Antibacterial aluminum alloy and its preparation method

Abstract

This invention provides an antibacterial aluminum alloy and its preparation method, relating to the field of antibacterial treatment technology. The antibacterial aluminum alloy comprises an aluminum alloy body and a nano-zinc oxide coating, the nano-zinc oxide coating being adhered to the aluminum alloy body. The antibacterial aluminum alloy and its preparation method provided by this invention can endow the antibacterial aluminum alloy with efficient and long-lasting antibacterial properties, while ensuring the mechanical properties of the antibacterial aluminum alloy and reducing costs.

Description

Technical Field

[0001] This invention relates to the field of antibacterial treatment technology, and in particular to an antibacterial aluminum alloy and its preparation method. Background Technology

[0002] Ensuring public health and safety is a crucial issue facing society today. In public places such as public transportation, shopping malls, and schools, common surfaces such as handrails, door handles, faucets, and elevator buttons harbor a large number of bacteria, viruses, and other microorganisms. While chemical disinfectants and other forms of microbial agents are effective against microorganisms, these bactericidal effects are temporary and do not provide long-lasting antibacterial protection.

[0003] Studies have shown that the survival time of microorganisms on object surfaces mainly depends on the chemical composition of those surfaces. Therefore, developing new surface treatment methods to ensure long-term inherent antibacterial activity is of great significance for reducing the risk of contamination in workplaces and public places. Aluminum alloys are metal materials that people frequently come into contact with in daily life, and antibacterial treatment of aluminum alloys can achieve positive and effective antibacterial effects.

[0004] In existing technologies, alloying metallic materials with antibacterial elements is one way to achieve the antibacterial function of metals. However, this method may affect the mechanical properties of the original material, reduce corrosion resistance and antibacterial effect, and is costly. Summary of the Invention

[0005] To address at least one of the technical problems existing in the background art, the present invention provides an antibacterial aluminum alloy and its preparation method, which enables the antibacterial aluminum alloy to possess efficient and long-lasting antibacterial properties, maintain the mechanical properties of the antibacterial aluminum alloy, and reduce costs. The specific technical solution is as follows:

[0006] The present invention provides an antibacterial aluminum alloy, comprising: an aluminum alloy body; and a nano zinc oxide coating, wherein the nano zinc oxide coating is attached to the aluminum alloy body.

[0007] This invention provides a method for preparing an antibacterial aluminum alloy as described above, comprising:

[0008] A porous alumina film is prepared on the surface of the aluminum alloy body;

[0009] The nano-zinc oxide coating is prepared on the porous alumina film.

[0010] According to an embodiment of the present invention, the step of preparing a porous alumina film on the surface of the aluminum alloy body includes:

[0011] The surface of the aluminum alloy body is ground and polished.

[0012] The aluminum alloy body is pretreated in alkaline and acidic solutions;

[0013] The aluminum alloy body is subjected to anodizing treatment;

[0014] The aluminum alloy body is subjected to heat treatment.

[0015] According to an embodiment of the present invention, the step of grinding and polishing the surface of the aluminum alloy body includes:

[0016] Use sandpaper to polish the surface of the aluminum alloy body;

[0017] The surface of the aluminum alloy body is polished with a polishing cloth;

[0018] Rinse the surface of the aluminum alloy body with a cleaning agent.

[0019] According to one embodiment of the present invention, the step of pretreating the aluminum alloy body in an alkaline solution and an acidic solution includes:

[0020] The aluminum alloy body is pretreated by being placed in the alkaline solution and the acidic solution respectively.

[0021] The aluminum alloy body is cleaned with deionized water.

[0022] According to an embodiment of the present invention, the step of anodizing the aluminum alloy body includes:

[0023] The aluminum alloy body and the stainless steel body are powered by an electrolytic power supply device, wherein the aluminum alloy body is the anode and the stainless steel body is the cathode.

[0024] According to an embodiment of the present invention, the step of heat treating the aluminum alloy body includes:

[0025] Heat the deionized water to 90℃-100℃;

[0026] After sealing and keeping warm in the deionized water for 15-30 minutes, remove and air dry.

