Antibacterial and corrosion-resistant acicular tiO2 / zno plating layer applied to surface of aluminum alloy and preparation method thereof

Abstract

The application belongs to the technical field of photocatalytic wear-resistant sterilization, and particularly relates to an antibacterial and corrosion-resistant acicular TiO2 / ZnO plating layer applied to an aluminum alloy surface and a preparation method thereof. The TiO2 / ZnO composite plating layer with excellent chemical stability and photocatalytic sterilization is prepared on the aluminum alloy surface by adopting atomic layer deposition technology. A PEG layer is further grafted on the surface of the TiO2 / ZnO composite plating layer by adopting a chemical method. The TiO2 / ZnO plating layer is prepared by adopting the method combining atomic layer deposition and chemical solution grafting, so that the substrate has the functions of photocatalytic sterilization, antibacterial, and adhesion resistance to pollutants such as bacteria, microorganisms, and inorganic salt deposits. Due to the high conformality of atomic layer deposition and the chemical method, the method can be used on substrates with any shape and size.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photocatalytic wear-resistant sterilization and specifically relates to an antibacterial corrosion-resistant needle-shaped TiO2 / ZnO plating layer applied to the surface of an aluminum alloy and a preparation method thereof. BACKGROUND

[0002] Aluminum alloy is one of the most commonly used materials in non-ferrous metals, has low density, good mechanical properties and processing performance, and has the characteristics of corrosion resistance, heat transfer and excellent electrical conductivity, and is non-toxic and easy to recycle, and is widely used in food processing, material chemical industry, ship industry, transportation, aerospace, optical instruments and other fields.

[0003] Due to air oxidation, an aluminum oxide film will be generated on the surface of the aluminum alloy, which can protect the aluminum alloy substrate from being eroded by the external environment, but cannot resist the adhesion and reproduction of bacteria, and the adhesion of bacteria will cause pollution to the aluminum alloy and affect its use performance, so it is necessary to modify the surface of the aluminum alloy to be corrosion-resistant and antibacterial. SUMMARY

[0004] In order to solve the above technical problems, the application provides an antibacterial corrosion-resistant needle-shaped TiO2 / ZnO plating layer applied to the surface of an aluminum alloy and a preparation method thereof, which uses atomic layer deposition technology (ALD) to prepare a ZnO-doped TiO2 plating layer with photocatalytic degradation sterilization and self-cleaning effect, and grafts a PEGs layer on the plating layer by using a chemical solution grafting method, so that the substrate has the ability to resist the adhesion of bacteria, microorganisms and other pollutants while having photocatalytic sterilization and antibacterial properties.

[0005] The application is realized by the following technical solutions.

[0006] The antibacterial corrosion-resistant needle-shaped TiO2 / ZnO plating layer applied to the surface of an aluminum alloy is prepared by alternately depositing a TiO2 layer and a ZnO layer on the surface of the aluminum alloy by using atomic layer deposition technology to prepare a composite plating layer, and then grafting a PEGs layer on the outer surface of the composite plating layer.

[0007] Preferably, the ZnO nanoparticles in the ZnO plating layer are needle-shaped.

[0008] Preferably, the thickness of the composite plating layer is 100-500 nm.

[0009] Preferably, the TiO2 / ZnO plating layer has a multilayer structure, which is one layer of 50-100 nm TiO2 plating layer and one layer of 5-10 nm ZnO plating layer alternately prepared.

[0010] The application also provides a preparation method of the antibacterial corrosion-resistant needle-shaped TiO2 / ZnO plating layer applied to the surface of an aluminum alloy, which comprises the following steps:

[0011] The preparation method of the composite coating combines atomic layer deposition and chemical solution grafting method. First, a TiO2 / ZnO coating with photocatalytic degradation and sterilization performance is deposited on the aluminum alloy substrate by atomic layer deposition, and then a PEGs layer with anti-fouling performance is grafted on the TiO2 / ZnO coating by chemical solution grafting method. Specifically:

[0012] S1, pretreating the surface of the aluminum alloy; depositing TiO2 layer and ZnO layer alternately on the pretreated aluminum alloy substrate by atomic layer deposition technology to prepare a composite coating;

[0013] S2, vacuum annealing the composite coating prepared in S1;

[0014] S3, grafting a polydopamine (PDA) layer on the surface of the composite coating treated in S2 by chemical solution grafting method, and then grafting a PEGs layer by chemical solution grafting method, thereby obtaining an antibacterial and corrosion-resistant needle-shaped TiO2 / ZnO coating.

