Preparation method of diatomite-based composite modified raw lacquer anticorrosive coating

Abstract

The present application belongs to the field of chemical modification treatment of paint, and particularly relates to a preparation method of diatomite-based composite modified raw lacquer anticorrosive paint. The preparation method comprises the following steps: step (1), gene editing of diatom: selecting genes related to adsorption of small organic carbon molecules and organic compounds in diatom as target genes, using gene editing technology CRISPR-Cas9 to perform gene knock-in, knock-out, point mutation or insertion editing on the target genes, and designing gRNA sequence to be combined with specific sites of the target genes; step (2), culture of the gene-edited diatom; step (3), preparation of diatomite-based composite material; step (4), modification; and step (5), mixing. The raw lacquer is modified in the present application, so that the raw lacquer has the ability of adsorbing small organic carbon molecules and organic pollutants, and an environmentally-friendly diatomite-based composite modified raw lacquer anticorrosive paint is obtained.

Description

Technical Field

[0001] This invention belongs to the field of chemical modification of coatings, and in particular relates to a method for preparing a diatomaceous earth-based composite material modified raw lacquer anticorrosive coating. Background Technology

[0002] The exploration, extraction, and transportation of oil and natural gas in the ocean, as well as port and offshore wind power facilities and large ships, all rely heavily on steel structures. Conventional metal equipment and transport vehicles operating at sea are subjected to long-term corrosion from harsh environments such as microbial fouling, high salinity, temperature fluctuations, and seawater erosion. This seriously threatens the service safety and lifespan of marine engineering materials, directly or indirectly causing significant losses to the national economy. Metal materials exposed to certain environments typically undergo chemical or electrochemical corrosion, generating a potential difference that forms a galvanic cell. Through electron transfer, a galvanic cell reaction occurs, leading to the dissolution and corrosion of the metal surface. However, current coatings inevitably suffer from various external conditions during service, resulting in damage and cracking, affecting the coating's stable internal structure and leading to poor long-term stability and low healing efficiency. Therefore, developing new lightweight, low-dosage, high-performance anti-corrosion coatings has become a key requirement for improving the service life and operational safety of marine engineering equipment, urgently necessitating research into new high-performance, low-surface-energy, multifunctional marine metal anti-corrosion coatings.

[0003] Raw lacquer, also known as "national lacquer" or "great lacquer," is a unique natural resource in my country. It is a water-in-oil resin primarily composed of urushiol, laccase, glycoproteins, and water. As a natural resin coating, raw lacquer is renewable and environmentally friendly. It possesses excellent mechanical properties, good gloss and thermal stability, and superior resistance to corrosion, water, durability, acid, and oxidation. Traditionally, raw lacquer has been mainly used in the coatings industry, earning the reputation of "King of Coatings" due to its high gloss, high hardness, and chemical resistance. However, its application scope is relatively limited, especially in recent years due to the impact of inexpensive and high-quality chemical coatings, leading to a sharp decline in the market share of raw lacquer coatings. This has had a significant impact on the entire raw lacquer industry. The strong sensitizing properties of urushiol and laccase, poor UV resistance, poor alkali resistance, easy oxidation and polymerization, and difficulty in separation pose significant obstacles to the application and development of urushiol and laccase-based products. These factors prevent the large-scale application of raw lacquer compared to industrial coatings.

[0004] Currently, most modifications to raw lacquer both domestically and internationally involve reacting it with compounds containing functional groups such as aldehydes, acids, and radicals, or with metal compounds, to improve its film-forming properties. For example, patent 200810118833.2 reports a method of reacting raw lacquer with rosin to obtain rosin-modified raw lacquer, reducing the drying time from 98 hours to 82 hours, increasing the hardness from B to HB, and improving the adhesion from grade 7 to grade 6-7. Patent 200510018542.2 reports a method of reacting raw lacquer with formaldehyde to obtain urushiol acetal, which is then crosslinked with epoxy resin to obtain raw lacquer acetal epoxy resin, significantly improving its film-forming properties. Patent 102140311 reports a method of preparing high-gloss black raw lacquer coatings by reacting raw lacquer with platinum hydroxide, resulting in a significantly shortened drying time after film formation.

[0005] However, although the film-forming properties of composite coatings prepared by current modification methods have been improved to some extent, the degree of performance improvement is low, the corrosion resistance of the coating film is poor, and most modification methods are complicated, cumbersome to operate, have long reaction times, low production efficiency, and high production costs.

[0006] To address the above problems, this invention is proposed. Summary of the Invention

[0007] This invention proposes a method for preparing a diatomaceous earth-based composite material modified raw lacquer anticorrosive coating. The method uses readily available raw materials, has a simple process, and is inexpensive. The coating components and structure of the diatomaceous earth-based modified raw lacquer anticorrosive composite coating are controllable, the microstructure is more uniform, and the mechanical properties, thermal insulation properties, corrosion resistance, and environmental performance are significantly improved.

[0008] The invention is characterized by using natural diatomaceous earth as a carrier to load a high-performance external corrosion inhibitor, and by using a hydrothermal reaction to grow hydrotalcite (LDHs) nanosheets with ion exchange properties on the surface of diatomaceous earth, thereby preparing a corrosion-inhibiting diatomaceous earth-based composite filler with slow-release and ion exchange capabilities.

[0009] Diatoms have undergone various gene editing processes using CRISPR-Cas9 gene editing technology. Specialized CRISPR design tools are used to design guide RNA sequences based on the target DNA sequence, precisely directing the CRISPR-Cas9 complex to specific sites on the target gene. This allows diatoms to enhance existing genes, introduce new genes, or modify protein structures to increase their affinity and adsorption capacity for small organic carbon molecules. The genetically modified diatoms are then cultivated and genetically modified strains are constructed to ensure the stability and reproducibility of the gene modification.

[0010] A "BG11" culture medium was prepared, and the nutrients for diatom growth, such as inorganic salts, organic carbon sources, and trace elements, were controlled according to their physiological characteristics to cultivate diatoms with uniform particle size (20-30 μm) and uniform pore size distribution. Genetically edited diatoms were loaded with nanomaterials and integrated into an environmentally friendly paint. The adsorption performance of the coating on small organic carbon molecules in the environment was tested. The mechanical properties, anti-corrosion properties, and environmental effects under different environmental conditions were also tested to evaluate the coating's performance.

