A rolling method for antibacterial titanium alloy plate

Abstract

The invention discloses a rolling method for an antibacterial titanium alloy plate, relating to the technical field of titanium alloy materials. An antibacterial agent, modified chitosan and guar gum are mixed, glycerol is used as a plasticizer, and ammonium tripolyphosphate is used as a cross-linking agent to prepare an antibacterial coating, which is then coated on the surface of the titanium alloy. The alkylated chitosan has a long hydrophobic chain and is tightly cross-linked with the guar gum under the cross-linking action of sodium tripolyphosphate, thereby synergistically improving the hydrophobic effect of the coating and blocking the adhesion of moisture and bacteria. Silver nanoparticles are evenly dispersed on the surface of montmorillonite. Through the effective combination of the two antibacterial effects, the antibacterial effect of the coating is fully exerted, while also protecting the titanium alloy plate and improving its corrosion resistance.

Description

Technical Field

[0001] The invention relates to the technical field of titanium alloy materials, and in particular to a rolling method for an antibacterial titanium alloy plate. Background Art

[0002] Titanium alloys, with their excellent corrosion resistance, fatigue resistance, and biocompatibility, are widely used in the medical field, particularly in implantable devices. Medical devices are diverse in model, complex in structure, and small in size. They come into contact with a variety of media during use, making them susceptible to stains, leading to the accumulation of microorganisms and potentially causing device infection. Safe and reliable medical devices are crucial for improving treatment efficiency.

[0003] Based on the bacterial growth mechanism, the existing antibacterial modification methods for metal material surfaces are summarized into two categories: modification methods that rely on active bactericidal coatings and modification methods that passively inhibit bacterial adhesion by controlling surface wettability. Although active modification methods can kill bacteria fundamentally, these bactericides have problems such as drug resistance, high cost, and biological toxicity in actual applications. Passive modification methods cannot kill bacteria directly, and once the surface is colonized by bacteria, the antibacterial effect will be lost. In order to achieve efficient, long-term, and safe cleaning of medical device surfaces, researchers have proposed an active-passive synergistic antibacterial modification method, combining chemical sterilization methods with anti-adhesion antibacterial methods to give full play to the advantages of both methods. This is the focus of future research. Summary of the Invention

[0004] The object of the present invention is to provide a rolling method for antibacterial titanium alloy plates to solve the problems raised in the background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for rolling an antibacterial titanium alloy plate, comprising the following steps:

[0006] The antibacterial agent, modified chitosan and guar gum are added to deionized water in sequence and soaked at 50-70°C for 2-3 hours. Then, the cross-linking agent and plasticizer are added to the solution and stirred for 2-3 hours. After removing bubbles with ultrasound, the film-forming solution is poured on a titanium alloy plate and dried to obtain an antibacterial titanium alloy plate.

[0007] Furthermore, the dosage ratio of the antibacterial agent, modified chitosan, guar gum, cross-linking agent, plasticizer and deionized water is 0.01-0.03 g: 0.2-0.6 g: 0.1-0.3 g: 0.004-0.009 g: 0.05-0.15 g: 10-40 mL.

[0008] Furthermore, the preparation method of the antibacterial agent is:

[0009] Silver nitrate is dispersed in deionized water, montmorillonite is added, and the mixture is stirred overnight. Tea polyphenols with a mass fraction of 5% are added, and the mixture is stirred at 70-90° C. for 1-2 hours. A sodium hydroxide solution with a molar concentration of 0.1 mol / L is added dropwise, and the pH is adjusted to 10. The mixture is dialyzed in deionized water for 48 hours, with the water replaced every 12 hours, and then freeze-dried to obtain an antibacterial agent.

[0010] It should be noted that in the lamellar structure of montmorillonite, tea polyphenols reduce silver nitrate into silver nanoparticles in situ and evenly disperse them inside and on the surface of montmorillonite.

[0011] Furthermore, the usage ratio of the silver nitrate, deionized water, montmorillonite and tea polyphenols is 0.01-0.05 g: 20 mL: 0.01-0.02 g: 10 mL.

[0012] Furthermore, the preparation method of the modified chitosan is:

[0013] Chitosan was dissolved in an acetic acid solution with a molar concentration of 0.2 M, and ethanol was added to dilute it to obtain a chitosan mixed solution. The pH value was adjusted to 5-5.5 with a sodium hydroxide solution with a molar concentration of 1 M, and an ethanol solution of dodecyl aldehyde with a mass concentration of 25 g / L was added and stirred evenly. Sodium cyanoborohydride was added and stirred at room temperature for 24 h. The pH value was adjusted to 6-7 with a sodium hydroxide solution with a molar concentration of 1 M, and then ethanol was added. The precipitate was collected, washed with ethanol, and vacuum dried to obtain modified chitosan.

