Rare-earth-based bionic nanomaterial as well as preparation method and application thereof

Abstract

The invention discloses a rare-earth-based bionic nano material as well as a preparation method and application thereof, and relates to the field of microbial pollution and anti-corrosion treatment. According to the invention, the active center of lactonase can be simulated by using a zinc-based material, and ester bonds in N-acyl homoserine lactone (AHL) molecules can be hydrolyzed by using the lactonase so as to block bacterial quorum sensing (QS) among bacterial florae, so that the antibacterial effect is achieved. Meanwhile, the outer layer of zinc is provided with a cerium element as a shell, so that on one hand, permeation of oxygen, moisture and corrosive ions can be prevented; on the other hand, the structure has hydrophobicity, and corrosion of moisture and salt ions to a metal matrix is further reduced through the hydrophobicity. Cerium and an oxide thereof have certain antibacterial ability and can have a synergistic effect with zinc, Ce can promote generation of Zn-N and generate strong electron interaction, better hydrophobicity is shown, and attachment and growth of microorganisms on the metal surface can be further inhibited.

Description

Technical Field

[0001] The present invention relates to the field of microbial contamination and anti-corrosion treatment, and in particular to a rare earth-based bionic nanomaterial and a preparation method and application thereof. Background Art

[0002] During the long-term service of marine engineering equipment and ship facilities, the dual effects of seawater corrosion and microbial corrosion have become the core problem restricting their reliability and lifespan. Seawater is a highly conductive electrolyte, rich in Cl - 、SO4 2- Corrosive ions such as sulfate-reducing bacteria (SRB) can accelerate the electrochemical corrosion process of metal substrates; and microorganisms such as sulfate-reducing bacteria (SRB) that are prevalent in the marine environment further induce localized corrosion and pitting through the formation of metabolites (such as sulfides) and biofilms, leading to an exponential increase in the risk of material failure. The current mainstream technology for marine corrosion protection relies on metal-based anti-corrosion coatings, which work through two mechanisms: (1) Ion release inhibition: Metal ions (such as Zn 2+ 、Cu 2+ ) can inhibit microbial attachment and biofilm formation; (2) Physical barrier protection: The dense coating can block seawater penetration and slow down the electrochemical corrosion rate.

[0003] However, existing technologies have significant limitations: (1) Functional singleness defect: Although nanomaterials represented by Zn-NC active centers have excellent biofilm removal capabilities, their salt corrosion resistance is insufficient (Cl- penetration causes damage to the coating passivation film); (2) Failure of synergistic protection: Traditional coatings are difficult to maintain a stable ion release rate in long-term high-salt environments, resulting in the attenuation of antibacterial performance and anti-corrosion effects over time; (3) Microbial adaptability: SRB and other bacterial communities are easily enriched in coating defects, accelerating the corrosion of the coating / substrate interface through metabolic products, forming a vicious cycle of "corrosion-biofilm-secondary corrosion".

[0004] Therefore, the development of multifunctional coating materials with long-term antibacterial properties, salt resistance, stability, and interfacial corrosion resistance has become the key to breaking through the bottleneck of corrosion protection for marine equipment. By doping and modifying metal-based coatings with rare earth elements (such as cerium), the electronic structure and interfacial reaction kinetics of metal-based coatings can be regulated, which is expected to achieve synergistic enhancement of corrosion inhibition and microbial protection. This is of great significance for extending the service life of marine engineering equipment in extreme environments. Summary of the Invention

[0005] Technical problem to be solved: In order to solve the problem of low enzyme activity and poor stability in high-salt environments, the present invention provides a rare earth-based bionic nanomaterial and its preparation method and application, which reduces the impact of metal corrosion and microbial corrosion on facilities and equipment, enhances the salt resistance and corrosion resistance of metal coating materials in high-salt environments, and improves stability.

[0006] Technical solution: A preparation method of a rare earth-based biomimetic nanomaterial, comprising the following steps: (1) dissolving a metallic zinc source and an organic ligand in an organic solvent at a molar ratio of 1:(3-5), mixing and stirring at room temperature, collecting a precipitate and washing it with an organic solvent, and then vacuum drying to obtain a zinc-based precursor; (2) mixing the zinc-based precursor obtained in step (1) with a cerium source, wherein the molar mass ratio of the zinc-based precursor to the cerium source is 1:(1-3), adding an organic solvent to dissolve the mixture, adding an organic ligand, wherein the molar mass ratio of the cerium source to the organic ligand is 1:(1-3), mixing and stirring at room temperature, centrifuging and separating the precipitate, washing the precipitate, and vacuum drying to obtain a cerium-doped precursor; (3) heating the cerium-doped precursor to 500-1000°C under a nitrogen atmosphere, calcining for 1-12 hours, and cooling the mixture to obtain a rare earth-based biomimetic nanomaterial (Zn@Ce).

