CN116288203A - Corrosion-resistant antibacterial biomedical composite coating and preparation method thereof - Google Patents

Abstract

The invention discloses a corrosion-resistant and antibacterial biomedical composite coating and a preparation method thereof, belonging to the technical field of biological materials. The coating material is composed of ZnO, CuO and _Cu2O , including a ZnO transition layer with a thickness of 50nm-100nm and a surface layer mixed with ZnO, CuO and _Cu2O with a thickness of 150nm-500nm. The composite coating metal oxide has stable properties, compact structure, good corrosion resistance, and can effectively protect the substrate; the needle-like protrusions increase the surface roughness and endow the coating with better surface hydrophilicity; at the same time The surface layer composed of ZnO, CuO and Cu ₂ O can effectively kill pathogenic microorganisms such as Staphylococcus aureus and Escherichia coli under the synergistic antibacterial enhancement effect, showing good antibacterial properties. The composite coating meets the dual requirements of corrosion resistance and antibacterial properties in vivo and in vitro, and is suitable as a functional coating for the surface of biomedical materials such as metal implants and surgical instruments.

Description

A kind of corrosion-resistant, antibacterial biomedical composite coating and preparation method thereof

technical field

The invention belongs to the technical field of biomedical functional coatings, and in particular relates to a corrosion-resistant and antibacterial biomedical composite coating and a preparation method thereof.

Background technique

When biomedical materials such as metal implants and surgical instruments are used in clinical practice, because their metal bonds are exposed, they are not resistant to corrosion by human body fluids, and they are easy to decompose and fail, resulting in a short service life of the implants; and the lack of antibacterial and antibacterial activities. Afterwards, it is easy to cause bacterial infection and inflammation, which will lead to problems such as failure of implantation surgery. In order to solve these problems, researchers have tried to combine active functional groups, metals and medical implant materials through grafting, deposition, spraying, mechanical blending and other modification methods to endow them with corrosion resistance and antibacterial properties. However, it has been found through practice that the above-mentioned technical means have shortcomings such as uneven distribution of modified materials on the surface, poor local corrosion resistance, and even affect the original high strength and biocompatibility of the matrix material, and the selected modified materials also exhibit However, there are some deficiencies such as low antibacterial activity and weak long-term antibacterial ability. What's more serious is that it is difficult to obtain better corrosion resistance and antibacterial property at the same time in the above research on the modification of implant materials.

Aiming at the defects left over from the previous research, the present invention has found through investigation that the magnetron sputtering technology has the advantages of simple operation process, high output, controllable product composition, etc., especially the coating prepared by it is directly coated on the base material surface, and the thickness can be controlled below a few hundred nanometers, which can basically not affect the inherent properties of the matrix material; at the same time, the crystal grains obtained by magnetron sputtering are nanocrystalline, which can be tightly stacked during deposition, and can be grown during subsequent annealing. It is further transformed into a dense structure, thereby effectively shielding the direct contact between the substrate and the outside world. On the other hand, the nanocrystals produced by magnetron sputtering can pierce the cell wall of pathogenic bacteria, which also has a positive effect on the antibacterial performance of the coating. From this point of view, the preparation of functional coatings by magnetron sputtering is the best technical means to improve the corrosion resistance and antibacterial properties of implant materials while avoiding other negative effects.

In the selection of modified materials, the active functional groups in the past are easy to be lost due to surface wear. Although the metal wear resistance is high, its hydration resistance is weak. Too fast decomposition not only affects the corrosion resistance of the coating, but also affects the corrosion resistance of the coating. It is that the long-term antibacterial ability of the coating is weak, and even cytotoxicity is produced due to excessive release. On the one hand, metal oxides inherit the antibacterial properties of metals by releasing ions, and on the other hand, they use the polar ion covalent bonds between metal atoms and oxygen atoms to resist hydration and increase their own corrosion resistance. However, due to the stability of metal oxides, it is difficult to obtain excellent antibacterial properties only by releasing metal ions, so it is necessary to find more ideal antibacterial metal oxide materials from the perspective of bactericidal mechanism. Among them, ZnO, CuO and Cu ₂ O not only have the advantages of the above-mentioned metal oxides, but also are typical n-type (ZnO) and p-type (CuO, Cu ₂ O) semiconductor materials, which can improve the photocatalytic activity by constructing a pn structure. Further, more "active oxygen" substances are produced in the visible light range, and the "active oxygen" is used to oxidize coenzyme A and interfere with its gene expression to further kill bacteria, thereby maintaining its chemical stability and corrosion resistance while improving its antibacterial properties performance.

The invention uses magnetron sputtering combined with subsequent annealing to prepare a corrosion-resistant and antibacterial composite coating; the composite coating has a transition layer and a surface layer double-layer structure, and a pn composite structure is constructed between the layers; at the same time, the surface layer is ZnO, CuO The mixed phase with Cu ₂ O builds a pn composite structure between the phases, thus utilizing Zn ²⁺ , Cu ¹⁺ , Cu ²⁺ ions, surface nano-grains, metal oxides and interlayer synergistic antibacterial Enhancement effect to obtain excellent antibacterial properties; at the same time, adjust the process parameters of magnetron sputtering and subsequent annealing process, endow the metal oxide in the composite coating with more stable properties and denser structure, and improve the composite coating. Corrosion resistance: Finally, the composite coating has good corrosion resistance and antibacterial performance at the same time, which can meet the needs of metal implants and other properties for the above properties, and then realize the application on its surface.

Contents of the invention

The present invention is based on the dual requirements of biomedical materials such as metal implants and medical devices for corrosion resistance and antibacterial properties. On the basis of avoiding the defects of previous studies, the invention adopts magnetron sputtering combined with subsequent annealing to prepare a ZnO transition layer and a biomedical composite coating with a mixture of ZnO, CuO and Cu ₂ O as the surface layer; the composite coating exhibits good hydrophilicity, body fluid corrosion resistance and antibacterial properties, which can meet the performance requirements of implant materials. Suitable for application on implant surfaces as a functional coating.

