketone after electroless copper plating treated by Example 1;

[0031] Figure 8 Shown is the result of the cross-cut test after the thermal shock test of the copper plating layer in Example 2 from 200 °C to cold water;

[0032] Figure 9 The figure shows the results of the thermal cycling test of the copper plating layer at -196°C to +120°C in Example 2;

[0033] Figure 10 The figure shows the SEM image of the surface of the conventional polyetheretherketone after copper plating in Comparative Example 1;

[0034] Figure 11 The figure shows the results of the cross-cut test after the thermal shock test of the copper plating layer in Comparative Example 1 from 200°C to cold water;

[0035] Figure 12 The figure shows the results of the thermal cycling test of the copper plating layer at -196°C to +120°C in Comparative Example 1;

[0036] Figure 13 The figure shows the SEM image of the surface of Comparative Example 2 after copper plating;

[0037] Figure 14 The figure shows the results of the cross-cut test after the thermal shock test of the copper plating layer in Comparative Example 2 from 200°C to cold water;

[0038] Figure 15 The figure shows the test results of the microscopic morphology of silver attached to the surface of polyetheretherketone in Comparative Example 3;

[0039] Figure 16 The figure shows the test results of the microscopic morphology of the copper plating layer on the surface of polyetheretherketone in Comparative Example 3. Detailed implementation manners

[0040] This application discloses a surface-modified polyetheretherketone, its preparation method and a metal-coated substrate. Those skilled in the art can draw on the content of this article and appropriately modify the process parameters to achieve it. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they are all regarded as included in this application. The products, processes and applications described in this application have been described through preferred embodiments. Relevant personnel can obviously make changes or appropriate changes and combinations to the processes and applications described in this article without departing from the content, spirit and scope of this application to implement and apply the technology of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts belong to the scope of protection of this application.

[0041] It should be noted that in this text, relational terms such as "first" and "second", "step 1" and "step 2", and "(1)" and "(2)" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element. At the same time, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0042] In a first aspect of the present application, a method for preparing a surface-modified polyetheretherketone is provided, comprising:

[0043] S1. Forming pores on the surface of polyetheretherketone by non-solvent induced phase separation method;

[0044] S2. Placing the polyetheretherketone in step S1 into a dopamine solution for treatment to obtain polyetheretherketone coated with polydopamine;

[0045] S3. Providing a carbon nitride-supported silver supramolecule, mixing it with a silver nitrate solution to obtain a mixed solution, and placing the polyetheretherketone in step S2 into the mixed solution to form uniformly attached silver particles on the surface of the polyetheretherketone; or

[0046] Providing a carbon nitride-supported iron supramolecule, mixing it with an iron nitrate solution to obtain a mixed solution, and placing the polyetheretherketone in step S2 into the mixed solution to form uniformly attached iron particles on the surface of the polyetheretherketone.

[0047] In some embodiments of the present application, step S1 includes:

[0048] Treating with a concentrated sulfuric acid solution, immersing in N,N-dimethylformamide solvent and deionized water respectively after treatment, ultrasonic stirring, and then drying. See Figure 1 and Figure 2 , a large number of microscopic pores are formed on the surface of the polyetheretherketone after sulfuric acid roughening to form capillaries. Since water does not wet the surface of the polyetheretherketone, the apparent contact angle of the polyetheretherketone surface increases under the action of the capillaries (115.7°), but the polyetheretherketone molecules undergo sulfonation with sulfuric acid, generating charged sulfonic acid groups on the polyetheretherketone molecular chain; the surface of the polyetheretherketone changes from high chemical inertness to a surface with relatively high chemical activity, thus facilitating the surface binding with subsequent dopamine molecules.