[0007] The metallic zinc source is zinc chloride, the organic ligand is 2-methylimidazole, the organic solvent is methanol, and the cerium source is cerium nitrate hexahydrate.

[0008] The mixing and stirring conditions in step (1) are: a rotation speed of 50 to 1000 r / min, a time of 1 to 5 hours, and a temperature of 20 to 50°C.

[0009] The drying time in step (1) is 1 to 12 hours, and the temperature is 50 to 100°C.

[0010] The molar mass ratio of the zinc-based precursor to the cerium source in step (2) is 1:(1-3).

[0011] The mixing and stirring conditions in step (2) are: a rotation speed of 50 to 800 r / min, a time of 1 to 12 h, and a temperature of 20 to 50° C.

[0012] The molar mass ratio of the cerium source to the organic ligand in step (2) is 1:(1-3).

[0013] The centrifugal conditions in step (2) are 4000-13000 r / min and the time is 10-20 min.

[0014] The vacuum drying time in step (2) is 1 to 12 hours, and the temperature is 50 to 100°C.

[0015] The rare earth-based bionic nanomaterial is prepared by the above method.

[0016] The application of the above rare earth-based bionic nanomaterials in the preparation of antibacterial coatings.

[0017] Beneficial Effects: The salt-resistant and corrosion-resistant rare earth-based biomimetic nanomaterial prepared by the present invention utilizes zinc-based materials to mimic the active center of lactonase. Lactonase hydrolyzes the ester bond in N-acylhomoserine lactone (AHL) molecules, thereby blocking quorum sensing (QS) between bacterial colonies and achieving an antibacterial effect. Furthermore, the zinc layer is encapsulated by cerium, a rare earth element that is important in metal corrosion and exhibits a high degradation rate. This prevents the penetration of oxygen, moisture, and corrosive ions. Furthermore, cerium itself possesses corrosion-resistant properties, reducing corrosion of the metal substrate, minimizing environmental impact, and enhancing material stability. Furthermore, the hydrophobic structure further reduces moisture and salt ion corrosion. Cerium and its oxides possess certain antibacterial properties and can act synergistically with zinc. Ce promotes the formation of Zn-N bonds, generating strong electronic interactions and exhibiting enhanced hydrophobicity, further inhibiting the attachment and growth of microorganisms on metal surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Experimental flow chart.

[0019] Figure 2 Zn@Ce morphology and structure diagram.

[0020] Figure 3 Conversion rate diagram.

[0021] Figure 4 Corrosion condition of steel sheet (30d). DETAILED DESCRIPTION

[0022] Example 1

[0023] (1) 9.85 g of 2-methylimidazole and 8.93 g of zinc nitrate hexahydrate were dissolved in methanol. The two solutions were mixed and stirred at room temperature. The white precipitate was collected and washed three times with methanol. Afterwards, the product was dried in a vacuum drying oven to obtain the product.

[0024] (2) 0.5 g of the above product, 0.94 g of cerium nitrate hexahydrate, and 1.62 g of 2-methylimidazole were dissolved in methanol, respectively. The two solutions were mixed and stirred at room temperature, and then filtered and centrifuged to collect the white precipitate, which was then washed. Thereafter, the precipitate was dried in a vacuum oven to obtain the final product.

[0025] (3) The sample was placed in a tube furnace and calcined at 700 °C for 5 h under a nitrogen atmosphere to obtain Zn@Ce.

[0026] The prepared Zn@Ce was used to degrade γ-enantholactone. γ-enantholactone was dissolved in 3.5 wt.% NaCl solution, the γ-enantholactone concentration was 0.01 mL / mL, and the conversion rate was 98%.

[0027] Example 2

[0028] (1) 9.85 g of 2-methylimidazole and 8.93 g of zinc nitrate hexahydrate were dissolved in methanol. The two solutions were mixed and stirred at room temperature. The white precipitate was collected and washed three times with methanol. Afterwards, the product was dried in a vacuum drying oven to obtain the product.