The purpose of the present invention is to propose a corrosion-resistant, antibacterial biomedical composite coating, which is composed of three materials: ZnO, CuO and Cu ₂ O, and has a ZnO transition layer of 50nm to 100nm and a ZnO, CuO and CuO of 150nm to 500nm. The Cu ₂ O composite layer is constructed to form a double-layer composite structure.

The cross-section of the ZnO, CuO and Cu ₂ O composite layer is nano-columnar crystals with an average diameter of 22nm-34nm and oriented arrangement, and the surface is dense fine crystal grains of 15nm-60nm combined with needle-like protrusions.

The metal oxides selected for the biomedical composite coating in the present invention are stable in properties, and form a compact structure through magnetron sputtering and subsequent annealing, and can also utilize the released metal ions, nanocrystal grains, and phase and structure The synergistic enhancement effect to antibacterial sterilization can meet the needs of implant materials for corrosion resistance and antibacterial performance, so it is suitable as a functional coating for the surface of metal implants, medical devices, etc.

The composite coating of the present invention has _a ZnO transition layer and a surface layer mixed with ZnO, CuO and _Cu2O . Phase-to-phase realization; the advantages of stable metal oxide properties, compact structure, synergistic antibacterial between phases and structures can endow the composite coating with better corrosion resistance and antibacterial properties, and is suitable as a biofunctional coating in metal implants. It can be applied on the surface of medical materials such as bodies and surgical instruments to achieve the dual purpose of protecting the body of medical materials and killing pathogenic microorganisms in vivo and in vitro.

Another object of the present invention is to provide a method for preparing a corrosion-resistant and antibacterial biomedical composite coating, which combines magnetron sputtering with subsequent annealing treatment; magnetron sputtering has the advantages of simple operation process, high output, and controllable product components. , mainly capable of preparing coatings with controllable thickness and nano-grain products; subsequent annealing can further strengthen the physical and chemical properties of the products, eliminate internal stress, and eliminate pores by promoting grain growth to further improve the compactness of the coating; When preparing a composite coating, the product can be controlled by adjusting the volume fraction of the mixed gas of Ar and _O2 , the sputtering power of the Zn target/Cu target, the magnetron sputtering time, the annealing temperature, the annealing time and the pressure in the annealing furnace chamber. The phase composition, transition layer and surface layer thickness, cross-section and surface morphology, etc., thereby changing the corrosion resistance and antibacterial performance of the composite coating, specifically including the following steps:

(1) The substrate was polished, and then placed in deionized water, absolute ethanol and acetone for ultrasonic cleaning; and the substrate was purged with _N2 gun and fixed on the sample stage in the magnetron sputtering chamber.

(2) The Zn and Cu targets are symmetrically installed on the target position and kept at 45° to the horizontal direction; seal the magnetron sputtering chamber, vacuumize, set the sample stage speed, adjust the distance between the sputtering target and the substrate, and adjust Working air pressure in preparation for magnetron sputtering.

(3) In a mixed gas atmosphere of Ar and O ₂ , first sputter the Zn target alone, and deposit a ZnO transition layer on the substrate; then adjust the volume ratio of the Ar and O ₂ mixed gas, and sputter the Zn and Cu targets at the same time. A surface layer mixed with ZnO, CuO and Cu ₂ O is deposited on the ZnO transition layer.

(4) The composite coating was taken out from the magnetron sputtering chamber and placed in an annealing furnace, annealed with _N2 as a protective gas, and the biomedical composite coating was obtained after natural cooling to room temperature.

Preferably, in the step (1) of the present invention, the substrate is polished step by step from coarse to fine with 200 mesh, 400 mesh, 600 mesh, 800 mesh, 1000 mesh, 1200 mesh, and 1500 mesh sandpaper.

Preferably, the substrate in step (1) of the present invention includes one of silicon substrate, titanium substrate, and bioglass; the purity of Zn and Cu metal targets in step (2) is ≥99%.

Preferably, the specific process of preparing for magnetron sputtering in the present invention is: start the mechanical pump and the molecular pump to pump the vacuum in the sputtering chamber to 1×10 ^-4 Pa～2×10 ^-4 Pa, set the sample stage The rotating speed is 15r/min; the distance between the sputtering target and the substrate is adjusted to 100mm, and the working pressure during sputtering is controlled at 0.7Pa.

Preferably, when step (3) of the present invention prepares the ZnO transition layer on the substrate by magnetron sputtering, Ar and _O in the mixed gas Relative content by volume fraction, Ar is 70%, O ₃₀ %; The sputtering power is 25W-30W, and the sputtering time is 30min-40min.

Preferably, when step (3) of the present invention prepares a _surface layer mixed with ZnO, CuO and Cu ₂ O by simultaneous sputtering on the ZnO transition layer, the relative content of Ar and O in the mixed gas is calculated by volume fraction, Ar The sputtering power of Zn metal _target is 45W-50W, the sputtering power of Cu metal target is 35W-45W, and the sputtering time is 10min-20min.

Preferably, during the annealing treatment in step (4) of the present invention, the annealing process parameter temperature is 450°C-500°C, the time is 1h-2h, the pressure in the cavity is 400Torr-430Torr, and the heating rate is 1.5°C/s.

Compared with the existing coating, the coating of the present invention is a composite coating, which can utilize the synergistic effect of phase and structure to improve the sterilization ability; it can obtain a dense structure by adjusting the parameters of magnetron sputtering and subsequent annealing ; The composite coating can have better corrosion resistance and antibacterial properties at the same time, and can meet the dual requirements of implant materials for the above-mentioned properties.

The beneficial effects of the present invention are as follows:

(1) The biomedical composite coating prepared by the present invention is composed of three metal oxides of ZnO, CuO and Cu ₂ O, and its polar ion covalent bond can resist hydration and exhibit corrosion resistance; it can release and kill The active ions of bacteria exhibit antibacterial properties; and as semiconductor materials, they can be used to build pn junctions.

