A preparation method for obtaining a nano-structured surface with both micro-nano topography on pure titanium by nano-treatment and its application

Abstract

The present invention discloses a preparation method and application thereof for nano-treating a pure titanium surface to obtain a nanostructure with both micro-nano morphology, and the preparation method is applicable to the nano-treating of pure titanium surfaces with various morphologies, and can prepare nanopores on pure titanium surfaces with different morphologies while retaining the original micron morphology as much as possible, so as to realize the preparation of nanopores with both micro-nano morphology on the pure titanium surface. In addition, the nanopores with both micro-nano morphology prepared on the pure titanium surface by the method have excellent hydrophilicity and protein adhesion performance, and have better mechanical properties than traditional nanotubes, and have the potential to be applied to pure titanium implants and bases for surface treatment. The present invention has broad application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical fields of nanoengineering, nano-treatment of pure titanium implants, micro-nano fabrication, and micro-nano topography, and relates to a preparation method and application for obtaining a nano-structure with both micro-nano topography on the surface of nano-treated pure titanium, specifically, a preparation method and application for obtaining a nano-structure with both micro-nano topography on the surface of nano-treated pure titanium implants. Background Art

[0002] As a widely used dental / bone implant material, the bioactivity of pure titanium is affected by surface topography, chemistry, and hydrophilicity. In order to enhance its surface activity and thus promote the regeneration and bonding of hard and soft tissues on its surface, physical and chemical means such as micron-scale roughening, hydrophilic modification, and ion implantation have been gradually applied to the surface of pure titanium implants. [1] In recent years, nanotechnology has been gradually applied to the treatment of the surface of pure titanium implants to prepare structures with nano-scale topography on their surfaces, so as to further enhance cell activity and regulate its functions.

[0003] Among many nanotechnologies, the electrochemical anodization method (EA) has the advantages of simple operation, high efficiency, and scalability to the surfaces of various metals. Through EA, a pore-tube-like nanostructure can be prepared on the surface of anodic titanium. [2] Briefly speaking, in EA, the anode and cathode metals are simultaneously immersed in an electrolyte containing F ions. Through a stable direct current supply, the surface of the anode metal is oxidized to synthesize soluble Ti-F compounds, which are dissolved in the electrolyte, thereby etching out pore-tube-like nanostructures such as nanopores or nanotubes. [3]

[0004] This pore-tube-like nanostructure not only increases the surface roughness but also provides a larger surface area, which helps to increase cell attachment points and promote cell proliferation and differentiation. In addition, these nanostructures can also serve as drug delivery systems to further promote tissue regeneration by slowly releasing growth factors or other bioactive molecules.

[0005] ​The nano-treatment of pure titanium by EA can be completed in an organic electrolyte or an aqueous electrolyte containing F ions, and the electrolyte can be either acidic or neutral. However, most acidic or aqueous electrolytes have strong corrosivity and conductivity, and usually dissolve the surface morphology of pure titanium during the EA process, preparing nanowires with a clustered distribution and relative independence, and then destroying the original micron-scale morphology on the surface of pure titanium implants. Establishing a neutral, organic electrolyte and adjusting the EA parameters may prepare a nanoporous structure on the surface of pure titanium, and it is expected to retain its original micron morphology to a certain extent while preparing the nano-morphology. In addition, it has been reported by predecessors that the elastic modulus of the relatively independent nanotubes prepared by EA is only 0.3-16.6 GPa [4] , and the gaps between the nanopores are filled with Ti-O-F complexes generated by EA, so it may have higher mechanical strength and be more suitable for preparing the surface of pure titanium implants and their accessories [5, 6] . Although some studies have found that surface-fused nanopores can be prepared on the surface of pure titanium by EA, a kind of EA system that can be widely applied to different pure titanium surfaces, retain the original micron morphology on the surface of pure titanium while preparing nanopores, and finally obtain a nano-structure with both micro-nano morphologies on the surface of pure titanium has not been clearly defined. In addition, as the most widely used material for preparing dental / bone implants and their accessories, the nanopores formed on the surface of pure titanium need to have certain mechanical strength, hydrophilicity and protein adhesion ability to ensure its mechanical stability and biological activity.