[0029] (2) 0.5 g of the above product, 1.98 g of cerium nitrate hexahydrate, and 1.62 g of 2-methylimidazole were dissolved in methanol, respectively. The two solutions were mixed and stirred at room temperature, and then filtered and centrifuged to collect the white precipitate, which was then washed. Thereafter, the precipitate was dried in a vacuum oven to obtain the final product.

[0030] (3) The sample was placed in a tube furnace and calcined at 700 °C for 5 h under a nitrogen atmosphere to obtain Zn@Ce.

[0031] The prepared Zn@Ce was used to degrade γ-enantholactone. γ-enantholactone was dissolved in 3.5 wt.% NaCl solution, the γ-enantholactone concentration was 0.01 mL / mL, and the conversion rate was 83%.

[0032] Example 3

[0033] (1) 9.85 g of 2-methylimidazole and 8.93 g of zinc nitrate hexahydrate were dissolved in methanol. The two solutions were mixed and stirred at room temperature. The white precipitate was collected and washed three times with methanol. Afterwards, the product was dried in a vacuum drying oven to obtain the product.

[0034] (2) 0.5 g of the above product, 0.47 g of cerium nitrate hexahydrate, and 1.62 g of 2-methylimidazole were dissolved in methanol, respectively. The two solutions were mixed and stirred at room temperature, and then filtered and centrifuged. The white precipitate was collected and washed. Thereafter, it was dried in a vacuum oven to obtain the final product.

[0035] (3) The sample was placed in a tube furnace and calcined at 700 °C for 5 h under a nitrogen atmosphere to obtain Zn@Ce.

[0036] The prepared Zn@Ce was used to degrade γ-enantholactone. γ-enantholactone was dissolved in 3.5 wt.% NaCl solution, the γ-enantholactone concentration was 0.01 mL / mL, and the conversion rate was 78%.

[0037] Example 4

[0038] (1) 9.85 g of 2-methylimidazole and 8.93 g of zinc nitrate hexahydrate were dissolved in methanol. The two solutions were mixed and stirred at room temperature. The white precipitate was collected and washed three times with methanol. Afterwards, the product was dried in a vacuum drying oven to obtain the product.

[0039] (2) 0.5 g of the above product, 0.94 g of cerium nitrate hexahydrate, and 1.62 g of 2-methylimidazole were dissolved in methanol, respectively. The two solutions were mixed and stirred at room temperature, and then filtered and centrifuged to collect the white precipitate, which was then washed. Thereafter, the precipitate was dried in a vacuum oven to obtain the final product.

[0040] (3) The sample was placed in a tube furnace and calcined at 800 °C for 2 h under a nitrogen atmosphere to obtain Zn@Ce.

[0041] The prepared Zn@Ce was used to degrade γ-heptanolactone. γ-heptanolactone was dissolved in 3.5 wt.% NaCl solution. The concentration of γ-heptanolactone was 0.01 mL / mL, and the conversion rate was 65%.

[0042] Example 5

[0043] (1) 9.85 g of 2-methylimidazole and 8.93 g of zinc nitrate hexahydrate were dissolved in methanol. The two solutions were mixed and stirred at room temperature. The white precipitate was collected and washed three times with methanol. Afterwards, the product was dried in a vacuum drying oven to obtain the product.

[0044] (2) 0.5 g of the above product, 0.94 g of cerium nitrate hexahydrate, and 1.62 g of 2-methylimidazole were dissolved in methanol, respectively. The two solutions were mixed and stirred at room temperature, and then filtered and centrifuged to collect the white precipitate, which was then washed. Thereafter, the precipitate was dried in a vacuum oven to obtain the final product.

[0045] (3) The sample was placed in a tube furnace and calcined at 1000 °C for 5 h under a nitrogen atmosphere to obtain Zn@Ce.

[0046] The prepared Zn@Ce was used to degrade γ-enantholactone. γ-enantholactone was dissolved in 3.5 wt.% NaCl solution, the γ-enantholactone concentration was 0.01 mL / mL, and the conversion rate was 54%.

[0047] Example 6

[0048] (1) 9.85 g of 2-methylimidazole and 8.93 g of zinc nitrate hexahydrate were dissolved in methanol. The two solutions were mixed and stirred at room temperature. The white precipitate was collected and washed three times with methanol. Afterwards, the product was dried in a vacuum drying oven to obtain the product.

[0049] (2) 0.5 g of the above product, 0.94 g of cerium nitrate hexahydrate, and 0.2 g of 2-methylimidazole were dissolved in methanol, respectively. The two solutions were mixed and stirred at room temperature, and then filtered and centrifuged to collect the white precipitate, which was then washed. Thereafter, the precipitate was dried in a vacuum oven to obtain the final product.