[0049] In certain embodiments of the present application, the dopamine solution includes dopamine and a tris-HCl buffer solution. Specifically, the pH value of the dopamine solution is 7-9, and it includes 1-3 g / L of dopamine and the tris-HCl buffer solution. See Figure 3 , after coating with polydopamine, due to the large number of hydrophilic catechol groups and amino groups on the surface of polydopamine, the hydrophilicity of the polyether ether ketone surface is improved, the contact angle is reduced, which is beneficial to the subsequent wetting of the polyether ether ketone surface by the silver nitrate activation solution and the electroless copper plating solution. At the same time, granular protrusions appear on the surface of the polyether ether ketone coated with polydopamine, and the surface becomes rougher, thereby increasing the active specific surface area of the subsequent titanium nitride-supported silver supramolecule or carbon nitride-supported iron supramolecule, and increasing the effective loading amount of silver active particles or iron active particles.

[0050] In certain embodiments of the present application, the carbon nitride-supported silver supramolecule is prepared by the following method:

[0051] A mixed solution of citric acid and silver nitrate is placed in an aqueous solution of cyanuric acid, mixed well, then placed in an aqueous solution of melamine, mixed well, and then centrifuged and collected, and dried; after drying, it is heat-treated in a protective gas atmosphere to obtain a carbon nitride-supported silver supramolecule, and its transmission electron microscope image is shown in Figure 4 .

[0052] The preparation method of the carbon nitride-iron supramolecule is prepared by referring to the preparation method of the carbon nitride-supported silver supramolecule:

[0053] A mixed solution of citric acid and iron nitrate is placed in an aqueous solution of cyanuric acid, mixed well, then placed in an aqueous solution of melamine, mixed well, and then centrifuged and collected, and dried; after drying, it is heat-treated in a protective gas atmosphere to obtain a carbon nitride-supported iron supramolecule.

[0054] Carbon nitride has an ultra-high nitrogen atom content and good coordination ability between nitrogen atoms and metal atoms, and is a good metal single-atom carrier. The supramolecule formed by hydrogen bond self-assembly can evenly distribute Ag / Fe atoms, control the content of Ag / Fe atoms, increase the surface area of carbon nitride, thereby achieving better dispersion and higher loading rate of Ag / Fe atoms. The introduction of single-atom Ag / Fe does not affect the structure of carbon nitride.

[0055] Taking the carbon nitride-supported silver supramolecule as an example, it is the main source of silver active particles in the present application. Single-atom silver can achieve 100% atomic utilization rate, and the catalytic active site density is high, which can maximize the active effect of silver. When using a silver nitrate solution alone for activation, the adsorption uniformity of silver is lower than that of using a carbon nitride supramolecule, and the effect is also not as high as that of single-atom catalysis.

[0056] In some other embodiments of the present application, the concentrations of citric acid and silver nitrate in the mixed solution of citric acid and silver nitrate are 1-2 mmol / L (such as 1 mmol / L, 1.5 mmol / L, 2 mmol / L, etc.) and 0.5-1 mmol / L (0.5 mmol / L, 0.75 mmol / L, 1 mmol / L, etc.) respectively; the concentration of cyanuric acid in the aqueous solution of cyanuric acid is 20-22 mmol / L, such as 20 mmol / L, 21 mmol / L, 22 mmol / L, etc.

[0057] In some embodiments of the present application, step S3 includes:

[0058] Adding the silver-loaded supramolecular carbon nitride to the silver nitrate solution for mixing, placing the polyetheretherketone coated with polydopamine obtained in S2 in the mixed solution, fully mixing under light-shielded conditions, and then freeze-drying and drying to form uniformly attached silver particles on the surface of the polyetheretherketone. See Figure 5 the EDS detection spectrum of Figure 6 and the micrograph of the polyetheretherketone after silver attachment, indicating that silver particles have been attached to the surface of the polyetheretherketone.

[0059] In some other embodiments of the present application, the concentration of silver nitrate in the mixed solution of the silver-loaded supramolecular carbon nitride and silver nitrate is 2-6 mol / L, and the concentration of the silver-loaded supramolecular carbon nitride is 0.02-0.05 mol / L, such as 0.02 mol / L, 0.03 mol / L, 0.04 mol / L, 0.05 mol / L, etc.