[0006] Therefore, it is urgent to design an EA system that can be widely applied to the surfaces of pure titanium with different morphologies, retain its original micron structure while preparing nano-structures, and prepare nano-structures with better mechanical strength than nanotubes, and explore its surface mechanical strength, hydrophilicity and protein adhesion ability. Summary of the Invention

[0007] In order to solve the deficiencies existing in the prior art, the present invention aims to provide a neutral, organic electrolyte-based EA system, which can be applied to the surfaces of pure titanium with different morphologies, retain its original micron-scale morphology while preparing nanopores, and then prepare a nanoporous structure with both micro-nano morphologies, especially suitable for the surfaces of pure titanium implants and their accessories.

[0008] Electrochemical anodic oxidation is a promising nanotechnology that creates nano-scale structures on the surface of pure titanium implants, opening up new possibilities for improving the bioactivity of implants and promoting rapid and effective bone integration. Through in-depth research and application optimization of this technology, it is expected that the clinical performance of titanium implants will be significantly improved in the future.

[0009] The main technical difficulties and problems to be overcome in the present invention are as follows: how to provide an EA system that can be widely used for pure titanium surfaces with different morphologies, and retain the original micron-scale morphology of the pure titanium surface while preparing nano-pores; the system has a certain ductility and can achieve the preparation of nano-structures with both micro- and nano-scale morphologies on pure titanium surfaces with different morphologies at voltages between 40 - 80V; the nano-pores with both micro- and nano-scale morphologies prepared in the present invention have better mechanical strength than nano-tubes and are suitable for the surface of bone implants; in addition, compared with the pure titanium surface, the surface of the nano-pores with both micro- and nano-scale morphologies prepared in the present invention has better hydrophilicity and protein adhesion ability, can be quickly wetted by plasma after being implanted into the human body, is beneficial to the adhesion of tissue proteins and cells, and also has a certain drug-loading function.

[0010] The present invention provides an EA system and method, which can prepare nano-pores with a certain stability and protein adhesion ability on pure titanium surfaces with different morphologies, and while preparing the nano-pores, try to retain the micron-scale morphology surface of the pure titanium surface, and finally obtain a surface feature of nano-structures with both micro- and nano-scale morphologies on the pure titanium surface.

[0011] The present invention provides a preparation method for nano-treating a pure titanium surface to obtain nano-structures with both micro- and nano-scale morphologies. The specific steps of the preparation method are as follows:

[0012] First step, stir deionized water with a volume fraction of 0.5 - 10% and ammonium fluoride with a mass fraction of 0.2 - 0.5% in an organic solvent ethylene glycol to prepare an electrolyte solution.

[0013] Second step, before preparing nano-pores on the pure titanium surface, pre-adjust the electrolyte solution obtained in the first step: by repeatedly performing electrochemical anodic oxidation (EA) on pure titanium (such as low-value pure titanium sheets and pure titanium rods), to adjust parameters such as the conductivity and pH of the electrolyte solution.

[0014] Third step, through the adjustment in the second step, adjust the conductivity of the electrolyte solution to be between 480 - 495 μs / cm 2 , and adjust the pH to be between 7.0 - 7.8 to achieve the optimal conditions for nano-pore preparation (refer to the literature [3, 5] published by the inventors).

[0015] Fourth step, in the electrolyte solution that has achieved the optimal conditions for nano-pore preparation obtained in the third step, apply a voltage of 40 - 80V to the pure titanium through a DC regulated power supply for EA, and it is possible to prepare nano-pore structures with a certain porosity and relatively uniform diameter on pure titanium surfaces with different roughnesses and morphologies, while retaining their original micron-scale morphology, and finally prepare nano-structures with both micro- and nano-scale morphologies on the pure titanium surface.

[0016] In the first step, the volume fraction of the deionized water is 0.5 - 10%, preferably 1 - 3%.

[0017] In the first step, the mass fraction of the ammonium fluoride is 0.2 - 0.5%, preferably 0.3%.

[0018] In the first step, the quality of the ethylene glycol is spectroscopically pure.

[0019] In the first step, the stirring speed is 300 - 1000 rpm, preferably 350 - 500 rpm.

[0020] In the first step, the stirring time is 30 - 60 minutes, preferably 40 - 45 minutes.

[0021] In the second step, the pure titanium is commercially available pure titanium, such as one or more of TA1, TA2, etc., preferably TA2.