[0015] Preferably, in S1, the pretreatment method for the surface of the aluminum alloy is as follows: polishing and polishing the aluminum alloy substrate, ultrasonic cleaning and drying the polished and polished aluminum alloy substrate, and the like, so that the surface of the aluminum alloy substrate is clean. After polishing and polishing the aluminum alloy substrate, ultrasonic cleaning with deionized water and anhydrous ethanol for 10-15 minutes, and then blowing dry with nitrogen.

[0016] Preferably, in S1, during the atomic layer deposition process, titanium tetraisopropoxide is used as the titanium source precursor, diethyl zinc is used as the zinc source precursor, and hydrogen peroxide (24-35% H2O2 aqueous solution) is used as the oxygen source to prepare a TiO2 coating with a thickness of 50-100 nm and a ZnO coating with a thickness of 5-10 nm. In a single cycle of the atomic layer deposition process, nitrogen is used as the purge gas, the pulse time of the titanium and zinc precursors is 0.1-0.5 s, the interval is 1-10 s, the purge time is 10-30 s, the pulse time of hydrogen peroxide or water is 0.1-0.5 s, and the purge time is 10-30 s. After each cycle of 50-100 nm TiO2 layer, a cycle of 5-10 nm ZnO layer is performed, and the total cycle is 100-500 nm.

[0017] Preferably, in S1, the evaporation temperature of the titanium precursor is 60-80℃, the evaporation temperature of the zinc precursor is 20-30℃, the deposition temperature is 100-200℃, and the base vacuum is not less than 50mtorr.

[0018] Preferably, in S2, the tube furnace is in a vacuum state, the annealing temperature is 100-500℃, and the annealing time is 2-6h.

[0019] Preferably, in S3, the method for grafting the polydopamine layer is that the composite coating after S2 is immersed in a dopamine hydrochloride buffer solution for 24h under light shielding condition, and then dried at 60 DEG C.

[0020] Preferably, in S3, the method for grafting the PEGs layer is that the composite coating with the grafted polydopamine layer is immersed in a PEG400-PEG2000 solution, and incubated at 80 DEG C for 24h.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] 1. The present application uses the atomic layer deposition (ALD) technology to combine TiO2 with corrosion resistance and ZnO coating with photocatalysis and sterilization performance to the substrate, improves the photocatalysis and sterilization performance of the single coating, and grafts PEGs on the coating, so that the substrate has the functions of resisting adhesion of pollutants such as bacteria, microorganisms and inorganic salt deposits while having corrosion resistance and sterilization performance.

[0023] 2. The traditional magnetron sputtering and other gas phase deposition method has poor wrap plating performance and is difficult to uniformly cover the inner wall of the micropore, the present application uses the ALD with nanoscale wrap plating performance and shape retention, can solve the problem of uniform coverage of the surface nanostructure of the modified coating, and due to the high shape retention characteristics of the ALD technology, it can be used on substrates of any shape and size. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic diagram of the TiO2 / ZnO composite coating structure provided by the embodiment 1 of the present application.

[0025] Figure 2 is the SEM of the needle-shaped ZnO coating provided by the embodiment 1 of the present application.

[0026] Figure 3 is the photodegradation performance diagram of the needle-shaped TiO2 / ZnO composite coating provided by the embodiment 1 of the present application.

[0027] Figure 4 is the sterilization performance diagram of the needle-shaped TiO2 / ZnO composite coating provided by the embodiment 1 of the present application.

[0028] Figure 5 is the contact angle change diagram of the needle-shaped TiO2 / ZnO composite coating provided by the embodiment 1 of the present application before and after grafting PEGs.

[0029] Figure 6 is the bacterial adhesion diagram of the needle-shaped TiO2 / ZnO composite coating provided by the embodiment 1 of the present application before (upper diagram) and after (lower diagram) grafting PEGs.

