Phenyl ether bimetal organic framework antifouling material, preparation method and application

Abstract

The invention discloses a phenyl ether bimetal organic framework antifouling material, a preparation method and application, and belongs to the technical field of marine antifouling materials. The preparation method comprises the following steps: 1) dissolving a carboxyl-containing phenyl ether organic ligand, a zinc salt and a lanthanide metal salt in a polar organic solvent, and carrying out a coordination reaction in a closed reaction container, so that zinc and lanthanide metal ions and carboxyl form coordinate bonds, and bridging the metal ions to form tetra-metal clusters; washing and drying crystals obtained after the reaction to obtain the phenyl ether-based bimetal organic framework; and 2) grinding the phenyl ether-based bimetal organic framework, uniformly dispersing the ground phenyl ether-based bimetal organic framework into the waterborne polyurethane resin, and fully mixing to obtain the phenyl ether-based bimetal organic framework antifouling material. The invention also provides an application of the antifouling material in marine antifouling and anticorrosion. The prepared antifouling material is low in synthesis cost and difficulty and stable in property, and has a remarkable inhibition effect on biological sedimentation of diatom, barnacle and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of marine antifouling materials, and particularly relates to a phenoxy-based bimetallic organic framework antifouling material, a preparation method and an application thereof. Background Art

[0002] Marine biofouling refers to the phenomenon that marine organisms such as barnacles, algae, bacteria, etc. settle, colonize and attach to the outer surface of underwater objects. This phenomenon widely exists on the surfaces of artificial facilities such as ships, offshore oil platforms, seawater cooling system pipes, aquaculture cages, etc. For a long time, it has greatly affected human activities in developing the ocean, causing huge economic and energy losses. At present, the solutions to marine biofouling include: 1) modifying the surface to improve surface properties such as surface roughness and hydrophobicity to increase the possibility of cell settlement; 2) releasing specific antifouling active substances to reduce biological settlement by regulating the key biochemical pathways of biofilm formation and inhibiting cell metabolism. These antifouling active substances usually act on the surface in the form of controlled release or functional interface, but a balance needs to be achieved between inhibiting fouling organisms and reducing environmental toxicity. Therefore, the research and development of new long-acting antifouling active substances with both low harmfulness and strong biofouling prevention ability has become an important research topic in the field of marine biofouling prevention and control.

[0003] Metal-organic frameworks (MOFs) are porous crystalline materials formed by the self-assembly of metal ions and organic ligands through coordination bonds. They combine the structural stability of inorganic materials and the molecular designability of organic materials. Their unique structures and properties have been widely applied in fields such as drug delivery, sensing, and catalysis. By selecting different types of metal ions and organic ligands, the pore size, specific surface area, and surface chemical properties of MOFs can be precisely regulated, which provides a high-capacity space for the encapsulation of antifouling active substances. The MOF framework can undergo controlled degradation in a seawater environment, realizing the gradual release of metal ions, organic ligands, and loaded small molecules therein. The components with antifouling activity can then interact with biological cells in the environment, kill the cells by disrupting their metabolic activities, inducing cell lysis and other ways, and realize the inhibition of biological settlement. Compared with traditional antifouling carriers (such as polymer microspheres and mesoporous silica), MOF materials, due to their structural programmability and release controllability, achieve high-efficiency loading, precise release, and environmental friendliness, showing potential in the field of marine antifouling and providing a new possibility for the development of efficient, long-acting, and low-environmental-stress antifouling technologies. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that the antifouling active substances for preventing and controlling marine biofouling in the prior art are difficult to have both strong antifouling activity and low biological toxicity, and to provide a phenoxy-based bimetallic organic framework antifouling material, a preparation method and an application thereof.