[0022] In the second step, the morphology of the pure titanium includes smooth titanium, rough titanium, micro - grooved titanium, etc.

[0023] In the second step, the form of the pure titanium includes pure titanium sheets, pure titanium rods, etc. The thickness of the pure titanium sheet is 0.2 - 0.5 mm, preferably 0.25 - 0.3 mm, and the diameter of the pure titanium rod is 1 mm - 10 mm, preferably 1 mm - 5 mm.

[0024] In the second step, the number of EA times is 2 - 8 times, preferably 3 - 5 times.

[0025] Before the second step, it also includes setting up an EA electrochemical treatment system: Pour the electrolyte obtained in the first step into a 500 ml beaker, cover the beaker with a foam sponge, pass the pure titanium of the cathode and anode through the foam sponge and immerse them in the electrolyte, connect the power supply to the pure titanium of the anode and cathode respectively for EA. The process of EA needs to be completed on a magnetic stirrer, adjust the rotation speed to 200 - 1000 revolutions, and continuously stir the electrolyte during the process; preferably, the pure titanium of the cathode and anode is the same or similar (for example, if the anode is a pure titanium sheet, the cathode should also be a pure titanium sheet of a similar thickness), and adjust the rotation speed to 300 - 500 revolutions.

[0026] In the second step, the pre - adjusted EA parameters are: 80 V, the maximum current is 50 mA, 2 hours for 1 time, and the total number of adjustment times is 2 - 10 times; preferably, the number of adjustment times is 4 - 6 times.

[0027] In the third step, the conductivity of the electrolyte is adjusted to 480 - 495 μs / cm 2 preferably 483 - 492 μs / cm 2 .

[0028] In the third step, the pH adjustment is between 7.0 and 7.8, preferably between 7.2 and 7.6.

[0029] In the fourth step, the DC regulated power supply provides a voltage of 40 - 80V, preferably 60 - 80V.

[0030] In the fourth step, the time of EA is 5 - 30 minutes, preferably 10 minutes.

[0031] The present invention also provides a titanium product prepared by the preparation method as described above. The nano - pore diameter on the surface of the titanium product is 40 - 60nm, the porosity is 10% - 15%, and the surface of the nano - pores is stable with basically no cracks.

[0032] The present invention also provides a nano - treatment system for pure titanium, and the system includes:

[0033] DC regulated power supply: The maximum voltage needs to be ≥80V, and the maximum current needs to be ≥50mA;

[0034] Closed electrolytic cell: The outer shell should be made of inert materials such as plastic or glass, and the top should be able to be closed. For example: a plastic beaker, and the top is closed by a plastic lid or foam plastic.

[0035] Neutral electrolyte: It needs to be prepared using ethylene glycol, deionized water and ammonium fluoride.

[0036] The present invention also provides the application of the preparation method as described above, the titanium product as described above, or the system as described above in the surface treatment of pure - titanium biomaterials.

[0037] Specifically, the pure - titanium biomaterials include intra - bone implants, dental implants and upper abutments, etc.

[0038] In the specific embodiment of the present invention, SEM (scanning electron microscope) and AFM (atomic force microscope) data illustrate that the present invention is applicable to pure titanium surfaces with different morphologies, including but not limited to polished smooth titanium, micro-grooved titanium polished along a single direction, and rough titanium with irregular surface morphology. SEM and AFM images also show that when preparing nanopores on pure titanium surfaces of different materials, the present invention will, to a certain extent, retain the original micron morphology of the pure titanium material, and finally achieve a surface with both micro- and nano-morphologies. XPS (X-ray photoelectron spectroscopy) and XRD (X-ray diffraction) data explain that when the present invention performs EA treatment on the pure titanium surface, the F element in the electrolyte will be introduced to the surface of the prepared nanopores, but will not change the crystal lattice of the pure titanium surface. WCA (water contact angle) data indicates that the present invention will greatly improve the hydrophilicity while preparing nanopores with both micro- and nano-morphologies on the pure titanium surface. The protein adhesion experiment demonstrates that the nanopores with both micro- and nano-morphologies prepared on the pure titanium surface by the present invention can enhance the adhesion of different proteins on its surface, indicating its good biological activity. In addition, nanoindentation experiment data shows that the nanopores with both micro- and nano-morphologies prepared on pure titanium surfaces with different morphologies have a Young's modulus of about 30 - 60 GPa and a hardness of 1.5 - 2.7 GPa, meeting the conditions for becoming dental / bone implants.