(2) The biomedical composite coating prepared by the present invention has a double-layer structure of a transition layer and a surface layer, can build a p-n junction between layers, and use the generated "active oxygen" to further improve its antibacterial ability.

(3) The thickness of the transition layer and the surface layer of the biomedical composite coating prepared by the present invention can be adjusted to the ranges of 50nm-100nm and 150nm-500nm respectively.

(4) The biomedical composite coating prepared by the present invention has a surface layer of a mixture of three metal oxides, ZnO, CuO and Cu ₂ O, which can build a pn junction between phases; use the generated "active oxygen" to further improve its own Antibacterial ability.

(5) The biomedical composite coating prepared by the present invention has a surface cross-section of nano columnar crystals with an average diameter of 22nm to 34nm and oriented arrangement, showing a compact structure, which can isolate the contact between human body fluids and implant materials.

(6) The biomedical composite coating prepared by the present invention, its surface layer surface is dense 15nm～60nm fine grains combined with needle-like protrusions, and the dense fine grains have improved the compactness of the coating surface; The protuberances can effectively kill bacteria by piercing the cell wall of microorganisms.

(7) The biomedical composite coating prepared by the present invention has a water contact angle of 9.18 ^○ ±0.73 ^○ to 28.75 ^○ ±1.64 ^○ under the joint action of the dense fine grains and needle-like protrusions on the surface layer, showing better hydrophilicity.

(8) The biomedical composite coating prepared by the present invention has a self-corrosion potential of -0.38V～-0.24V in the simulated human body fluid under the joint action of the metal oxide itself and the dense structure, which is significantly greater than that of the titanium substrate- The self-corrosion potential of 0.70V～-0.65V shows better corrosion resistance to human body fluids.

(9) The biomedical composite coating prepared by the present invention has a bacteriostatic effect on 1×10 ⁶ CFU/ml E. The rate is 93.2%-99.7%, and the bacteriostasis rate against 1×10 ⁶ CFU/ml Staphylococcus aureus is 91.0%-99.8%, all higher than 90%, showing excellent bactericidal effect.

(10) The biomedical composite coating prepared by the present invention has good corrosion resistance and antibacterial property at the same time.

Description of drawings

Fig. 1 is the X-ray diffraction (XRD) pattern of the biomedical composite coating obtained in Example 1.

Figure 2 is the surface morphology of the biomedical composite coating obtained in Example 2 under a scanning electron microscope (SEM).

Figure 3 is the cross-sectional morphology of the biomedical composite coating obtained in Example 3 under a scanning electron microscope (SEM).

Fig. 4 is the 3D surface microscopic morphology of the biomedical composite coating obtained in Example 1 by an atomic force microscope (AFM).

Figure 5 is (a) UV-Vis Diffuse Reflectance Spectrum (UV-VisDRS) and (b) Photoluminescence Spectrum (PL) of the biomedical composite coating obtained in Example 1.

Fig. 6 is a comparison diagram of the potentiodynamic polarization Tafel curves of the biomedical composite coating obtained in Example 1 and the metal titanium sheet substrate.

Fig. 7 is the water contact angle test diagram of the metal titanium sheet substrate (a) and the biomedical composite coating (b) obtained in Example 1.

Fig. 8 is a photo of the colonies of the biomedical composite coating obtained in Example 1 and the metal titanium sheet directly contacted with the target bacteria Escherichia coli and Staphylococcus aureus for 1 hour, and then cultured on the bacterial suspension for 24 hours.

Detailed ways

The following examples are a series of detailed descriptions aimed at the material characteristics and preparation methods of the present invention, which should not be construed as limiting the claims of the present invention. It should also be pointed out that several replacements and improvements made without departing from the concept of the present invention all belong to the protection scope of the present invention. Unless otherwise specified, the raw materials used in the present invention are commercially available conventional products, and the lowest grade is analytically pure.

Example 1

A corrosion-resistant and antibacterial biomedical composite coating, which is composed of three materials: ZnO, CuO and Cu ₂ O, has a transition layer and a surface layer with a double-layer composite structure; the transition layer is 50nm of ZnO, and the surface layer is 150nm of ZnO, CuO and Cu ₂ O mixture; the surface section is nano-columnar crystals with an average diameter of 22nm and oriented arrangement, and the surface is dense 15nm fine grains combined with needle-like protrusions.

The preparation method of the biomedical composite coating described in this embodiment is magnetron sputtering combined with a subsequent annealing process, which specifically includes the following steps:

(1) Use metal titanium sheets as the base, and use 200 mesh, 400 mesh, 600 mesh, 800 mesh, 1000 mesh, 1200 mesh, and 1500 mesh sandpaper to polish step by step from coarse to fine; Ultrasonic cleaning in water, ethanol and acetone for 30 min each; and the substrate was purged with _N2 gun and fixed on the sample stage in the magnetron sputtering chamber.

(2) Install the Zn and Cu targets with a purity of ≥99% symmetrically on the target position, and keep it at 45° to the horizontal direction; seal the magnetron sputtering chamber, use the mechanical pump and the molecular pump to reduce the vacuum in the sputtering chamber Pump to 1×10 ^-4 Pa～2×10 ^-4 Pa, set the rotation speed of the sample stage to 15r/min; adjust the distance between the sputtering target and the substrate to 100mm, and control the working pressure at 0.7Pa during sputtering .

(3) Under the Ar/ _{O mixed gas atmosphere with Ar and O2 volume} fraction contents of 70% and 30% respectively, sputter the Zn target separately with a sputtering power of 25W and continue for 30min, and deposit ZnO transition on the substrate first. layer; then adjust the Ar and O ₂ volume fraction content in the Ar/O ₂ mixed gas atmosphere to 90% and 10%, and sputter the Zn target and the Cu target at the same time with the sputtering power of 45W and 35W respectively and continue for 10min. A surface layer composed of ZnO, CuO and Cu ₂ O is deposited on the layer.

