A method for improving the biotribological properties and corrosion resistance of titanium alloy surfaces

Abstract

The present application relates to a kind of methods for improving the biological friction and corrosion resistance of titanium alloy surface.Hydroxylation treatment is carried out on the surface of titanium alloy;Silane coupling agent and dopamine are grafted on the surface of titanium alloy after hydroxylation treatment;CS / MXene hydrogel coating is formed on the surface of titanium alloy, i.e.completion.Compared with the prior art, the present application obtains CS / MXene grafted on the surface of titanium alloy by self-assembly means, thereby improving the biological tribological properties of titanium alloy, and improving the corrosion resistance of the surface of titanium alloy.The CS / MXene coating obtained by construction can effectively reduce the wear rate of titanium alloy in simulated body fluid when rubbing, reduce the friction coefficient of the friction system, and improve the body fluid corrosion resistance of the surface of titanium alloy.

Description

Technical Field

[0001] This invention belongs to the field of material surface coating preparation technology, and in particular relates to a method for improving the biotribability and corrosion resistance of titanium alloy surfaces. Background Technology

[0002] Titanium alloys, due to their light weight, excellent mechanical properties, and good biocompatibility, have been widely used in orthopedic internal fixation systems, artificial joint replacements, and other hard tissue implants. However, the poor tribological properties of titanium alloys as bone implants significantly impact implantation failure. Furthermore, titanium alloys have poor surface wear resistance. When implanted in the human body and exposed to corrosive bodily fluids, these fluids weaken the passivation ability of the titanium alloy, leading to the dissolution of toxic ions such as Al and V. In addition, these toxic ions can disrupt the bioactive interaction between the implant and the tissue. During joint movement, titanium alloy implants experience wear due to friction with other materials. Therefore, improving the wear resistance and resistance to bodily fluid corrosion of titanium alloy surfaces can effectively extend the lifespan of titanium alloy implants.

[0003] Research is underway to enhance the surface biofunctionality (wetting, tribological properties, resistance to body fluid corrosion, osseointegration, tissue and cell culture growth, etc.) of surfaces using surface modification techniques. Surfaces with micro / nanotextures or ordered roughness can improve surface resistance to body fluid corrosion and tribological properties. Nanomaterial-coated implants are becoming increasingly popular for artificial hip joint implants. Compared with other biomaterials, nanomaterial implants possess inherited physical and mechanical properties, good thermal stability, chemical inactivity, and biocompatibility. The acceptability of nanomaterial implants has also improved in recent years. However, grafting metal coatings onto metal surfaces remains challenging.

[0004] In recent years, materials with bio-tribulation and corrosion resistance have become a research hotspot in the field of biomedical materials.

[0005] For example, Chinese patent application CN 107841778 A discloses a method for surface modification of medical metallic materials. This Chinese patent document only verifies the strong corrosion resistance of graphene oxide (GO), and GO also has great potential in the field of biomedical materials applications. However, it should be noted that this patent document does not disclose research on wear resistance, and the bonding strength between the coating and the substrate will also affect the tribological properties of the titanium alloy and the cortical bone surface, as well as the corrosion resistance of the titanium alloy surface.

[0006] For example, Chinese patent application CN 114246978 A discloses a method for improving the biocompatibility and corrosion resistance of titanium alloy surfaces, comprising the following steps: (1) hydroxylating the titanium alloy surface; (2) grafting a silane coupling agent and dopamine onto the hydroxylated titanium alloy surface; and (3) finally grafting an Fe3O4 / HA coating onto the titanium alloy, thus completing the process. This patent application mentions that the material has excellent biocompatibility and promising applications in medical materials. However, it does not verify the wear resistance and corrosion resistance, nor does it demonstrate further application in medical materials.

[0007] Based on the above materials, it can be seen that there is a lack of an effective method in the existing technology that can simultaneously and effectively improve the wear resistance and corrosion resistance of titanium alloy surfaces. Summary of the Invention

[0008] Given the current lack of methods in the art to simultaneously and effectively improve the wear resistance and corrosion resistance of titanium alloy surfaces, this invention provides a method for improving the biotribability and corrosion resistance of titanium alloy surfaces.