[0039] During the process of preparing nanopores with both micro- and nano-morphologies on the pure titanium surface, the present invention can retain the micron morphology of the original implant surface, and finally obtain a nanopore structure with both micro- and nano-morphologies on the pure titanium surface.

[0040] Advantageous technical effects of the present invention compared with the prior art: The main advantage of the present invention is that it can be applied to pure titanium surfaces with different morphologies, and while preparing nanopores on the pure titanium surface, retain its original micron-level morphology, and finally prepare a nano-structure with both micro- and nano-morphologies on the pure titanium surface; the nanopore structure with both micro- and nano-morphologies prepared by the present invention on the pure titanium surface is a surface-fused nanotube structure. Compared with simple nanotubes, the nanopores have better mechanical strength and stability (advantages compared with nanotubes); the nanopore structure with both micro- and nano-morphologies prepared by the present invention on the pure titanium surface can significantly improve the hydrophilicity and protein adhesion ability of the pure titanium surface, providing a basis for its further clinical transformation on the implant surface. Description of the Drawings

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0042] Figure 1 Schematic diagram of the preparation method for obtaining a nano - structure with both micro - and nano - morphologies on the surface of nano - treated pure titanium according to the present invention.

[0043] Figure 2 Scanning electron microscope (SEM) images showing the micro - and nano - porous structures with both micro - and nano - morphologies prepared on the surfaces of pure titanium with different morphologies by the electrochemical oxidation (EA) system of the present invention.

[0044] Figure 3 Atomic force microscope (AFM) images showing the characteristics of pure titanium and the micro - and nano - porous structures with both micro - and nano - morphologies prepared on the surface of pure titanium according to the present invention: (A) Smooth titanium has a smooth surface. The nanopores S80 (D) (smooth nanopores) prepared on its surface have micron - scale morphology but are relatively smooth, while the nano - scale morphology is relatively rough; (B) Rough titanium has a micron - scale rough surface, and the nanopores R80 (E) (rough nanopores) prepared on its surface retain their original micron - scale morphology and are nanopores with both micro - and nano - morphologies; (C) Micro - grooved titanium has a micron - scale morphology, i.e., micro - grooves, and the nanopores M60 (F) (micro - grooved nanopores) prepared on its surface are based on its original micro - grooved surface and retain their original micron - scale morphology.

[0045] Figure 4 X - ray photoelectron spectroscopy (XPS) and X - ray diffraction (XRD) diagrams indicating the chemical differences between pure titanium and the micro - and nano - porous structures with both micro - and nano - morphologies prepared on the surface of pure titanium according to the present invention: The left figure is the XPS diagram, and the right figure is the XRD diagram.

[0046] Figure 5 Water contact angle (WCA) experiments indicating that the micro - and nano - porous structures with both micro - and nano - morphologies prepared on different pure titanium surfaces according to the present invention all have better hydrophilicity.

[0047] Figure 6 Protein adhesion experiments indicating that compared with pure titanium, all the micro - and nano - porous structures with both micro - and nano - morphologies prepared on different pure titanium surfaces according to the present invention can adhere more proteins.

[0048] Figure 7 Nano - indentation experiments indicating that for the micro - and nano - porous structures with both micro - and nano - morphologies obtained by nano - treating the surface of pure titanium according to the preparation method of the present invention, the Young's modulus of its surface is about 30 - 60 GPa, and the hardness is 1.5 - 2.7 GPa. Compared with the reported titanium nanotubes with a Young's modulus of only 0.3 - 16.6 GPa and a hardness of 2 (0.1 - 0.3 GPa) [4, 7] , the said nanoporous structure has better mechanical properties. Detailed implementation manners

[0049] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0050] The present invention is further described in detail in conjunction with the following specific examples and drawings, and the protection content of the present invention is not limited to the following examples. Without departing from the spirit and scope of the inventive concept, changes and advantages that can be thought of by those skilled in the art are included in the present invention, and the attached claims are the scope of protection. The process, conditions, reagents, experimental methods, etc. for implementing the present invention, except for the contents specifically mentioned below, are all common knowledge and common common sense in the art, and the present invention does not specifically limit the content.

