PEEK surface hydroxylation graphite film modification method

Abstract

The invention discloses a PEEK surface hydroxylation graphite film modification method, and particularly relates to the technical field of integrated circuit manufacturing. The method comprises the following specific steps: firstly, carrying out ultrasonic cleaning on a PEEK substrate by using acetone and absolute ethyl alcohol, polishing the PEEK substrate by using diamond grinding paste, and then activating the PEEK substrate by using argon plasma; then, ultraviolet and ozone combined treatment is adopted, hydroxyl is introduced to the surface of PEEK under the atmosphere of ultraviolet light of 185 / 254 nm and humid ozone, and a PEEK-OH active layer is formed; dispersing graphene oxide in a sodium borate buffer solution, and then adding a silane coupling agent KH560 to form a uniform dispersion solution; then graphene oxide and KH560 are synchronously deposited on the surface of hydroxylated PEEK at a constant potential through electrochemical deposition; and finally, carrying out vacuum drying, and carrying out heat treatment under the protection of argon to promote interface covalent bonding and partial thermal reduction of the graphene oxide.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit manufacturing technology, and to a method for modifying PEEK surfaces with hydroxylated graphite films. Background Technology

[0002] Polyetheretherketone (PEEK), a high-performance specialty engineering plastic, exhibits great application potential in aerospace, medical devices, and electronic components due to its excellent mechanical strength, high-temperature resistance, chemical corrosion resistance, and inherent insulation properties. Especially in the field of integrated circuit manufacturing technology, the development of high-frequency, high-power devices has placed higher demands on the comprehensive performance of packaging and substrate materials, making PEEK one of the ideal alternatives to traditional materials such as epoxy resins.

[0003] However, PEEK's inherent chemical inertness and low surface energy make it difficult to form strong and stable interfaces with other functional materials, severely limiting its application in functional scenarios requiring surface conductivity, heat dissipation, or electromagnetic shielding. To overcome this bottleneck, existing technologies typically employ wet chemical methods such as concentrated sulfuric acid sulfonation to hydroxylate the PEEK surface, aiming to introduce active functional groups. While these methods can achieve some surface modification, the severe acid corrosion inevitably leads to the breakage of macromolecular chains on the PEEK surface, forming a fragile degradation layer with a loose structure and low cohesive strength. This fragile layer not only fails to provide a stable substrate for subsequent functional layers but also, due to its severely deteriorated mechanical properties and chemical stability, causes the modified PEEK to face three core challenges: weak interfacial bonding, easy interruption of conductive pathways, and poor long-term chemical stability.

[0004] In other words, existing technologies struggle to construct a functionalized layer on the surface of PEEK that simultaneously achieves high-strength interfacial bonding, excellent conductivity, and long-term chemical stability without compromising the superior properties of the PEEK matrix. This technological bottleneck severely limits the application of PEEK in high-end fields such as integrated circuits. Therefore, developing a novel, green modification method that balances efficient surface modification with material bulk protection has become a critical technical problem urgently needing to be solved in this field. Summary of the Invention

[0005] To overcome the above-mentioned defects of the prior art, embodiments of the present invention provide a method for modifying PEEK surface with hydroxylated graphite film, which solves the problem that traditional PEEK modification will damage the bulk properties of PEEK, and that it is difficult to achieve high-strength bonding, conductivity and high chemical stability on the PEEK surface at the same time.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for modifying PEEK surface with hydroxylated graphite film specifically includes the following steps: S1: The PEEK substrate is ultrasonically cleaned with acetone and anhydrous ethanol for 15 minutes in sequence to completely remove surface organic matter and grease. Then it is rinsed with deionized water, dried, and mechanically polished with diamond polishing paste until the surface is smooth. S2: Treat the surface with argon plasma in a vacuum chamber for 5 minutes to further activate the surface and remove residual contaminants; S3: Place the pretreated PEEK sample in a combined ultraviolet and ozone treatment device. Under normal pressure, irradiate the sample surface with a high-intensity ultraviolet light source while simultaneously introducing moist ozone gas. The treatment time is 10–60 minutes, allowing hydroxyl groups to be introduced into the PEEK surface under the synergistic effect of photochemical and ozone oxidation. , forming surface activated This enables simultaneous covalent bonding of silane coupling agents with the PEEK surface and graphene oxide; S4: Disperse graphene oxide in sodium borate buffer solution and sonicate for 2 hours. After a uniform graphene oxide dispersion is formed, add silane coupling agent KH560 and stir to mix evenly. S5: Hydroxylated PEEK was used as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl electrode as the reference electrode. Electrochemical deposition was then performed at a constant potential. After the deposition was complete, the sample was gently rinsed with deionized water to remove loose particles that were physically adsorbed. S6: The deposited sample is placed in a vacuum drying oven for treatment to remove moisture and promote KH560 curing, and then heated and held under argon protection.