[0009] This invention constructs a chitosan-MXene hydrogel coating on the surface of titanium alloy through self-assembly, thereby improving the biotribological properties of titanium alloy and enhancing the corrosion resistance of the titanium alloy surface.

[0010] The objective of this invention can be achieved through the following technical solutions:

[0011] This invention provides a method for improving the biotribulation and corrosion resistance of titanium alloy surfaces, comprising the following steps:

[0012] (1) Hydroxylation treatment of titanium alloy surface;

[0013] (2) Grafting silane coupling agent and dopamine onto the surface of hydroxylated titanium alloy;

[0014] (3) A chitosan-MXene-based hydrogel coating is formed on the titanium alloy surface after the treatment in step (2), and the process is complete.

[0015] In one embodiment of the present invention, in step (1), the titanium alloy is pre-polished mechanically and cleaned with acetone before undergoing hydroxylation treatment.

[0016] In one embodiment of the present invention, step (1) specifically involves immersing the titanium alloy in a potassium hydroxide solution, thereby completing the process. Furthermore, the concentration of the potassium hydroxide solution is 2–6 mol / L (e.g., 5 mol / L); the immersion temperature is 20–80°C, and the immersion time is 12–16 h (e.g., 12 h).

[0017] In one embodiment of the present invention, the method for grafting silane coupling agent and dopamine onto the surface of the hydroxylated titanium alloy in step (2) is specifically as follows:

[0018] The hydroxylated titanium alloy is first placed in a silane coupling agent solution for self-assembly, then cleaned, dried, and then immersed in a dopamine solution to complete the process.

[0019] Furthermore, the mass concentration of the silane coupling agent solution (specifically, KH550, KH560, KH570, KH792, etc.) is 30 g / L, the self-assembly time is 8 h, and the pH is adjusted to 8.5 with hydrochloric acid.

[0020] The dopamine solution has a mass concentration of 30 g / L, the soaking time is 12–24 h, and the pH is adjusted to 8.5 with tris(hydroxymethyl)aminomethane. The dopamine used can be dopamine hydrochloride, etc.

[0021] In one embodiment of the present invention, in step (3), the method for forming a chitosan-MXene hydrogel coating on the surface of the titanium alloy is as follows: the titanium alloy is placed in an aqueous solution of chitosan-MXene and irradiated with a xenon lamp (for example, for 15 min, 20 min, etc.), thus completing the construction of the chitosan-MXene hydrogel coating on the surface of the titanium alloy.

[0022] In one embodiment of the present invention, in step (3), the preparation method of the aqueous solution of chitosan-MXene (CS-MXene) is as follows: dissolve MXene in water, and then add chitosan, acetic acid, acrylic acid, 2,4,6-trimethylbenzoyl diphenyloxyphosphine (TPO) and N,N-methylenebisacrylamide in sequence, stir evenly with a magnetic stirrer, and degas in an ultrasonic chamber for 10 min.

[0023] In one embodiment of the present invention, the concentration of MXene in the aqueous solution of CS-MXene is 0.01-0.05 g / 10 g deionized water.

[0024] In one embodiment of the present invention, the titanium alloy is a Ti6Al4V alloy.

[0025] The technical solution of this application employs a chemical self-assembly method to prepare a CS-MXene hydrogel coating on the surface of a titanium alloy. Furthermore, this application systematically measures the tribological properties of the titanium alloy surface under SBF (simulated body fluid) lubrication and its anti-corrosion performance in SBF solution. The study shows that the CS-MXene hydrogel coating on the surface has a more positive effect on reducing the coefficient of friction and wear rate, possibly due to the transformation of sliding friction into rolling friction.

[0026] Based on the dynamic interaction mechanism of hydrogels and the principle of matching the interfacial mechanical properties of titanium alloys and silicon carbide microspheres, a smart self-healing viscoelastic coating is constructed on the surface of titanium alloys using a polymer / inorganic hybrid hydrogel through chemical assembly technology. The dynamic interaction of the hydrogels is activated by xenon lamp irradiation to achieve self-repair of the damaged coating.