[0030] Figure 7It is a schematic diagram of an atomic layer deposition equipment structure provided by the application. DETAILED DESCRIPTION

[0031] In order for those skilled in the art to better understand the technical solutions of the present application and to implement them, the present application will be further described below in conjunction with specific embodiments and drawings, but the embodiments are not limiting of the present application.

[0032] The experimental methods and detection methods described in the following embodiments are all conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified.

[0033] The present application adopts a combination of atomic layer deposition technology and chemical solution method, uses aluminum alloy as a substrate, prepares a needle-shaped TiO2 / ZnO coating layer on the surface, and grafts PEGs thereon, and the atomic layer deposition technology relies on the adsorption of alternating precursors or vapor pulses on the surface of the aluminum alloy and the subsequent chemical reaction to deposit a nano-thin film (TiO2 / ZnO coating layer), which can realize the uniform preparation of the TiO2 coating layer on the surface of the aluminum alloy with micropores, and the low deposition temperature can effectively reduce the damage to the substrate, thereby forming a composite coating layer with corrosion resistance and sterilization performance on the surface of the substrate.

[0034] The finally prepared coating structure is as shown in the figure: Figure 1 The TiO2 / ZnO coating layer is alternately deposited on the surface of the substrate, and PEGs are grafted on the outermost ZnO, so that the substrate has corrosion resistance, sterilization performance, and resistance to adhesion of pollutants such as bacteria, microorganisms, and inorganic salt deposits.

[0035] The content of the present application will be specifically described below through the following embodiments.

[0036] Embodiment 1

[0037] The preparation method of the antibacterial and corrosion-resistant needle-shaped TiO2 / ZnO coating layer applied to the surface of an aluminum alloy includes the following steps:

[0038] S1, polishing, polishing, cleaning and drying treatment are performed on the surface of the aluminum alloy substrate, and the treated aluminum alloy substrate is placed into a reaction cavity.

[0039] Titanium tetraisopropoxide is used as a titanium source precursor, diethyl zinc is used as a zinc source precursor, hydrogen peroxide is used as an oxygen source, and nitrogen is used as a purge gas in the atomic layer deposition process cycle.

[0040] The process parameters are set as follows: titanium precursor evaporation temperature 80℃, zinc precursor evaporation temperature 20℃, deposition temperature 150℃, different ALD pneumatic valves control different precursors, and the specific labels are as follows: Figure 7As shown, the titanium precursor source bottle is controlled by valve 1 and valve 2, the hydrogen peroxide source bottle is controlled by valve 3, and the zinc precursor source bottle is controlled by valve 4 and valve 5. The actual vacuum chamber component inner surface film actual preparation process is as follows:

[0041] S11, depositing a single cycle TiO2 / ZnO nanometer multilayer modulation film: first open ALD pneumatic valve 1 for 0.5s, interval 1s, open ALD pneumatic valve 2, inject titanium source precursor 0.5s; nitrogen blowing for 15s, restore to original pressure; open ALD pneumatic valve 3, inject oxygen source 0.1s; nitrogen blowing for 15s, restore to original pressure, for a single TiO2 small cycle, cycle 100 times; then open ALD pneumatic valve 4 for 0.5s, interval 1s, open ALD pneumatic valve 5, inject zinc source precursor 0.5s; nitrogen blowing for 15s, restore to original pressure; open ALD pneumatic valve 3, inject oxygen source 0.1s; nitrogen blowing for 15s, restore to original pressure, for a single ZnO small cycle, cycle 50 times.

[0042] The above steps constitute a TiO2 / ZnO modulation cycle layer preparation cycle.

[0043] S12, repeat S11 for 10 times; the thickness of the finally prepared TiO2 / ZnO composite coating is 300nm.

[0044] S2, place the prepared sample into a tube furnace, set the annealing temperature to 500℃, and the annealing time to 4h.

[0045] S3, place the annealed TiO2 / ZnO composite coating into a dopamine-hydrochloric acid-tris buffer solution, avoid light for 24h, then dry at 60℃, and then immerse the TiO2 / ZnO composite coating with grafted PDA layer into a PEG1500 solution, incubate at 80℃, and stir for 24h.