[0007] Preferably, the main component of the PEEK substrate in S1 is a semi-crystalline linear aromatic polymer, chemically known as polyether ether ketone.

[0008] Preferably, the particle size of the diamond polishing paste used in S1 decreases from 10 μm to 1 μm.

[0009] Preferably, the power of the plasma treatment in the vacuum chamber of S2 is 50-100W and the vacuum degree is 10-50 Pa.

[0010] Preferably, the wavelength of the high-intensity ultraviolet light source in S3 is 185 / 254nm.

[0011] Preferably, in the S3 ultraviolet ozone combined treatment equipment, 50-200 ppm of ozone and air with a humidity of 40-80%RH are added.

[0012] Preferably, in step S4, 1.0 wt% of silane coupling agent KH560 is added to the uniform graphene oxide dispersion.

[0013] Preferably, in S4, the graphene oxide is dispersed in a sodium borate buffer solution with pH 9.0±0.5 and 0.025M and ultrasonically treated for 2 hours to form a graphene oxide concentration of 1.0 g / L.

[0014] Preferably, deposition is performed in S5 at a constant potential of -1.2 V for 300 seconds.

[0015] Preferably, in step S6, the deposited sample is placed in a vacuum drying oven at 80±10℃ for 2 hours and then heated to 250±10℃ under an argon atmosphere for 1 hour.

[0016] The technical effects and advantages of the present invention regarding the modification method of PEEK surface hydroxylated graphite film are as follows: 1. This invention employs a synergistic mechanism of ultraviolet light excitation and ozone oxidation, belonging to photochemical surface modification. 185nm ultraviolet light can break down ozone in the air. Ozone is generated when 254nm ultraviolet light excites the benzene ring structure on the PEEK surface, making it easier for it to decompose with ozone. Free radical reactions enable mild and controllable hydroxylation.

[0017] 2. In this invention, graphene oxide carries a negative charge during the electrochemical deposition and simultaneous modification of graphite-like films. Under the action of an electric field, it is deposited onto the PEEK surface. At the same time, the silanoxy end of the KH560 molecule in the solvent undergoes hydrolysis and condensation with the hydroxyl groups on the PEEK surface and the oxygen-containing functional groups on the graphene oxide to form Si-OC covalent bonds, thereby achieving simultaneous chemical grafting.

[0018] 3. In this invention, the deposited sample is heated to 250°C and held at that temperature for 1 hour under argon protection. This method can enhance the interfacial bonding force between the components and achieve partial thermal reduction of graphene oxide to improve the conductivity of the sample.

[0019] 4. In this invention, hydroxylation does not require the use of concentrated sulfuric acid sulfonation, which avoids damage to the PEEK bulk structure caused by concentrated sulfuric acid. At the same time, the silane coupling agent KH560 achieves chemical bridging during the deposition process, forming a stable covalent bond interface of PEEK-OH-KH560 type graphite film, overcoming the problem of uneven dispersion between fillers. Attached Figure Description

[0020] Figure 1 This is the chemical formula of the PEEK monomer proposed in this invention; Figure 2 This is a flowchart of a method for modifying PEEK surface hydroxylated graphite film according to the present invention. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0023] Example 1 This embodiment provides a method for modifying a PEEK surface with a hydroxylated graphite film, the specific implementation steps of which include: Experimental materials: PEEK, acetone, anhydrous ethanol, argon, graphene oxide, KH560, and platinum sheet were used as the counter electrode and the Ag / AgCl electrode.

