CN118325460A - Preparation method and application of efficient anti-fouling metal organic framework-polymer composite material - Google Patents

Abstract

The invention discloses a preparation method and application of a high-efficiency antifouling metal organic framework-polymer composite material, and belongs to the field of marine antifouling agent preparation. The method comprises the following steps: respectively dissolving 2, 5-dihydroxyterephthalic acid and anhydrous copper acetate in an organic solvent; respectively adding the prepared 2, 5-dihydroxyterephthalic acid solution and the anhydrous copper acetate solution into a culture dish; the precipitated crystal, namely Cu (II) -MOF, is placed in a polytetrafluoroethylene container, and the dried Cu (II) -MOF crystal is placed in a pyrrole-containing solution container, and after heating, the crystal in the polytetrafluoroethylene container is changed into black, so that Cu (I) -MOF/PPy is obtained. The efficient antifouling metal organic frame-polymer composite material prepared by the preparation method is applied to long-acting marine antifouling. By the method, the overall antifouling performance of the material is improved, a way is provided for developing efficient antifouling performance paint in ocean engineering, and the method has great commercial value.

Description

A preparation method and application of a highly effective antifouling metal organic framework-polymer composite material

Technical Field

The present invention belongs to the field of preparation of marine antifouling agents, and specifically relates to a preparation method and application of a high-efficiency antifouling metal organic framework-polymer composite material with metal ion controlled release and photothermal synergy.

Background technique

The world is entering an era of great marine development. As marine development continues to expand in depth and breadth, the development and application of marine engineering materials have received unprecedented attention. When marine engineering equipment is in service in seawater environments, its key metal parts are susceptible to biofouling caused by the effects of the seawater environment.

"Marine biofouling" refers to the adverse accumulation of biomolecules, microorganisms, algae and other marine organisms on the surface of building materials and hulls underwater. The fouling organisms continuously metabolize and secrete extracellular polymers to form biofilms. Biofilms provide nutrition and barriers for the organisms inside them, and mature biofilms show dissolved oxygen gradients and pH gradients. Therefore, biofilms are prone to secondary pollution and microbial corrosion (MIC) by promoting extracellular electron transfer. At present, a large number of studies have confirmed that metal oxide nanoparticles can effectively destroy the microbial membrane barrier, release active ingredients, slow down the formation of biofilms and ultimately lead to bacterial death. Among them, cuprous oxide (Cu ₂ O) has excellent anti-fouling properties due to its internal stable Cu ⁺ , and is therefore regarded as a good anti-fouling agent. However, traditional commercial cuprous oxide particles still have the following shortcomings: such as the explosive release of cuprous ions, high toxicity, potential health threats, and the easy oxidation and weak stability of Cu ⁺ limit the application of Cu ₂ O nanoparticles in the field of anti-fouling.

Metal-organic frameworks (MOFs) are porous coordination polymers composed of metal ions and organic ligands through coordination bonds. They have the advantages of large specific surface area, adjustable microstructure, and stability, and can be used as stable marine antifouling agents. However, according to the theory of hard and soft acids and bases, Cu ⁺ with soft acid properties can only coordinate with soft bases containing sulfur and nitrogen elements, and has poor stability. Therefore, it is of great significance to break the theory of hard and soft acids and bases and prepare stable Cu(Ⅰ)-MOF with common carboxylic acids as ligands. By introducing a suitable reducing agent, the divalent copper ions of Cu(Ⅱ)-MOF can be reduced to monovalent copper ions to form a new MOFs structure. Selecting and regulating reducing agents that have photothermal effects can solve the problems of insufficient or excessive reduction in the above-mentioned in-situ phase transformation, and give Cu(Ⅰ)-MOF photothermal synergy. Through the above method, MOFs are firmly combined with polymers to form a stable metal-organic framework-polymer composite material, achieving a broad-spectrum and long-lasting antifouling ability and solving the fouling problem faced by marine engineering materials.