[0050] (3) The sample was placed in a tube furnace and calcined at 1000 °C for 5 h under a nitrogen atmosphere to obtain Zn@Ce.

[0051] The prepared Zn@Ce was used to degrade γ-enantholactone. γ-enantholactone was dissolved in 3.5 wt.% NaCl solution, the concentration of γ-enantholactone was 0.01 mL / mL, and the conversion rate was 45%.

[0052] Example 7

[0053] (1) 9.85 g of 2-methylimidazole and 8.93 g of zinc nitrate hexahydrate were dissolved in methanol. The two solutions were mixed and stirred at room temperature. The white precipitate was collected and washed three times with methanol. Afterwards, the product was dried in a vacuum drying oven to obtain the product.

[0054] (2) 0.5 g of the above product, 0.94 g of cerium nitrate hexahydrate, and 0.8 g of 2-methylimidazole were dissolved in methanol, respectively. The two solutions were mixed and stirred at room temperature, and then filtered and centrifuged to collect the white precipitate, which was then washed. Thereafter, the precipitate was dried in a vacuum oven to obtain the final product.

[0055] (3) The sample was placed in a tube furnace and calcined at 1000 °C for 5 h under a nitrogen atmosphere to obtain Zn@Ce.

[0056] The prepared Zn@Ce was used to degrade γ-enantholactone. γ-enantholactone was dissolved in 3.5 wt.% NaCl solution, the concentration of γ-enantholactone was 0.01 mL / mL, and the conversion rate was 48%.

[0057] Example 8

[0058] (1) Using the Zn@Ce material prepared in Example 1, 0.15 g was added to 20 g of epoxy resin, coated on the surface of a steel sheet, and immersed in a 3.5% NaCl solution for one month.

[0059] (2) Using the Zn-NC material prepared in Control Example 1, 0.15 g was added to 20 g of epoxy resin, coated on the surface of a steel sheet, and immersed in a 3.5% NaCl solution for one month.

[0060] (3) Immerse the blank steel sheet in 3.5% NaCl solution for one month.

[0061] The corrosion resistance of the prepared Zn@Ce material is significantly improved compared with the blank steel sheet and Zn-NC material ( Figure 4 ).

[0062] Comparative Example 1

[0063] (1) 9.85 g of 2-methylimidazole and 8.93 g of zinc nitrate hexahydrate were dissolved in methanol, mixed and stirred at room temperature, and the white precipitate was collected and washed three times with methanol, and vacuum dried to obtain the product.

[0064] (2) 0.5 g of the above product was directly placed in a tube furnace and calcined at 700 °C for 2 h under a nitrogen atmosphere to obtain pure Zn-NC material.

[0065] The prepared Zn-NC was used to degrade γ-enantholactone. γ-enantholactone was dissolved in a 3.5 wt.% NaCl solution. The concentration of γ-enantholactone was 0.01 mL / mL, and the conversion rate was 73%.

[0066] Comparative Example 2

[0067] (1) 3.23 g of Ce(NO3)3·6H2O and 7.50 g of urea were dissolved in 15 mL of deionized water and then mixed with a solution consisting of 17.00 g of NaOH and 45 mL of deionized water.

[0068] (2) The resulting solution was stirred and mixed for 0.5 h, and then transferred to a 150 mL stainless steel autoclave and heated at 140°C for 24 h.

[0069] (3) The obtained precipitate was purified, dried, dried at 80 °C for 12 h, and calcined in air at 350 °C for 4 h to obtain the final sample.

[0070] The prepared CeO2 was used to degrade γ-enantholactone. γ-enantholactone was dissolved in a 3.5 wt.% NaCl solution with a γ-enantholactone concentration of 0.01 mL / mL and a conversion rate of 52%.

[0071] Comparative Example 3

[0072] (1) Weigh 0.3 g of zinc nitrate hexahydrate and dissolve it in beaker A containing 15 mL of methanol; weigh 0.39 g of 2-methylimidazole and dissolve it in beaker B containing 15 mL of methanol, and stir them magnetically for 30 minutes to prepare a mixed solution.

[0073] (2) Solution A was quickly injected into solution B and magnetic stirring was continued at room temperature for 10 h. After the reaction was complete, the product was centrifuged and washed three times with methanol and dried in an oven at 70°C for 12 h.