[0014] It should be noted that the alkyl chains were grafted onto the amino groups of the chitosan backbone through the Schiff base reaction, as shown below.

[0015]

[0016] Furthermore, the volume ratio of the chitosan mixed solution to the dodecyl aldehyde ethanol solution is 30-50:1-2.

[0017] Furthermore, the ratio of chitosan, acetic acid solution and ethanol solution in the chitosan mixed solution is 1-6 g: 200-250 mL: 100-200 mL.

[0018] Furthermore, the amount of sodium cyanoborohydride used is 3 mol / chitosan single molecule; and the chitosan is shrimp shell chitosan with a molecular weight of 512 KDa.

[0019] Furthermore, the cross-linking agent is sodium tripolyphosphate.

[0020] Furthermore, the plasticizer is glycerol.

[0021] Compared with the prior art, the present invention has the following beneficial effects: (1) alkylated chitosan has a long hydrophobic chain and is tightly cross-linked with guar gum under the cross-linking action of sodium tripolyphosphate, which synergistically improves the hydrophobic effect of the coating, blocks the adhesion of moisture and bacteria, and improves the antibacterial and corrosion resistance of the coating; (2) tea polyphenols participate in the formation of silver nanoparticles and serve as a surface capping agent to impart stability to the nanoparticles; the layered morphology of montmorillonite nanosheets avoids the agglomeration of silver nanoparticles during the synthesis process of silver nanoparticles, and the silver nanoparticles are uniformly dispersed on the surface of montmorillonite. At the same time, the nanosilver particles effectively increase the space between the montmorillonite sheets, increase the pore complexity of the coating, provide a more active place for the release of silver nanoparticles, and thus improve the antibacterial ability of the coating; (3) the hydrophobicity of the coating surface hinders the adhesion and entry of bacteria and moisture, and the chitosan and silver nanoparticles inside the coating have bactericidal and antibacterial properties. Through the effective combination of the two antibacterial effects, the antibacterial effect of the coating is fully exerted, and at the same time, it can also protect the titanium alloy plate and improve its corrosion resistance. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] The present invention provides a technical solution: a rolling method for an antibacterial titanium alloy plate.

[0024] Example 1

[0025] S1. Disperse 0.034 g of silver nitrate in 20 mL of deionized water, add 0.01 g of montmorillonite, stir overnight, then add 10 mL of 5% tea polyphenol solution, add 0.1 mol / L sodium hydroxide solution dropwise, adjust the pH to 10, stir at 80°C for 1 h, dialyze in deionized water for 48 h, changing the water every 12 h, and then freeze-dry to obtain an antibacterial agent;

[0026] S2, 4g chitosan is dissolved in 220mL 0.2M acetic acid solution, then diluted with 150mL ethanol, obtain the mixed solution of chitosan, and with 1M sodium hydroxide solution, pH value is adjusted to 5.1, add 25g / L and go into the ethanolic solution 10mL of dodecyl aldehyde, stir, add sodium cyanoborohydride (3 moles / chitosan monomer), and at room temperature stir 24h, use 1M sodium hydroxide solution that pH is adjusted to 7, then add ethanol, collect precipitate, use ethanol washing, after vacuum drying at room temperature, obtain modified chitosan;

[0027] S3. Add 0.02g of antibacterial agent, 0.4g of modified chitosan and 0.2g of guar gum to 20mL of deionized water in sequence, soak in a water bath at 60℃ for 2h, then add 0.006g of sodium tripolyphosphate and 0.1g of glycerol to the solution, stir for 2h, remove bubbles with ultrasound, pour the film-forming solution on a titanium alloy plate, and dry at room temperature to obtain an antibacterial titanium alloy plate.