[0051] The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0053] The present invention discloses a preparation method and application of nano-treating a pure titanium surface to obtain a nanostructure with both micro-nano morphology. The preparation method is suitable for nano-treating pure titanium surfaces with various morphologies, and can prepare nanopores on pure titanium surfaces with different morphologies while retaining the original micron morphology as much as possible, thereby realizing the preparation of nanopores with both micro-nano morphology on the pure titanium surface. In addition, the nanopores with both micro-nano morphology prepared on the pure titanium surface by the preparation method have excellent hydrophilicity and protein adhesion properties, and have better mechanical properties than traditional nanotubes, and have the potential to be applied to the surface treatment of pure titanium implants and bases. The present invention has broad application prospects.

[0054] Unless otherwise specified, the test materials used in the examples of the present invention are all conventional biochemical reagents. Example

[0055] Experimental Materials:

[0056] Reagents: ethylene glycol (spectrally pure), deionized water, ammonium fluoride (super pure).

[0057] Equipment: A DC regulated power supply with a voltage range greater than or equal to 80V and a maximum current greater than or equal to 50mA, e.g., Keysight E36106B, an analytical balance, a magnetic stirrer.

[0058] Apparatus: Measuring cylinders, magnetic rotors, plastic beakers, magnetic stirrers (maximum rotation speed greater than or equal to 1000 rpm), sponge materials, parafilm sealing membranes, and several pure titanium sheets.

[0059] Experimental method:

[0060] The preparation method for obtaining a nano-structured pure titanium surface with both micro- and nano-topographies in the present invention is as Figure 1 shown, and the specific steps are as follows:

[0061] 1. Preparation of electrolyte: Under the precise guidance of an analytical balance and a measuring cylinder, prepare an ethylene glycol electrolyte containing 1% by volume of deionized water and 0.3% by mass of ammonium fluoride. For example, accurately weigh 1.5 g of ammonium fluoride powder and 5 ml of deionized water, and then pour them into 495 ml of ethylene glycol solution. Add a cleaned magnetic rotor to the solution and stir for 30 - 60 minutes under the action of a magnetic stirrer to fully dissolve and uniformly mix the ammonium fluoride powder.

[0062] 2. Preparation of pure titanium: The rough titanium is a commercially available pure titanium sheet, slightly polished with 200 - mesh sandpaper, with a thickness of 0.25 mm, and the length and width can be cut to a suitable size with scissors, such as 10 mm * 10 mm; the micro-grooved titanium is the rough titanium polished sequentially with 500, 1000, and 1500 - mesh sandpapers along a single direction; the smooth titanium is the rough titanium polished sequentially with 500, 1000, 1500, 2000, 3000, and 5000 - mesh sandpapers along multiple directions and then polished with polishing paste + polishing cloth. After repeatedly rinsing the prepared titanium sheets with deionized water + absolute ethanol, immerse them in absolute ethanol for ultrasonic cleaning and air drying.

[0063] 3. Setup of the EA electrochemical treatment system: Pour the electrolyte obtained in step 1 into a 500 - ml beaker, cover the beaker with a foam sponge, insert the pure titanium sheets of the cathode and anode through the foam sponge and immerse them in the electrolyte, and connect the power supply to the anode titanium and cathode titanium respectively for EA. The EA process needs to be completed on a magnetic stirrer, adjust the rotation speed to 350 - 500 revolutions, and continuously stir the electrolyte during the process.

[0064] 4. Electrolyte pre-conditioning: This part refers to the previously published articles [3, 5]. Through repeated EA of pure titanium (including rough titanium, micro-grooved titanium and smooth titanium, with no limit on surface roughness), the EA parameters were adjusted to: 80V, maximum current 50mA, 2 hours per time, and a total of 5-10 times, so that the conductivity of the electrolyte obtained in step 1 was 480~495μs / cm 2 , pH is adjusted between 7.0 and 7.8. The pre-adjustment of the electrolyte obtained in step 1 of this embodiment is consistent with the electrochemical system used in the formal EA process.

[0065] 5. EA process: Apply the electrolyte pre-adjusted in step 4, adjust the EA parameters to: voltage 40, 60 or 80V, maximum current 30-40mA, each EA preparation time for nanopores is 10 minutes, and EA is performed on pure titanium (rough titanium, micro-grooved titanium and smooth titanium). Nanopore structures with a certain porosity and relatively uniform diameter and micro-nano morphology can be prepared on the surface of pure titanium with different roughness and morphology, namely, each group of nanopores S80, M60, R80.