[0027] Specifically, this invention first activates the surface of a titanium alloy by chemically assembling an adhesive to enhance the adhesion of the hydrogel coating. Secondly, using chitosan as the core monomer of the hydrogel, functional photothermal nanohybrids are designed and synthesized as synergistic monomers. Simultaneously, other synergistic monomers are preferentially selected for in-situ crosslinking, forming a smart hydrogel coating on the titanium alloy surface. The photothermal effect activates the dynamic interactions of the hydrogel, enabling the coating to self-repair after damage.

[0028] Furthermore, this invention investigates the influence of the photothermal effect of nano-hybrids on the degree of crosslinking, mechanical properties, and self-healing ability of hydrogels. By establishing a friction system between titanium alloy and silicon carbide microspheres, the influence mechanism of silicon carbide microspheres on the lubricity and wear resistance of the hydrogel coating is studied. The interfacial tribological behavior and the interaction between the thickness of the lubricating film formed during friction, the coating's self-healing ability, wettability, and mechanical strength are explored.

[0029] Based on the research results, a method for improving the biotribological properties and corrosion resistance of titanium alloy surfaces was determined. This invention constructs CS-MXene on the surface of titanium alloys through self-assembly, thereby improving the biotribological properties of titanium alloys and enhancing the corrosion resistance of titanium alloy surfaces. The overall process is simple and the effect is outstanding.

[0030] In the technical solution of the present invention, CS-MXene is grafted onto the surface of titanium alloy by self-assembly, thereby improving the biotribological properties of titanium alloy and enhancing the corrosion resistance of titanium alloy surface.

[0031] The obtained CS-MXene coating can effectively reduce the wear rate of titanium alloys during friction in simulated body fluids, reduce the friction coefficient of the friction system, and improve the corrosion resistance of the titanium alloy surface to body fluids.

[0032] To enhance the interfacial bonding between the CS-MXene coating and the titanium alloy surface, an adhesion layer grafting treatment is performed on the titanium alloy surface. This application constructs a CS-MXene coating on the surface of medical titanium alloy using a self-assembly method, which is an innovative surface treatment process for improving titanium alloys and a technical solution that was previously impossible for those skilled in the art to achieve.

[0033] Furthermore, the construction of this coating can significantly improve the resistance of titanium alloy surfaces to body fluid corrosion.

[0034] Finally, it should be noted that the surface construction method mentioned in this invention has good theoretical research value and industrial application prospects. It provides a brand-new approach for effectively improving the biotribological properties of titanium alloys and enhancing the corrosion resistance of titanium alloy surfaces, thereby further broadening the application prospects of this construction method in the field of orthopedic medicine.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] 1. This invention innovatively constructs a CS-MXene coating on the surface of titanium alloy using a self-assembly method. This construction method is simple, feasible, environmentally friendly, and non-toxic.

[0037] 2. Compared with existing technologies, after successfully preparing a CS-MXene coating on the surface of titanium alloy using this construction method, the wear resistance of the surface is significantly improved and the microhardness is significantly increased.

[0038] 3. Compared with existing technologies, the CS-MXene coating successfully prepared on the surface of titanium alloy using this construction method exhibits superior resistance to body fluid corrosion.

[0039] 4. Compared with existing technologies, the biotribological properties of titanium alloy surfaces are significantly improved after successful preparation of CS / MXene coatings using this construction method. This is reflected in a significant reduction in the coefficient of friction of the titanium alloy and a significant decrease in the wear rate of the titanium alloy surface.

[0040] 5. Compared with the prior art, the CS-MXene coating on the titanium alloy surface obtained by the construction method described in this invention has a strong bond with the titanium alloy substrate surface, and it can be seen that the corrosion resistance is improved. Attached Figure Description

[0041] Figure 1 The diagram shows the tribological properties of the CS-MXene coating on the alloy surface in Example 2, the friction coefficient diagram of SBF lubrication (a), the average friction coefficient diagram (b), the Bode impedance diagram (c), and the Tafel diagram (d).