[0024] Experimental objective: A graphite-like film layer was constructed on the PEEK surface by combining physical and chemical multi-step processing techniques.

[0025] Experimental steps: S1: The PEEK substrate is ultrasonically cleaned with acetone and anhydrous ethanol for 15 minutes in sequence to completely remove surface organic matter and grease. Then, it is rinsed with deionized water, dried, and mechanically polished with diamond polishing paste with a particle size decreasing from 10 to 1 μm until the surface is smooth. S2: Treat the surface with argon plasma at a power of 100W and a vacuum degree of 10Pa for 5 minutes in a vacuum chamber to further activate the surface and remove residual contaminants; S3: Place the pretreated PEEK sample in a combined ultraviolet and ozone treatment device. Under normal pressure, irradiate the sample surface with a high-intensity ultraviolet light source with wavelengths of 185nm / 254nm, while simultaneously introducing air containing 200ppm ozone at 80% RH. The treatment time is 60 minutes, allowing hydroxyl groups to be introduced into the PEEK surface under the synergistic effect of photochemical and ozone oxidation. , forming surface activated ; S4: Disperse 0.1g of graphene oxide in 100mL of sodium borate buffer solution with pH 9.0 and sonicate for 2 hours. After a uniform graphene oxide dispersion is formed, add 1.0wt% of silane coupling agent KH560 and stir to mix evenly. S5: Hydroxylated PEEK was used as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The electrode was then deposited at a constant potential of -1.2V for 300 seconds. After the deposition was complete, the sample was gently rinsed with deionized water to remove loosely adsorbed particles. S6: Place the deposited sample in a vacuum drying oven at 80°C for 2 hours to remove moisture and promote KH560 curing, then heat to 250°C under argon protection and hold for 1 hour.

[0026] Experimental results: See Table 1 for details.

[0027] Table 1: Test Results of Example 1

[0028] Example 1 achieved the optimal overall effect of high-performance graphite-like film modification on PEEK surfaces by precisely controlling multi-step process parameters. This example employed argon plasma pretreatment with 100W power and 10Pa vacuum to effectively activate the PEEK surface and remove contaminants, providing abundant reaction sites for subsequent hydroxylation. Subsequently, the synergistic effect of 185nm / 254nm dual-band ultraviolet light and air containing moderate concentrations of ozone and humidity was utilized, referencing... Figure 1 The chemical formula of PEEK was determined, and the method described in Example 1 was used to efficiently excite the benzene ring of PEEK and promote its oxidation. The generation of free radicals enabled mild and high-density hydroxylation of the surface, laying the foundation for a strong interfacial bond. During the electrochemical deposition process, graphene oxide was uniformly deposited under the action of an electric field. At the same time, the silane coupling agent KH560 underwent hydrolysis and condensation with the hydroxyl groups on the PEEK surface and the oxygen-containing functional groups of graphene oxide, forming a stable Si-OC covalent bond bridging interface in situ. Finally, after vacuum drying at 80℃ and heat treatment under argon protection at 250℃, not only was the full curing and interfacial cross-linking of KH560 promoted, but also the partial thermal reduction of graphene oxide was achieved, thereby significantly enhancing the interfacial bond, improving conductivity, and ensuring excellent chemical stability and hydrophilicity.

[0029] Example 2 This embodiment provides a method for modifying a PEEK surface with a hydroxylated graphite film, the specific implementation steps of which include: Experimental materials: PEEK, acetone, anhydrous ethanol, argon, graphene oxide, KH560, and platinum sheet were used as the counter electrode and the Ag / AgCl electrode.