[0005] The specific technical solution adopted by the present invention is as follows:

[0006] In the first aspect, the present invention provides a preparation method of a phenyl ether-based bimetallic organic framework antifouling material, and the specific steps are as follows:

[0007] S1: Dissolve a phenyl ether organic ligand containing carboxyl, a zinc salt, and a lanthanide metal salt in a polar organic solvent to obtain a mixed solution; place the mixed solution in a closed reaction vessel for a coordination reaction, so that zinc and lanthanide metal ions form coordination bonds with carboxyl, and bridge metal ions to form a tetrametal cluster; after washing and drying the crystals obtained after the reaction, a phenyl ether-based bimetallic organic framework is obtained;

[0008] S2: Grind the phenyl ether-based bimetallic organic framework obtained in step S1 and uniformly disperse it in a waterborne polyurethane resin, and fully mix to obtain a phenyl ether-based bimetallic organic framework antifouling material.

[0009] Preferably, in step S1, the lanthanide metal salt is gadolinium nitrate or cerium nitrate; the zinc salt is zinc nitrate.

[0010] Preferably, in step S1, the phenyl ether organic ligand containing carboxyl is 4,4'-dicarboxydiphenyl ether or 5,5'-isophthalic acid oxide.

[0011] Preferably, in step S1, the molar ratio of the phenyl ether organic ligand containing carboxyl, the zinc salt, and the lanthanide metal salt is (1.5 - 2.5):1:1.

[0012] Preferably, the polar organic solvent is N,N-dimethylformamide or N,N-diethylformamide.

[0013] Preferably, in step S1, the coordination reaction is carried out in a stainless steel autoclave, the temperature is set at 120 - 170 °C, and the reaction time is 72 - 96 h.

[0014] Preferably, in step S1, the crystals are washed with methanol and then dried under vacuum at room temperature.

[0015] Preferably, in step S2, the mass fraction of the phenyl ether-based bimetallic organic framework added to the waterborne polyurethane resin is 0.1 - 1%.

[0016] In the second aspect, the present invention provides a phenyl ether-based bimetallic organic framework antifouling material prepared by using the preparation method described in the first aspect.

[0017] In the third aspect, the present invention provides an application of the phenyl ether-based bimetallic organic framework antifouling material described in the second aspect in marine antifouling and anticorrosion. The phenyl ether-based bimetallic organic framework antifouling material described in the second aspect is coated on the surface of a substrate to be antifouled and anticorroded, and the coating thickness is 50 ± 5 μm.

[0018] The present invention has the following beneficial effects compared with the prior art:

[0019] (1) The phenyl ether-based bimetallic organic framework material prepared by the present invention has novel morphology, composition and structure, and realizes the controllable preparation of lanthanide metal MOF with 4,4'-dicarboxydiphenyl ether as the ligand for the first time, thus expanding the types of bimetallic organic framework materials.

[0020] (2) Among the ligands used in the phenyl ether-based bimetallic organic framework material prepared by the present invention, the organic ligand 4,4'-dicarboxydiphenyl ether and the metal ligands zinc ion and lanthanide metal ion all have certain antifouling activities. By efficiently combining various substances with antifouling activities through the metal-organic framework structure and then dispersing them in the waterborne polyurethane resin, a phenyl ether-based bimetallic organic framework antifouling material is obtained. This antifouling material exhibits good performance in inhibiting the settlement of organisms such as bacteria, algae and barnacles.

[0021] (3) The phenyl ether-based bimetallic organic framework antifouling material prepared by the present invention has good tolerance to common solvents. In addition, this antifouling material can achieve the long-term slow release of antifouling active substances through the slow degradation of the MOF structure in the environment, overcoming the short effective time of traditional antifouling coatings, thus providing a more lasting antifouling effect. Description of the Drawings

[0022] Figure 1 X-ray diffraction pattern of the gadolinium ion-based phenyl ether-based bimetallic organic framework prepared in Example 1;

[0023] Figure 2 Scanning electron microscope image of the gadolinium ion-based phenyl ether-based bimetallic organic framework prepared in Example 1;

[0024] Figure 3 X-ray photoelectron spectrum of the gadolinium ion-based phenyl ether-based bimetallic organic framework prepared in Example 1;

[0025] Figure 4 Fourier transform infrared spectrum of the gadolinium ion-based phenyl ether-based bimetallic organic framework prepared in Example 1;