[0066] The groups of nanopores S80, M60, and R80 obtained by the above method were respectively measured by SEM, AFM, XPS, XRD, water contact angle experiment WCA (experimental instrument: OCA Pro15 Dataphysics; liquid: deionized water; amount of liquid added each time: 2 μL; taking a photo 1 second after adding to measure the contact angle), protein adhesion experiment, and nanoindentation experiment (experimental equipment: Agilent-G200; indenter: Berkovich triangular indenter, angle of 142.3°; pressure direction: perpendicular to the sample surface, maximum pressure of 10000 μN) to measure the groups of nanopores S80, M60, and R80 obtained in the embodiment of the present invention, thereby characterizing the nanopores prepared on the pure titanium surface in the embodiment of the present invention.

[0067] The nanopores (groups of nanopores S80, M60, and R80) prepared on the pure titanium surface in the present invention and their characterizations are as follows:

[0068] like Figure 2As shown, under the EA system of the present invention, it is noted that: compared with pure titanium, in the embodiments of the present invention, smooth titanium (STi), micro-grooved titanium (MTi), and rough titanium (RTi) surfaces are oxidized at 40V, 60V, and 80V for 10 minutes to obtain a nano-porous structure on the surface of anodized pure titanium. The present invention discovers that a surface-fused nano-porous structure can be prepared on the surfaces of pure titanium with three different morphologies, and while preparing the nano-pores, the original micron-scale morphology can be retained, ultimately achieving a nano-porous structure with both micro- and nano-morphologies. Smooth titanium: has a smooth morphology, and the nano-pores prepared on its surface have a nano-morphology; micro-grooved titanium: has parallel micro-grooves on its surface, and the nano-pores prepared on its surface are regularly arranged along the micro-grooves on its surface; rough titanium: has an irregular surface roughness, and the nano-pores prepared on its surface will to a certain extent retain its original micron-scale irregular roughness. In addition, through SEM analysis, the diameters of the nano-pores (S80, R80) prepared on the surfaces of smooth titanium and rough titanium at 80V in the embodiments of the present invention are similar to the diameter of the nano-pores prepared on the surface of micro-grooved titanium at 60V (M60). Therefore, S80, R80, and M60 are selected for subsequent experimental analysis and comparison.

[0069] As Figure 3 shown, smooth titanium (A) has a smooth surface, and the nano-pores S80 (D) (smooth nano-pores) prepared on its surface have a surface with a nano-morphology; rough titanium (B) has a micron-scale rough surface, and the nano-pores R80 (E) (rough nano-pores) prepared on its surface are nano-pores that retain its original micron-morphology and have both micro- and nano-morphologies; micro-grooved titanium (C) has a micron-scale morphology, namely micro-grooves, and the morphology of the nano-pores M60 (F) (micro-grooved nano-pores) prepared on its surface is based on its original micro-grooved surface and retains its original micron-morphology.

[0070] As Figure 4 shown, the left figure is an XPS diagram: compared with the surface of pure titanium, the nano-pores with both micro- and nano-morphologies prepared on the surface of pure titanium in the embodiments of the present invention have an F element component. This indicates that during the EA oxidation process, the F element in the electrolyte is introduced into the surface of pure titanium, forming a Ti-F / Ti-O-F complex. Moreover, for the nano-pores (each group of nano-pores S80, M60, R80) prepared on different pure titanium surfaces in the embodiments of the present invention, all the nano-pore surfaces have better hydrophilicity and can be wetted by plasma and tissue fluid faster in the human body, having the potential to promote tissue healing. It is noted that the nano-pores with both micro- and nano-morphologies prepared by EA vegetation have the potential to be applied on the surfaces of implants and abutments. The right figure is an XRD diagram, indicating that there is no obvious difference in the surface lattice and the phase of the pure titanium surface for the nano-pores with both micro- and nano-morphologies prepared on the surface of pure titanium in the embodiments of the present invention.