[0030] Experimental objective: The effects of varying the processing power and vacuum level of argon plasma in the vacuum chamber on the activation of PEEK surfaces and the removal of residual contaminants were investigated.

[0031] Experimental steps: S1: The PEEK substrate is ultrasonically cleaned with acetone and anhydrous ethanol for 15 minutes in sequence to completely remove surface organic matter and grease. Then, it is rinsed with deionized water, dried, and mechanically polished with diamond polishing paste with a particle size decreasing from 10 to 1 μm until the surface is smooth. S2: Treat the surface with argon plasma at a power of 50W and a vacuum degree of 50Pa for 5 minutes in a vacuum chamber to further activate the surface and remove residual contaminants; S3: Place the pretreated PEEK sample in a combined ultraviolet and ozone treatment device. Under normal pressure, irradiate the sample surface with a high-intensity ultraviolet light source with wavelengths of 185nm / 254nm, while simultaneously introducing air containing 200ppm ozone at 80% RH. The treatment time is 60 minutes, allowing hydroxyl groups to be introduced into the PEEK surface under the synergistic effect of photochemical and ozone oxidation. , forming surface activated ; S4: Disperse 0.1g of graphene oxide in 100mL of sodium borate buffer solution with pH 9.0 and sonicate for 2 hours. After a uniform graphene oxide dispersion is formed, add 1.0wt% of silane coupling agent KH560 and stir to mix evenly. S5: Hydroxylated PEEK was used as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The electrode was then deposited at a constant potential of -1.2V for 300 seconds. After the deposition was complete, the sample was gently rinsed with deionized water to remove loosely adsorbed particles. S6: Place the deposited sample in a vacuum drying oven at 80°C for 2 hours to remove moisture and promote KH560 curing, then heat to 250°C under argon protection and hold for 1 hour.

[0032] Experimental results: See Table 2 for details.

[0033] Table 2: Test Results of Example 2

[0034] Due to the reduced plasma processing power and increased vacuum, the plasma energy was insufficient, failing to fully activate the PEEK surface and generate enough active sites, resulting in a significant decrease in the surface hydroxyl density. This initial lack of activation made it difficult for the subsequent silane coupling agent KH560 to form a strong covalent bond interface, ultimately leading to a comprehensive decline in interfacial bonding strength, conductivity, and chemical stability.

[0035] Example 3 This embodiment provides a method for modifying a PEEK surface with a hydroxylated graphite film, the specific implementation steps of which include: Experimental materials: PEEK, acetone, anhydrous ethanol, argon, graphene oxide, KH560, and platinum sheet were used as the counter electrode and the Ag / AgCl electrode.

[0036] Experimental objective: The effects of reducing ozone concentration and air humidity in a combined ultraviolet and ozone treatment device on the hydroxylation effect and subsequent modification performance of PEEK surface were investigated.

[0037] Experimental steps: S1: The PEEK substrate is ultrasonically cleaned with acetone and anhydrous ethanol for 15 minutes in sequence to completely remove surface organic matter and grease. Then, it is rinsed with deionized water, dried, and mechanically polished with diamond polishing paste with a particle size decreasing from 10 to 1 μm until the surface is smooth. S2: Treat the surface with argon plasma at a power of 100W and a vacuum degree of 10Pa for 5 minutes in a vacuum chamber to further activate the surface and remove residual contaminants; S3: Place the pretreated PEEK sample in a combined ultraviolet and ozone treatment device. Under normal pressure, irradiate the sample surface with a high-intensity ultraviolet light source with wavelengths of 185nm / 254nm, while simultaneously introducing air containing 50ppm ozone at a humidity of 40%RH. The treatment time is 60 minutes, allowing hydroxyl groups to be introduced into the PEEK surface under the synergistic effect of photochemical and ozone oxidation. , forming surface activated ; S4: Disperse 0.1g of graphene oxide in 100mL of sodium borate buffer solution with pH 9.0 and sonicate for 2 hours. After a uniform graphene oxide dispersion is formed, add 1.0wt% of silane coupling agent KH560 and stir to mix evenly. S5: Hydroxylated PEEK was used as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The electrode was then deposited at a constant potential of -1.2V for 300 seconds. After the deposition was complete, the sample was gently rinsed with deionized water to remove loosely adsorbed particles. S6: Place the deposited sample in a vacuum drying oven at 80°C for 2 hours to remove moisture and promote KH560 curing, then heat to 250°C under argon protection and hold for 1 hour.