[0011] The active anti-corrosion coating prepared by this composite filler can not only release the corrosion inhibitor to the substrate (alloy) surface through a slow-release mechanism, but also the LDH nanosheets on the filler surface can adsorb corrosive anions, thereby further delaying the corrosion of the substrate. By loading the corrosion inhibitor onto the diatomaceous earth-based composite material, direct contact between the corrosion inhibitor and the coating prepared from refined lacquer can be avoided; it exhibits good compatibility with lacquer and can be uniformly dispersed in the coating; the preparation process is simple and allows for mass production. Furthermore, by modifying the lacquer to enable the adsorption of organic carbon molecules and organic pollutants, an environmentally friendly diatomaceous earth-based composite material modified lacquer anti-corrosion coating is obtained.

[0012] This application provides a method for preparing a diatomaceous earth-based composite material modified raw lacquer anticorrosive coating, the preparation method comprising the following steps:

[0013] Step (1) Gene editing of diatoms: Select genes related to the adsorption of small organic carbon molecules and organic compounds, and use gene editing technology CRISPR-Cas9 to perform gene knock-in, knockout, point mutation, or insertion editing, and design gRNA sequences to be compounded into specific sites of the target gene.

[0014] Step (2): Cultivating gene-edited diatoms:

[0015] First, prepare the "BG11" culture medium:

[0016] Inorganic salts and trace elements are mixed with water to obtain "BG11" culture medium. The contents of each component in "BG11" culture medium are as follows: sodium nitrate 1-3 g / L, dipotassium hydrogen phosphate 0.02-0.06 g / L, magnesium sulfate heptahydrate 0.05-0.07 g / L, boric acid 2-4 mg / L, and manganese chloride 1-3 mg / L.

[0017] The gene-edited diatoms from step (1) were then cultured in the “BG11” medium under the following conditions: temperature 20-30℃, light intensity 50-150 μmol photons / (m²). 2 s), culture time 8-16 hours, pH 7.3-7.5, to obtain disc-shaped diatoms;

[0018] Step (3), Preparation of diatomaceous earth-based composite materials:

[0019] Select disc-shaped diatoms with a particle size of 20-30 μm and a pore size of 200-300 nm from step (2), load magnesium aluminum hydrotalcite onto the diatomite obtained from the diatoms, and then load an external corrosion inhibitor to obtain a diatomite-based composite material.

[0020] Step (4), Modification: The diatomite-based composite material obtained in step (3) is modified to be oleophilic to obtain an oleophilic diatomite-based composite material;

[0021] Step (5), Mixing: Add the oleophilic diatomite-based composite material obtained in step (5) to the raw lacquer to prepare a diatomite-based composite material modified raw lacquer anti-corrosion coating.

[0022] Preferably, the specific operation of step (1) is as follows:

[0023] CRISPR-Cas9 is used for gene knock-in, knockout, point mutation, or insertion editing to alter the gene sequence of an organism. The designed gRNA (guide RNA) pairs with the target gene sequence, directing the Cas9 protein to cleave it, and then the desired gene mutation is introduced through the cell's repair mechanisms. Specifically, the gRNA and Cas9 expression protein can be combined to obtain a synthetic plasmid. Then, using polyethyleneimine (PEI) or liposome transfection reagents, the synthetic plasmid is directly introduced into target cells via chemical methods or electroporation to obtain the target gene edited by the CRISPR-Cas9 system.

[0024] Preferably, the process of loading magnesium aluminum hydrotalcite onto diatomite obtained from diatoms and then loading an exogenous corrosion inhibitor in step (3) specifically includes the following steps:

[0025] Magnesium nitrate, aluminum nitrate, and urea were added to the diatomaceous earth aqueous solution in step (3), and the mixture was stirred again to obtain a mixture, wherein Mg 2+ / Al 3+ The molar ratio is 1:1 to 4:1, and the total molar ratio of urea to cations is 5:1 to 1:1;

[0026] Then, the above mixture is reacted at 100℃-160℃ for 8-16 hours. After the reaction is cooled to room temperature, it is washed and the material is dried under vacuum to obtain the composite material.

[0027] The above-mentioned composite material, external corrosion inhibitor sodium phosphate, and water are mixed and stirred, and then dried to obtain the diatomaceous earth-based composite material.

[0028] Preferably, the specific operation of step (4) is as follows:

[0029] The diatomaceous earth-based composite material obtained in step (3) is dispersed in an ethanol solution and subjected to alcoholysis reaction with alkylsiloxanes to branch the fatty acid linkers on the surface of the diatomaceous earth-based composite material, so that it changes from hydrophilic to lipophilic, and thus obtains an lipophilic diatomaceous earth-based composite material.

[0030] Preferably, the specific operation of step (5) is as follows: the oleophilic diatomaceous earth-based composite material obtained in step (4) is dispersed in a solvent to prepare a filler, and added to the raw lacquer at a filler to raw lacquer mass ratio of 4% to 10% to obtain a diatomaceous earth-based composite material modified raw lacquer anti-corrosion coating.

[0031] A solvent is a liquid that can dissolve lipophilic substances to a certain extent at room temperature.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The diatoms in this application were genetically modified using CRISPR-Cas9 to enhance existing genes, introduce new genes, and modify protein structures. Compared to unedited diatoms, the diatoms obtained in this application exhibit enhanced affinity and adsorption capacity for small organic carbon molecules and organic pollutants in raw lacquer.

[0034] 2. A further feature of this application is that the genetically modified diatoms are cultured using a specific "BG11" culture medium to obtain diatoms with uniform particle size and pore size. The diatomaceous earth-based composite material obtained using these gene-edited diatoms is then combined with raw lacquer to prepare a diatomaceous earth-based composite material modified raw lacquer anti-corrosion coating.

[0035] 3. The diatomaceous earth-based composite material modified lacquer of this application uses natural lacquer as a base, which is an environmentally friendly material that is non-toxic, non-polluting, and inexpensive. The modified diatomaceous earth-based composite material is oleophilic and hydrophobic, and can be uniformly dispersed in lacquer coatings, avoiding agglomeration and effectively compensating for the defects that occur after the natural drying of lacquer.

[0036] 4. In this application, tung oil extracted from tung tree fruit is boiled at high temperature to form a higher degree of polymerization, which is used as a filler to improve the crosslinking density and anti-corrosion properties of raw lacquer.

[0037] 5. The anti-corrosion coating prepared by this invention not only possesses the barrier effect provided by diatomaceous earth-based composite materials, extending the path of corrosive ion penetration, but also achieves a synergistic anti-corrosion effect with raw lacquer. Compared to the original raw lacquer coating, its anti-corrosion performance is significantly improved. The raw materials in this application are directly derived from natural biomass, and the natural inorganic substances endow the raw lacquer with environmentally friendly and multifunctional characteristics. Attached Figure Description

[0038] Figure 1 This is a microscope image of the diatomaceous earth-based composite material from Example 1.