[0028] Example 2

[0029] S1. Disperse 0.04 g of silver nitrate in 25 mL of deionized water, add 0.02 g of montmorillonite, stir overnight, then add 15 mL of 5% tea polyphenol solution, add 0.1 mol / L sodium hydroxide solution dropwise, adjust the pH to 10, stir at 80°C for 1 h, dialyze in deionized water for 48 h, changing the water every 12 h, and then freeze-dry to obtain an antibacterial agent;

[0030] S2, 4.5g chitosan is dissolved in 230mL 0.2M acetic acid solution, then diluted with 150mL ethanol, obtain the mixed solution of chitosan, and with 1M sodium hydroxide solution, pH value is adjusted to 5.1, add 25g / L and go into the ethanolic solution 15mL of dodecyl aldehyde, stir, add sodium cyanoborohydride (3 moles / chitosan monomer), and at room temperature stir 24h, use 1M sodium hydroxide solution that pH is adjusted to 7, then add ethanol, collect precipitate, use ethanol washing, after vacuum drying at room temperature, obtain modified chitosan;

[0031] S3. Add 0.025g of antibacterial agent, 0.45g of modified chitosan and 0.25g of guar gum to 25mL of deionized water in sequence, soak in a water bath at 60℃ for 2h, then add 0.005g of sodium tripolyphosphate and 0.15g of glycerol to the solution, stir for 2h, remove bubbles with ultrasound, pour the film-forming solution on a titanium alloy plate, and dry at room temperature to obtain an antibacterial titanium alloy plate.

[0032] Example 3

[0033] S1. Disperse 0.04 g of silver nitrate in 25 mL of deionized water, add 0.02 g of montmorillonite, stir overnight, then add 20 mL of 5% tea polyphenol solution, add 0.1 mol / L sodium hydroxide solution dropwise, adjust the pH to 10, stir at 80°C for 1 h, dialyze in deionized water for 48 h, changing the water every 12 h, and then freeze-dry to obtain an antibacterial agent;

[0034] S2, 5g chitosan is dissolved in 250mL 0.2M acetic acid solution, then diluted with 160mL ethanol, obtain the mixed solution of chitosan, and with 1M sodium hydroxide solution, pH value is adjusted to 5.1, add 25g / L and go into the ethanolic solution 16mL of dodecyl aldehyde, stir, add sodium cyanoborohydride (3 moles / chitosan monomer), and at room temperature stir 24h, use 1M sodium hydroxide solution that pH is adjusted to 7, then add ethanol, collect precipitate, use ethanol washing, after vacuum drying at room temperature, obtain modified chitosan;

[0035] S3. Add 0.03g of antibacterial agent, 0.5g of modified chitosan and 0.3g of guar gum to 30mL of deionized water in sequence, soak in a water bath at 60℃ for 2h, then add 0.007g of sodium tripolyphosphate and 0.12g of glycerol to the solution, stir for 2h, remove bubbles with ultrasound, pour the film-forming solution on a titanium alloy plate, and dry at room temperature to obtain an antibacterial titanium alloy plate.

[0036] Example 4

[0037] S1. Disperse 0.05 g of silver nitrate in 15 mL of deionized water, add 0.01 g of montmorillonite, stir overnight, then add 15 mL of 5% tea polyphenol solution, add 0.1 mol / L sodium hydroxide solution dropwise, adjust the pH to 10, stir at 80°C for 1 h, dialyze in deionized water for 48 h, changing the water every 12 h, and then freeze-dry to obtain an antibacterial agent;

[0038] S2, 5.5g chitosan is dissolved in 280mL 0.2M acetic acid solution, then diluted with 180mL ethanol, obtain the mixed solution of chitosan, and with 1M sodium hydroxide solution, pH value is adjusted to 5.1, add 25g / L and go into the ethanolic solution 20mL of dodecyl aldehyde, stir, add sodium cyanoborohydride (3 moles / chitosan monomer), and at room temperature stir 24h, use 1M sodium hydroxide solution that pH is adjusted to 7, then add ethanol, collect precipitate, use ethanol washing, after vacuum drying at room temperature, obtain modified chitosan;

[0039] S3. Add 0.02g of antibacterial agent, 0.55g of modified chitosan and 0.3g of guar gum to 30mL of deionized water in sequence, soak in a water bath at 60℃ for 2h, then add 0.008g of sodium tripolyphosphate and 0.1g of glycerol to the solution, stir for 2h, remove bubbles with ultrasound, pour the film-forming solution on a titanium alloy plate, and dry at room temperature to obtain an antibacterial titanium alloy plate.