[0038] Experimental results: See Table 3 for details.

[0039] Table 3: Test Results of Example 3

[0040] The use of low ozone concentrations and air humidity in ultraviolet ozone treatment makes it crucial... Insufficient free radical generation leads to low efficiency of photochemical hydroxylation reaction on the PEEK surface. Despite extending the treatment time, the number of active hydroxyl sites introduced on the surface remains scarce, which seriously affects the subsequent grafting amount and binding strength of graphene oxide and coupling agent, resulting in significant deterioration of various performance indicators.

[0041] Example 4 This embodiment provides a method for modifying a PEEK surface with a hydroxylated graphite film, the specific implementation steps of which include: Experimental materials: PEEK, acetone, anhydrous ethanol, argon, graphene oxide, tris(diisooctylphosphoyloxy) and platinum sheet as counter electrode, Ag / AgCl electrode.

[0042] Experimental objective: By changing the type of coupling agent added to the graphene oxide dispersion, the effects of different coupling agents on the surface modification of PEEK were investigated.

[0043] Experimental steps: S1: The PEEK substrate is ultrasonically cleaned with acetone and anhydrous ethanol for 15 minutes in sequence to completely remove surface organic matter and grease. Then, it is rinsed with deionized water, dried, and mechanically polished with diamond polishing paste with a particle size decreasing from 10 to 1 μm until the surface is smooth. S2: Treat the surface with argon plasma at a power of 100W and a vacuum degree of 10Pa for 5 minutes in a vacuum chamber to further activate the surface and remove residual contaminants; S3: Place the pretreated PEEK sample in a combined ultraviolet and ozone treatment device. Under normal pressure, irradiate the sample surface with a high-intensity ultraviolet light source with wavelengths of 185nm / 254nm, while simultaneously introducing air containing 200ppm ozone at 80% RH. The treatment time is 60 minutes, allowing hydroxyl groups to be introduced into the PEEK surface under the synergistic effect of photochemical and ozone oxidation. , forming surface activated ; S4: Disperse 0.1g of graphene oxide in 100mL of sodium borate buffer solution with pH 9.0 and sonicate for 2 hours. After a uniform graphene oxide dispersion is formed, add 1.0wt% tris(diisooctylphosphoyloxy)titanate coupling agent and stir to mix evenly. S5: Hydroxylated PEEK was used as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The electrode was then deposited at a constant potential of -1.2V for 300 seconds. After the deposition was complete, the sample was gently rinsed with deionized water to remove loosely adsorbed particles. S6: Place the deposited sample in a vacuum drying oven at 80°C for 2 hours to remove moisture and promote the curing of tris(diisooctylphosphoyloxy)titanate coupling agent. Then, heat the sample to 250°C under argon protection and hold for 1 hour.

[0044] Experimental results: See Table 4 for details.

[0045] Table 4: Test Results of Example 4

[0046] Replacing the silane coupling agent KH560 with a titanate coupling agent, although the surface hydroxylation is sufficient, the titanate mainly bridges the interface through coordination bonds and physical adsorption. The interfacial bond formed between PEEK and graphene oxide by the titanate is much weaker than the stable Si-OC covalent bond formed by KH560. This leads to a significant decrease in interfacial bonding strength, chemical stability, and conductivity, highlighting the key role of KH560 in constructing a stable covalent interface.

[0047] Example 5 This embodiment provides a method for modifying a PEEK surface with a hydroxylated graphite film, the specific implementation steps of which include: Experimental materials: PEEK, acetone, anhydrous ethanol, argon, graphene oxide, KH560, and platinum sheet were used as the counter electrode and the Ag / AgCl electrode.