[0046] Example 2

[0047] The application discloses a preparation method of an antibacterial and corrosion-resistant needle-shaped TiO2 / ZnO coating applied to an aluminum alloy surface.

[0048] S1, polish, polish, clean and dry the surface of the aluminum alloy substrate, and place the treated aluminum alloy substrate into a reaction cavity.

[0049] Titanium tetraisopropoxide is used as the titanium source precursor, diethyl zinc is used as the zinc source precursor, hydrogen peroxide is used as the oxygen source, and nitrogen is used as the blowing gas in the atomic layer deposition process cycle.

[0050] The process parameters are set as follows: titanium precursor evaporation temperature 80℃, zinc precursor evaporation temperature 20℃, deposition temperature 150℃, different ALD pneumatic valves control different precursors, and the specific labels are as followsFigure 7 As shown, the titanium precursor source bottle is controlled by valve 1 and valve 2, the hydrogen peroxide source bottle is controlled by valve 3, and the zinc precursor source bottle is controlled by valve 4 and valve 5. The actual vacuum chamber component inner surface film actual preparation process is as follows:

[0051] S11, depositing a single period TiO2 / ZnO nanometer multilayer modulation film: first open ALD pneumatic valve 1 for 0.5s, interval 1s, open ALD pneumatic valve 2, inject titanium source precursor 0.5s; nitrogen blowing 15s, restore to original pressure; open ALD pneumatic valve 3, inject oxygen source 0.1s; nitrogen blowing 15s, restore to original pressure, for a single TiO2 small cycle, cycle 100 times; then open ALD pneumatic valve 4 for 0.5s, interval 1s, open ALD pneumatic valve 5, inject zinc source precursor 0.5s; nitrogen blowing 15s, restore to original pressure; open ALD pneumatic valve 3, inject oxygen source 0.1s; nitrogen blowing 15s, restore to original pressure, for a single ZnO small cycle, cycle 20 times, the above steps constitute a TiO2 / ZnO modulation period layer preparation cycle.

[0052] S12, repeat S11 for 20 times; the thickness of the finally prepared TiO2 / ZnO composite coating is 500nm.

[0053] S2, place the prepared sample in a tube furnace, set the annealing temperature to 100℃, and the annealing time to 6h.

[0054] S3, place the annealed TiO2 / ZnO composite coating into a hydrochloric acid dopamine-tris buffer solution, avoid light for 24h, then dry at 60℃, and then immerse the TiO2 / ZnO composite coating with grafted PDA layer into a PEG1000 solution, incubate at 80℃, and stir for 24h.

[0055] Example 3

[0056] The application discloses a preparation method of an antibacterial and corrosion-resistant needle-shaped TiO2 / ZnO coating applied to an aluminum alloy surface.

[0057] S1, polish, polish, clean and dry the surface of the aluminum alloy substrate, and place the treated aluminum alloy substrate into a reaction chamber.

[0058] Titanium tetraisopropoxide is used as the titanium source precursor, diethyl zinc is used as the zinc source precursor, and hydrogen peroxide is used as the oxygen source, and nitrogen is used as the blowing gas in the atomic layer deposition process cycle.

[0059] Set the process parameters: titanium precursor evaporation temperature 80℃, zinc precursor evaporation temperature 20℃, deposition temperature 150℃, different ALD pneumatic valves control different precursors, and the specific labels are as shown in Figure 7As shown, the titanium precursor source bottle is controlled by valve 1 and valve 2, the hydrogen peroxide source bottle is controlled by valve 3, and the zinc precursor source bottle is controlled by valve 4 and valve 5. The actual vacuum chamber component inner surface film actual preparation process is as follows:

[0060] S11, depositing a single period TiO2 / ZnO nanometer multilayer modulation film: first open ALD pneumatic valve 1 for 0.5 s, interval 1 s, open ALD pneumatic valve 2, inject titanium source precursor 0.5 s; nitrogen blowing 15 s, restore to original pressure; open ALD pneumatic valve 3, inject oxygen source 0.1 s; nitrogen blowing 15 s, restore to original pressure, for a single TiO2 small cycle, cycle 100 times; then open ALD pneumatic valve 4 for 0.5 s, interval 1 s, open ALD pneumatic valve 5, inject zinc source precursor 0.5 s; nitrogen blowing 15 s, restore to original pressure; open ALD pneumatic valve 3, inject oxygen source 0.1 s; nitrogen blowing 15 s, restore to original pressure, for a single ZnO small cycle, cycle 20 times, the above steps constitute a TiO2 / ZnO modulation period layer preparation cycle.