[0060] In some embodiments of the present application, the polyetheretherketone includes unmodified polyetheretherketone, carbon nanotube-modified polyetheretherketone, carbon fiber-modified polyetheretherketone, and glass fiber-modified polyetheretherketone.

[0061] In the second aspect of the present application, a surface-modified polyetheretherketone prepared by the preparation method is provided.

[0062] In the third aspect of the present application, a metal-coated substrate is provided, including the surface-modified polyetheretherketone of the present application and a metal coating plated on the surface of the surface-modified polyetheretherketone.

[0063] In some embodiments of the present application, the metal coating is a copper coating using an electroless plating process; electroless copper plating is performed on the surface of the surface-treated polyetheretherketone. The coating is uniform and dense, the tensile strength of the coating solder joint is ≥7 MPa, it can withstand the thermal cycle test of -196°C to +120°C, and the metal coating on the surface of the polyetheretherketone still maintains good bonding strength in a wide temperature range environment. At the same time, a thermal shock experiment of 200°C to cold water is performed on the copper plating layer. After the thermal shock experiment, a cross-cut test is performed on the coating. It can be seen from the metallurgical microscope that the cross-cut boundary of the coating is neat, indicating that the coating adhesion is relatively good.

[0064] In each group of comparative experiments provided in this application, unless otherwise specified, except for the differences pointed out in each group, other experimental conditions, materials, etc. are kept consistent to ensure comparability. The experimental materials and reagents used in the examples can be obtained from commercial channels unless otherwise specified.

[0065] The following further describes a surface-modified polyetheretherketone, its preparation method, and a metal-plated substrate provided in this application.

[0066] Example 1:

[0067] (1) Treat polyetheretherketone by nonsolvent-induced phase separation

[0068] Treat polyetheretherketone with concentrated sulfuric acid solution for 1 - 3 min. After treatment, immerse it in N,N-dimethylformamide (DMF) solvent and deionized water respectively, stir ultrasonically for 10 min, and then dry it.

[0069] (2) Coating with dopamine

[0070] Prepare a dopamine solution with a concentration of 2 g / L and a pH of 8.5 using tris-HCl buffer solution (where the tris concentration is 10 mmol / L). Vertically immerse the polyetheretherketone treated in step (1) into the dopamine solution, stir at room temperature for 24 h. Under the action of oxygen, dopamine undergoes self-oxidative polymerization to coat a layer of polydopamine on the surface of polyetheretherketone. Then place it in a vacuum oven at 60 - 80 °C and dry for 6 - 8 h to obtain polyetheretherketone coated with polydopamine.

[0071] (3) Prepare silver-loaded supramolecular carbon nitride

[0072] Place the mixed solution of citric acid and silver nitrate (the concentrations of citric acid and silver nitrate are 1 - 2 mmol / L and 0.5 - 1 mmol / L respectively) in an aqueous solution of cyanuric acid (20 - 22 mmol / L), stir ultrasonically for 10 - 15 min, then place it in an aqueous solution of melamine (20 - 22 mmol / L), stir ultrasonically for 4 - 5 h, then collect by centrifugation, and place it in a vacuum oven at 60 - 80 °C and dry for 24 - 26 h. After drying, place it in an argon flow, and perform high-temperature treatment at 650 - 700 °C for 4 - 6 h to obtain silver-loaded supramolecular carbon nitride.

[0073] (4) Polyetheretherketone loaded with silver particles

[0074] Add the silver-loaded carbon nitride supramolecule to a silver nitrate solution (2 - 6 mol / L) and mix. Place the polyetheretherketone coated with polydopamine obtained in step (2) into the mixed solution, stir for 2 - 3 h under dark conditions, then place it in a freeze dryer for 24 h to remove moisture, and then place it in a vacuum oven at 180 - 200 °C for 2 h to obtain silver particles evenly attached to the surface of the polyetheretherketone.