[0048] Experimental objective: By varying the temperature and duration of vacuum drying to ensure the samples were not completely dried, the effects of incomplete drying on the properties of the modified samples were investigated.

[0049] Experimental steps: S1: The PEEK substrate is ultrasonically cleaned with acetone and anhydrous ethanol for 15 minutes in sequence to completely remove surface organic matter and grease. Then, it is rinsed with deionized water, dried, and mechanically polished with diamond polishing paste with a particle size decreasing from 10 to 1 μm until the surface is smooth. S2: Treat the surface with argon plasma at a power of 100W and a vacuum degree of 10Pa for 5 minutes in a vacuum chamber to further activate the surface and remove residual contaminants; S3: Place the pretreated PEEK sample in a combined ultraviolet and ozone treatment device. Under normal pressure, irradiate the sample surface with a high-intensity ultraviolet light source with wavelengths of 185nm / 254nm, while simultaneously introducing air containing 200ppm ozone at 80% RH. The treatment time is 60 minutes, allowing hydroxyl groups to be introduced into the PEEK surface under the synergistic effect of photochemical and ozone oxidation. , forming surface activated ; S4: Disperse 0.1g of graphene oxide in 100mL of sodium borate buffer solution with pH 9.0 and sonicate for 2 hours. After a uniform graphene oxide dispersion is formed, add 1.0wt% of silane coupling agent KH560 and stir to mix evenly. S5: Hydroxylated PEEK was used as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The electrode was then deposited at a constant potential of -1.2V for 300 seconds. After the deposition was complete, the sample was gently rinsed with deionized water to remove loosely adsorbed particles. S6: Place the deposited sample in a vacuum drying oven at 60°C for 1 hour to promote KH560 curing.

[0050] Experimental results: See Table 5 for details.

[0051] Table 5: Test Results of Example 5

[0052] Because the drying temperature was lowered and the time was shortened in the post-processing stage, and the critical 250℃ heat treatment step was omitted, the hydrolysis and condensation reaction of KH560 was insufficient, the interfacial cross-linking and curing were inadequate and defective, and the graphene oxide failed to achieve effective thermal reduction, which ultimately led to a significant reduction in the interfacial bonding strength and electrical continuity.

[0053] Comparative Example 1 This embodiment provides a method for hydroxylation of a conventional PEEK surface, the specific implementation steps of which include: Experimental materials: PEEK, acetone, anhydrous ethanol, concentrated sulfuric acid.

[0054] Experimental objective: The traditional concentrated sulfuric acid sulfonation method was used to hydroxylate PEEK on its surface as a control sample to compare the modification effect of the method of the present invention.

[0055] Experimental steps: S1: The PEEK is ultrasonically cleaned in sequence with acetone and anhydrous ethanol to remove organic matter and grease from the PEEK surface. S2: Immerse the cleaned PEEK sample completely in 95% concentrated sulfuric acid, then heat the system to 50-70°C and stir continuously for 5-30 minutes. After the reaction is complete, quickly remove the sample. S3: Immediately transfer the sample obtained from the reaction to a large amount of ice-water mixture for quenching, and then immerse the sample in a dilute sodium hydroxide solution for hydrolysis treatment at room temperature for 2 hours; S4: Rinse the sample repeatedly with plenty of deionized water until the water is neutral, and finally dry it in a vacuum drying oven at 60-80℃.

[0056] Experimental results: See Table 6 for details.

[0057] Table 6: Test Results of Comparative Example 1

[0058] The traditional concentrated sulfuric acid sulfonation method used in Comparative Example 1 introduces a high density of hydroxyl groups on the PEEK surface through severe acid corrosion and hydrolysis. However, the severe corrosion caused by the strong acid also leads to serious degradation of the PEEK surface, forming a fragile degradation layer with a loose structure and low cohesive strength. This fragile layer not only fails to provide a stable base for subsequent functionalization, but also suffers from extremely low interfacial bonding strength and difficulty in establishing conductive pathways due to its poor mechanical properties and chemical instability. Ultimately, it exhibits systemic performance defects such as deteriorated bonding force, extremely high surface resistance, poor chemical stability, and limited improvement in wettability. This fully exposes the fundamental limitations of traditional wet chemical methods in pursuing surface modification while severely damaging the material matrix and making it difficult to construct high-quality functional interfaces.