[0026] Figure 5 X-ray diffraction pattern of the cerium ion-based phenyl ether-based bimetallic organic framework prepared in Example 2;

[0027] Figure 6 Scanning electron microscope image of the cerium ion-based phenyl ether-based bimetallic organic framework prepared in Example 2;

[0028] Figure 7 X-ray photoelectron spectrum of the cerium ion-based phenyl ether-based bimetallic organic framework prepared in Example 2;

[0029] Figure 8 Fourier infrared spectrum of the cerium ion-based phenylether bimetallic organic framework prepared for Example 2;

[0030] Figure 9 Tafel curve of the antifouling material prepared in Example 3 using the material prepared in Example 1;

[0031] Figure 10 Tafel curve of ordinary polyurethane resin used in Example 3. Detailed implementation manners

[0032] The present invention will be further described and illustrated below in conjunction with the accompanying drawings and specific implementation manners. The technical features of each implementation manner in the present invention can be combined correspondingly without conflict.

[0033] Example 1

[0034] This example provides a preparation method of a gadolinium ion-based phenylether bimetallic organic framework antifouling material, which is specifically as follows:

[0035] Dissolve 0.516 g of 4,4'-dicarboxydiphenyl ether, 0.297 g of zinc nitrate hexahydrate and 0.398 g of gadolinium nitrate hexahydrate in 30 mL of N,N-dimethylformamide to obtain a mixed solution. The molar ratio of 4,4'-dicarboxydiphenyl ether, zinc nitrate hexahydrate and gadolinium nitrate hexahydrate is 2:1:1.

[0036] Place the above mixed solution in a stainless steel autoclave with a Teflon lining and react at 150 °C for 72 hours to obtain white blocky crystals. Filter the crystals, wash them with methanol, and dry them under vacuum at room temperature to obtain a gadolinium ion-based phenylether bimetallic organic framework (MOF), named H2OBA@Gd. After grinding the above gadolinium ion-based phenylether bimetallic organic framework, disperse it evenly in the aqueous polyurethane resin according to a mass ratio of 1% to obtain a gadolinium ion-based phenylether bimetallic organic framework antifouling material. It should be noted that the obtained product is relatively stable in air and conventional organic solvents (such as tetrahydrofuran, methanol, ethanol, acetone, etc.).

[0037] Characterize and analyze the gadolinium ion-based phenylether bimetallic organic framework prepared in Example 1, which is specifically as follows:

[0038] Use a PANALYTICAL X'Pert3 Powder type X-ray diffractometer (Cu-Kα target, λ = 1.5406 Å, scanning range 5° - 80°) to analyze the crystal structure of the above metal-organic framework material, and complete the spectrum analysis and structure refinement through MDI Jade 6 software. The results are as Figure 1As shown, the peak at about 2θ = 10° belongs to the diffraction peak of the (011) crystal plane of the zinc-based MOF; the peak at about 2θ = 28° belongs to the characteristic peak of the (222) crystal plane of cubic gadolinium oxide, which matches the standard card (ICDD PDF#12-0797). The above diffraction peaks prove that the prepared gadolinium ion-based phenylether bimetallic organic framework has a complete crystal form and meets the design expectations.

[0039] The surface morphology of the sample was characterized using a Carl Zeiss Sigma 500 field emission scanning electron microscope (acceleration voltage 5 kV, working distance 8 mm). Before the test, the material was sputter-coated with gold (Au target, sputtering thickness 5 nm) to enhance conductivity and avoid charge accumulation. The results are as Figure 2 shown. The gadolinium ion-based phenylether bimetallic organic framework prepared in this example exhibits a uniform regular cubic columnar structure, with a single crystal size of 200 - 300 nm and an aspect ratio of approximately 8:1; the crystal surface is smooth and the edges are clear, without obvious defects, indicating good control of crystallinity during the synthesis process.