(4) The above composite coating was placed in the annealing furnace again, and annealed at 450 °C for 1 h with _N2 as a protective gas, during which the pressure in the furnace cavity was guaranteed to be 400 Torr, and the heating rate was 1.5 °C/s. After naturally cooling to room temperature, a composite coating on the metal titanium sheet is obtained.

The biomedical composite coating described in Example 1 is characterized by X-ray diffraction, and the characterization spectrum results are as shown in Figure 1; As can be seen from Figure 1, the X-ray diffraction peak produced by the composite coating has an intensity and peak position comparable to that of JCPDS The standard cards 36-1451, 89-2529, and 78-2076 correspond to each other, confirming that the surface layer product of the composite coating is a mixture of ZnO, CuO and Cu ₂ O.

Example 2

A corrosion-resistant and antibacterial biomedical composite coating, which is composed of three materials: ZnO, CuO and Cu ₂ O, has a transition layer and a surface layer with a double-layer composite structure; the transition layer is 100nm of ZnO, and the surface layer is 500nm of ZnO, CuO and Cu ₂ O mixture; the surface section is nano-columnar crystals with an average diameter of 34nm and aligned alignment, and the surface is dense 60nm fine grains combined with needle-like protrusions.

The preparation method of the biomedical composite coating described in this embodiment is magnetron sputtering combined with a subsequent annealing process, which specifically includes the following steps:

(1) Choose Bioglass45S5 biological glass sheet as the substrate, and use 200 mesh, 400 mesh, 600 mesh, 800 mesh, 1000 mesh, 1200 mesh, and 1500 mesh sandpaper to polish step by step from coarse to fine; Ultrasonic cleaning in water, ethanol and acetone for 30 min each; and the substrate was purged with _N2 gun and fixed on the sample stage in the magnetron sputtering chamber.

(2) Install the Zn and Cu targets with a purity of ≥99% symmetrically on the target position, and keep it at 45° to the horizontal direction; seal the magnetron sputtering chamber, use the mechanical pump and the molecular pump to reduce the vacuum in the sputtering chamber Pump to 1×10 ^-4 Pa～2×10 ^-4 Pa, set the rotation speed of the sample stage to 15r/min; adjust the distance between the sputtering target and the substrate to 100mm, and control the working pressure at 0.7Pa during sputtering .

(3) Under the Ar/ _{O mixed gas atmosphere with Ar and O2 volume} fraction contents of 70% and 30% respectively, the Zn target is sputtered separately with a sputtering power of 30W and lasts for 40min, and the ZnO transition is first deposited on the substrate. layer; then adjust the Ar and O ₂ volume fraction content in the Ar/O ₂ mixed gas atmosphere to 70% and 30%, and sputter the Zn target and the Cu target simultaneously with the sputtering power of 50W and 45W respectively and continue for 20min. A surface layer composed of ZnO, CuO and Cu ₂ O is deposited on the layer.

(4) The above composite coating was placed in the annealing furnace again, and annealed at a temperature of 500 °C for 2 h with _N2 as a protective gas, during which the pressure in the furnace cavity was ensured to be 430 Torr, and the heating rate was 1.5 °C/s. After naturally cooling to room temperature, the composite coating on the Bioglass45S5 biological glass sheet was obtained.

The surface of the biomedical composite coating described in Example 2 is characterized by a scanning electron microscope (SEM), and the results are as shown in Figure 2; As can be seen from Figure 2, there are a large number of needle-like protrusions growing upwards on the surface of the composite coating , these protrusions are formed by the sputtering deposition of some nano-columnar crystals relying on the advantage of directional growth; under these protrusions, there are fine grains with an average particle size of no more than 60nm; the protrusions and the grains are closely arranged with each other as Composite coatings provide a dense surface.

Example 3

A corrosion-resistant and antibacterial biomedical composite coating, which is composed of three materials: ZnO, CuO and Cu ₂ O, has a transition layer and a surface layer with a double-layer composite structure; the transition layer is 78nm ZnO, and the surface layer is 422nm ZnO, CuO and Cu ₂ O mixture; the surface section is nano-columnar crystals with an average diameter of 30nm and aligned alignment, and the surface is dense 30nm fine grains combined with needle-like protrusions.

The preparation method of the biomedical composite coating described in this embodiment is magnetron sputtering combined with a subsequent annealing process, which specifically includes the following steps:

(1) Use pure silicon wafers as the base, and use 200 mesh, 400 mesh, 600 mesh, 800 mesh, 1000 mesh, 1200 mesh, and 1500 mesh sandpaper to polish step by step from coarse to fine; Each of ethanol and acetone was ultrasonically cleaned for 30 min; and the substrate was purged with _N2 gun and fixed on the sample stage in the magnetron sputtering chamber.

(2) Install the Zn and Cu targets with a purity of ≥99% symmetrically on the target position, and keep it at 45° to the horizontal direction; seal the magnetron sputtering chamber, use the mechanical pump and the molecular pump to reduce the vacuum in the sputtering chamber Pump to 1×10 ^-4 Pa～2×10 ^-4 Pa, set the rotation speed of the sample stage to 15r/min; adjust the distance between the sputtering target and the substrate to 100mm, and control the working pressure at 0.7Pa during sputtering .

(3) Under the Ar/ _{O mixed gas atmosphere with Ar and O2 volume} fraction contents of 70% and 30% respectively, sputter the Zn target separately with 28W sputtering power and continue for 30min, deposit ZnO transition first on the substrate layer; then adjust the Ar and O ₂ volume fraction content in the Ar/O ₂ mixed gas atmosphere to 80% and 20%, and sputter the Zn target and the Cu target at the same time with the sputtering power of 45W and 40W respectively and continue for 12min. A surface layer composed of ZnO, CuO and Cu ₂ O is deposited on the layer.