[0074] (3) The obtained ZIF-8 sample was placed in a tube furnace and heated in air at 2°C·min -1 The sample was heated to 400 °C at a heating rate of 100 °C and kept at that temperature for 2 h. After cooling naturally, the white sample was taken out to obtain MOF-derived ZnO.

[0075] The prepared ZnO was used to degrade γ-enantholactone. γ-enantholactone was dissolved in a 3.5 wt.% NaCl solution. The concentration of γ-enantholactone was 0.01 mL / mL, and the conversion rate was 58%.

[0076] Comparative Example 4

[0077] (1) 9.85 g of 2-methylimidazole and 8.93 g of zinc nitrate hexahydrate were dissolved in methanol, mixed and stirred at room temperature, and the white precipitate was collected and washed three times with methanol, and vacuum dried to obtain the product.

[0078] (2) 0.1 g of ZIF-8 was immersed in 15 mL of methanol solution containing 20.8 mg of H2PtCl4, and the mixture was stirred at room temperature for 24 h. Subsequently, 10 mL of NaBH4 / BH6N solution (0.001 mM) was quickly added to the mixture under vigorous stirring. After 2 h of reaction, the Pt@ZIF-8 composite was obtained by centrifugation, washing three times with methanol, and drying at 60°C overnight.

[0079] The prepared Pt@ZIF-8 was used to degrade γ-heptanolactone. γ-heptanolactone was dissolved in 3.5% NaCl solution, the concentration of γ-heptanolactone was 0.01 mL / mL, and the conversion rate was 60%.

Claims

1. A method for preparing rare earth-based bionic nanomaterials, characterized in that: The following steps are involved: (1) dissolving a metallic zinc source and an organic ligand in an organic solvent at a molar ratio of 1:(3-5), mixing and stirring at room temperature, collecting the precipitate, washing it with an organic solvent, and then vacuum drying it to obtain a zinc-based precursor; (2) mixing the zinc-based precursor obtained in step (1) with a cerium source, wherein the molar mass ratio of the zinc-based precursor to the cerium source is 1:(1-3), adding an organic solvent to dissolve the mixture, and then adding an organic ligand, wherein the molar mass ratio of the cerium source to the organic ligand is 1:(1-3), mixing and stirring at room temperature, centrifuging and precipitating the mixture, washing the mixture, and vacuum drying the mixture to obtain a cerium-doped precursor; (3) The cerium-doped precursor is heated to 500-1000° C. in a nitrogen atmosphere, calcined for 1-12 hours, and cooled to obtain a rare earth-based biomimetic nanomaterial (Zn@Ce).

2. The method for preparing rare earth-based biomimetic nanomaterials according to claim 1, wherein: The metallic zinc source is zinc chloride, the organic ligand is 2-methylimidazole, the organic solvent is methanol, and the cerium source is cerium nitrate hexahydrate.

3. The method for preparing rare earth-based biomimetic nanomaterials according to claim 1, characterized in that: The mixing and stirring conditions in step (1) are: a rotation speed of 50 to 1000 r / min, a time of 1 to 5 hours, and a temperature of 20 to 50°C.

4. The method for preparing the rare earth-based biomimetic nanomaterial according to claim 1, wherein: The drying time in step (1) is 1 to 12 hours, and the temperature is 50 to 100°C.

5. The method for preparing rare earth-based biomimetic nanomaterials according to claim 1, wherein: The molar mass ratio of the zinc-based precursor to the cerium source in step (2) is 1:(1-3).

6. The method for preparing rare earth-based biomimetic nanomaterials according to claim 1, characterized in that: The mixing and stirring conditions in step (2) are: a rotation speed of 50 to 800 r / min, a time of 1 to 12 h, and a temperature of 20 to 50° C. The method for preparing rare earth-based biomimetic nanomaterials according to claim 1, characterized in that the molar mass ratio of the cerium source to the organic ligand in step (2) is 1:(1-3).

7. The method for preparing rare earth-based biomimetic nanomaterials according to claim 1, characterized in that: The centrifugal conditions in step (2) are 4000-13000 r / min and the time is 10-20 min.

8. The method for preparing rare earth-based biomimetic nanomaterials according to claim 1, characterized in that: The vacuum drying time in step (2) is 1 to 12 hours, and the temperature is 50 to 100°C.

9. Rare earth-based bionic nanomaterials prepared by the method according to any one of claims 1 to 8.

10. Use of the rare earth-based bionic nanomaterial according to claim 9 in the preparation of antibacterial coatings.

Images