[0040] A Thermo Scientific K-Alpha X-ray photoelectron spectrometer (X-ray source: monochromatic Al Kα, energy 1486.6 eV, spot size 400 μm, energy resolution ≤0.5 eV) was used to analyze the surface element valence states of the gadolinium ion-based phenylether bimetallic organic framework in an ultra-high vacuum environment (<5×10 -8 mbar). The binding energy was calibrated using the C 1s standard peak (284.8 eV), and the spectral peak fitting and background subtraction were completed using Avantage software. The results are as Figure 3 shown. The characteristic peaks of Zn 2p 3 / 2 were observed at 1020.8 ± 0.2 eV, and Zn 2p 1 / 2 at 1046.9 ± 0.2 eV, which is consistent with the typical binding energy range (1021 - 1023 eV) of Zn 2+ , indicating that zinc participates in the MOF coordination structure in the +2 valence state; the Gd 4d 5 / 2 peak is located at 143.5 ± 0.3 eV, which is in line with the oxidation state characteristics of Gd 3+ (reference standard data: Gd 2 O 3 , PDF#12-0797), verifying the presence of the gadolinium oxide component.

[0041] The chemical structure of the gadolinium ion-based phenylether bimetallic organic framework was characterized using a Thermo Fisher Scientific Nicolet iS20 Fourier transform infrared spectrometer (spectral range 4000–400 cm -1 , resolution 4 cm -1 , and 32 scans). The results are as Figure 4 shown. The C=O asymmetric stretching vibration peak of the free carboxylic acid group of the organic ligand 4,4'-dicarboxydiphenyl ether is located at 1674 cm -1 , while the C=O stretching vibration peak of the metal-organic framework material prepared in this example is significantly red-shifted to 1670 cm -1 , indicating that deprotonation coordination occurs between the carboxylic acid group and the metal ion, confirming that the organic ligand is successfully coordinated with the metal center through the carboxylic acid group, and the MOF framework structure is constructed according to the design goal.

[0042] Example 2

[0043] A method for preparing a cerium ion-based phenylether bimetallic organic framework antifouling material is provided in this example, as follows:

[0044] 0.516 g of 4,4'-dicarboxydiphenyl ether, 0.297 g of zinc nitrate hexahydrate, and 0.434 g of cerium nitrate hexahydrate were dissolved in 30 mL of N,N-dimethylformamide to obtain a mixed solution. The molar ratio of 4,4'-dicarboxydiphenyl ether, zinc nitrate hexahydrate, and cerium nitrate hexahydrate is 2:1:1.

[0045] The above mixed solution was placed in a stainless steel autoclave with a Teflon lining and reacted at 150 °C for 72 hours to obtain white blocky crystals. The crystals were filtered, washed with methanol, and dried under vacuum at room temperature to obtain a cerium ion-based phenylether bimetallic organic framework (MOF), named H2OBA@Ce. After grinding the above cerium ion-based phenylether bimetallic organic framework, it was uniformly dispersed in an aqueous polyurethane resin at a mass ratio of 1% to obtain a cerium ion-based phenylether bimetallic organic framework antifouling material. It should be noted that the obtained product is relatively stable in air and conventional organic solvents (such as tetrahydrofuran, methanol, ethanol, acetone, etc.).

[0046] The cerium ion-based phenylether bimetallic organic framework prepared in Example 2 was characterized and analyzed, as follows:

[0047] The crystal structure of the above metal-organic framework MOF material was analyzed using a PANALYTICAL X'Pert3 Powder X-ray diffractometer (Cu-Kα target, λ = 1.5406 Å, scanning range 5°~80°), and the spectrum analysis and structure refinement were completed using MDI Jade 6 software. The results are asFigure 5 As shown, the peak at about 2θ = 10° belongs to the diffraction peak of the (011) crystal plane of the zinc-based MOF; the peaks at about 2θ = 28.5° and 2θ = 33° belong to the characteristic peaks of the (111) and (200) crystal planes of cubic cerium oxide, which match the standard card (JCPDS 34 - 0394). The above diffraction peaks prove that the prepared cerium ion-based phenyl ether bimetallic organic framework has a complete crystal form and meets the design expectations. Figure 6 This is the scanning electron microscope image of the cerium ion-based phenyl ether bimetallic organic framework prepared in this example. It can be seen that the surface of the crystal is smooth and the edges are clear, without obvious defects, indicating that the crystallinity is well controlled during the synthesis process.