[0061] S12, repeat S11 for 20 times; the thickness of the finally prepared TiO2 / ZnO composite coating is 500 nm.

[0062] S2, place the prepared sample in a tube furnace, set the annealing temperature to 500℃, and the annealing time to 2h.

[0063] S3, place the annealed TiO2 / ZnO composite coating into a hydrochloric acid dopamine-tris buffer solution, avoid light for 24h, then dry at 60℃, and then immerse the TiO2 / ZnO composite coating with grafted PDA layer into a PEG2000 solution, incubate at 80℃, and stir for 24h.

[0064] Comparative Example 1

[0065] Aluminum alloy substrate.

[0066] Comparative Example 2

[0067] Only TiO2 is prepared on the surface of the aluminum alloy substrate, and the parameters for preparing the TiO2 layer are the same as in Example 1.

[0068] The material prepared in Example 1 is characterized below, and the specific characterization results are shown as follows.

[0069] Figure 2 is an SEM image of the needle-shaped ZnO coating provided in Example 1 of the present application. As can be seen from the SEM image, Figure 2 As can be seen, the ZnO in the ZnO coating is in a needle-shaped structure.

[0070] Figure 3This is a photodegradation performance diagram of the needle-like TiO2 / ZnO composite coating provided in Example 1 of the present invention. Methyl orange was used as the experimental subject to detect its degradation effect. Figure 3 As can be seen, (a) is the transmittance diagram of the coated sample in Example 1 degrading methyl orange. The closer to 0, the less methyl orange is present, indicating that methyl orange is almost completely degraded over time, demonstrating a good degradation effect. (b) is the transmittance diagram of the uncoated sample degrading methyl orange. Under the same wavelength detection, the methyl orange content is higher. In (c), the transparent sample on the left is the coated sample, and the uncoated sample is the substrate. After UV irradiation, the coated sample on the left has almost completely degraded the methyl orange. This shows that the TiO2 / ZnO composite coating prepared on the substrate in this invention has good photocatalytic degradation performance.

[0071] Figure 4 The bactericidal performance of the needle-shaped TiO2 / ZnO composite coating provided in Example 1 of this invention was tested using Staphylococcus aureus as the experimental subject. Figure 4 As can be seen, the aluminum substrate surface without coating treatment in Comparative Example 1 had the highest content of Staphylococcus aureus. In Comparative Example 2, after preparing a TiO2 layer on the aluminum substrate surface, the number of Staphylococcus aureus was reduced compared to Comparative Example 1. In the composite coating prepared in Example 1, the amount of Staphylococcus aureus was the lowest, and the sterilization rate reached 99.67%. This shows that the composite coating prepared by the present invention can effectively sterilize.

[0072] Figure 5 This is a diagram showing the contact angle change of the needle-like TiO2 / ZnO composite coating provided in Example 1 of the present invention before and after PEG grafting. It can be seen that the hydrophilicity of the material surface is enhanced after PEG grafting. Figure 6 The images show bacterial adhesion of the needle-like TiO2 / ZnO composite coating before and after PEG grafting. The top image shows bacterial adhesion before PEG grafting, while the bottom image shows bacterial adhesion after PEG grafting. It can be seen that without PEG grafting, the composite coating can kill a large number of adhered bacteria, but some viable bacteria can still be observed. After PEG grafting, the bacteria are almost completely eradicated. This demonstrates that PEG grafting enables the substrate to possess both photocatalytic bactericidal and antibacterial properties, as well as the ability to resist the adhesion of bacteria, microorganisms, and other contaminants.

[0073] The properties of the materials in Examples 2 and 3 are similar to those in Example 1, and will not be described in detail here.

