A phenyl ether-based bimetallic organic framework antifouling material, preparation method and application

Abstract

The present invention discloses a phenyl ether-based bimetallic organic framework antifouling material, its preparation method, and its application, belonging to the technical field of marine antifouling materials. The preparation method is as follows: 1) A phenyl ether organic ligand containing a carboxyl group, a zinc salt, and a lanthanide metal salt are dissolved in a polar organic solvent and placed in a sealed reaction vessel for a coordination reaction, whereby the zinc and lanthanide metal ions form coordination bonds with the carboxyl groups, bridging the metal ions to form a tetrametallic cluster; the resulting crystals are washed and dried to obtain the phenyl ether-based bimetallic organic framework; 2) the phenyl ether-based bimetallic organic framework is ground and uniformly dispersed in an aqueous polyurethane resin, followed by thorough mixing to obtain the phenyl ether-based bimetallic organic framework antifouling material. The present invention also provides the application of the antifouling material in marine antifouling and anticorrosion applications. The antifouling material prepared by the present invention has low synthesis cost and difficulty, stable properties, and significant inhibitory effect on the settlement of organisms such as diatoms and barnacles.

Description

Technical Field

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

[0002] Marine biofouling refers to the settlement, colonization, and attachment of marine organisms, such as barnacles, algae, and bacteria, to the exterior surfaces of underwater objects. This phenomenon is widespread on the surfaces of artificial structures such as ships, offshore oil platforms, seawater cooling system pipes, and aquaculture cages. It has long significantly impacted human ocean development and resulted in significant economic and energy losses. Current approaches to combating marine biofouling include: 1) surface modification to enhance surface properties, such as roughness and hydrophobicity, to increase the likelihood of cell deposition; and 2) the release of specific antifouling agents that reduce biofouling by modulating key biochemical pathways in biofilm formation and inhibiting cellular metabolism. These antifouling agents typically act on surfaces through controlled release or functional interfaces, but a balance must be struck between inhibiting fouling organisms and reducing environmental toxicity. Therefore, the development of novel, long-lasting antifouling agents that combine low hazard potential with robust biofouling prevention capabilities has become a crucial 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 with the molecular designability of organic materials. Their unique structure and properties have led to widespread applications in drug delivery, sensing, catalysis, and other fields. By varying the types of metal ions and organic ligands, the pore size, specific surface area, and surface chemical properties of MOFs can be precisely controlled, providing a high-capacity space for the encapsulation of antifouling active substances. MOF frameworks undergo controlled degradation in seawater, allowing the gradual release of metal ions, organic ligands, and loaded small molecules. The antifouling active components can then interact with biological cells in the environment, killing them by disrupting their metabolic activity and inducing cell lysis, thereby inhibiting biodeposition. Compared to traditional antifouling carriers (such as polymer microspheres and mesoporous silica), MOFs, due to their structural programmability and controllable release, achieve efficient loading, precise release, and environmentally friendly properties. They demonstrate promising potential in marine antifouling applications and offer new possibilities for the development of highly effective, long-lasting, and low-stress antifouling technologies. Summary of the Invention

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

[0005] The specific technical solutions adopted in the present invention are as follows:

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

[0007] 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 sealed reaction vessel for a coordination reaction, so that the zinc and lanthanide metal ions form coordination bonds with the carboxyl groups, bridging the metal ions to form a tetrametallic cluster; washing and drying the crystals obtained after the reaction to obtain a phenyl ether-based bimetallic organic framework;

[0008] S2: Grind the phenyl ether-based bimetallic organic framework obtained in step S1 and evenly disperse the mixture in an aqueous polyurethane resin, and mix the mixture thoroughly 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; and the zinc salt is zinc nitrate.

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

[0011] Preferably, 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.

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

[0013] Preferably, 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.