[0048] Using a Thermo Scientific K-Alpha type X-ray photoelectron spectrometer (X-ray source: monochromatic Al Kα, energy 1486.6 eV, spot size 400 μm, energy resolution ≤0.5 eV), surface element valence state analysis was carried out on the cerium ion-based phenyl ether bimetallic organic framework in an ultra-high vacuum environment (<5×10 -8 mbar). The binding energy was calibrated with the C 1s standard peak (284.8 eV), and the spectral peak fitting and background subtraction were completed through Avantage software. The results are as Figure 7 shown. The observed Zn 2p 3 / 2 characteristic peak is located at 1022.2 ± 0.2 eV, and Zn 2p 1 / 2 is located at 1045.1 ± 0.2 eV, which is consistent with the typical binding energy range of Zn 2+ (1021 - 1023 eV), indicating that zinc participates in the MOF coordination structure in the +2 valence state; the Ce 3d 5 / 2 peak is located at 885.7 ± 0.2 eV, which conforms to the characteristic of the Ce 3+ oxidation state (reference standard data: Ce 2 O 3 , PDF#34 - 0394), verifying the existence of the cerium oxide component.

[0049] Using a Thermo Fisher Scientific Nicolet iS20 type Fourier transform infrared spectrometer (spectral range 4000–400 cm -1 , resolution 4 cm -1 , scanning times 32 times), chemical structure characterization was carried out on the cerium ion-based phenyl ether bimetallic organic framework. The results are as Figure 8As shown, the C=O asymmetric stretching vibration peak of the free carboxylic acid group of the organic ligand 4,4'-dicarboxydiphenyl ether is located at 1674 cm -1 , while the C=O stretching vibration peak of the metal-organic framework material prepared in this example is significantly red-shifted to 1671 cm -1 , indicating that the carboxylic acid group undergoes deprotonation coordination with metal ions, confirming that the organic ligand is successfully coordinated with the metal center through the carboxylic acid group, and the MOF framework structure is constructed according to the design goal.

[0050] Example 3

[0051] In this example, the corrosion test was carried out using the gadolinium ion-based phenylether bimetallic organic framework antifouling material prepared in Example 1 and a common polyurethane coating, as follows:

[0052] Using an AMETEK PARSTAT 4000A type electrochemical workstation (three-electrode system, the reference electrode is a saturated calomel electrode (SCE), the counter electrode is a platinum electrode, and the working electrode is the antifouling material or the common polyurethane coating prepared in Example 1), Tafel polarization curve tests were carried out in a simulated seawater environment (3.5 wt% NaCl solution, 25 ± 0.5 °C). Before the test, the specimen was immersed until the open circuit potential was stable, the scanning rate was 1 mV / s, the scanning range was ±0.2 V, and the data acquisition conforms to ASTM G5 standard. The results are as Figure 9 、 Figure 10 shown, Figure 9 is the Tafel curve of the antifouling material prepared in Example 1, Figure 10 is the Tafel curve of the common polyurethane resin.

[0053] After testing, the self-corrosion potential of the gadolinium ion-based phenylether bimetallic organic framework antifouling material in Example 1 is -0.444 V, and the corrosion current density is 2.1×10 -8 A / cm 2 ; the self-corrosion potential of the common polyurethane coating is -0.472 V, and the corrosion current density is 6.7×10 -7 A / cm 2 . The corrosion current density of the phenylether bimetallic organic framework antifouling material prepared by the present invention is reduced by about 96.9% compared with the common coating, indicating that its corrosion tendency is significantly reduced.

[0054] Example 4

[0055] In this example, the seawater antifouling and anticorrosion test was carried out using the gadolinium ion-based phenylether bimetallic organic framework antifouling material prepared in Example 1 and a common polyurethane coating, as follows:

[0056] The antifouling material obtained in Example 1 and the ordinary polyurethane coating were respectively and evenly coated on the surface of Q235 carbon steel substrate, and the coating thickness was 50 ± 5 μm, meeting the ISO 2808 standard. The specimens were suspended in the tidal zone of the East China Sea (latitude 30.0°, longitude 122.2°), with a salinity of 3.2 - 3.5%, and the test period was 15 days.