[0040] Comparative Example 1

[0041] S1. Disperse 0.034 g of silver nitrate in 20 mL of deionized water, add 0.01 g of montmorillonite, stir overnight, then add 10 mL of 5% tea polyphenol solution, add 0.1 mol / L sodium hydroxide solution dropwise, adjust the pH to 10, stir at 80°C for 1 h, dialyze in deionized water for 48 h, changing the water every 12 h, and then freeze-dry to obtain an antibacterial agent;

[0042] S2. 0.02 g of antibacterial agent, 0.4 g of chitosan and 0.2 g of guar gum were added to 20 mL of deionized water in sequence and soaked in a water bath at 60 ° C for 2 h. Subsequently, 0.006 g of sodium tripolyphosphate and 0.1 g of glycerol were added to the solution and stirred for 2 h. After removing bubbles with ultrasound, the film-forming solution was poured on a titanium alloy plate and dried at room temperature to obtain an antibacterial titanium alloy plate.

[0043] Comparative Example 2

[0044] S1, 4g chitosan was dissolved in 220mL 0.2M acetic acid solution, then diluted with 150mL ethanol to obtain a mixed solution of chitosan, and with 1M sodium hydroxide solution, the pH value was adjusted to 5.1, 25g / L was added into 10mL of an ethanol solution of dodecyl aldehyde, stirred, sodium cyanoborohydride (3 moles / chitosan monomer) was added, and stirred at room temperature for 24h, 1M sodium hydroxide solution was used to adjust the pH to 7, then ethanol was added, and the precipitate was collected and washed with ethanol. After vacuum drying at room temperature, modified chitosan was obtained;

[0045] S3. Add 0.002g of silver nanoparticles, 0.4g of modified chitosan and 0.2g of guar gum to 20mL of deionized water in sequence, soak in a water bath at 60℃ for 2h, then add 0.006g of sodium tripolyphosphate and 0.1g of glycerol to the solution, stir for 2h, remove bubbles with ultrasound, pour the film-forming solution on a titanium alloy plate, and dry at room temperature to obtain an antibacterial titanium alloy plate.

[0046] Comparative Example 3

[0047] S1, 4g chitosan was dissolved in 220mL 0.2M acetic acid solution, then diluted with 150mL ethanol to obtain a mixed solution of chitosan, and with 1M sodium hydroxide solution, the pH value was adjusted to 5.1, 25g / L was added into 10mL of an ethanol solution of dodecyl aldehyde, stirred, sodium cyanoborohydride (3 moles / chitosan monomer) was added, and stirred at room temperature for 24h, 1M sodium hydroxide solution was used to adjust the pH to 7, then ethanol was added, and the precipitate was collected and washed with ethanol. After vacuum drying at room temperature, modified chitosan was obtained;

[0048] S3. Add 0.4 g of modified chitosan and 0.2 g of guar gum to 20 mL of deionized water in sequence, soak in a water bath at 60 ° C for 2 h, then add 0.006 g of sodium tripolyphosphate and 0.1 g of glycerol to the solution, stir for 2 h, remove bubbles with ultrasound, pour the film-forming solution on the titanium alloy plate, and dry it at room temperature to obtain an antibacterial titanium alloy plate.

[0049] Comparative Example 4

[0050] 0.4 g chitosan and 0.2 g guar gum were added to 20 mL deionized water in sequence and soaked in a 60°C water bath for 2 h. Subsequently, 0.006 g sodium tripolyphosphate and 0.1 g glycerol were added to the solution and stirred for 2 h. After removing bubbles with ultrasound, the film-forming solution was poured onto a titanium alloy plate and dried at room temperature to obtain an antibacterial titanium alloy plate.

[0051] The performance of each embodiment and comparative example was experimentally tested; the antibacterial properties of the samples were tested by the inhibition zone (ZOI) and colony counting methods. Escherichia coli and Staphylococcus aureus were selected as reference strains for the antibacterial test. For ZOI, the nutrient agar medium in the culture dish was inoculated with 107-108 CFU / mL of 100 μL of bacteria. The titanium alloy plate was placed on the culture dish and cultured with bacteria at 37°C for 24 hours. Then, the diameter of the inhibition zone was measured, and three replicates were tested for each sample; the static water contact angle was measured by a contact angle goniometer using the sessile drop method, the image of water spreading on the sample surface was recorded by a camera, and the contact angle was analyzed by professional software. Three measurements were performed on each sample; according to the ISO2782 standard, the film was subjected to a nitrogen permeability test on a gas permeability measuring device.

[0052] The test results are shown in Table 1.