(4) The above composite coating was placed in the annealing furnace again, and annealed at a temperature of 470 °C for 1.2 h with _N2 as a protective gas. During this period, the pressure in the furnace cavity was guaranteed to be 415 Torr, and the heating rate was 1.5 °C/s. After naturally cooling to room temperature, a composite coating on a pure silicon wafer is obtained.

The section of the biomedical composite coating described in embodiment 3 is characterized by scanning electron microscopy (SEM), and the results are as shown in Figure 3; As can be seen from Figure 3, the surface layer in the composite coating shows an average appearance from the cross section. Nano-columnar crystals with a diameter of no more than 30nm and directional arrangement of each crystal grain; there is a relatively obvious dividing line in the middle and lower part of the columnar crystals, which is the gap between the ZnO transition layer and the surface layer mixed with ZnO, CuO and Cu ₂ O interface, confirming that the composite coating has a double-layer composite structure; the thickness of the transition layer was measured to be 78nm, and the thickness of the surface layer was 422nm.

Example 4

A corrosion-resistant and antibacterial biomedical composite coating, which is composed of three materials: ZnO, CuO and Cu ₂ O, has a transition layer and a surface layer with a double-layer composite structure; the transition layer is 80nm of ZnO, and the surface layer is 450nm of ZnO, CuO and Cu ₂ O mixture; the surface section is nano-columnar crystals with an average diameter of 24nm and aligned alignment, and the surface is dense 38nm fine grains combined with needle-like protrusions.

The preparation method of the biomedical composite coating described in this embodiment is magnetron sputtering combined with a subsequent annealing process, which specifically includes the following steps:

(1) Use titanium-aluminum alloy sheets as the base, and use 200 mesh, 400 mesh, 600 mesh, 800 mesh, 1000 mesh, 1200 mesh, and 1500 mesh sandpaper to polish step by step from coarse to fine; Ultrasonic cleaning in water, ethanol and acetone for 30 min each; and the substrate was purged with _N2 gun and fixed on the sample stage in the magnetron sputtering chamber.

(2) Install the Zn and Cu targets with a purity of ≥99% symmetrically on the target position, and keep it at 45° to the horizontal direction; seal the magnetron sputtering chamber, use the mechanical pump and the molecular pump to reduce the vacuum in the sputtering chamber Pump to 1×10 ^-4 Pa～2×10 ^-4 Pa, set the rotation speed of the sample stage to 15r/min; adjust the distance between the sputtering target and the substrate to 100mm, and control the working pressure at 0.7Pa during sputtering .

(3) Under the Ar/ _{O mixed gas atmosphere with Ar and O2 volume} fraction contents of 70% and 30% respectively, sputter the Zn target separately with 26W sputtering power and continue for 35min, deposit ZnO transition first on the substrate layer; then adjust the Ar and O ₂ volume fraction content to 85% and 15% in the Ar/O ₂ mixed gas atmosphere, and sputter the Zn target and the Cu target at the same time with the sputtering power of 47W and 38W respectively and continue for 15min, and the ZnO transition A surface layer composed of ZnO, CuO and Cu ₂ O is deposited on the layer.

(4) The above composite coating was placed in the annealing furnace again, and annealed at 460 °C for 1.7 h with N ₂ as the protective gas. During this period, the pressure in the furnace cavity was guaranteed to be 425 Torr, and the heating rate was 1.5 °C/s. After naturally cooling to room temperature, a composite coating on the titanium-aluminum alloy sheet is obtained.

Example 5

A corrosion-resistant and antibacterial biomedical composite coating, which is composed of three materials: ZnO, CuO and Cu ₂ O, has a transition layer and a surface layer with a double-layer composite structure; the transition layer is 72nm ZnO, and the surface layer is 408nm ZnO, CuO and Cu ₂ O mixture; the surface section is nano-columnar crystals with an average diameter of 23nm and aligned alignment, and the surface is dense 28nm fine grains combined with needle-like protrusions.

The preparation method of the biomedical composite coating described in this embodiment is magnetron sputtering combined with a subsequent annealing process, which specifically includes the following steps:

(1) Choose Bioglass45S5 biological glass sheet as the substrate, and use 200 mesh, 400 mesh, 600 mesh, 800 mesh, 1000 mesh, 1200 mesh, and 1500 mesh sandpaper to polish step by step from coarse to fine; Ultrasonic cleaning in water, ethanol and acetone for 30 min each; and the substrate was purged with _N2 gun and fixed on the sample stage in the magnetron sputtering chamber.

(2) Install the Zn and Cu targets with a purity of ≥99% symmetrically on the target position, and keep it at 45° to the horizontal direction; seal the magnetron sputtering chamber, use the mechanical pump and the molecular pump to reduce the vacuum in the sputtering chamber Pump to 1×10 ^-4 Pa～2×10 ^-4 Pa, set the rotation speed of the sample stage to 15r/min; adjust the distance between the sputtering target and the substrate to 100mm, and control the working pressure at 0.7Pa during sputtering .

(3) Under the Ar/ _{O mixed gas atmosphere with Ar and O2 volume} fraction contents of 70% and 30% respectively, the Zn target is sputtered separately with a sputtering power of 28W and lasts for 32min, and the ZnO transition is first deposited on the substrate. layer; then adjust the Ar and O ₂ volume fraction content in the Ar/O ₂ mixed gas atmosphere to 88% and 12%, and sputter the Zn target and the Cu target simultaneously with the sputtering power of 48W and 35W respectively and continue for 10min. A surface layer composed of ZnO, CuO and Cu ₂ O is deposited on the layer.

(4) The above composite coating was placed in the annealing furnace again, and annealed at 450 °C for 1.3 h with N ₂ as the protective gas. During this period, the pressure in the furnace cavity was guaranteed to be 410 Torr, and the heating rate was 1.5 °C/s. After naturally cooling to room temperature, the composite coating on the Bioglass45S5 biological glass sheet was obtained.