[0039] Figure 2 This is a microscope image of the diatomaceous earth-based composite material from Example 2.

[0040] Figure 3 This is a microscope image of the diatomaceous earth-based composite material in Example 3.

[0041] Figure 4 This is a microscope image of the diatomaceous earth-based composite material in Example 4.

[0042] Figure 5 This is a microscope image of the hydrophobic and oleophilic diatomaceous earth-based composite material of Example 2.

[0043] Figure 6 This is a graph showing the adsorption performance of organic pollutants. Detailed Implementation

[0044] The present invention will be described below with reference to specific embodiments, but the implementation of the present invention is not limited thereto. Experimental methods not specifically described in the embodiments generally use conventional conditions and conditions described in the manual, or conditions recommended by the manufacturer. The general equipment, materials, reagents, etc., used are all commercially available unless otherwise specified. The raw materials used in the following embodiments and comparative examples are all commercially available.

[0045] Examples 1-4 respectively use the CRISPR-Cas9 gene editing technology to perform gene knock-in, knockout, point mutation and insertion editing on diatoms.

[0046] Example 1

[0047] (1) Gene editing of diatoms:

[0048] The target gene (cell surface receptor) related to the adsorption of small organic carbon molecules and volatile organic compounds (VOCs) in the disc-shaped diatom (purchased from the Institute of Hydrobiology, Chinese Academy of Sciences) was selected and gene knocked in using the CRISPR-Cas9 gene editing technology. The gRNA sequence CRISPR-Cas9 complex was designed and inserted into the specific site of the target gene.

[0049] The specific method is as follows:

[0050] In this embodiment, the target gene sequences are silaffin-1A and silaffin-1B genes, which contain amino acid sequences related to the adsorption of small organic carbon molecules and volatile organic compounds (VOCs). The corresponding amino acid sequences are located in the complete coding regions of GCF_000223395.1 and GCF_012275535.1 obtained from the database https: / / www.ncbi.nlm.nih.gov / . Silaffin-1A and silaffin-1B are hydrolysis products of sil1p. sil1p contains a large number of RXL motifs, consisting of 265 amino acid residues. The 19 amino acid residues at the N-terminus form a signal peptide for translocation to the endoplasmic reticulum; amino acid residues 20-107 are an N-terminal domain with unknown function; and amino acid residues 108-265 are a strongly basic and highly repetitive C-terminus.

[0051] CRISPR-Cas9 design tools are used to knock-in genes and alter an organism's gene sequence. These tools guide an RNA sequence based on the target DNA sequence. The RNA sequence is typically a 20-base "guide sequence" that pairs with the target DNA sequence. This RNA sequence has a "PAM" sequence (ProtospacerAdjacentMotif, a specific DNA sequence that the CRISPR-Cas9 system must recognize, usually NGG, where N can be any nucleotide) that binds to the Cas9 protein. Ensuring a Cas9-compliant PAM sequence near the 3' end of the RNA sequence is crucial for Cas9 to bind to the target gene and initiate editing. Two separate RNA sequences are designed as gRNAs for gene knock-in of silaffin-1A and silaffin-1B, respectively.

[0052] The designed gRNA (guide RNA) pairs with the target gene sequences (silaffin-1A and silaffin-1B), guiding the Cas9 protein to cleave, and then introducing the desired gene mutation through the cell's repair mechanism. Therefore, using the above genetic engineering techniques, a CRISPR-Cas9 complex containing the designed gRNA and Cas9 protein is constructed. This can be achieved by synthesizing plasmids to combine the gRNA and Cas9 expression protein. Specifically, the CRISPR-Cas9 complex can be constructed using polyethyleneimine (PEI) or liposome transfection reagents. The CRISPR-Cas9 system construct (i.e., the synthesized plasmid) is directly introduced into the target cell using chemical methods or electroporation to obtain the target gene edited by the CRISPR-Cas9 system (i.e., the CRISPR-Cas9 complex).

[0053] The edited target gene sequences were also found within the complete coding regions of GCF_000223395.1 and GCF_012275535.1 obtained from the database at https: / / www.ncbi.nlm.nih.gov / .

[0054] Cells successfully edited were identified and selected using an antibiotic resistance marker screening method. The disc-shaped diatom cells containing the target gene were then cultured to obtain gene-edited diatoms. The edited target gene sequence in the diatom cells was analyzed using PCR and sequencing techniques to ensure the accuracy and effectiveness of the gene knock-in. Simultaneously, phenotypic changes, gene expression levels, and protein structures of the diatoms were observed to verify the structure of the edited diatoms.

[0055] (2) Cultivating gene-edited diatoms:

[0056] To prepare "BG11" medium for culturing disc-shaped diatoms: Dissolve inorganic salts such as 1 g / L sodium nitrate (NaNO3), 0.02 g / L dipotassium hydrogen phosphate (K2HPO4), and 0.05 g / L magnesium sulfate heptahydrate (MgSO47H2O) in distilled water. Add a trace element solution, including 2 mg / L boric acid (H3BO3) and 1 mg / L manganese chloride (MnCl24H2O), to the dissolved solution.

[0057] Genetically edited diatoms were inoculated into "BG11" medium, and the culture conditions were set at a temperature of 20℃ and a light intensity of 150 μmol photons / (m²). 2 The culture medium was incubated for 8 hours with moderate stirring to ensure uniform nutrient distribution, at a pH of 7.3-7.5, to obtain disc-shaped diatoms. Diatoms were then collected from water samples, filtered, washed, and dried to remove moisture, yielding diatomaceous earth.

[0058] 100 mg of diatomaceous earth with uniform particle size (20-25 μm), pore size of 200 nm, and uniform pore distribution on the surface was selected. The method involved screening the diatomaceous earth sample through 300-mesh and 2000-mesh sieves, selecting particles with uniform particle size (below 300 mesh and above 2000 mesh) that met the 20-25 μm particle size requirement. The fine morphology of the diatomaceous earth was observed using SEM to determine if the pore size was indeed 200 nm, and the surface structure was also observed to assess the uniformity of the pores.

[0059] Disperse the above 100mg of diatomaceous earth in a beaker containing 70ml of deionized water and stir magnetically for 10 minutes to obtain an aqueous solution of diatomaceous earth.