[0071] As Figure 5As shown, the present invention used the water contact angle experiment (WCA) to measure the hydrophilicity of the pure titanium surface and the surfaces of the nano-pores with both micro- and nano-morphologies on the pure titanium obtained in the embodiments of the present invention (nano-pores S80, M60, and R80 in each group). The results showed that the hydrophilicity of the pure titanium surface without EA treatment was average (the water contact angle was 55.05 ± 1.30°), while the hydrophilicity of all the surfaces of the nano-pore structures with both micro- and nano-morphologies on the pure titanium was significantly better than that of the pure titanium surface (the contact angle was 11.33 - 14.47°), and the difference was statistically significant. The WCA experiment of the present invention found that the nano-pore structure with both micro- and nano-morphologies prepared by EA treatment on the pure titanium surface would significantly improve the hydrophilicity of the titanium sample surface, which was suitable for preparing materials with strong hydrophilicity, especially medical intraosseous / dental implants and their accessories.

[0072] As Figure 6 shown, the protein adhesion experiment (materials: pure titanium and nano-pores S80, M60, and R80 in each group) [8, 9] showed that: compared with the pure titanium surface, all the nano-pores with both micro- and nano-morphologies prepared on the pure titanium surface in the embodiments of the present invention (nano-pores S80, M60, and R80 in each group) had better protein adhesion ability. The protein adhesion ability of the nano-pores S80 and R80 on the pure titanium surface obtained by EA at 80V voltage in the embodiments of the present invention was higher than that of the nano-pore M60 on the pure titanium surface obtained at 60V voltage. It included the most common albumin (BSA), mucoprotein, fibronectin, and histone in plasma. The experiment indicated that the nano-treated pure titanium implant was beneficial to the adhesion of protein components in plasma and tissue fluid on its surface, which helped the adhesion of cells on its surface, etc. In addition, the increased protein adhesion amount also indicated that the nano-treated pure titanium implant, with the nano-pores with both micro- and nano-morphologies prepared on the pure titanium surface, had the potential to be used as a drug carrier to achieve local drug loading - controlled release and further improve its biological activity in vivo.

[0073] Albumin, as the most common protein in plasma, its adhesion can assist the colonization and adhesion of other cells on the material surface; mucoprotein is a common protein in saliva, and its adhesion can regulate cell adhesion and growth; fibronectin is an important component of the extracellular matrix, and its adhesion is beneficial to the adhesion of fibroblasts, etc. and the secretion of extracellular matrix; while histone is a positively charged protein, and its adhesion can, to a certain extent, simulate the loading of positively charged drug molecules on the surface of the nano-treated implant.

[0074] As Figure 7As shown, the nanoindentation experiment (experimental equipment: Agilent-G200; indenter: Berkovich triangular indenter with an angle of 142.3°; pressure direction: perpendicular to the sample surface, maximum pressure: 10,000 μN) indicates that the nanohole structure with both micro-nano topography prepared on the surface of the pure titanium material by the embodiment of the present invention has a Young's modulus of about 30-60 GPa and a hardness of 1.5-2.7 GPa on its surface. Compared with the Young's modulus of 0.3-16.6 GPa and hardness of less than 1.0 GPa of traditional nanotubes [4] , the nanohole structure has better mechanical properties.

[0075] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0076] 1. T. Guo, K. Gulati, H. Arora, P. Han, B. Fournier, S. Ivanovski,Orchestrating soft tissue integration at the transmucosal region of titaniumimplants, Acta Biomater 124 (2021) 33-49.

[0077] 2. K. Gulati, H.-J. Moon, T. Li, P.T. Sudheesh Kumar, S. Ivanovski,Titania nanopores with dual micro- / nano-topography for selective cellularbioactivity, Materials Science and Engineering: C 91 (2018) 624-630.

[0078] 3. T. Guo, N.A.K. Oztug, P. Han, S. Ivanovski, K. Gulati, Old is Gold: Electrolyte Aging Influences the Topography, Chemistry, and Bioactivity of Anodized TiO2 Nanopores, ACS Applied Materials & Interfaces 13(7) (2021) 7897-7912.

[0079] 4. S. Durdu, G. Cihan, E. Yalcin, A. Altinkok, Characterization and mechanical properties of TiO2 nanotubes formed on titanium by anodic oxidation, Ceramics International 47(8) (2021) 10972-10979.

[0080] 5. T. Guo, S. Ivanovski, K. Gulati, Tuning electrolyte aging in titanium anodization to fabricate nano-engineered implants, Surface and Coatings Technology 447 (2022) 128819.