Example 6

A corrosion-resistant and antibacterial biomedical composite coating, which is composed of three materials: ZnO, CuO and Cu ₂ O, has a transition layer and a surface layer with a double-layer composite structure; the transition layer is 95nm ZnO, and the surface layer is 220nm ZnO, CuO and Cu ₂ O mixture; the surface section is nano-columnar crystals with an average diameter of 30nm and aligned alignment, and the surface is dense 45nm fine grains combined with needle-like protrusions.

The preparation method of the biomedical composite coating described in this embodiment is magnetron sputtering combined with a subsequent annealing process, which specifically includes the following steps:

(1) Use metal titanium sheets as the base, and use 200 mesh, 400 mesh, 600 mesh, 800 mesh, 1000 mesh, 1200 mesh, and 1500 mesh sandpaper to polish step by step from coarse to fine; then place them in ionized water, anhydrous Each of ethanol and acetone was ultrasonically cleaned for 30 min; and the substrate was purged with _N2 gun and fixed on the sample stage in the magnetron sputtering chamber.

(2) Install the Zn and Cu targets with a purity of ≥99% symmetrically on the target position, and keep it at 45° to the horizontal direction; seal the magnetron sputtering chamber, use the mechanical pump and the molecular pump to reduce the vacuum in the sputtering chamber Pump to 1×10 ^-4 Pa～2×10 ^-4 Pa, set the rotation speed of the sample stage to 15r/min; adjust the distance between the sputtering target and the substrate to 100mm, and control the working pressure at 0.7Pa during sputtering .

(3) Under the Ar/ _{O mixed gas atmosphere with Ar and O2 volume} fraction contents of 70% and 30% respectively, sputter the Zn target separately with 29W sputtering power and continue for 38min, deposit ZnO transition first on the substrate layer; then adjust the Ar and O ₂ volume fraction content to 75% and 25% in the Ar/O ₂ mixed gas atmosphere, and sputter the Zn target and the Cu target simultaneously with the sputtering power of 45W and 37W respectively and last for 13min. A surface layer composed of ZnO, CuO and Cu ₂ O is deposited on the layer.

(4) The above composite coating was placed in the annealing furnace again, and annealed at 480 °C for 1.1 h with _N2 as the protective gas. During this period, the pressure in the furnace cavity was guaranteed to be 405 Torr, and the heating rate was 1.5 °C/s. After naturally cooling to room temperature, a composite coating on the metal titanium sheet is obtained.

Example 7

A corrosion-resistant and antibacterial biomedical composite coating, which is composed of three materials: ZnO, CuO and Cu ₂ O, has a transition layer and a surface layer with a double-layer composite structure; the transition layer is 95nm ZnO, and the surface layer is 420nm ZnO, CuO and Cu ₂ O mixture; the surface section is nano-columnar crystals with an average diameter of 28nm and aligned alignment, and the surface is dense 52nm fine grains combined with needle-like protrusions.

The preparation method of the biomedical composite coating described in this embodiment is magnetron sputtering combined with a subsequent annealing process, which specifically includes the following steps:

(1) Select pure metal titanium sheets as the base, and use 200 mesh, 400 mesh, 600 mesh, 800 mesh, 1000 mesh, 1200 mesh, and 1500 mesh sandpaper to polish step by step from coarse to fine; Ultrasonic cleaning in water, ethanol and acetone for 30 min each; and the substrate was purged with _N2 gun and fixed on the sample stage in the magnetron sputtering chamber.

(2) Install the Zn and Cu targets with a purity of ≥99% symmetrically on the target position, and keep it at 45° to the horizontal direction; seal the magnetron sputtering chamber, use the mechanical pump and the molecular pump to reduce the vacuum in the sputtering chamber Pump to 1×10 ^-4 Pa～2×10 ^-4 Pa, set the rotation speed of the sample stage to 15r/min; adjust the distance between the sputtering target and the substrate to 100mm, and control the working pressure at 0.7Pa during sputtering .

(3) Under the Ar/ _{O mixed gas atmosphere with Ar and O2 volume} fraction contents of 70% and 30% respectively, the Zn target is sputtered separately with a sputtering power of 30W and lasts for 40min, and the ZnO transition is first deposited on the substrate. layer; then adjust the Ar and O ₂ volume fraction content in the Ar/O ₂ mixed gas atmosphere to 78% and 22%, and sputter the Zn target and the Cu target at the same time with the sputtering power of 45W and 45W respectively and continue for 20min. A surface layer composed of ZnO, CuO and Cu ₂ O is deposited on the layer.

(4) The above composite coating was placed in the annealing furnace again, and annealed at a temperature of 500 °C for 2 h with _N2 as a protective gas, during which the pressure in the furnace cavity was ensured to be 415 Torr, and the heating rate was 1.5 °C/s. After naturally cooling to room temperature, a composite coating on the metal titanium sheet is obtained.

Example 8

A corrosion-resistant and antibacterial biomedical composite coating, which is composed of three materials: ZnO, CuO and Cu ₂ O, has a transition layer and a surface layer with a double-layer composite structure; the transition layer is 55nm ZnO, and the surface layer is 385nm ZnO, CuO and Cu ₂ O mixture; the surface section is nano-columnar crystals with an average diameter of 30nm and aligned alignment, and the surface is dense 48nm fine grains combined with needle-like protrusions.

The preparation method of the biomedical composite coating described in this embodiment is magnetron sputtering combined with a subsequent annealing process, which specifically includes the following steps:

(1) Select pure metal titanium sheets as the base, and use 200 mesh, 400 mesh, 600 mesh, 800 mesh, 1000 mesh, 1200 mesh, and 1500 mesh sandpaper to polish step by step from coarse to fine; Ultrasonic cleaning in water, ethanol and acetone for 30 min each; and the substrate was purged with _N2 gun and fixed on the sample stage in the magnetron sputtering chamber.