[0075] Example 2:

[0076] Perform electroless copper plating on the polyetheretherketone treated in Example 1. The electroless copper plating solution contains the following components: copper sulfate 6 g / L, formaldehyde 12 mL / L, potassium hydroxide 2 g / L, sodium potassium tartrate 28 g / L, and stabilizer 0.2 mg / L.

[0077] During electroless copper plating, the solution temperature is 30 °C - 36 °C, and the electroless copper plating time is 100 - 120 min. After the copper plating is completed, perform the surface mount pad pull-off strength test according to 5.3.3.2 in the test method for multi-layer printed circuit boards for aerospace QJ832B - 2011.

[0078] Figure 7 The results show that for the surface of the polyetheretherketone after surface treatment, the electroless copper plating layer is uniform and dense, and the pull-off strength of the plating layer solder joints is ≥ 7 MPa;

[0079] Perform a thermal shock experiment on the copper plating layer from 200 °C to cold water. After the thermal shock test, perform a cross-cut test on the plating layer. Using a metallurgical microscope, it can be seen that the cross-cut boundary of the plating layer is neat ( Figure 8 ), indicating that the adhesion of the plating layer is relatively good. Further test the adhesion of the plating layer using a -196 °C to +120 °C thermal cycling test. After 10 thermal cycles, there are no phenomena such as peeling, blistering, and falling off of the plating layer ( Figure 9 ), indicating that it can withstand the -196 °C to +120 °C thermal cycling test, and the metal plating layer on the surface of the polyetheretherketone still maintains good bonding strength in a wide temperature range environment.

[0080] Comparative Example 1:

[0081] This comparative example is a conventional polyetheretherketone copper plating process

[0082] Provide a substrate of polyetheretherketone material. Then, clean the surface of the polyetheretherketone material with anhydrous ethanol to remove surface oil stains, and then perform roughening treatment on the degreased polyetheretherketone material using a chemical roughening method. The chemical roughening solution includes the following components: sulfuric acid 300 mL / L, chromium trioxide 100 g / L. The chemical roughening treatment temperature is 60 °C, and the chemical roughening treatment time is 20 min.

[0083] The activated and reduced polyetheretherketone (PEEK) materials after chemical roughening are processed. The activation is carried out using a palladium chloride solution with a PdCl₂ concentration of 0.2 g / L for 30 s. Then, the reduction treatment is carried out. The reduction treatment solution is a sodium hypophosphite solution with a Na₂H₂PO₂ concentration of 18 - 22 g / L for 1 min. The surface electroless copper plating treatment is carried out on the activated and reduced PEEK, and the process is the same as that in Example 2.

[0084] The performance of the copper plating layer is tested, such as Figure 10 and Figure 11 shown. The surface uniformity of the copper plating layer is poor. A thermal shock experiment of 200 °C - cold water is carried out on the copper plating layer. After the thermal shock test, a cross-cut test is carried out on the coating. It can be seen by using a metallurgical microscope that the cross-cut boundary of the coating is uneven, indicating that the adhesion of the coating is relatively poor.

[0085] The adhesion of the coating is further tested by a thermal cycle test of -196 °C - +120 °C ( Figure 12 ). After 10 thermal cycles, peeling and falling off phenomena occur on the coating, further indicating poor adhesion of the coating.

[0086] Comparative Example 2:

[0087] The process of this Comparative Example 2 refers to Example 1, with the difference that silver-loaded supramolecular on carbon nitride is not used;

[0088] (1) Treatment of PEEK by non-solvent induced phase separation

[0089] PEEK is treated with concentrated sulfuric acid solution for 1 - 3 min. After treatment, it is immersed in N,N-dimethylformamide (DMF) solvent and deionized water respectively, ultrasonic stirred for 10 min, and then dried.

[0090] (2) Coating with dopamine

[0091] A dopamine solution with a concentration of 2 g / L and a pH of 8.5 is prepared with tris-HCl buffer solution (where the tris concentration is 10 mmol / L). The PEEK treated in step (1) is vertically immersed in the dopamine solution and stirred at room temperature for 24 h. Dopamine forms a layer of polydopamine on the surface of PEEK through self-oxidative polymerization under the action of oxygen. Then, it is placed in a vacuum oven at 60 - 80 °C and dried for 6 - 8 h to obtain PEEK coated with polydopamine.