[0081] 6. T. Guo, S. Ivanovski, K. Gulati, Fresh or aged: Short time anodization of titanium to understand the influence of electrolyte aging on titania nanopores, Journal of Materials Science & Technology 119 (2022) 245-256.

[0082] 7. K. Oh, K. Lee, J. Choi, Influence of geometry and crystalstructures of TiO2 nanotubes on micro Vickers hardness, Materials Letters 192(2017) 137-141.

[0083] 8. T. Guo, N.A.K. Oztug, P. Han, S. Ivanovski, K. Gulati, Untwiningthe topography-chemistry interdependence to optimize the bioactivity of nano-engineered titanium implants, Applied Surface Science 570 (2021) 151083.

[0084] 9. T. Guo, N.A.K. Oztug, P. Han, S. Ivanovski, K. Gulati, Influenceof sterilization on the performance of anodized nanoporous titanium implants,Materials Science and Engineering: C 130 (2021) 112429.

Claims

1. A method for preparing a nanostructure with micro-nano morphology by nano-treating the surface of pure titanium, characterized in that: The preparation method The following steps are involved: The first step is to stir deionized water and ammonium fluoride in an organic solvent, ethylene glycol, to prepare an electrolyte containing 0.5-10% by volume of deionized water and 0.2-0.5% by mass of ammonium fluoride; the stirring speed is 300-1000 rpm; the stirring time is 30-60 minutes; The second step is to pre-adjust the electrolyte obtained in the first step before preparing nanopores on the surface of pure titanium: the conductivity and pH parameters of the electrolyte are adjusted by repeatedly electrochemically anodizing pure titanium; Before the second step, it also includes building an electrochemical anodizing electrochemical treatment system: pouring the electrolyte obtained in the first step into a 500ml beaker and covering the beaker with a foam sponge, immersing the cathode and anode pure titanium through the foam sponge into the electrolyte, and connecting the power supply to the anode and cathode pure titanium respectively for electrochemical anodizing; the electrochemical anodizing process needs to be completed on a magnetic stirrer, adjusting the speed to 200-1000 rpm, and the electrolyte needs to be continuously stirred during the process; The third step is to adjust the conductivity of the electrolyte to 480-495 μs / cm by adjusting the electrolyte in the second step. 2 , pH was adjusted between 7.0 and 7.8 to achieve the best conditions for nanopore preparation; In the fourth step, in the electrolyte obtained in the third step to achieve the optimal conditions for nanopore preparation, a voltage of 40-80V is provided by a DC voltage regulator to electrochemically anodize pure titanium, so that nanopore structures with a certain porosity and relatively uniform diameter can be prepared on the pure titanium surface with different roughness and morphology, while retaining its original micron-level morphology, and finally a nanostructure with both micro-nano morphology is prepared on the pure titanium surface; The morphology of the pure titanium includes smooth titanium and rough titanium; The rough titanium is a commercially available pure titanium sheet, which is slightly polished with 200-grit sandpaper to a thickness of 0.25 mm; The smooth titanium is rough titanium that is repeatedly polished in multiple directions using 500, 1000, 1500, 2000, 3000 and 5000 grit sandpaper in sequence, and then polished using polishing paste + polishing cloth.

2. The preparation method according to claim 1, characterized in that In the first step, The quality of the ethylene glycol is spectrally pure.

3. The preparation method according to claim 1, characterized in that: In the second step, The number of times of electrochemical anodization is 2-8 times.

4. The preparation method according to claim 1, characterized in that: In the second step, The pre-adjusted electrochemical anodizing parameters are: 80V, maximum current 50mA, 2 hours per time, and the number of adjustments is 2-10 times.

5. The preparation method according to claim 1, characterized in that: In the fourth step, the electrochemical anodization time is 5-30 minutes.

6. The titanium product prepared by the preparation method according to any one of claims 1 to 5, characterized in that: The nanopores on the surface of the titanium product have a pore size of 40-60 nm and a porosity of 10%-15%, and the surface of the nanopores is stable with substantially no cracks.

7. Use of the preparation method according to any one of claims 1 to 5 or the titanium product according to claim 6 in the surface treatment of pure titanium biomaterials, wherein the pure titanium biomaterials include endosseous implants, dental implants and upper abutments.

Images