[0074] The prepared antibacterial and corrosion-resistant needle-shaped TiO2 / ZnO plating layer applied to the surface of an aluminum alloy has corrosion-resistant and antibacterial properties, and the preparation method adopts atomic layer deposition technology, which has nanoscale wrap plating and shape retention, can solve the problem of uniform coverage of the surface nanostructure of the modified plating layer, and due to the high shape retention characteristics of the ALD technology, it can be used on substrates of any shape and size. This is a functional feature that traditional magnetron sputtering and other gas deposition technologies with poor wrap plating cannot achieve, especially for materials with a surface micro-nano porous structure, traditional technologies are difficult to uniformly cover the inner wall of the micropore, and the coating uniformity is poor, which further leads to the deterioration of the coating functionality. The composite plating layer preparation method proposed in the application can fundamentally break through such technical bottlenecks and realize the preparation of high-performance modified coatings.

[0075] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, these modifications and variations are also intended to be included.

Claims

1. An antibacterial and corrosion-resistant needle-like TiO2 / ZnO coating applied to the surface of aluminum alloys, characterized in that, A composite coating was prepared by alternating deposition of TiO2 and ZnO layers on the surface of an aluminum alloy using atomic layer deposition (ALD) technology. Then, a PEGs layer was grafted onto the outer surface of the composite coating. The ZnO layer exhibits a needle-like structure; The TiO2 / ZnO coating has a multilayer structure, consisting of a 50-100nm TiO2 coating layer, covered by a 5-10nm ZnO coating layer, which are prepared alternately. A polydopamine layer is first grafted onto the outermost ZnO layer, followed by a PEGs layer. The thickness of the composite coating is 100~500 nm; During atomic layer deposition, tetraisopropoxide titanium was used as the titanium source precursor, diethylzinc as the zinc source precursor, and a hydrogen peroxide aqueous solution with a mass fraction of 24%~35% was used as the oxygen source.

2. The method for preparing an antibacterial and corrosion-resistant needle-like TiO2 / ZnO coating applied to an aluminum alloy surface according to claim 1, characterized in that, Includes the following steps: S1. Pre-treat the aluminum alloy surface; use atomic layer deposition (ALD) to alternately deposit TiO2 and ZnO layers on the pre-treated aluminum alloy substrate to prepare a composite coating. S2. Vacuum annealing treatment is performed on the S1 composite coating; S3. First, graft a polydopamine layer onto the surface of the composite coating after S2 treatment, and then graft a PEGs layer to obtain an antibacterial and corrosion-resistant needle-like TiO2 / ZnO coating.

3. The preparation method according to claim 2, characterized in that, In S1, during atomic layer deposition, tetraisopropoxide titanium was used as the titanium source precursor, diethylzinc was used as the zinc source precursor, and a 24%–35% hydrogen peroxide aqueous solution was used as the oxygen source. Nitrogen was used as the purge gas in each cycle. The pulse times for the titanium and zinc source precursors were 0.1–0.5 s, with intervals of 1–10 s, and the purge time was 10–30 s. The hydrogen peroxide pulse time was 0.1–0.5 s, and the purge time was 10–30 s. After each cycle, a 50–100 nm TiO2 layer was formed, followed by a 5–10 nm ZnO layer, with a total cycle length of 100–500 nm.

4. The preparation method according to claim 2, characterized in that, In S1, the evaporation temperature of the titanium source precursor is 60~80℃, the evaporation temperature of the zinc source precursor is 20~30℃, the deposition temperature is 100~200℃, and the background vacuum is not less than 50mtorr.

5. The preparation method according to claim 2, characterized in that, In S2, the annealing temperature is 100~500℃ and the annealing time is 2~6h.

6. The preparation method according to claim 2, characterized in that, In S3, the method for grafting the polydopamine layer is to immerse the composite coating treated in S2 in a dopamine hydrochloride buffer solution for 24 hours under light-protected conditions, and then dry it.

7. The preparation method according to claim 2, characterized in that, In S3, the method of grafting PEGs layers is to immerse the composite coating with grafted polydopamine layers in a solution of PEG400~PEG2000 and keep it at 80°C for 24 hours.

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