[0060] (3) Preparation of diatomaceous earth-based composite materials:

[0061] In step (2), 3.58 mmol of magnesium nitrate (Mg(NO3)2·6H2O), 3.58 mmol of aluminum nitrate (Al(NO3)3·6H2O), and 21.45 mmol of urea were subsequently added to the diatomaceous earth dispersion, and the mixture was stirred again for 30 minutes. Among these, Mg... 2+ / Al 3+ The molar ratio of urea to cations was 1:1, and the total molar ratio of urea to cations was 5:1. The stirred mixture was then reacted at 100°C for 8 hours in a polytetrafluoroethylene-lined stainless steel autoclave. After cooling to room temperature, the mixture was washed three to four times with deionized water and alcohol by centrifugation. The resulting mixture was then vacuum-dried at 60°C for 12 hours to obtain a composite material, labeled DE-MgAl-CO3. 2- LDH.

[0062] Weigh 1.5 g of sodium phosphate into a beaker containing 100 mL of deionized water and stir thoroughly to obtain a phosphoric acid solution with an ionic state of 0.15 mol / L. Add 0.15 g of dry DE-MgAl-CO3... 2- LDH was added to the above phosphoric acid solution, and the mixture was magnetically stirred at a rate of 350 r / min for 6 hours, followed by vacuum drying at 60°C for 12 hours to obtain the diatomaceous earth-based composite material.

[0063] Figure 1 This is a microscope image of the diatomaceous earth-based composite material from Example 1. Figure 1 MgAl-CO3 can be observed 2- The LDH nanosheets are vertically and horizontally embedded on the surface of diatomaceous earth, exhibiting a relatively dense and uniform morphology. However, the nanosheets show large-area aggregation, indicating that this morphology can enhance the interaction with raw lacquer to a certain extent.

[0064] (4) Modification:

[0065] The diatomaceous earth-based composite material from step (3) was dispersed in an ethanol solution and subjected to alcoholysis with dodecylsiloxane to graft aliphatic chains onto the surface of the two-dimensional material, changing it from hydrophilic to lipophilic, thus obtaining an lipophilic diatomaceous earth-based composite material. Specifically, 1g of the diatomaceous earth-based composite material was added to 100mL of ethanol and uniformly dispersed in the ethanol by stirring or ultrasonication; 1g of dodecylsiloxane was added, and alcoholysis was carried out at 30°C for 24h. The alcohol groups in the siloxane reacted with the hydroxyl groups on the surface of the diatomaceous earth-based composite material, attaching aliphatic chains to the surface of the diatomaceous earth-based composite material; the product was separated from the solution by centrifugation to remove unreacted siloxane and other byproducts, ultimately obtaining the lipophilic diatomaceous earth-based composite material.

[0066] (5) Mixing

[0067] An oleophilic diatomaceous earth-based composite material was dispersed in tung oil (boiled tung oil and / or polymerized tung oil) to prepare a filler. In this embodiment, boiled tung oil was selected and purchased from Gaide Chemicals.

[0068] The mass ratio of oleophilic diatomaceous earth-based composite material to boiled tung oil is 1:2.

[0069] Adding 4% by mass of filler to refined lacquer (i.e., the filler:refined lacquer mass ratio is 1:24) yields a diatomaceous earth-based composite material modified lacquer anticorrosive coating.

[0070] The performance of the diatomaceous earth-based composite material modified raw lacquer anticorrosive coating was tested, and the results are shown in Tables 1 and 2.

[0071] Its physical and mechanical properties and corrosion resistance are as follows: hardness 4H; impact strength grade 50kg / cm; flexibility 0.5mm; surface drying time ≤4h; actual drying time ≤13h; alkali resistance 62h; high temperature resistance 380℃; salt spray resistance ≥1100h; boiling water resistance ≥1100h.

[0072] Example 2

[0073] (1) Gene editing of diatoms:

[0074] The target gene (cell surface receptor) associated with the adsorption of small organic carbon molecules and volatile organic compounds (VOCs) was selected from disc-shaped diatoms (purchased from the Institute of Hydrobiology, Chinese Academy of Sciences) and knocked out using the gene editing technology CRISPR-Cas9. The gRNA sequence CRISPR-Cas9 complex was designed and inserted into a specific site of the target gene.

[0075] Specifically, in this embodiment, the target gene sequences are silaffin-1A and silaffin-1B genes, which contain amino acid sequences related to the adsorption of small organic carbon molecules and volatile organic compounds (VOCs). The corresponding amino acid sequences are located within the complete coding regions of GCF_000223395.1 and GCF_012275535.1 obtained from the database https: / / www.ncbi.nlm.nih.gov / . Silaffin-1A and silaffin-1B are hydrolysis products of sil1p. Sil1p contains a large number of RXL motifs, consisting of 265 amino acid residues. The 19 amino acid residues at the N-terminus form a signal peptide for translocation to the endoplasmic reticulum; amino acid residues 20-107 are an N-terminal domain with unknown function; and amino acid residues 108-265 are a strongly basic and highly repetitive C-terminus.

[0076] Gene knockout is performed using CRISPR-Cas9 design tools to alter the gene sequence of an organism. These tools guide an RNA sequence based on the DNA sequence at the target site. The RNA sequence is typically a 20-base "guide sequence" that pairs with the target DNA sequence. This RNA sequence contains a "PAM" sequence (ProtospacerAdjacentMotif, a specific DNA sequence that the CRISPR-Cas9 system must recognize, usually NGG, where N can be any nucleotide) that binds to the Cas9 protein. Ensuring a Cas9-compliant PAM sequence near the 3' end of the RNA sequence is crucial for Cas9 to bind to the target gene and initiate editing. Two separate RNA sequences are designed as gRNAs for gene knockout of silaffin-1A and silaffin-1B, respectively.

[0077] The designed gRNA (guide RNA) pairs with the target gene sequences (silaffin-1A and silaffin-1B), guiding the Cas9 protein to cleave, and then introducing the desired gene mutation through the cell's repair mechanism. Therefore, using the above genetic engineering techniques, a CRISPR-Cas9 complex containing the designed gRNA and Cas9 protein is constructed. This can be achieved by synthesizing plasmids to combine the gRNA and Cas9 expression protein. Specifically, the CRISPR-Cas9 complex can be constructed using polyethyleneimine (PEI) or liposome transfection reagents. The CRISPR-Cas9 system construct (i.e., the synthesized plasmid) is directly introduced into the target cell using chemical methods or electroporation to obtain the target gene edited by the CRISPR-Cas9 system (i.e., the CRISPR-Cas9 complex).

[0078] The edited target gene sequences were also found within the complete coding regions of GCF_000223395.1 and GCF_012275535.1 obtained from the database at https: / / www.ncbi.nlm.nih.gov / .