[0053] Table 1: Experimental results of various embodiments and comparative examples

[0054] sample Antibacterial rate (%) Water contact angle (degrees) <![CDATA[Permeability × 10 -17 (m 2 ·s -1 ·Pa -1 )]]> Example 1 99.8 148.7 3.91 Example 2 99.5 145.8 4.02 Example 3 99.1 141.5 4.11 Example 4 98.9 139.9 4.21 Comparative Example 1 80.6 126.7 5.36 Comparative Example 2 72.4 123.7 5.70 Comparative Example 3 51.7 120.6 5.84 Comparative Example 4 37.9 109.2 6.31

[0055] According to the experimental results, the antibacterial and bactericidal properties of the silver nanoparticles and chitosan in the embodiment and the tight cross-linked network formed by hydrophobically modified chitosan and guar gum improve the hydrophobicity of the coating. The two antibacterial effects synergistically promote the antibacterial properties of the coating as a whole. In addition, the layered structure of montmorillonite further helps the dispersion of the silver nanoparticles, also provides more active sites, helps to form a cross-linked system with a complex structure, blocks the entry of moisture and bacteria, and also improves the corrosion resistance of the titanium alloy plate. In the comparative example, the silver nanoparticles may be aggregated, affecting its antibacterial effect. The chitosan and guar gum are cross-linked without introducing a hydrophobic long chain, and its hydrophobic properties are worse than those of the embodiment. In addition, antibacterial is carried out in the form of a hydrophobic coating. Only chitosan has certain antibacterial properties inside the coating, and the overall effect is not as good as that of the embodiment.

[0056] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A rolling method for antibacterial titanium alloy sheet, characterized by: The following steps are involved: An antibacterial agent, modified chitosan, and guar gum are sequentially added to deionized water and soaked at 50-70° C. for 2-3 hours. A crosslinking agent and a plasticizer are then added to the solution, stirred for 2-3 hours, and after removing bubbles with ultrasound, the film-forming solution is poured onto a titanium alloy plate and dried to obtain an antibacterial titanium alloy plate. The dosage ratio of the antibacterial agent, modified chitosan, guar gum, cross-linking agent, plasticizer and deionized water is 0.01-0.03 g: 0.2-0.6 g: 0.1-0.3 g: 0.004-0.009 g: 0.05-0.15 g: 10-40 mL; The preparation method of the antibacterial agent is: Disperse silver nitrate in deionized water, add montmorillonite, stir overnight, add 5% by mass of tea polyphenols, stir at 70-90°C for 1-2 hours, dropwise add 0.1 mol / L sodium hydroxide solution, adjust the pH to 10, dialyze in deionized water for 48 hours, replace the water every 12 hours, and then freeze-dry to obtain an antibacterial agent; The preparation method of the modified chitosan is: Chitosan was dissolved in an acetic acid solution having a molar concentration of 0.2 M, and ethanol was added to dilute the solution to obtain a chitosan mixed solution. The pH value was adjusted to 5-5.5 with a sodium hydroxide solution having a molar concentration of 1 M, and an ethanol solution of dodecyl aldehyde having a mass concentration of 25 g / L was added, and the mixture was stirred evenly. Sodium cyanoborohydride was added, and the mixture was stirred at room temperature for 24 h. The pH value was adjusted to 6-7 with a sodium hydroxide solution having a molar concentration of 1 M, and then ethanol was added. The precipitate was collected, washed with ethanol, and vacuum dried to obtain modified chitosan. The cross-linking agent is sodium tripolyphosphate.

2. The rolling method of an antibacterial titanium alloy sheet according to claim 1, characterized in that: The usage ratio of the silver nitrate, deionized water, montmorillonite and tea polyphenol is 0.01-0.05 g: 20 mL: 0.01-0.02 g: 10 mL.

3. The rolling method of the antibacterial titanium alloy sheet according to claim 1, characterized in that: The volume ratio of the chitosan mixed solution to the dodecyl aldehyde ethanol solution is 30-50:1-2.

4. The rolling method of the antibacterial titanium alloy sheet according to claim 1, characterized in that: The usage ratio of chitosan, acetic acid solution and ethanol solution in the chitosan mixed solution is 1-6 g: 200-250 mL: 100-200 mL.

5. The rolling method of an antibacterial titanium alloy sheet according to claim 1, characterized in that: The chitosan is shrimp shell chitosan with a molecular weight of 512 KDa.

6. The method for rolling an antibacterial titanium alloy sheet according to claim 1, wherein: The plasticizer is glycerol.

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