[0092] (3) The polyetheretherketone coated with polydopamine obtained in step (2) was placed in a silver nitrate solution (2 - 6 mol / L) for treatment, and then the activated polyetheretherketone material was subjected to a reduction treatment. The reduction treatment solution was a sodium hypophosphite solution with a Na2H2PO2 concentration of 18 - 22 g / L and a reduction time of 1 min. The activated and reduced polyetheretherketone was subjected to electroless copper plating on the surface, and the process was the same as in Example 2.

[0093] The performance of the copper plating layer was tested, such as Figure 13 and 14 As shown, the surface uniformity of the copper plating layer was poor. A thermal shock experiment of 200 °C - cold water was carried out on the copper plating layer. After the thermal shock test, a cross-cut test was carried out on the plating layer. It can be seen from the metallurgical microscope that the cross-cut boundary of the plating layer was uneven, indicating that the bonding force of the plating layer was relatively poor. The tensile strength of the plating layer solder joint was tested, and the measured tensile strength of the plating layer solder joint was 1.02 MPa, which was much lower than the tensile strength of the plating layer solder joint after using carbon nitride-loaded supramolecular particles.

[0094] Comparative Example 3:

[0095] The process of this comparative example referred to Example 1, and the difference was that the concentrations of citric acid and silver nitrate were different when preparing carbon nitride-loaded silver supramolecules;

[0096] (1) Treating polyetheretherketone by non-solvent induced phase separation

[0097] The polyetheretherketone was treated with concentrated sulfuric acid solution for 1 - 3 min, and after treatment, it was immersed in N,N-dimethylformamide (DMF) solvent and deionized water respectively, ultrasonically stirred for 10 min, and then dried.

[0098] (2) Coating with dopamine

[0099] A dopamine solution with a concentration of 2 g / L and a pH of 8.5 was prepared with tris-HCl buffer solution (where the tris concentration was 10 mmol / L). The polyetheretherketone treated in step (1) was vertically immersed in the dopamine solution and stirred at room temperature for 24 h. Dopamine was coated with a layer of polydopamine on the surface of the polyetheretherketone through self-oxidative polymerization under the action of oxygen. Then it was placed in a vacuum oven at 60 - 80 °C and dried for 6 - 8 h to obtain polyetheretherketone coated with polydopamine.

[0100] (3) Preparing carbon nitride-loaded silver supramolecules

[0101] A mixed solution of citric acid and silver nitrate (the concentrations of citric acid and silver nitrate are 10 - 20 mmol / L and 5 - 10 mmol / L respectively) is placed in an aqueous solution of cyanuric acid (20 - 22 mmol / L), ultrasonically stirred for 10 - 15 min, then placed in an aqueous solution of melamine (20 - 22 mmol / L), ultrasonically stirred for 4 - 5 h, then centrifuged and collected, and dried in a vacuum oven at 60 - 80 °C for 24 - 26 h. After drying, it is placed in an argon stream and heat-treated at 650 - 700 °C for 4 - 6 h to obtain silver-loaded carbon nitride supramolecules.

[0102] (4) Silver-loaded polyetheretherketone microparticles

[0103] The silver-loaded carbon nitride supramolecules are added to a silver nitrate solution (2 - 6 mol / L) and mixed. The polyetheretherketone coated with polydopamine obtained in step (2) is placed in the mixed solution, stirred for 2 h - 3 h under light-shielded conditions, then placed in a freeze dryer for 24 h to remove moisture, and then placed in a vacuum oven at 180 - 200 °C for 2 h to obtain silver microparticles uniformly attached to the surface of polyetheretherketone.

[0104] Microscopic tests were carried out on the silver-loaded carbon nitride supramolecules, and the results are shown in Figure 15 , silver agglomerated and was not distributed on the surface of carbon nitride in the form of single atoms.