Summary of the invention

In view of the problems in the prior art, the present invention provides a method for preparing a highly effective antifouling metal organic framework-polymer composite material and its application. The purpose is to achieve in-situ phase transformation and synthesis of empowered polymer materials simultaneously by a simple preparation method, to prepare a highly effective antifouling composite material with a stable structure and photothermal effect, and to use it for antifouling of marine engineering metal materials. To achieve the above purpose, the technical solution adopted by the present invention is as follows:

A method for preparing a highly effective antifouling metal organic framework-polymer composite material comprises the following steps:

Step 1: Weigh 2,5-dihydroxyterephthalic acid (DOBDC) and anhydrous copper acetate and dissolve them in an organic solvent respectively, and perform ultrasonic treatment to form a uniform solution; take the prepared DOBDC solution and place it in a culture dish, and then add the anhydrous copper acetate solution into the culture dish; after standing, the crystals precipitated in the culture dish are Cu(Ⅱ)-MOF as a precursor, and pour the crystals and mother liquor into a filter device, stand and dry, and then collect;

Step 2: Place the dried Cu(Ⅱ)-MOF crystals in an open polytetrafluoroethylene container, and then place the container in a glass container containing a pyrrole solution. Cover the mouth of the glass container and seal it tightly. Then, place the sealed glass container in a vacuum drying oven. Under heating conditions, the color of the crystals in the polytetrafluoroethylene container changes to black, thereby obtaining a metal organic framework-polymer composite material Cu(Ⅰ)-MOF/PPy.

Furthermore, in step 1, the molar ratio of DOBDC to anhydrous copper acetate is 1:1-1:4, and the solution concentration ranges from 30M to 80M.

Furthermore, the organic solvent in step 1 is a mixed solution of N,N-dimethylformamide and acetonitrile in a volume ratio of 1:1.

Furthermore, in step 1, the volume ratio of the DOBDC solution to the anhydrous copper acetate solution in the culture dish is 5:1.

Furthermore, the standing time described in step 1 is more than 12 hours, and the relative humidity of the environment is 10% to 50%.

Furthermore, filter paper is placed in the filtering device described in step 1, and the filter paper is a qualitative analysis filter paper.

Furthermore, the mass volume ratio of the crystals to the pyrrole solution in step 2 is 10-50 mg: 1-5 mL.

Furthermore, the setting temperature of the vacuum drying oven described in step 2 is 60-100° C., and the heating time is more than 4 hours.

A highly effective antifouling metal organic framework-polymer composite material is prepared by adopting the preparation method.

The highly effective antifouling metal organic framework-polymer composite material is applied as an effective strategy for surface protection of marine metal materials in long-term marine antifouling, and is applied to the surfaces of various marine engineering metal materials by spraying.

Add diluent to adjust the viscosity. During the spraying process, the direction of the spray gun should always be parallel to the surface of the metal material being sprayed and perpendicular to the spray fan to ensure the uniformity of the coating. The spray gun should run at a steady speed of 300~400mm/s.

Compared with the prior art, the preparation method and application of the highly efficient and long-lasting antifouling metal organic framework-polymer composite material of the present invention are widely applicable to the antifouling of various marine engineering metal materials. It has the following beneficial effects:

1) Creatively developed a highly efficient antifouling metal organic framework-polymer composite material and its preparation method. Through post-treatment, in-situ phase transformation and synthesis of empowered polymer materials were simultaneously achieved. The original Cu(Ⅱ)-MOF was converted into Cu(Ⅰ)-MOF and doped with polymer components with photothermal effects to enhance the overall antifouling performance of the material.

2) Cu(Ⅰ)-MOF breaks the theory of soft and hard acid and base. It is a new MOF structure with soft acid Cu ⁺ as metal site and hard base DOBDC as ligand.

3) The preparation method of the present invention is simple, the equipment cost is low, and it is easy to mass produce.

4) The prepared metal organic framework-polymer composite material has the characteristics of nano size, stable copper ion precipitation, photothermal effect, etc. The multiple effects work synergistically to achieve excellent anti-fouling effect.

5) Only a very small amount of metal organic framework-polymer composite materials is needed to achieve efficient antifouling performance, which can achieve long-term stable and efficient antifouling, providing a way for the development of efficient antifouling coatings in marine engineering and has great commercial value.