[0027] According to an embodiment of the present invention, the step of preparing the nano-zinc oxide coating on the porous alumina film includes:

[0028] A mixed solution is obtained by mixing HMTA solution and zinc salt solution;

[0029] The aluminum alloy body is immersed in the mixed solution;

[0030] The aluminum alloy body is subjected to annealing heat treatment.

[0031] According to an embodiment of the present invention, the step of mixing the HMTA solution and the zinc salt solution to obtain a mixed solution includes:

[0032] Add an appropriate amount of dispersant to the mixed solution.

[0033] According to an embodiment of the present invention, the step of immersing the aluminum alloy body in the mixed solution includes:

[0034] The mixture is stirred;

[0035] The surface of the aluminum alloy body is ultrasonically cleaned.

[0036] According to an embodiment of the present invention, the step of annealing the aluminum alloy body includes:

[0037] The aluminum alloy body is heated to 100℃-400℃ and maintained for 1-2 hours.

[0038] This invention provides an antibacterial aluminum alloy and its preparation method. By preparing a nano zinc oxide coating on the aluminum alloy body, the antibacterial aluminum alloy can achieve efficient and long-lasting antibacterial properties. The preparation method of the antibacterial aluminum alloy provided by this invention can be summarized as several steps: grinding and polishing, alkaline washing and acid washing, anodizing, sealing treatment, preparation of antibacterial coating, and heat treatment. The preparation method is simple and reliable, can reduce costs, and can ensure the mechanical properties of the antibacterial aluminum alloy. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0040] Figure 1 This is a schematic flowchart of the preparation method of antibacterial aluminum alloy provided in the embodiments of the present invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0042] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0044] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0045] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0046] In related technologies, alloying metallic materials with antibacterial elements is one way to achieve the antibacterial function of metals. However, this method may affect the mechanical properties of the original material, reduce corrosion resistance and antibacterial effect, and is costly.

[0047] To address the aforementioned issues, this invention provides an antibacterial aluminum alloy and its preparation method, which can achieve efficient and long-lasting antibacterial properties while ensuring the mechanical properties of the antibacterial aluminum alloy and reducing costs.

[0048] This invention provides an antibacterial aluminum alloy, comprising an aluminum alloy body and a nano-zinc oxide coating, the nano-zinc oxide coating being adhered to the aluminum alloy body. The main component of the nano-zinc oxide coating is nano-zinc oxide, which possesses extremely high chemical activity and excellent catalytic and photocatalytic activity, as well as resistance to infrared and ultraviolet radiation and bactericidal functions, and good fluidity. In this invention embodiment, the nano-zinc oxide exhibits superior antibacterial effects against *Escherichia coli* and *Staphylococcus aureus*, and possesses long-term effective antibacterial properties without leading to drug resistance. The aluminum alloy body can be of grades such as AA6065 or AA6063. The nano-zinc oxide coating, adhering to the aluminum alloy body, maintains the excellent mechanical properties of the aluminum alloy while simultaneously improving its corrosion resistance and antibacterial effect.

[0049] like Figure 1 As shown, this embodiment of the invention provides a method for preparing an antibacterial aluminum alloy as described above. The preparation method includes:

[0050] S100. A porous alumina film is prepared on the surface of an aluminum alloy body.

[0051] Alumina film is a characteristic of aluminum materials. It is a dense layer of aluminum oxide that covers the surface of the aluminum alloy and can prevent further oxidation of the aluminum alloy.

[0052] S200, Prepare a nano-zinc oxide coating on a porous alumina film.

[0053] The nano-zinc oxide coating, an antibacterial component in this invention, comprises nano-zinc oxide and exhibits superior antibacterial effects against Escherichia coli and Staphylococcus aureus. Adhering to a porous alumina film, the nano-zinc oxide coating can disinfect bacteria and other microorganisms on the aluminum alloy substrate.

[0054] In some embodiments of the present invention, the step of preparing a porous alumina film on the surface of an aluminum alloy body includes:

[0055] The surface of the aluminum alloy body is ground and polished.