[0079] Cells successfully edited were identified and selected using an antibiotic resistance marker screening method. The disc-shaped diatom cells containing the target gene were then cultured to obtain gene-edited diatoms. The edited target gene sequence in the diatom cells was analyzed using PCR and sequencing techniques to ensure the accuracy and effectiveness of gene knockout. Simultaneously, phenotypic changes, gene expression levels, and protein structures of the diatoms were observed to verify the structure of the edited diatoms.

[0080] (2) Cultivating gene-edited diatoms:

[0081] To prepare "BG11" medium for culturing disc-shaped diatoms: Dissolve inorganic salts such as 1 g / L sodium nitrate (NaNO3), 0.02 g / L dipotassium hydrogen phosphate (K2HPO4), and 0.05 g / L magnesium sulfate heptahydrate (MgSO47H2O) in distilled water. Add a trace element solution, including 2 mg / L boric acid (H3BO3) and 1 mg / L manganese chloride (MnCl24H2O), to the dissolved solution.

[0082] Genetically edited diatoms were inoculated into "BG11" medium, and the culture conditions were set at a temperature of 30℃ and a light intensity of 50-150 μmol photons / (m²). 2 The culture medium was incubated for 8 hours with moderate stirring to ensure uniform nutrient distribution, at pH 7.5, to obtain disc-shaped diatoms. Diatoms were then collected from water samples, filtered, washed, and dried to remove moisture, yielding diatomaceous earth.

[0083] 100 mg of diatomaceous earth samples with uniform particle size (20-25 μm), pore size of 300 nm, and uniform pore distribution were selected. The method involved screening the diatomaceous earth samples through 300-mesh and 2000-mesh sieves, selecting particles with uniform particle size (below 300 mesh and above 2000 mesh) that met the 20-25 μm particle size requirement. The fine morphology of the diatomaceous earth was observed using SEM to determine if the pore size was indeed 300 nm, and the surface structure of the diatomaceous earth was also observed to assess the uniformity of the pores.

[0084] Disperse the above 100mg of diatomaceous earth in a beaker containing 70ml of deionized water and stir magnetically for 10 minutes to obtain an aqueous solution of diatomaceous earth.

[0085] (3) Preparation of diatomaceous earth-based composite materials:

[0086] In step (2), 4.77 mmol of magnesium nitrate (Mg(NO3)2·6H2O), 2.38 mmol of aluminum nitrate (Al(NO3)3·6H2O), and 21.45 mmol of urea were subsequently added to the diatomaceous earth dispersion, and the mixture was stirred again for 30 minutes. Among these, Mg... 2+ / Al 3+ The molar ratio of urea to cations was 2:1, and the total molar ratio of urea to cations was 5:1. Then, the reaction was carried out in a polytetrafluoroethylene-lined stainless steel autoclave at 100°C for 8 hours. After the reaction was cooled to room temperature, the mixture was washed three to four times with deionized water and alcohol by centrifugation. The resulting mixture was then vacuum-dried at 60°C for 12 hours to obtain a composite material labeled as DE-MgAl-CO3. 2- LDH.

[0087] Weigh 1.5 g of sodium phosphate into a beaker containing 100 mL of deionized water and stir thoroughly to obtain a phosphoric acid solution with an ionic state of 0.15 mol / L. Add 0.15 g of dry DE-MgAl-CO3... 2- LDH was added to the above phosphoric acid solution, and the mixture was magnetically stirred at a rate of 350 r / min for 6 hours, followed by vacuum drying at 60°C for 12 hours to obtain the diatomaceous earth-based composite material. Figure 2 This is a microscope image of the diatomaceous earth-based composite material from Example 2. Figure 2 MgAl-CO3 can be observed 2- The LDH nanosheets are vertically and laterally embedded on the surface of diatomaceous earth, with a relatively dense and uniformly distributed thin morphology. Furthermore, no large-area aggregation of nanosheets occurs, proving that this morphology can enhance the interaction with raw lacquer.

[0088] (4) Modification:

[0089] The diatomaceous earth-based composite material from step (3) was dispersed in an ethanol solution and subjected to an alcoholysis reaction using octadecylsiloxane. This reaction caused aliphatic chains to be branched onto the surface of the two-dimensional material, changing its hydrophilicity to lipophilicity, thus obtaining an lipophilic diatomaceous earth-based composite material. Specifically, 1g of the diatomaceous earth-based composite material was added to 100mL of ethanol and dispersed uniformly in the ethanol by stirring or ultrasonication. 1g of octadecylsiloxane was added, and the mixture was subjected to an alcoholysis reaction at 60°C for 24 hours. The alcohol groups in the siloxane reacted with the hydroxyl groups on the surface of the diatomaceous earth-based composite material, attaching aliphatic chains to the surface. The product was then separated from the solution by centrifugation, filtration, or other methods to remove unreacted siloxane and other byproducts, ultimately yielding the lipophilic diatomaceous earth-based composite material.

[0090] Figure 5 This is a microscope image of the hydrophobic and oleophilic diatomaceous earth-based composite material of Example 2. Figure 5 The uniform and dense particle distribution suggests that the aliphatic chains are well dispersed in the diatomaceous earth-based composite material, which helps to improve the uniformity of the coating.

[0091] (5) Mixing

[0092] An oleophilic diatomaceous earth-based composite material was dispersed in tung oil (boiled tung oil, polymerized tung oil) to prepare a filler. In this embodiment, boiled tung oil was selected and purchased from Gaide Chemicals.

[0093] The oleophilic diatomaceous earth-based composite material and the boiled tung oil were mixed at a mass ratio of 1:2. 6% by mass of filler was added to refined raw lacquer (i.e., the filler:refined raw lacquer mass ratio was 3:47) to obtain a diatomaceous earth-based composite material modified raw lacquer anti-corrosion coating.

[0094] The performance of the diatomaceous earth-based composite material modified raw lacquer anticorrosive coating was tested, and the results are shown in Tables 1 and 2.

[0095] Its physical and mechanical properties and corrosion resistance are as follows: hardness 5H; impact strength grade 50kg / cm; flexibility 0.5mm; surface drying time ≤2h; complete drying time ≤10h; alkali resistance 68h; high temperature resistance 400℃; salt spray resistance ≥1100h; boiling water resistance ≥1100h.

[0096] Example 3

[0097] (1) Gene editing of diatoms:

[0098] We selected disc-shaped diatoms (purchased from the Institute of Hydrobiology, Chinese Academy of Sciences) and used CRISPR-Cas9 gene editing technology to perform point mutations on the target gene (cell surface receptor) related to the adsorption of small organic carbon molecules and organic compounds (VOCs). We then designed gRNA sequences and CRISPR-Cas9 complexes to be inserted into specific sites of the target gene.