(2) Install the Zn and Cu targets with a purity of ≥99% symmetrically on the target position, and keep it at 45° to the horizontal direction; seal the magnetron sputtering chamber, use the mechanical pump and the molecular pump to reduce the vacuum in the sputtering chamber Pump to 1×10 ^-4 Pa～2×10 ^-4 Pa, set the rotation speed of the sample stage to 15r/min; adjust the distance between the sputtering target and the substrate to 100mm, and control the working pressure at 0.7Pa during sputtering .

(3) Under the Ar/ _{O mixed gas atmosphere with Ar and O2 volume} fraction contents of 70% and 30% respectively, the Zn target was sputtered separately with a sputtering power of 27W and lasted for 31min, and the ZnO transition was first deposited on the substrate. layer; then adjust the Ar and O ₂ volume fraction content to 84% and 16% in the Ar/O ₂ mixed gas atmosphere, and sputter the Zn target and Cu target simultaneously with the sputtering power of 48W and 42W respectively and continue for 17min. A surface layer composed of ZnO, CuO and Cu ₂ O is deposited on the layer.

(4) The above composite coating was placed in the annealing furnace again, and annealed at a temperature of 475 °C for 1.6 h with _N2 as a protective gas, during which the pressure in the furnace cavity was guaranteed to be 425 Torr, and the heating rate was 1.5 °C/s. After being naturally cooled to room temperature, a composite coating on a pure metal titanium sheet is obtained.

In order to study the relevant properties of the biomedical composite coating prepared by the present invention, the present invention randomly selects the biomedical composite coating obtained in Example 1 for detection, and the specific results are analyzed as follows:

The cross-section of the biomedical composite coating described in Example 1 is characterized by atomic force microscopy (AFM), and its surface microscopic 3D morphology is as shown in Figure 4; as can be seen from Figure 4, the surface of the composite coating is composed of a large number of dwarf crystals. The tall grains and a small number of tall grains are in close contact with each other, which is basically consistent with the results of the SEM electron microscope observation. The tall grains are needle-like protrusions, while the short grains correspond to those dense and fine grains.

The morphology of the biomedical composite coating obtained in Examples 2-8 is similar to that of Example 1. The surface of the composite coating is composed of a large number of short grains and a small number of tall grains in close contact with each other.

The optical characteristics of the biomedical composite coating described in Example 1 were characterized, and the ultraviolet-visible light diffuse reflectance spectrum in the wavelength range of 300nm to 800nm and the photoluminescence spectrum at an excitation wavelength of 285nm were respectively tested to study the composite coating. The light absorption ability of the layer and the recombination rate of electron-hole pairs generated by visible light; and compared with the uncoated Bioglass45S5 bioglass sheet, the two spectra were recorded as shown in Figure 5 (a) and (b). From the ultraviolet-visible light diffuse reflectance spectrum in Figure 5(a), it can be seen that the absorption intensity of the above-mentioned composite coating is much higher than that of the uncoated Bioglass45S5 bioglass in the range of visible light with a wavelength of 400nm to 800nm. This absorption behavior is theoretically The above composite coatings are guaranteed to have excellent photocatalytic properties. From the photoluminescence spectrum in Figure 5(b), it can be seen that the fluorescence intensity of the bioglass sheet is much higher than that of the composite coating, and the decrease in luminescence intensity usually means that the recombination degree of photoexcited radiation is reduced, and its photocatalytic activity is increased, which indicates that The recombination of ZnO and CuO(Cu ₂ O) inhibits electron-hole recombination and forms a good heterojunction structure in the composite coating. The combination of these types of semiconductor materials helps to improve photocatalytic efficiency, thereby promoting the generation of "active oxygen species".

The properties of the biomedical composite coating obtained in Examples 2-8 are similar to those in Example 1. The combination of two types of semiconductor materials in the composite coating helps to improve the photocatalytic efficiency, thereby promoting the generation of "active oxygen".

Using the simulated human body fluid as the electrolyte, the above-mentioned biomedical composite coating as the working electrode, the metal platinum sheet as the negative electrode, and the saturated calomel electrode as the reference electrode, a CHI600E electrochemical workstation was used to carry out the potentiodynamic polarization test, and compared with the non-coated layer of pure titanium metal for comparison. During the test, the equilibrium open circuit potential (E _ocp ) was established through 1800s, and then the potentiodynamic Tafel polarization curve was recorded at a scanning speed of 0.01V/s, and the detected Tafel curve was linearly extrapolated to obtain the corrosion potential (E _corr ) of the sample And key parameters such as corrosion current density (I _corr ), the Tafel curve is shown in Figure 6. It can be seen from Figure 6 that the potential corresponding to the tip of the Tafel curve is the self-corrosion potential (E _corr ), and the more positive the potential, the lower the tendency of the material to corrode in the simulated human body fluid. Compared with the E _corr of -0.68V for the pure titanium sheet substrate, the self-corrosion potential of the composite coating shifted significantly to the positive potential direction, with a higher E _corr (-0.25V), indicating that its corrosion resistance is better Excellent, can better protect the base material.

The properties of the biomedical composite coatings obtained in Examples 2 to 8 are similar to those in Example 1, with excellent corrosion resistance and better protection of the base material.

With deionized water as the water contact angle test solution, the wettability test of the biomedical composite coating described in Example 1 was carried out by using the SL200KS type professional contact angle meter, and compared with the pure metal titanium sheet without coating; by Yang The equation calculates the angle at which the two contact each other when the droplet falls freely on the sample surface, and its water contact wetting angle is shown in Figure 7; it can be seen from Figure 7(a) that the water contact angle of a pure metal titanium sheet is 77.37 ^○ ±1.85 ^○ , less than 90 ^○ , showing hydrophilicity; after the composite coating is deposited on the surface of titanium metal, the water contact angle shown in Figure 7(b) has been further reduced to 14.18 ^○ ±0.77 ^○ , The hydrophilicity is further enhanced with the aid of higher surface roughness contributed by both needle-like protrusions and fine particles.

The properties of the biomedical composite coatings obtained in Examples 2-8 are similar to those in Example 1, and the hydrophilicity is further improved.