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

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

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

[0017] In a 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, wherein the phenyl ether-based bimetallic organic framework antifouling material described in the second aspect is coated on the surface of a substrate to be antifouling and anticorrosion, and the coating thickness is 50±5 μm.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The phenyl ether-based bimetallic organic framework material prepared by the present invention has a novel morphology, composition and structure. It is the first time that the controllable preparation of lanthanide metal MOF with 4,4'-dicarboxydiphenyl ether as a ligand has been achieved, thereby 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'-dicarboxyl diphenyl ether and the metal ligands zinc ions and lanthanide metal ions all have certain antifouling activity. A variety of substances with antifouling activity are efficiently combined through the metal-organic framework structure and then dispersed in a waterborne polyurethane resin to obtain a phenyl ether-based bimetallic organic framework antifouling material. This antifouling material exhibits good performance in inhibiting the deposition of bacteria, algae, barnacles, and other organisms.

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

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

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

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

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

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

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

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

[0029] Figure 8 This is a Fourier transform infrared spectrum of the cerium ion-based phenyl ether bimetallic organic framework prepared in Example 2;

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

[0031] Figure 10 This is the Tafel curve of the common polyurethane resin used in Example 3. DETAILED DESCRIPTION

[0032] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention may be combined accordingly, provided that there is no conflict between them.

[0033] Example 1

[0034] This embodiment provides a method for preparing a phenyl ether-based bimetallic organic framework antifouling material based on gadolinium ions, 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, wherein the molar ratio of 4,4'-dicarboxydiphenyl ether, zinc nitrate hexahydrate, and gadolinium nitrate hexahydrate is 2:1:1.

[0036] The mixed solution was placed in a Teflon-lined stainless steel autoclave and reacted at 150°C for 72 hours, yielding white blocky crystals. The crystals were filtered, washed with methanol, and dried under vacuum at room temperature to yield a gadolinium ion-based phenyl ether bimetallic organic framework (MOF), designated H2OBA@Gd. The gadolinium ion-based phenyl ether bimetallic organic framework was ground and uniformly dispersed in an aqueous polyurethane resin at a mass ratio of 1% to yield a gadolinium ion-based phenyl ether bimetallic organic framework antifouling material. Notably, the resulting product was stable in both air and common organic solvents (such as tetrahydrofuran, methanol, ethanol, and acetone).

[0037] The gadolinium ion-based phenyl ether bimetallic organic framework prepared in Example 1 was characterized and analyzed as follows:

[0038] The crystal structure of the metal-organic framework 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. Figure 1As shown, the peak around 2θ = 10° is attributed to the (011) crystal plane diffraction peak of the zinc-based MOF, and the peak around 2θ = 28° is attributed 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 phenyl ether-based bimetallic organic framework has a complete crystal form and meets the design expectations.

[0039] The surface morphology of the samples was characterized using a Carl Zeiss Sigma 500 field emission scanning electron microscope (accelerating voltage 5 kV, working distance 8 mm). Before testing, the material was gold-sputtered (Au target, sputtering thickness 5 nm) to enhance conductivity and avoid charge accumulation. Figure 2 As shown, the gadolinium ion-based phenyl ether-based 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 has clear edges without obvious defects, indicating that the crystallinity is well controlled during the synthesis process.

[0040] The X-ray photoelectron spectrometer (X-ray source: monochromated Al Kα, energy 1486.6 eV, beam spot size 400 μm, energy resolution ≤ 0.5 eV) was used in an ultra-high vacuum environment (<5×10 -8 The surface element valence state of the gadolinium ion-based phenyl ether bimetallic organic framework was analyzed at 100 mbar. The binding energy was calibrated with the C 1s standard peak (284.8 eV), and the spectrum was fitted and background subtracted using Avantage software. The results are shown in Figure 2. Figure 3 As shown in the figure, the characteristic peaks of Zn 2p3 / 2 are observed at 1020.8±0.2 eV and Zn 2p1 / 2 are observed at 1046.9±0.2 eV, which are similar to those of Zn 2+ The typical binding energy range of Zn is consistent with that of Zn (1021~1023 eV), indicating that Zn participates in the MOF coordination structure in the +2 valence state; the Gd 4d5 / 2 peak is located at 143.5 ± 0.3 eV, which is consistent with the Gd 3+ Oxidation state characteristics (reference standard data: Gd2O3, PDF#12-0797) verify the presence of gadolinium oxide components.