[0099] Specifically, in this embodiment, the target gene sequences are silaffin-1A and silaffin-1B genes, which contain amino acid sequences related to the adsorption of small organic carbon molecules and volatile organic compounds (VOCs). The corresponding amino acid sequences are located within the complete coding regions of GCF_000223395.1 and GCF_012275535.1 obtained from the database https: / / www.ncbi.nlm.nih.gov / . Silaffin-1A and silaffin-1B are hydrolysis products of sil1p. Sil1p contains a large number of RXL motifs, consisting of 265 amino acid residues. The 19 amino acid residues at the N-terminus form a signal peptide for translocation to the endoplasmic reticulum; amino acid residues 20-107 are an N-terminal domain with unknown function; and amino acid residues 108-265 are a strongly basic and highly repetitive C-terminus.

[0100] CRISPR-Cas9 design tools are used to perform point mutations that alter the gene sequence of an organism. These tools guide an RNA sequence based on the DNA sequence at the target site. The RNA sequence is typically a 20-base "guide sequence" that pairs with the target DNA sequence. This RNA sequence has a "PAM" sequence (ProtospacerAdjacentMotif, a specific DNA sequence that the CRISPR-Cas9 system must recognize, usually NGG, where N can be any nucleotide) that binds to the Cas9 protein. Ensuring a Cas9-compliant PAM sequence near the 3' end of the RNA sequence is crucial for Cas9 to bind to the target gene and initiate editing. Two separate RNA sequences are designed as gRNAs for point mutations in silaffin-1A and silaffin-1B, respectively.

[0101] The designed gRNA (guide RNA) pairs with the target gene sequences (silaffin-1A and silaffin-1B), guiding the Cas9 protein to cleave, and then introducing the desired gene mutation through the cell's repair mechanism. Therefore, using the above genetic engineering techniques, a CRISPR-Cas9 complex containing the designed gRNA and Cas9 protein is constructed. This can be achieved by synthesizing plasmids to combine the gRNA and Cas9 expression protein. Specifically, the CRISPR-Cas9 complex can be constructed using polyethyleneimine (PEI) or liposome transfection reagents. The CRISPR-Cas9 system construct (i.e., the synthesized plasmid) is directly introduced into the target cell using chemical methods or electroporation to obtain the target gene edited by the CRISPR-Cas9 system (i.e., the CRISPR-Cas9 complex).

[0102] The edited target gene sequences were also found within the complete coding regions of GCF_000223395.1 and GCF_012275535.1 obtained from the database at https: / / www.ncbi.nlm.nih.gov / .

[0103] Cells successfully edited were identified and selected using an antibiotic resistance marker screening method. The disc-shaped diatom cells containing the target gene were then cultured to obtain gene-edited diatoms. The edited target gene sequence in the diatom cells was analyzed using PCR and sequencing techniques to ensure the accuracy and effectiveness of the point mutation. Simultaneously, phenotypic changes, gene expression levels, and protein structures of the diatoms were observed to verify the structure of the edited diatoms.

[0104] (2) Cultivating gene-edited diatoms:

[0105] To prepare "BG11" medium for culturing disc-shaped diatoms: Dissolve inorganic salts such as 3 g / L sodium nitrate (NaNO3), 0.06 g / L disodium hydrogen phosphate (K2HPO4), and 0.07 g / L magnesium sulfate heptahydrate (MgSO47H2O) in distilled water. Add trace element solution, including 4 mg / L boric acid (H3BO3) and 3 mg / L manganese chloride (MnCl24H2O), to the dissolved solution.

[0106] Genetically edited diatoms were inoculated into "BG11" medium, and the culture conditions were set as follows: temperature 20-30℃, light intensity 50-150 μmol photons / (m²). 2 (s), for 16 hours, with moderate stirring of the culture medium to ensure uniform nutrient distribution, pH 7.3-7.5, to obtain disc-shaped diatoms. Water samples were collected to obtain diatoms, which were then filtered, washed, and dried to remove moisture, yielding diatomaceous earth.

[0107] 100 mg of diatomaceous earth samples with uniform particle size (25-30 μm), pore size of 200 nm, and uniform pore distribution were selected. The method involved screening the diatomaceous earth samples through 300-mesh and 2000-mesh sieves, selecting particles with uniform particle size (below 300 mesh and above 2000 mesh) that met the 25-30 μm particle size requirement. The fine morphology of the diatomaceous earth was observed using SEM to determine if the pore size was indeed 200 nm, and the surface structure of the diatomaceous earth was also observed to assess the uniformity of the pores.

[0108] Disperse the above 100mg of diatomaceous earth in a beaker containing 70ml of deionized water and stir magnetically for 10 minutes to obtain an aqueous solution of diatomaceous earth.

[0109] (3) Preparation of diatomaceous earth-based composite materials:

[0110] In step (2), 5.36 mmol of magnesium nitrate (Mg(NO3)2·6H2O), 1.79 mmol of aluminum nitrate (Al(NO3)3·6H2O), and 21.45 mmol of urea were subsequently added to the diatomaceous earth dispersion, and the mixture was stirred again for 30 minutes. Among these, Mg... 2+ / Al 3+ The molar ratio of urea to cations was 3:1, and the total molar ratio of urea to cations was 1:1. Then, the reaction was carried out in a polytetrafluoroethylene-lined stainless steel autoclave at 160°C for 16 hours. After the reaction mixture cooled to room temperature, it was washed three to four times with deionized water and alcohol by centrifugation. The resulting mixture was then vacuum-dried at 60°C for 12 hours to obtain a composite material labeled as DE-MgAl-CO3. 2- LDH.

[0111] Weigh 1.5 g of sodium phosphate into a beaker containing 100 mL of deionized water and stir thoroughly to obtain a phosphoric acid solution with an ionic state of 0.15 mol / L. Add 0.15 g of dry DE-MgAl-CO3... 2- LDH was added to the above phosphoric acid solution, and the mixture was magnetically stirred at a rate of 350 r / min for 6 hours, followed by vacuum drying at 60°C for 12 hours to obtain the diatomaceous earth-based composite material. Figure 3 This is a microscope image of the diatomaceous earth-based composite material in Example 3. Figure 3 MgAl-CO3 can be observed 2- The LDH grows vertically on the diatomaceous earth surface, and the stacked layers exhibit a nano-flower-like distribution, which is relatively dense. This demonstrates that the ordered stacking may affect the thickness and density of the coating, and thus affect the performance of the modified lacquer.