[0042] Figure 2 The image shows the characterization of the CS / MXene coating in Example 2, where (a) shows the FITR (Infrared Spectrum) and (b) shows the XRD pattern.

[0043] Figure 3 This is a contact angle test diagram of the CS / MXene coating on the alloy surface in Example 2. Detailed Implementation

[0044] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0045] In the following embodiments, the silane coupling agent used is KH550, the dopamine used is dopamine hydrochloride, and the other raw materials or processing techniques, unless otherwise specified, are all conventional commercially available raw materials or conventional processing techniques in the art.

[0046] Example 1

[0047] This embodiment uses titanium alloy and provides a CS-MXene composite coating on the surface of Ti6Al4V alloy and its preparation method to improve its surface corrosion resistance and biotribological properties. The preparation method includes the following steps:

[0048] The titanium alloy was polished to a surface roughness of 0.5 μm, cleaned three times with acetone and deionized water respectively, dried with nitrogen, and then immersed in a 5 mol / L KOH solution for 12-24 h. Then it was placed in a 30 g / L silane coupling agent solution and reacted for 2 h to assemble a silane film.

[0049] After washing the obtained sample with water, it was placed in a 2 g / L dopamine solution and reacted for 12-24 h to assemble a polydopamine adhesion layer on the surface. The sample was then removed, cleaned, and set aside for later use.

[0050] 0.01 g, 0.03 g, and 0.05 g of MXene were dissolved in 10 g of water, and the resulting hydrogels were named accordingly. Then, 0.24 g of chitosan, 0.2 g of acetic acid, 6 g of acrylic acid, 0.01 g of 2,4,6-trimethylbenzoyl diphenyloxyphosphine (TPO), and 0.01 g of N'N-methylenebisacrylamide were sequentially added to the above aqueous solution containing MXene. After uniform stirring with a magnetic stirrer, the solution was degassed in an ultrasonic chamber for 10 min to obtain an aqueous solution of CS-MXene. 5 mL of the pre-treated solution was poured into a petri dish (20 cm in diameter) containing Ti6Al4V alloy and irradiated with a xenon lamp for 15-30 min to form a CS-MXene hydrogel coating on the titanium alloy surface.

[0051] The biotribological properties of titanium alloys in SBF solution were tested using a reciprocating friction testing machine. The test results showed that the CS-MXene coated sample surface exhibited a lower coefficient of friction and wear rate.

[0052] The chemical composition of the CS-MXene coated samples was characterized by FTIR infrared spectroscopy and XRD.

[0053] The contact angle of the test samples was measured. It was found that the wettability of the titanium alloy surface coated with the CS-MXene coating was improved compared to the blank titanium alloy group.

[0054] Example 2

[0055] The medical-grade titanium alloy sheet used in this embodiment is a Ti6Al4V alloy, a raw material from a medical device company, and the CS-MXene coating used was prepared in the laboratory. The preparation method includes the following steps:

[0056] The surface of the Ti6Al4V alloy was polished to a roughness of 0.1 μm, rinsed several times with deionized water, and then immersed in a 5 mol / L KOH solution for 6 h. Subsequently, it was immersed in a 1 wt% silane coupling agent aqueous solution to assemble a silane adhesion layer for 6 h. After drying the surface with nitrogen, it was immersed in a 30 g / L dopamine solution to assemble a polydopamine transition layer for 6 h. The sample was then removed, cleaned, and dried with nitrogen for later use.

[0057] 0g, 0.01g, 0.03g, and 0.05g of MXene were dissolved in 10g of water, respectively. These hydrogels were named CS, CS-MXene-0.1%, CS-MXene-0.3%, and CS-MXene-0.5% according to the amount added. Then, 0.24g of chitosan, 0.2g of acetic acid, 6g of acrylic acid, 0.01g of 2,4,6-trimethylbenzoyl diphenyloxyphosphine (TPO), and 0.01g of N,N-methylenebisacrylamide were sequentially added to the above aqueous solution containing MXene. After uniform stirring with a magnetic stirrer, the solution was degassed in an ultrasonic chamber for 10 minutes to obtain an aqueous solution of CS-MXene. The previously treated titanium alloy was placed in the aqueous solution of CS-MXene and irradiated with a xenon lamp for approximately 15-30 minutes to form a CS-MXene hydrogel coating on the surface of the Ti6Al4V alloy.