The antibacterial ability of the prepared composite coating against Escherichia coli and Staphylococcus aureus was detected by plate colony counting method; 100 μL of Staphylococcus aureus and Escherichia coli with a turbidimetric concentration of 1×10 ⁶ CFU/ml were drawn with a pipette gun The suspension was slowly titrated on the surface of the sterilized sample, and after standing for 1 hour, quickly use a pipette to draw sterile saline to rinse the surface of the sample until the reacted bacterial solution was diluted 100 times, and then use a pipette to absorb 100 μL The diluted bacterial suspension was spread on the nutrient agar medium, and continued to cultivate at 37°C for 24 hours. The colonies of the bacteria on the agar plate were shown in Figure 8; Bacteria, after contact with the pure metal titanium sheet, the bacterial proliferation is not affected, and its colony covers the entire agar plate, which is similar to the result of direct culture of the bacterial suspension, which shows that the pure metal titanium sheet has no bactericidal and antibacterial effect. In contrast, the number of cultured colonies on the subsequent agar plate of the bacterial suspension that had been exposed to the composite coating was greatly reduced, and it had obvious killing effects on both bacteria, showing better broad-spectrum antibacterial properties. The metal titanium sheet was used as the control group. The antibacterial rates of the composite coating against Escherichia coli and Staphylococcus aureus were 95.5% and 93.1%, respectively, both of which were greater than 90%, showing a strong bactericidal effect.

The properties of the biomedical composite coatings obtained in Examples 2-8 are similar to those in Example 1, and have strong bactericidal and sterilizing effects.

Claims (10)

1. a corrosion-resistant, antibacterial biomedical composite coating, is characterized in that: described composite coating is made up of ZnO, CuO and Cu ₂ O three kinds of materials, is ZnO transition layer on the double-layer structure substrate, surface layer is with Composite layer of mixed ZnO, CuO and Cu ₂ O. 2. The corrosion-resistant and antibacterial biomedical composite coating according to claim 1, characterized in that: the thickness of the ZnO transition layer is 50nm-100nm; the thickness of the composite layer formed by mixing ZnO, CuO and _Cu2O is 150nm-500nm . 3. The corrosion-resistant and antibacterial biomedical composite coating according to claim 1, characterized in that: the cross-section of the composite layer formed by mixing ZnO, CuO and Cu ₂ O has an average diameter of 22nm to 34nm and aligned nano-columnar crystals, Its surface is dense 15nm-60nm fine crystal grains combined with needle-like protrusions. 4. the preparation method of corrosion-resistant, antibacterial biomedical composite coating described in claim 1, is characterized in that, specifically comprises the following steps: (1) The substrate is polished, and then placed in deionized water, absolute ethanol and acetone for ultrasonic cleaning; and the substrate is purged with _N gun and fixed on the sample stage in the magnetron sputtering chamber; (2) The Zn and Cu targets are symmetrically installed on the target position and kept at 45° to the horizontal direction; seal the magnetron sputtering chamber, vacuumize, set the sample stage speed, adjust the distance between the sputtering target and the substrate, and adjust Working air pressure, in preparation for magnetron sputtering; (3) In a mixed gas atmosphere of Ar and O ₂ , first sputter the Zn target alone, and deposit a ZnO transition layer on the substrate; then adjust the volume ratio of the Ar and O ₂ mixed gas, and sputter the Zn and Cu targets at the same time. A surface layer mixed with ZnO, CuO and Cu ₂ O is deposited on the ZnO transition layer; (4) The composite coating was taken out from the magnetron sputtering chamber and placed in an annealing furnace, annealed with _N2 as a protective gas, and the biomedical composite coating was obtained after natural cooling to room temperature. 5. according to the preparation method of the described corrosion-resistant, antibacterial biomedical composite coating of claim 4, it is characterized in that: in step (1), base is used respectively 200 orders, 400 orders, 600 orders, 800 orders, 1000 orders, 1200 orders 1500 mesh sandpaper from coarse to fine. 6. according to the preparation method of the described corrosion resistance of claim 4, antibacterial biomedical composite coating, it is characterized in that: the base in the described step (1) comprises a kind of in silicon substrate, titanium substrate, biological glass; The purity of the Zn and Cu metal targets in step (2) is more than or equal to 99%. 7. The method for preparing a corrosion-resistant and antibacterial biomedical composite coating according to claim 4, characterized in that: a mechanical pump and a molecular pump are used to pump the vacuum in the sputtering chamber to 1×10 ⁻⁴ Pa～2× 10 ^-4 Pa, set the rotation speed of the sample stage at 15r/min; adjust the distance between the sputtering target and the substrate to 100mm, and control the working pressure at 0.7Pa during sputtering. 8. according to the preparation method of the described anticorrosion of claim 4, antibacterial biomedical composite coating, it is characterized in that: when described step (3) prepares ZnO transition layer by magnetron sputtering on the substrate, in the mixed gas Ar and O The relative content of ₂ is calculated by volume fraction, Ar is 70%, O ₂ is 30%; the sputtering power is 25W-30W, and the sputtering time is 30min-40min. 9. according to the preparation method of the described corrosion-resistant, antibacterial biomedical composite coating of claim 4, it is characterized in that: described step (3) prepares ZnO, CuO and Cu ₂ O mixed by sputtering simultaneously on the ZnO transition layer When the surface layer, the relative content of Ar and _O2 in the mixed gas is calculated by volume fraction, Ar is 70% to 90%, _O2 is 10% to 30%; the sputtering power of Zn metal target is 45W to 50W, and the sputtering power of Cu metal The sputtering power of the target is 35W-45W, and the sputtering time is 10min-20min. 10. The method for preparing a corrosion-resistant and antibacterial biomedical composite coating according to claim 4, characterized in that: during the annealing treatment in step (4), the annealing process parameter temperature is 450°C to 500°C, and the time is 1h to 2h. The pressure inside is 400Torr～430Torr, and the heating rate is 1.5°C/s.

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