[0056] The aluminum alloy body is pretreated in alkaline and acidic solutions;

[0057] The aluminum alloy body is anodized.

[0058] The aluminum alloy body is heat-treated.

[0059] Grinding the aluminum alloy body allows you to achieve a specific surface roughness, resulting in a smooth surface. Polishing the surface of the aluminum alloy body further reduces this surface roughness, making the surface bright and smooth.

[0060] Pretreatment of the aluminum alloy body can remove residual impurities from its surface through acid-base chemical reactions. NaOH solution can be used as an alkaline solution, and HCl solution can be used as an acidic solution.

[0061] Anodizing the aluminum alloy body can yield an aluminum oxide film.

[0062] Typically, heat treatment of the anodized aluminum alloy body can remove residual dirt and oxides from the alumina film, which facilitates the subsequent preparation of a nano zinc oxide coating on the alumina film.

[0063] In some embodiments of the present invention, the steps of grinding and polishing the surface of the aluminum alloy body include:

[0064] Use sandpaper to polish the surface of the aluminum alloy body;

[0065] Polish the surface of the aluminum alloy body with a polishing cloth;

[0066] Rinse the surface of the aluminum alloy body with a cleaning agent.

[0067] To ensure the polishing effect, various grades of sandpaper can be used to polish the surface of the aluminum alloy body. Sandpapers such as 400#, 800#, and 1200# can be used to polish the surface of the aluminum alloy body.

[0068] During the polishing process, a polishing cloth can be used to polish the surface until the surface of the aluminum alloy body is smooth and flat.

[0069] The cleaning agent can be anhydrous ethanol, deionized water, or acetone, etc. Cleaning with the cleaning agent can remove the impurities remaining on the surface of the aluminum alloy body.

[0070] In some embodiments of the present invention, the step of pretreating the aluminum alloy body in an alkaline solution and an acidic solution includes:

[0071] The aluminum alloy body was pretreated by being placed in alkaline solution and acidic solution respectively.

[0072] Clean the aluminum alloy body with deionized water.

[0073] The alkaline solution used here can be NaOH solution, and the acidic solution can be HCl solution. NaOH solution is a strong alkaline solution, and HCl solution is a strong acidic solution. After grinding and polishing, the surface of the aluminum alloy body will have residual metal debris and other impurities. These impurities can react with NaOH solution and HCl solution. After rinsing with deionized water, the residual impurities on the surface of the aluminum alloy body can be removed. The concentration of NaOH solution and HCl solution can be 5 mol / L. The aluminum alloy body is placed in NaOH solution and HCl solution for 10 seconds respectively to ensure that the reaction is complete.

[0074] In some embodiments of the present invention, the step of anodizing the aluminum alloy body includes:

[0075] The aluminum alloy body and the stainless steel body are powered by an electrolytic power supply device, with the aluminum alloy body serving as the anode and the stainless steel body serving as the cathode.

[0076] In this process, the aluminum alloy body acts as the anode and the stainless steel body as the cathode. After energizing, an anodizing reaction can occur in the electrolyte. The electrolyte can be a 12wt% H3PO4 solution, a 12V DC voltage is used, the current density is approximately 0.05A / dm2, and the anodizing time for the aluminum alloy is 30 minutes.

[0077] In some embodiments of the present invention, the step of heat treating the aluminum alloy body includes:

[0078] Heat the deionized water to 90℃-100℃;

[0079] After sealing and keeping warm in deionized water for 15-30 minutes, remove and air dry.

[0080] Deionized water can be heated to 90℃, and then the aluminum alloy body can be placed in the deionized water and sealed for 15 minutes before being removed and dried. Sealing the aluminum alloy body in deionized water constitutes a water-sealing process, which prevents corrosion and facilitates the subsequent adhesion of the nano-zinc oxide coating.

[0081] In some embodiments of the present invention, the step of preparing a nano-zinc oxide coating on a porous alumina film includes:

[0082] A mixed solution is obtained by mixing HMTA solution and zinc salt solution;

[0083] The aluminum alloy body is immersed in the mixed solution;

[0084] The aluminum alloy body is subjected to annealing heat treatment.