[0112] (4) Modification:

[0113] The diatomaceous earth-based composite material from step (3) was dispersed in an ethanol solution and subjected to alcoholysis with dodecylsiloxane to graft aliphatic chains onto the surface of the two-dimensional material, changing it from hydrophilic to lipophilic, thus obtaining an lipophilic diatomaceous earth-based composite material. Specifically, 1g of the diatomaceous earth-based composite material was added to 100mL of ethanol and uniformly dispersed in the ethanol by stirring or ultrasonication; 1g of dodecylsiloxane was added, and alcoholysis was carried out at 50°C for 20h. The alcohol groups in the siloxane reacted with the hydroxyl groups on the surface of the diatomaceous earth-based composite material, attaching aliphatic chains to the surface of the diatomaceous earth-based composite material; the product was separated from the solution by centrifugation to remove unreacted siloxane and other byproducts, ultimately obtaining the lipophilic diatomaceous earth-based composite material.

[0114] (5) Mixing

[0115] An oleophilic diatomaceous earth-based composite material was dispersed in tung oil (boiled tung oil, polymerized tung oil) to prepare a filler. In this embodiment, boiled tung oil was selected and purchased from Gaide Chemicals.

[0116] The oleophilic diatomaceous earth-based composite material is mixed with boiled tung oil at a mass ratio of 1:2. Adding 8% by mass of filler to refined raw lacquer (i.e., a filler:refined raw lacquer mass ratio of 2:23) yields a diatomaceous earth-based composite material modified raw lacquer anti-corrosion coating.

[0117] The performance of the diatomaceous earth-based composite material modified raw lacquer anticorrosive coating was tested, and the results are shown in Tables 1 and 2.

[0118] Its physical and mechanical properties and corrosion resistance are as follows: hardness 5H; impact strength grade 55kg / cm; flexibility 0.5mm; surface drying time ≤2h; complete drying time ≤10h; alkali resistance 65h; high temperature resistance 420℃; salt spray resistance ≥1100h; boiling water resistance ≥1100h.

[0119] Example 4

[0120] (1) Gene editing of diatoms:

[0121] Disc-shaped diatoms (purchased from the Institute of Hydrobiology, Chinese Academy of Sciences) were selected to target genes (cell surface receptors, membrane channels, adsorbed proteins, or other related proteins) related to the adsorption of small organic carbon molecules and volatile organic compounds (VOCs). Gene insertion was performed using the gene editing technology CRISPR-Cas9, and gRNA sequences of CRISPR-Cas9 complexes were designed to be inserted into specific sites of the target genes.

[0122] Specifically, in this embodiment, the target gene sequences are silaffin-1A and silaffin-1B genes, which contain amino acid sequences related to the adsorption of small organic carbon molecules and volatile organic compounds (VOCs). The corresponding amino acid sequences are located within the complete coding regions of GCF_000223395.1 and GCF_012275535.1 obtained from the database https: / / www.ncbi.nlm.nih.gov / . Silaffin-1A and silaffin-1B are hydrolysis products of sil1p. Sil1p contains a large number of RXL motifs, consisting of 265 amino acid residues. The 19 amino acid residues at the N-terminus form a signal peptide for translocation to the endoplasmic reticulum; amino acid residues 20-107 are an N-terminal domain with unknown function; and amino acid residues 108-265 are a strongly basic and highly repetitive C-terminus.

[0123] CRISPR-Cas9 design tools are used to insert genes and alter the gene sequence of an organism. These tools guide an RNA sequence based on the DNA sequence at the target site. The RNA sequence is typically a 20-base "guide sequence" that pairs with the target DNA sequence. This RNA sequence has a "PAM" sequence (ProtospacerAdjacentMotif, a specific DNA sequence that the CRISPR-Cas9 system must recognize, usually NGG, where N can be any nucleotide) that binds to the Cas9 protein. Ensuring a Cas9-compliant PAM sequence near the 3' end of the RNA sequence is crucial for Cas9 to bind to the target gene and initiate editing. Two separate RNA sequences are designed as gRNAs for gene insertion into silaffin-1A and silaffin-1B, respectively.

[0124] The designed gRNA (guide RNA) pairs with the target gene sequences (silaffin-1A and silaffin-1B), guiding the Cas9 protein to cleave, and then introducing the desired gene mutation through the cell's repair mechanism. Therefore, using the above genetic engineering techniques, a CRISPR-Cas9 complex containing the designed gRNA and Cas9 protein is constructed. This can be achieved by synthesizing plasmids to combine the gRNA and Cas9 expression protein. Specifically, the CRISPR-Cas9 complex can be constructed using polyethyleneimine (PEI) or liposome transfection reagents. The CRISPR-Cas9 system construct (i.e., the synthesized plasmid) is directly introduced into the target cell using chemical methods or electroporation to obtain the target gene edited by the CRISPR-Cas9 system (i.e., the CRISPR-Cas9 complex).

[0125] The edited target gene sequences were also found within the complete coding regions of GCF_000223395.1 and GCF_012275535.1 obtained from the database at https: / / www.ncbi.nlm.nih.gov / .

[0126] Cells successfully edited were identified and selected using an antibiotic resistance marker screening method. The disc-shaped diatom cells containing the target gene were then cultured to obtain gene-edited diatoms. The edited target gene sequence in the diatom cells was analyzed using PCR and sequencing techniques to ensure the accuracy and effectiveness of the gene insertion. Simultaneously, phenotypic changes, gene expression levels, and protein structures of the diatoms were observed to verify the structure of the edited diatoms.

[0127] (2) Cultivating gene-edited diatoms:

[0128] To prepare "BG11" medium for culturing disc-shaped diatoms: Dissolve inorganic salts such as 3 g / L sodium nitrate (NaNO3), 0.06 g / L disodium hydrogen phosphate (K2HPO4), and 0.07 g / L magnesium sulfate heptahydrate (MgSO47H2O) in distilled water. Add trace element solution, including 4 mg / L boric acid (H3BO3) and 3 mg / L manganese chloride (MnCl24H2O), to the dissolved solution.

[0129] Genetically edited diatoms were inoculated into "BG11" medium, and the culture conditions were set at a temperature of 30℃ and a light intensity of 50 μmol photons / (m²). 2 The culture medium was incubated for 16 hours with moderate stirring to ensure uniform nutrient distribution, at a pH of 7.3-7.5, to obtain disc-shaped diatoms. Diatoms were then collected from water samples, filtered, washed, and dried to remove moisture, yielding diatomaceous earth.

[0130] 100 mg of diatomaceous earth samples with uniform particle size (25-30 μm), pore size of 300 nm, and uniform pore distribution were selected. The method involved screening the diatomaceous earth samples through 300-mesh and 2000-mesh sieves, selecting particles with uniform particle size (below 300 mesh and above 2000 mesh) that met the 25-30 μm particle size requirement. The fine morphology of the diatomaceous earth was observed using SEM to determine if the pore size was indeed 300 nm, and the surface structure of the diatomaceous earth was also observed to assess the uniformity of the pores.