6) It has a wide range of applications and is suitable for anti-fouling applications of various marine engineering metal materials. It can be stably coated on the surface of metal materials and maintain a high anti-fouling effect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of the preparation of a highly efficient antifouling metal organic framework-polymer composite material according to the present invention;

FIG2 is a scanning electron microscope image (SEM) of Cu(Ⅰ)-MOF/PPy prepared in Example 1 of the present invention;

FIG3 is a SEM-EDS element distribution diagram of Cu(Ⅰ)-MOF/PPy prepared in Example 1 of the present invention;

FIG4 is an X-ray diffraction pattern (XRD) of Cu(Ⅰ)-MOF/PPy prepared in Example 1 of the present invention;

FIG5 is an X-ray photoelectron spectrum (XPS) of Cu(Ⅰ)-MOF/PPy prepared in Example 1 of the present invention;

FIG6 is a scanning electron microscope image (SEM) of the Cu(Ⅰ)-MOF prepared in Comparative 1 of the present invention;

FIG7 is a photothermal effect diagram of Cu(Ⅰ)-MOF/PPy prepared in Example 1 of the present invention;

FIG8 is a graph showing the bacterial survival rate of Cu(Ⅰ)-MOF/PPy prepared in Example 1 of the present invention;

9 is a diagram showing the effects of long-term inhibition of bacterial biofilm formation and destruction of mature bacterial biofilms by Cu(Ⅰ)-MOF/Ppy prepared in Example 1 of the present invention, Cu(Ⅰ)-MOF prepared in Comparative Example 1, and commercial cuprous oxide in Comparative Example 2;

Figure 10 is a diagram showing the long-term effects of Cu(I)-MOF/PPy prepared in Example 1 of the present invention, Cu(I)-MOF prepared in Comparative Example 1, and commercial cuprous oxide in Comparative Example 2 on algae cell respiration.

Detailed ways

In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation method, structure, characteristics and effects of the present invention application are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

Experimental methods without specifying specific conditions are usually carried out under conventional conditions, such as those described in textbooks and experimental guides, or under conditions recommended by manufacturers, which are well known or easily known to those skilled in the art. The following embodiments are only preferred embodiments of the present invention and do not limit the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

The embodiment of the present invention explores the antifouling performance of each component in the synthesized high-efficiency antifouling metal organic framework-polymer composite material. Among them, the metal organic framework-polymer composite material not only has a MOF structure that continuously releases copper ions, but also has a polymer layer that provides photothermal effects and increases material stability, which greatly enhances its antifouling ability. The composite material has 100% resistance to bacteria and 85.3% resistance to algae, providing a way for the development of high-efficiency antifouling coatings in marine engineering. The preparation flow chart of the high-efficiency antifouling metal organic framework-polymer composite material in this embodiment is shown in Figure 1.

The present invention is further described below by specific embodiments:

Example

A method for preparing a highly efficient antifouling metal organic framework-polymer composite material and its application, the preparation flow chart of which is shown in FIG1 , specifically comprises the following steps:

Step 1: Weigh a certain amount of 2,5-dihydroxyterephthalic acid (DOBDC) and anhydrous copper acetate and dissolve them in an organic solvent (V _{N,N -dimethylformamide} : V _acetonitrile = 1:1) at concentrations of 40 M and 80 M, respectively. Ultrasonicate for 5 minutes to form a uniform solution; take 4 mL of the prepared DOBDC solution and place it in a culture dish, then drip 800 μL of anhydrous copper acetate solution into the culture dish drop by drop. After standing for 12 hours in an environment with a relative humidity of 50%, the crystals precipitated in the culture dish are the Cu(Ⅱ)-MOF as the precursor; pour the crystals and the mother liquor into the set up funnel device, stand and dry, and then collect;

Step 2: Place 20 mg of Cu(Ⅱ)-MOF crystals in a polytetrafluoroethylene container, place the container in a sealed container containing 3 mL of pyrrole solution, and heat it in a vacuum drying oven at 85 °C for 4 hours to obtain the metal organic framework-polymer composite material Cu(Ⅰ)-MOF/PPy.

Step 3: The prepared metal organic framework-polymer composite material Cu(Ⅰ)-MOF/PPy is applied to the surface of various marine engineering metal materials by spraying.

Specifically, add diluent to adjust the viscosity, and the direction of the spray gun should always be parallel to the surface of the metal material to be coated and perpendicular to the spray fan to ensure the uniformity of the coating. The spray gun running speed is 300~400mm/s.