[0057] Through testing, it was found that only slight corrosion occurred at the edges of the specimens of the antifouling material in Example 1 (the corrosion area ratio ≤ 5%), and the attached organisms were mainly trace diatoms, without large fouling organisms; pitting corrosion occurred on the surface of the ordinary polyurethane coating control group (the corrosion area ratio ≥ 10%), indicating a small amount of biological settlement. The results of this example are consistent with the conclusion in Example 3 that the corrosion current density decreased by 96.9%, verifying the strong correlation between laboratory data and actual environmental performance, and indicating that the phenyl ether-based bimetallic organic framework antifouling material prepared by the present invention has good anti-corrosion and anti-biofouling properties.

[0058] The above-described embodiments are only a preferred solution of the present invention, but they are not intended to limit the present invention. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all technical solutions obtained by adopting equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A method for preparing a phenyl ether-based bimetallic organic framework antifouling material, characterized in that: The specific steps are as follows: S1: dissolving a carboxyl-containing phenyl ether organic ligand, a zinc salt, and a lanthanide metal salt in a polar organic solvent to obtain a mixed solution; placing the mixed solution in a closed reaction vessel for coordination reaction, so that zinc and lanthanide metal ions form coordination bonds with the carboxyl group and bridge metal ions to form a four-metal cluster; washing and drying the crystals obtained after the reaction to obtain a phenyl ether-based bimetallic organic framework; S2: Grind the phenyl ether-based bimetallic organic framework obtained in step S1 and evenly disperse it in an aqueous polyurethane resin, and mix them thoroughly to obtain a phenyl ether-based bimetallic organic framework antifouling material.

2. The method for preparing the phenyl ether-based bimetallic organic framework antifouling material according to claim 1, characterized in that: In step S1, the lanthanide metal salt is gadolinium nitrate or cerium nitrate; and the zinc salt is zinc nitrate.

3. The method for preparing the phenyl ether-based bimetallic organic framework antifouling material according to claim 1, characterized in that: The carboxyl-containing phenyl ether organic ligand in step S1 is 4,4'-dicarboxy diphenyl ether or 5,5'-oxidized isophthalic acid.

4. The method for preparing the phenyl ether-based bimetallic organic framework antifouling material according to claim 1, characterized in that: In step S1, the molar ratio of the carboxyl-containing phenyl ether organic ligand, the zinc salt and the lanthanide metal salt is (1.5-2.5):1:

1.

5. The method for preparing the phenyl ether-based bimetallic organic framework antifouling material according to claim 1, characterized in that: The polar organic solvent is N,N-dimethylformamide or N,N-diethylformamide.

6. The method for preparing the phenyl ether-based bimetallic organic framework antifouling material according to claim 1, characterized in that: The coordination reaction in step S1 is carried out in a stainless steel autoclave, the temperature is set to 120-170° C., and the reaction time is 72-96 h.

7. The method for preparing the phenyl ether-based bimetallic organic framework antifouling material according to claim 1, characterized in that: The crystals in step S1 are washed with methanol and then dried in vacuum at room temperature.

8. The method for preparing the phenyl ether-based bimetallic organic framework antifouling material according to claim 1, characterized in that: The mass fraction of the phenyl ether-based bimetallic organic framework added to the waterborne polyurethane resin in step S2 is 0.1-1%.

9. A phenyl ether-based bimetallic organic framework antifouling material prepared by the preparation method according to any one of claims 1 to 8.

10. An application of the phenyl ether-based bimetallic organic framework antifouling material according to claim 9 in marine antifouling and anticorrosion, characterized in that: The phenyl ether-based bimetallic organic framework antifouling material according to claim 9 is coated on the surface of a substrate that needs to be antifouled and anticorrosive, and the coating thickness is 50±5 μm.

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