[0059] Example 1 employs an optimized argon plasma pretreatment and UV / ozone synergistic hydroxylation process, combined with simultaneous electrochemical deposition of KH560 coupling agent and thorough subsequent heat treatment, to achieve high surface hydroxyl density (12.8 atomic), strong interfacial adhesion (5B grade), and low surface resistivity (1.5 × 10⁻⁶). 3 It boasts the best overall performance in terms of Ω / sq, high chemical stability (98%), and good hydrophilicity (42°).

[0060] Example 2 used a lower plasma processing power (50W) and a higher vacuum degree (50Pa), resulting in insufficient surface activation, a decrease in hydroxyl density to 9.5 atoms, and reduced interfacial bonding strength (4B level) and conductivity (5.0×10⁻⁶). 4 The Ω / sq and chemical stability (85%) decreased simultaneously.

[0061] Example 3 used a lower ozone concentration (50 ppm) and air humidity (40% RH). Although the treatment time was extended to 60 minutes, the hydroxylation efficiency was still low, with a hydroxyl density of only 8.0 atoms, which severely affected the subsequent interfacial bonding strength (3B level) and conductivity (1.0 × 10⁻⁶). 5 Ω / sq).

[0062] In Example 4, a titanate coupling agent was used instead of KH560. Although a high hydroxyl density (12.5 atoms) was maintained, the interfacial bonding mechanism changed from covalent bonds to weaker coordinate bonds, resulting in a significant deterioration in interfacial bonding strength (2B grade) and chemical stability (65%).

[0063] Example 5 used insufficient post-treatment conditions (drying at 60°C for 1 hour, omitting the 250°C heat treatment), resulting in insufficient interfacial cross-linking and curing. Although the hydroxyl density remained at 12.0 atoms, the interfacial bonding strength (3B grade) and conductivity (1.0 × 10⁻⁶) were poor. 5 The Ω / sq ratio decreased significantly.

[0064] Comparative Example 1, using the traditional concentrated sulfuric acid sulfonation method, achieved the highest surface hydroxyl density (14.0 atomic), but surface degradation caused by strong acid corrosion resulted in a fragile interface layer, leading to extremely poor interfacial adhesion (Class 1B) and near-insulation (>1.0 × 10⁻⁶). 5 It has a low Ω / sq content and poor chemical stability (60%).

[0065] Comparing the examples and comparative examples, Example 1 achieves the optimal balance in surface activation, hydroxylation efficiency, interfacial bonding, and post-treatment. It cleverly replaces chemical corrosion with photochemical modification, constructs covalent interfaces through simultaneous electrodeposition, and enhances cross-linking and conductivity through heat treatment, thereby improving the overall performance of the graphite-like film modification on the PEEK surface. This makes it suitable for precision devices requiring high interfacial bonding strength, conductivity, and durability. Example 2, while having a complete process, suffers from insufficient initial activation, limiting its overall effectiveness. Example 3 uses mild hydroxylation conditions, but insufficient reaction efficiency restricts performance. Example 4 uses different coupling agents, but the interfacial bonding strength is insufficient. Example 5 employs a simplified post-treatment process, but the interfacial curing is incomplete. The comparative examples highlight the limitations of traditional wet chemical methods, which, while achieving surface modification, sacrifice the material's intrinsic properties. Therefore, this invention, through multi-step synergistic optimization, achieves effective surface functionalization while perfectly preserving the excellent properties of the PEEK matrix, solving the industry problem of traditional methods failing to balance efficient modification and material protection.