FIG2 is a scanning electron microscope image (SEM) of Cu(Ⅰ)-MOF/PPy prepared in Example 1 of the present invention. As shown in FIG2, the scanning electron microscope image shows that the Cu(Ⅰ)-MOF/PPy in Example 1 presents a spindle-shaped morphology, the surface is covered with dense nanosheets, and the overall microscopic morphology presents a multi-level structure. As shown in FIG3, the element distribution diagram of SEM-EDS clearly shows that the copper and nitrogen elements on the sample are evenly distributed, indicating that there are functional polymer materials inside the composite material. According to the analysis of the X-ray diffraction diagram (FIG4), it can be seen that the prepared Cu(Ⅰ)-MOF/PPy and the precursor Cu(Ⅱ)-MOF present a completely different structure, which further confirms the in-situ phase transition. As shown in FIG5, the X-ray photoelectron spectrum shows that the precursor Cu(Ⅱ)-MOF is a MOF with Cu ²⁺ as the metal site, in which a small amount of Cu ⁺ comes from the reducibility of the test X-ray, while the prepared Cu(Ⅰ)-MOF/PPy is a MOF with Cu ⁺ as the metal site, which confirms the comprehensiveness of the reduction reaction. In summary, the Cu(Ⅰ)-MOF/PPy in Example 1 is a composite material formed by a new structure MOF with Cu ⁺ as the metal site and a functional polymer PPy. Pyrrole is not only a reducing agent during the preparation process, but also can form polypyrrole, further enhancing the stability and antifouling ability of the material. As shown in Figure 7, the Cu(Ⅰ)-MOF/PPy in Example 1 has a certain photothermal effect due to its internal functional polymer. Under the irradiation of a xenon lamp, the temperature on the surface of the composite material can reach 80 ° C within 30 seconds, and the composite material responds very quickly to simulated sunlight. In the four cycles of turning on and off the lights, the rates of heating and cooling are very considerable. The almost consistent maximum temperature in the four cycles shows that Cu(Ⅰ)-MOF/PPy has excellent stability as a photothermal agent. As shown in Figure 8, the antifouling ability of Cu(Ⅰ)-MOF/PPy was evaluated by bacterial survival rate. The survival rates of Gram-negative Escherichia coli, Pseudomonas aeruginosa, Gram-positive Staphylococcus aureus, and Bacillus vietnamense, which are widely present in the ocean, were significantly reduced under the action of extremely low concentrations of Cu(Ⅰ)-MOF/PPy, indicating that Cu(Ⅰ)-MOF/PPy has significant broad-spectrum antifouling ability due to Cu ⁺ .

Comparative Example 1

A method for preparing a metal organic framework-polymer composite material comprises the following steps:

Step 1: Weigh a certain amount of 2,5-dihydroxyterephthalic acid (DOBDC) and anhydrous copper acetate and dissolve them in an organic solvent (V _{N,N -dimethylformamide} : V _acetonitrile = 1:1) at concentrations of 40 M and 80 M, respectively. Ultrasonicate for 5 minutes to form a uniform solution. Take 4 mL of the prepared DOBDC solution and place it in a culture dish. Then drip 800 μL of anhydrous copper acetate solution into the culture dish drop by drop. After standing for 12 hours in an environment with a relative humidity of 50%, the crystals precipitated in the culture dish are the Cu(Ⅱ)-MOF precursor.

Step 2: Weigh 1 mmol of L-ascorbic acid and dissolve it in 8 mL of N,N -dimethylformamide. Add the prepared L-ascorbic acid solution into a 10 mL centrifuge tube containing 20 mg of Cu(Ⅱ)-MOF crystals. After standing for 12 hours, the metal organic framework material Cu(Ⅰ)-MOF is obtained.

Figure 6 is a scanning electron microscope image (SEM) of the Cu(I)-MOF prepared in Comparative Example 1 of the present invention. As shown in Figure 6, the scanning electron microscope image shows that the Cu(I)-MOF in Comparative Example 1 has a dispersed nanosheet morphology and does not have the multi-level structure morphology presented by the composite material, which confirms that the formation of polypyrrole has a certain adjustment effect on the morphology of the composite material.

Comparative Example 2

Commercially available cuprous oxide for use in the marine industry was used.

As shown in Figure 9, the anti-biofilm and mature biofilm destruction capabilities of Cu(Ⅰ)-MOF/PPy after pre-immersion were investigated to illustrate the long-term antifouling effect of Cu(Ⅰ)-MOF/PPy. The anti-biofilm rates of commercially available Cu ₂ O after pre-immersion against Pseudomonas aeruginosa and Bacillus vietnam were only 45% and 74%, while the anti-biofilm rates of Cu(Ⅰ)-MOF/PPy were 96.3% and 100%, respectively. The anti-biofilm rates of Cu(Ⅰ)-MOF/PPy under simulated sunlight were all 100%. Moreover, the mature biofilm destruction rate of Cu(Ⅰ)-MOF/PPy under simulated sunlight reached 100%, which fully demonstrated that the copper ions released in large quantities by Cu(Ⅰ)-MOF/PPy have excellent antifouling ability, and the photothermal effect of Cu(Ⅰ)-MOF/PPy further enhances the antifouling effect, and has long-term antifouling potential.