[0041] Thermo Fisher Scientific Nicolet iS20 Fourier transform infrared spectrometer (spectral range 4000–400 cm -1 , resolution 4 cm -1 , scanning times 32 times), the chemical structure of the phenyl ether-based bimetallic organic framework based on gadolinium ions was characterized. Figure 4 As shown in the figure, the C=O asymmetric stretching vibration peak of the free carboxylic acid group of the organic ligand 4,4'-dicarboxyl diphenyl ether is located at 1674 cm -1 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 the carboxylic acid groups undergo deprotonated coordination with metal ions, confirming that the organic ligands are successfully coordinated with the metal center through the carboxylic acid groups, and the MOF skeleton structure is constructed according to the design target.

[0042] Example 2

[0043] This embodiment provides a method for preparing a cerium ion-based phenyl ether-based bimetallic organic framework antifouling material, which is specifically as follows:

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

[0045] The mixed solution was placed in a Teflon-lined stainless steel autoclave and reacted at 150°C for 72 hours, yielding white blocky crystals. The crystals were filtered, washed with methanol, and dried under vacuum at room temperature to yield a cerium-based phenyl ether-based bimetallic organic framework (MOF), designated H2OBA@Ce. The cerium-based phenyl ether-based bimetallic organic framework was ground and uniformly dispersed in a water-based polyurethane resin at a mass ratio of 1% to yield a cerium-based phenyl ether-based bimetallic organic framework antifouling material. Notably, the resulting product was stable in both air and common organic solvents (such as tetrahydrofuran, methanol, ethanol, and acetone).

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

[0047] The crystal structure of the 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. Figure 5As shown, the peak at around 2θ = 10° is attributed to the (011) crystal plane diffraction peak of the zinc-based MOF; the peaks at around 2θ = 28.5° and 2θ = 33° are attributed 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-based bimetallic organic framework has a complete crystal form and meets the design expectations. Figure 6 This is a scanning electron microscope image of the cerium ion-based phenyl ether bimetallic organic framework prepared in this example. It can be seen that the crystal surface is smooth and the edges are clear, without obvious defects, indicating that the crystallinity is well controlled during the synthesis process.

[0048] The X-ray photoelectron spectrometer (X-ray source: monochromated Al Kα, energy 1486.6 eV, beam spot size 400 μm, energy resolution ≤ 0.5 eV) was used in an ultra-high vacuum environment (<5×10 -8 The surface element valence state of the cerium ion-based phenyl ether bimetallic organic framework was analyzed at 100 mbar. The binding energy was calibrated with the C 1s standard peak (284.8 eV), and the spectrum was fitted and background subtracted using Avantage software. The results are shown in Figure 2. Figure 7 As shown in the figure, the characteristic peaks of Zn 2p3 / 2 are observed at 1022.2±0.2 eV and Zn 2p1 / 2 are observed at 1045.1±0.2 eV, which are similar to those of Zn 2+ The typical binding energy range of Zn is consistent with that of Zn (1021~1023 eV), indicating that Zn participates in the MOF coordination structure with a +2 valence state; the Ce 3d5 / 2 peak is located at 885.7 ± 0.2 eV, which is consistent with the Ce 3+ Oxidation state characteristics (reference standard data: Ce2O3, PDF#34-0394) verify the presence of cerium oxide components.

[0049] Thermo Fisher Scientific Nicolet iS20 Fourier transform infrared spectrometer (spectral range 4000–400 cm -1 , resolution 4 cm -1 , scanning times 32 times), the chemical structure of the phenyl ether-based bimetallic organic framework based on cerium ions was characterized. The results are as follows Figure 8 As shown in the figure, the C=O asymmetric stretching vibration peak of the free carboxylic acid group of the organic ligand 4,4'-dicarboxyl diphenyl ether is located at 1674 cm -1 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 groups undergo deprotonated coordination with metal ions, confirming that the organic ligands are successfully coordinated with the metal center through the carboxylic acid groups, and the MOF skeleton structure is constructed according to the design target.