[0066] refer to Figure 2The flowchart clearly shows the complete process of the PEEK surface hydroxylation graphite film modification method, starting from pretreatment, to surface hydroxylation, to functional layer construction, and finally to post-treatment to achieve stable bonding of the interface and performance optimization of the functional layer; the whole process is closely linked, forming a green, efficient modification technology path that can significantly improve the conductivity and interfacial bonding of PEEK surface.

[0067] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims.

[0068] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for modifying PEEK surfaces with hydroxylated graphite-like films, characterized in that, Specifically, the following steps are included: S1: The PEEK substrate is ultrasonically cleaned with acetone and anhydrous ethanol for 15 minutes in sequence to completely remove surface organic matter and grease. Then it is rinsed with deionized water, dried, and mechanically polished with diamond polishing paste until the surface is smooth. S2: Treat the surface with argon plasma in a vacuum chamber for 5 minutes to further activate the surface and remove residual contaminants; S3: Place the pretreated PEEK sample in a combined ultraviolet and ozone treatment device. Under normal pressure, irradiate the sample surface with a high-intensity ultraviolet light source while simultaneously introducing moist ozone gas. The treatment time is 10–60 minutes, allowing hydroxyl groups to be introduced into the PEEK surface under the synergistic effect of photochemical and ozone oxidation. , forming surface activated This enables simultaneous covalent bonding of silane coupling agents with the PEEK surface and graphene oxide; S4: Disperse graphene oxide in sodium borate buffer solution and sonicate for 2 hours. After a uniform graphene oxide dispersion is formed, add silane coupling agent KH560 and stir to mix evenly. S5: Hydroxylated PEEK was used as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl electrode as the reference electrode. Electrochemical deposition was then performed at a constant potential. After the deposition was complete, the sample was gently rinsed with deionized water to remove loose particles that were physically adsorbed. S6: The deposited sample is placed in a vacuum drying oven for treatment to remove moisture and promote KH560 curing, and then heated and held under argon protection.

2. The method for modifying a PEEK surface with a hydroxylated graphite film as described in claim 1, characterized in that, The main component of the PEEK substrate in S1 is a semi-crystalline linear aromatic polymer, chemically known as polyether ether ketone.

3. The method for modifying a PEEK surface with a hydroxylated graphite film as described in claim 1, characterized in that, The diamond polishing paste used in S1 has a particle size that decreases from 10 μm to 1 μm.

4. The method for modifying a PEEK surface with a hydroxylated graphite film as described in claim 1, characterized in that, The power of plasma treatment in the vacuum chamber of S2 is 50-100W, and the vacuum degree is 10-50 Pa.

5. The method for modifying a PEEK surface with a hydroxylated graphite film as described in claim 1, characterized in that, The high-intensity ultraviolet light source in S3 has a wavelength of 185 / 254nm.

6. The method for modifying a PEEK surface with a hydroxylated graphite film as described in claim 1, characterized in that, In the S3 ultraviolet-ozone combined treatment equipment, air with 50-200 ppm ozone and a humidity of 40-80%RH is added.

7. The method for modifying a PEEK surface with a hydroxylated graphite film as described in claim 1, characterized in that, In S4, 1.0 wt% of silane coupling agent KH560 is added to a uniform graphene oxide dispersion.

8. The method for modifying a PEEK surface with a hydroxylated graphite film as described in claim 1, characterized in that, In S4, graphene oxide was dispersed in a sodium borate buffer solution with pH 9.0±0.5 and 0.025M and ultrasonicated for 2 hours to form a graphene oxide concentration of 1.0 g / L.

9. The method for modifying a PEEK surface with a hydroxylated graphite film as described in claim 1, characterized in that, Deposited in S5 at a constant potential of -1.2 V for 300 seconds.

10. The method for modifying a PEEK surface with a hydroxylated graphite film as described in claim 1, characterized in that, In S6, the deposited sample was placed in a vacuum drying oven at 80±10℃ for 2 hours and then heated to 250±10℃ under an argon atmosphere for 1 hour.

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