As shown in Figure 10, the Cu ⁺ and photothermal synergistic anti-algae long-term effect of Cu(Ⅰ)-MOF/PPy was further evaluated by algae respiratory activity. The respiratory activity of typical marine algae Chlorella and Isochrysis was reduced by 79~85% under the action of pre-immersion Cu(Ⅰ)-MOF/PPy, while Cu(Ⅰ)-MOF/PPy under sunlight irradiation showed the lowest algae respiratory activity. In summary, based on the synergistic antifouling ability of Cu ⁺ and photothermal, Cu(Ⅰ)-MOF/PPy has a high-efficiency and long-lasting broad-spectrum antifouling ability.

The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims (10)

1. The preparation method of the efficient antifouling metal organic framework-polymer composite material is characterized by comprising the following steps of:

step 1: 2, 5-dihydroxyterephthalic acid and anhydrous copper acetate are weighed and respectively dissolved in an organic solvent, and ultrasonic treatment is carried out to form a uniform solution; placing the prepared 2, 5-dihydroxyterephthalic acid solution into a culture dish, and then adding an anhydrous copper acetate solution into the culture dish; standing, pouring the crystal and mother liquor into a filtering device, standing, drying and collecting crystals precipitated in a culture dish, namely Cu (II) -MOF serving as a precursor;

Step 2: placing the dried Cu (II) -MOF crystal in an open polytetrafluoroethylene container, placing the container in a container containing pyrrole solution, covering the container tightly, then reinforcing and sealing, placing the closed container in a vacuum drying oven, heating, and converting the crystal color in the polytetrafluoroethylene container into black to obtain the metal organic framework-high polymer composite Cu (I) -MOF/PPy.

2. The method for preparing the efficient antifouling metal organic framework-polymer composite material according to claim 1, wherein in the step 1, the molar ratio of the 2, 5-dihydroxyterephthalic acid to the anhydrous copper acetate is 1:1-1:4, and the concentration range of the solution is 30-80M.

3. The method for preparing a high-efficiency antifouling metal organic framework-polymer composite material according to claim 1, wherein in the step 1, the organic solvent is a mixed solution of N, N-dimethylformamide and acetonitrile.

4. The method for preparing the efficient antifouling metal organic framework-polymer composite material according to claim 1, wherein in the step 1, the volume ratio of the 2, 5-dihydroxyterephthalic acid solution to the anhydrous copper acetate solution in the culture dish is 5:1.

5. The method for preparing the efficient antifouling metal organic framework-polymer composite material according to claim 1, wherein in the step 1, the standing time is more than 12 hours, and the relative humidity of the environment is 10% -50%.

6. The method for preparing the efficient antifouling metal organic framework-polymer composite material according to claim 1, wherein in the step 1, filter paper is placed in a filtering device, and qualitative analysis of the filter paper is adopted.

7. The method for preparing the efficient antifouling metal organic framework-polymer composite material according to claim 1, wherein in the step 2, the mass-volume ratio of the crystal to the pyrrole solution is 10-50 mg:1-5 ml.

8. The method for preparing the efficient antifouling metal organic framework-polymer composite material according to claim 1, wherein in the step 2, the setting temperature of a vacuum drying oven is 60-100 ℃, and the heating time is more than 4 hours.

9. The application of the efficient antifouling metal organic frame-polymer composite material prepared by the preparation method of any one of claims 1-8 as an effective strategy for protecting the surface of marine metal materials in the aspect of long-acting marine antifouling, wherein the efficient antifouling metal organic frame-polymer composite material is coated on the surfaces of various marine engineering metal materials in a spraying manner.

10. The application of the efficient antifouling metal organic frame-polymer composite material as the effective strategy for marine metal material surface protection in the aspect of long-term marine antifouling according to claim 9, wherein the viscosity is adjusted by adding a diluent, the running direction of the spray gun is always parallel to the surface of the sprayed metal material and perpendicular to the spraying sector in the spraying process, so that the uniformity of a coating is ensured, and the running speed of the spray gun is 300-400 mm/s.