[0050] Example 3

[0051] This example uses the gadolinium ion-based phenyl ether-based bimetallic organic framework antifouling material prepared in Example 1 and a common polyurethane coating to conduct corrosion tests, specifically as follows:

[0052] Tafel polarization curves were measured using an AMETEK PARSTAT 4000A electrochemical workstation (three-electrode system, with a saturated calomel electrode (SCE) as the reference electrode, a platinum electrode as the counter electrode, and the antifouling material prepared in Example 1 or a conventional polyurethane coating as the working electrode) in a simulated seawater environment (3.5 wt% NaCl solution, 25±0.5°C). Before testing, the sample was immersed until the open circuit potential stabilized. The scan rate was 1 mV / s, the scan range was ±0.2 V, and data acquisition complied with ASTM G5 standards. The results are shown in Figure 5. Figure 9 、 Figure 10 As shown, Figure 9 is the Tafel curve of the antifouling material prepared in Example 1, Figure 10 This is the Tafel curve using ordinary polyurethane resin.

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

[0054] Example 4

[0055] This example uses the gadolinium ion-based phenyl ether-based bimetallic organic framework antifouling material prepared in Example 1 and a common polyurethane coating to conduct seawater antifouling and anticorrosion tests, specifically as follows:

[0056] The antifouling material obtained in Example 1 and a conventional polyurethane coating were uniformly applied to the surface of a Q235 carbon steel substrate, with a coating thickness of 50 ± 5 μm, in compliance with ISO 2808. The specimens were suspended in the tidal range zone of the East China Sea (30.0°N, 122.2°E), with a salinity of 3.2–3.5%, for 15 days.

[0057] Testing revealed that the antifouling material in Example 1 exhibited only slight corrosion at the edges of the specimen (corrosion area ≤ 5%), with attached organisms primarily consisting of trace diatoms, with no large fouling organisms. The control group, coated with a standard polyurethane coating, exhibited pitting corrosion (corrosion area ≥ 10%), indicating minimal biofouling. These results are consistent with the 96.9% reduction in corrosion current density reported in Example 3, confirming the strong correlation between laboratory data and actual environmental performance. This demonstrates that the phenylene ether-based bimetallic organic framework antifouling material prepared in this invention exhibits excellent anti-corrosion and anti-biofouling properties.

[0058] The embodiment described above is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Persons skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent substitution or equivalent transformation falls within the scope of protection 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 sealed reaction vessel for a coordination reaction, so that the zinc and lanthanide metal ions form coordination bonds with the carboxyl groups, bridging the metal ions to form a tetrametallic cluster; washing and drying the crystals obtained after the reaction to obtain a phenyl ether-based bimetallic organic framework; S2: grinding the phenyl ether-based bimetallic organic framework obtained in step S1 and uniformly dispersing the resulting mixture in an aqueous polyurethane resin, and thoroughly mixing the mixture to obtain a phenyl ether-based bimetallic organic framework antifouling material; 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; the coordination reaction in step S1 is carried out in a stainless steel autoclave at a temperature of 120-170° C. for a reaction time of 72-96 h.

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'-dicarboxydiphenyl 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: The polar organic solvent is N,N-dimethylformamide or N,N-diethylformamide.

5. 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 vacuo at room temperature.

6. 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%.

7. A phenyl ether-based bimetallic organic framework antifouling material prepared by the preparation method according to any one of claims 1 to 6.

8. An application of the phenyl ether-based bimetallic organic framework antifouling material according to claim 7 in marine antifouling and anticorrosion, characterized in that: The phenyl ether-based bimetallic organic framework antifouling material according to claim 7 is coated on the surface of a substrate that needs to be antifouling and anticorrosive, and the coating thickness is 50±5 μm.

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