[0058] The biotribological properties of titanium alloys in dry friction and SBF solution were tested using a reciprocating friction testing machine. The test results showed that the CS-MXene sample surface exhibited a low coefficient of friction and wear rate.

[0059] The chemical composition of the CS-MXene coated samples was characterized by FTIR infrared spectroscopy and XRD.

[0060] The contact angle of the test samples was measured. It was found that the wettability of the titanium alloy surface coated with the CS / MXene coating was improved compared to the blank titanium alloy group.

[0061] In the image below Figure 1 a is the average friction coefficient diagram. Figure 1 b is the wear rate diagram of the hydrogel coating. Figure 1c is the Bode plot; Figure 1 d represents the Tafel curve; Figure 2 a is the infrared image. Figure 2 b is the infrared image of MXene; Figure 3 The contact angle diagram of the sample is shown in Table 1, which displays the electrochemical parameters of the sample in SBF solution.

[0062] Combination Figure 1-3 ,from Figure 1 As can be clearly seen in (a), the coefficient of friction (COF) of the CS-MXene-0.3% hydrogel coating is the smallest, indicating that the CS-MXene-0.3% hydrogel coating plays a good protective role for Ti6Al4V. The CS-MXene-0.3% hydrogel coating has good wear resistance in wet friction and improves the wear resistance of titanium alloy. Figure 1 (b) Similarly, the CS-MXene-0.3% hydrogel coating exhibits the lowest wear rate, indicating excellent wear resistance in simulated body fluids. Figure 1 (c) is the Bode plot, which shows that the resistivity of these titanium alloy samples is Ti6Al4V (0.89×10⁻⁶). 4 Ω·cm 2 ), CS(1.8×10 5 Ω·cm 2 ), CS-MXene-0.1% (1.4×10) 5 Ω·cm 2 ), CS-MXene-0.3% (2.70×10) 5 Ω·cm 2 ) and CS-MXene-0.5% (2.30×10 5 Ω·cm 2 CS-MXene-0.3% exhibits the highest impedance value and the best corrosion resistance. (Tafel curve) Figure 1 d) shows a similar trend. The corrosion potential and corrosion current density of the fitted Ti6Al4V alloy samples are shown in Table 1. The displayed I... Corr The sequence was CS-MXene-0.5% (35.85 nA / cm). -2 ) <CS-MXene-0.3%345(89.66nA / cm -2 ) <CS-MXene-0.1%(115.3nA / cm -2 ) <CS(148.0nA / cm -2 ) <Ti6Al4V(2960nA / cm -2The results showed that the hydrogel coating reduced the corrosion current density at 347, with the CS-MXene-0.5% based hydrogel coating showing the best effect. CS-MXene-0.5% I Corr The lowest value was 35.85 nA / cm. -2 .

[0063] Figure 1 (d) is the Tafel plot. The corrosion inhibition rate can be calculated according to the following formula. The calculation results are shown in Table 1 below.

[0064]

[0065] It can be clearly seen that the corrosion inhibition rate of CS-MXene-0.5% reached 99.20%, indicating that the Ti-CS-MXene hydrogel coating improved the corrosion resistance of Ti6Al4V. This is mainly because the MXene sheet acts as a corrosion barrier, has high corrosion inhibition performance, and forms an effective physical separation between the covered substrate and the simulated corrosive medium in the SBF simulated body fluid.

[0066] Table 1. Electrochemical parameters of Ti6Al4V, CS, CS-MXene-0.1%, CS-MXene-0.3%, and CS-MXene-0.5% hydrogel coatings.