[0105] The polyetheretherketone after step (4) is electrolessly copper-plated, and the process is the same as in Example 2.

[0106] Performance tests were carried out on the copper-plated layer as follows Figure 16 As shown, the surface uniformity of the copper-plated layer is poor. A thermal shock experiment of 200 °C - cold water was carried out on the copper-plated layer, and the coating bulged after the thermal shock test.

[0107] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for preparing a surface-modified polyetheretherketone, characterized in that: include: S1. Forming pores on the surface of polyetheretherketone by non-solvent induced phase separation method; S2. The polyetheretherketone in S1 is placed in a dopamine solution to obtain a polyetheretherketone coated with polydopamine; S3 provides a carbon nitride-supported silver supramolecule, which is mixed with a silver nitrate solution to obtain a mixed solution, and the polyetheretherketone in S2 is placed in the mixed solution to form uniformly attached silver particles on the surface of the polyetheretherketone; or Providing carbon nitride loaded iron supramolecules, mixing the carbon nitride loaded iron supramolecules with a ferric nitrate solution to obtain a mixed solution, placing the polyetheretherketone in S2 in the mixed solution, and forming uniformly attached iron particles on the surface of the polyetheretherketone.

2. The preparation method according to claim 1, characterized in that: Step S1 includes: The treated product was treated with a concentrated sulfuric acid solution, and then immersed in an N,N-dimethylformamide solvent and deionized water respectively, ultrasonically stirred, and then dried.

3. The preparation method according to claim 1, characterized in that: The dopamine solution comprises dopamine and a tris-HCl buffer solution.

4. The preparation method according to claim 1 or 3, characterized in that: The dopamine solution has a pH value of 7-9 and comprises 1-3 g / L dopamine and a tris-HCl buffer solution.

5. The preparation method according to claim 1, characterized in that: The carbon nitride-supported silver supramolecule is prepared according to the following method: The mixed solution of citric acid and silver nitrate is placed in a cyanuric acid aqueous solution, fully mixed, then placed in a melamine aqueous solution, fully mixed, then centrifuged and collected, and dried; after drying, placed in a protective gas atmosphere for high temperature treatment to obtain carbon nitride-supported silver supramolecules; The carbon nitride-supported iron supramolecule is prepared according to the following method: The mixed solution of citric acid and ferric nitrate is placed in a cyanuric acid aqueous solution, fully mixed, then placed in a melamine aqueous solution, fully mixed, then centrifuged and collected, and dried; after drying, it is placed in a protective gas atmosphere for high-temperature treatment to obtain carbon nitride-loaded silver supramolecules.

6. The preparation method according to claim 5, characterized in that: The concentrations of citric acid and silver nitrate in the mixed solution of citric acid and silver nitrate are 1-2 mmol / L and 0.5-1 mmol / L respectively; the concentration of cyanuric acid in the cyanuric acid aqueous solution is 20-22 mmol / L; and the concentration of melamine in the melamine aqueous solution is 20-22 mmol / L.

7. The preparation method according to claim 1, characterized in that: Step S3 includes: The carbon nitride-loaded silver supramolecules are added to the silver nitrate solution and mixed. The polyetheretherketone coated with polydopamine obtained in S2 is placed in the mixed solution, mixed under light-proof conditions, and then freeze-dried and dried to form uniformly attached silver particles on the surface of the polyetheretherketone.

8. The preparation method according to claim 1, characterized in that: The polyetheretherketone includes unmodified polyetheretherketone, carbon nanotube modified polyetheretherketone, carbon fiber modified polyetheretherketone and glass fiber modified polyetheretherketone.

9. The surface-modified polyetheretherketone prepared by the preparation method according to any one of claims 1 to 8.

10. A metal-plated substrate, characterized in that: The invention comprises the surface-modified polyetheretherketone as claimed in claim 9 and a metal coating plated on the surface of the surface-modified polyetheretherketone.

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