[0085] In this process, either ZnCl2 or Zn(NO3)2 solution can be used as the zinc salt solution. The aluminum alloy substrate is immersed in the mixed solution for reaction, and Zn(OH)2 nanoparticles can be deposited on the surface of the aluminum alloy substrate. After annealing the aluminum alloy substrate with the Zn(OH)2 nanoparticles, an antibacterial aluminum alloy with a nano-zinc oxide coating is obtained. The HMTA solution is a hexamethylenetetramine solution, which provides an alkaline environment for the reaction.

[0086] In some embodiments of the present invention, the step of mixing the HMTA solution and the zinc salt solution to obtain a mixed solution includes:

[0087] Add an appropriate amount of dispersant to the mixed solution.

[0088] Taking HMTA solution and ZnCl2 solution as examples, the molar concentration of HMTA solution is 0.1 mol / L, the molar concentration of ZnCl2 solution is 0.075 mol / L, and the ratio of HMTA solution to ZnCl2 solution is 2:1. Citric acid can be used as the dispersant.

[0089] In some embodiments of the present invention, the step of immersing the aluminum alloy body in the mixed solution includes:

[0090] Stir the mixture;

[0091] The surface of the aluminum alloy body is ultrasonically cleaned.

[0092] Taking HMTA solution and ZnCl2 solution as an example, after the aluminum alloy body is immersed in a mixed solution of HMTA solution and ZnCl2 solution, stirring the nano-mixed solution can facilitate the chemical reaction between the mixed solution and the surface of the aluminum alloy body. The stirring time is 2 hours, and the temperature of the mixed solution during stirring is 80℃. During the ultrasonic cleaning process, deionized water can be used to clean the aluminum alloy body, which can remove loosely bonded particles on the surface of the aluminum alloy body.

[0093] In some embodiments of the present invention, the step of annealing the aluminum alloy body includes:

[0094] Heat the aluminum alloy body to 100℃-400℃ and maintain it for 1-2 hours.

[0095] The Zn(OH)2 nanoparticles attached to the surface of the aluminum alloy body can generate nano zinc oxide after being heated at high temperature.

[0096] The antibacterial properties of the antibacterial aluminum alloy in this invention are then tested through a series of comparative experiments:

[0097] In the control group, the surface of the aluminum alloy body was only ground, polished, and cleaned;

[0098] A porous alumina film was prepared on the surface of the aluminum alloy body in Experimental Group 1, but no nano zinc oxide coating was prepared.

[0099] A nano zinc oxide coating was prepared on the surface of the aluminum alloy body in Experimental Group 2, wherein the temperature of the aluminum alloy body during annealing heat treatment was 150℃.

[0100] A nano zinc oxide coating was prepared on the surface of the aluminum alloy body in Experiment Group 3, wherein the temperature of the aluminum alloy body during annealing heat treatment was 250℃.

[0101] A nano-zinc oxide coating was prepared on the surface of the aluminum alloy body in Experiment 4, wherein the temperature of the aluminum alloy body during annealing heat treatment was 350℃.

[0102] Using Escherichia coli and Staphylococcus aureus as test strains, the immersion method was employed for testing:

[0103] 1. The concentration of Escherichia coli and Staphylococcus aureus in the bacterial culture should be controlled at 1*10^7 cfu / mL;

[0104] 2. Place the sterilized antibacterial aluminum alloy sample into a six-well plate, add 3 mL of the prepared bacterial solution (enough to cover the sample), and incubate at 37℃ with shaking for 2, 4 and 6 hours respectively. Take 0.1 mL, dilute it, and spread it on the plate. Incubate at 37℃ for 18-24 hours.

[0105] 3. Calculate the antibacterial rate using the following formula:

[0106] R(%) = [(BA) / B] x 100%

[0107] R represents the antibacterial rate, where A (CFU / mL) is the average number of bacteria in the experimental group and B (CFU / mL) is the average number of bacteria in the control group.

[0108] The specific test results of the antibacterial properties are shown in Table 1.