[0067]

[0068] The effect of hydrogel coating on the surface wettability of Ti6Al4V alloy was studied, such as... Figure 3 As shown. Compared with the CA value of the blank titanium alloy (83.47°), the CA value of the hydrogel-coated Ti6Al4V alloy surface is slightly lower, proving that the hydrogel coating of Ti6Al4V alloy enhances the wettability of Ti6Al4V alloy. This is due to the hydrophilicity of the hydroxyl and amino groups in CS and the carboxyl groups in acrylic acid. Compared with the hydrogel-coated sample, the CA value of the CS-MXene sample decreases slightly with the increase of MXene content. The CA value of CS-MXene-0.5% hydrogel is 67.83°. The main reason is that MXene exhibits aggregation. The two-dimensional material MXene contains a large number of hydrophilic groups -F, -OH, -O and -Cl. Some -OH groups in MXene do not participate in crosslinking and exposure. The results show that the contact angle (CA) value of the Ti6Al4V alloy surface coated with CS-MXene-0.5% hydrogel is reduced.

[0069] Example 3:

[0070] This embodiment provides a surface construction method to improve the tribological properties of metal-to-metal friction systems and enhance resistance to body fluid corrosion. The specific steps are basically the same as in Example 1, except that in this embodiment, 0.24g chitosan, 0.2g acetic acid, 6g acrylic acid, and 0.01g 2,4,6-trimethylbenzoyl diphenyloxyphosphine (TPO) are added sequentially to a 10ml sample vial. After uniform stirring with a magnetic stirrer, the sample is degassed in an ultrasonic chamber for 10 minutes and then irradiated with a xenon lamp for approximately 20 minutes.

[0071] Example 4:

[0072] Most of the components are the same as in Example 1, except that 0.1% of MXene was added.

[0073] Example 5:

[0074] Most of the results are the same as in Example 1, except that 0.3% of MXene is added.

[0075] Example 6:

[0076] Most of the components are the same as in Example 1, except that 0.5% of MXene is added.

[0077] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for improving the biotribulation and corrosion resistance of titanium alloy surfaces, characterized in that, Includes the following steps: (1) Hydroxylation treatment of titanium alloy surface; (2) Grafting silane coupling agent and dopamine onto the surface of the hydroxylated titanium alloy: First, place the hydroxylated titanium alloy in a silane coupling agent solution for self-assembly, then clean and dry it, and then immerse it in a dopamine solution to complete the process. (3) Forming a CS / MXene hydrogel coating on the titanium alloy surface after step (2): Take the titanium alloy after step (2) and place it in an aqueous solution of CS-MXene, and irradiate it with a xenon lamp to complete the grafting of the CS-MXene hydrogel coating on the titanium alloy surface. The preparation method of CS-MXene aqueous solution is as follows: dissolve MXene in water, then add chitosan, acetic acid, acrylic acid, and 2,4,6-trimethylbenzoyldiphenyloxyphosphine in sequence, stir evenly with a magnetic stirrer, and then depore in an ultrasonic chamber; the concentration of MXene in CS-MXene aqueous solution is 0.01-0.05 g / 10 g water.

2. The method for improving the biotribulation and corrosion resistance of titanium alloy surfaces according to claim 1, characterized in that, In step (1), the titanium alloy is pre-polished mechanically and cleaned with acetone before undergoing hydroxylation treatment.

3. The method for improving the biotribulation and corrosion resistance of titanium alloy surfaces according to claim 1, characterized in that, In step (1), the hydroxylation process specifically involves immersing the titanium alloy in a potassium hydroxide solution to complete the treatment.

4. The method for improving the biotribatability and corrosion resistance of titanium alloy surfaces according to claim 3, characterized in that, The concentration of potassium hydroxide solution is 2~6 mol / L; the soaking temperature is 20~80℃, and the time is 12~16h.

5. The method for improving the biotribulation and corrosion resistance of titanium alloy surfaces according to claim 1, characterized in that, The dopamine solution has a mass concentration of 30 g / L, and the soaking time is 12-24 h.

6. The method for improving the biotribatability and corrosion resistance of titanium alloy surfaces according to claim 1, characterized in that, The alloy is a Ti6Al4V alloy.

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