[0109]

[0110] Table 1

[0111] As shown in Table 1, the aluminum alloy body with nano zinc oxide coating has obvious antibacterial effects against Escherichia coli and Staphylococcus aureus. The antibacterial performance of the aluminum alloy body after annealing heat treatment at 250℃ is even better. After 4 hours, the antibacterial rates against Escherichia coli and Staphylococcus aureus are 99.87% and 99.56%, respectively.

[0112] In summary, the antibacterial aluminum alloy and its preparation method provided by the embodiments of the present invention can achieve efficient and long-lasting antibacterial properties by preparing a nano zinc oxide coating on the aluminum alloy body. The preparation method of the antibacterial aluminum alloy provided by the present invention can be summarized as several steps including grinding and polishing, alkaline washing and acid washing, anodizing, sealing treatment, preparation of antibacterial coating, and heat treatment. The preparation method is simple and reliable, can reduce costs, and can ensure the mechanical properties of the antibacterial aluminum alloy.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An antibacterial aluminum alloy, characterized in that, include: Aluminum alloy body; A nano zinc oxide coating is attached to the aluminum alloy body. The method for preparing the antibacterial aluminum alloy includes: preparing a porous alumina film on the surface of the aluminum alloy body; The nano-zinc oxide coating was prepared on the porous alumina film; The step of preparing the nano-zinc oxide coating on the porous alumina film includes: mixing an HMTA solution and a zinc salt solution to obtain a mixed solution; immersing the aluminum alloy body in the mixed solution; and subjecting the aluminum alloy body to annealing heat treatment. The step of annealing the aluminum alloy body includes: heating the aluminum alloy body to 250°C and maintaining it for 1-2 hours.

2. A method for preparing the antibacterial aluminum alloy according to claim 1, characterized in that, include: A porous alumina film is prepared on the surface of the aluminum alloy body; The nano-zinc oxide coating is prepared on the porous alumina film.

3. The preparation method according to claim 2, characterized in that, The step of preparing a porous alumina film on the surface of the aluminum alloy body includes: The surface of the aluminum alloy body is ground and polished. The aluminum alloy body is pretreated in alkaline and acidic solutions; The aluminum alloy body is subjected to anodizing treatment; The aluminum alloy body is subjected to heat treatment.

4. The preparation method according to claim 3, characterized in that, The steps of grinding and polishing the surface of the aluminum alloy body include: Use sandpaper to polish the surface of the aluminum alloy body; The surface of the aluminum alloy body is polished with a polishing cloth; Rinse the surface of the aluminum alloy body with a cleaning agent.

5. The preparation method according to claim 3, characterized in that, The step of pretreating the aluminum alloy body in alkaline and acidic solutions includes: The aluminum alloy body is pretreated by being placed in the alkaline solution and the acidic solution respectively. The aluminum alloy body is cleaned with deionized water.

6. The preparation method according to claim 3, characterized in that, The step of anodizing the aluminum alloy body includes: The aluminum alloy body and the stainless steel body are powered by an electrolytic power supply device, wherein the aluminum alloy body is the anode and the stainless steel body is the cathode.

7. The preparation method according to claim 3, characterized in that, The step of heat treating the aluminum alloy body includes: Heat the deionized water to 90℃-100℃; After sealing and keeping warm in the deionized water for 15-30 minutes, remove and air dry.

8. The preparation method according to claim 2, characterized in that, The step of preparing the nano-zinc oxide coating on the porous alumina film includes: A mixed solution is obtained by mixing HMTA solution and zinc salt solution; The aluminum alloy body is immersed in the mixed solution; The aluminum alloy body is subjected to annealing heat treatment.

9. The preparation method according to claim 8, characterized in that, The step of mixing the HMTA solution and the zinc salt solution to obtain a mixed solution includes: Add an appropriate amount of dispersant to the mixed solution.

10. The preparation method according to claim 8, characterized in that, The step of immersing the aluminum alloy body in the mixed solution includes: The mixture is stirred; The surface of the aluminum alloy body is ultrasonically cleaned.

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