[0131] Disperse the above 100mg of diatomaceous earth in a beaker containing 70ml of deionized water and stir magnetically for 10 minutes to obtain an aqueous solution of diatomaceous earth.

[0132] (3) Preparation of diatomaceous earth-based composite materials:

[0133] In step (2), 5.72 mmol of magnesium nitrate (Mg(NO3)2·6H2O), 1.43 mmol of aluminum nitrate (Al(NO3)3·6H2O), and 21.45 mmol of urea were subsequently added to the diatomaceous earth dispersion, and the mixture was stirred again for 30 minutes. 2+ / Al 3+ The molar ratio of urea to cations was 4:1, and the total molar ratio of urea to cations was 1:1. Then, the reaction was carried out in a polytetrafluoroethylene-lined stainless steel autoclave at 160°C for 16 hours. After the reaction mixture cooled to room temperature, it was washed three to four times with deionized water and alcohol by centrifugation. The resulting mixture was then vacuum-dried at 60°C for 12 hours to obtain a composite material labeled as DE-MgAl-CO3. 2- LDH.

[0134] Then, in step (2), step DE-MgAl-CO3 2- Sodium phosphate, a corrosion inhibitor, is added to the LDH dispersion. The specific method is as follows: Weigh 1.5 g of sodium phosphate into a beaker containing 100 mL of deionized water and stir thoroughly to obtain a phosphoric acid solution with an ionic state of 0.15 mol / L. Then, add 0.15 g of dry DE-MgAl-CO3... 2- LDH was added to the above phosphoric acid solution, and the mixture was magnetically stirred at a rate of 350 r / min for 6 hours, followed by vacuum drying at 60°C for 12 hours to obtain the diatomaceous earth-based composite material. Figure 4 This is a microscope image of the diatomaceous earth-based composite material in Example 4. Figure 4 MgAl-CO3 can be observed 2- LDH flakes are relatively small and agglomerate, which may affect the thickness and density of the final coating, and thus the performance of the modified lacquer.

[0135] (4) Modification:

[0136] The diatomaceous earth-based composite material from step (3) is dispersed in an ethanol solution and subjected to alcoholysis with dodecylsiloxane or octadecylsiloxane. This process branches aliphatic chains onto the surface of the two-dimensional material, transforming it from hydrophilic to lipophilic, resulting in an lipophilic diatomaceous earth-based composite material. Specifically, 1g of the diatomaceous earth-based composite material is added to 100mL of ethanol and uniformly dispersed using stirring or ultrasonication. 1g of dodecylsiloxane is added, and the mixture is subjected to alcoholysis at 45°C for 24 hours. The alcohol groups in the siloxane react with the hydroxyl groups on the surface of the diatomaceous earth-based composite material, attaching aliphatic chains to the surface. The product is then separated from the solution by filtration to remove unreacted siloxane and other byproducts, ultimately yielding the lipophilic diatomaceous earth-based composite material.

[0137] (5) Mixing

[0138] An oleophilic diatomaceous earth-based composite material was dispersed in tung oil (boiled tung oil, polymerized tung oil) to prepare a filler. In this embodiment, boiled tung oil was selected and purchased from Gaide Chemicals.

[0139] The oleophilic diatomaceous earth-based composite material is mixed with boiled tung oil at a mass ratio of 1:2. Adding 10% by mass of filler to refined raw lacquer (i.e., a filler-to-refined raw lacquer mass ratio of 1:9) yields a diatomaceous earth-based composite material modified raw lacquer anti-corrosion coating.

[0140] The performance of the diatomaceous earth-based composite material modified raw lacquer anticorrosive coating was tested, and the results are shown in Tables 1 and 2.

[0141] Its physical and mechanical properties and corrosion resistance are as follows: hardness 5H; impact strength grade 60kg / cm; flexibility 0.5mm; surface drying time ≤2h; actual drying time ≤10h; alkali resistance 66h; high temperature resistance 390℃; salt spray resistance ≥1100h; boiling water resistance ≥1100h.

[0142] Comparative Example 1

[0143] The diatomaceous earth-based composite material modified raw lacquer anticorrosive coating was prepared according to the method of Example 1. The only difference from Example 1 is that the diatoms were not genetically edited.

[0144] Physical and mechanical properties and corrosion resistance tests:

[0145] The raw lacquer in Tables 1 and 2 is the refined raw lacquer obtained in step (5) of Example 1 above. It is obtained by collecting, filtering, and other processing steps to refine and purify the lacquer liquid (purchased from Xi'an Raw Lacquer Coatings Research Institute). Refining and purification are standard procedures in the art. The common diatomaceous earth in Tables 1 and 2 is commercially available diatomaceous earth from Tianjin Damao Chemical Reagent Co., Ltd.

[0146] Tables 1 and 2 demonstrate that, compared to raw lacquer, ordinary diatomaceous earth, and the diatomaceous earth-based composite material modified raw lacquer anticorrosive coating of Comparative Example 1, the physical and mechanical properties and anticorrosive performance of the diatomaceous earth-based composite material modified raw lacquer anticorrosive coatings of Examples 1-4 are significantly improved.

[0147] Environmentally relevant testing (LAC):

[0148] The life cycle of a material is often referred to as MLCA, which applies LCA to the assessment of the material's life cycle to evaluate the resource consumption, water, and air pollution of functional materials during production, use, and disposal.

[0149] The environmental friendliness of the diatomaceous earth-based composite material modified raw lacquer anticorrosive coating of Example 2 was determined and evaluated using scientific and technological methods and testing methods, as shown in Table 3. The test data in the table show that the material is non-toxic, harmless, low-toxic and low-emission.

[0150] The coating obtained in Example 1 was subjected to environmental protection tests, and the results are shown in Table 4.

[0151] A comparison between Table 4 and Table 3 shows that the raw material production in Table 3 involves less resource consumption and lower air pollution.

[0152] Therefore, this application optimizes the adsorption performance of gene-edited diatoms for organic pollutants. By introducing or modifying adsorption-related genes, the adsorption capacity of coatings for organic pollutants is enhanced, improving the treatment effect of anti-corrosion coatings on organic matter. This results in better stability of the coatings under different environments and improves their environmental friendliness. The reason may be that gene editing alters the physiological characteristics of diatoms, such as changes in surface functional genes affecting adsorption efficiency, or changes in morphology that may also lead to variations in adsorption capacity.

[0153] Adsorption performance test of organic pollutants:

[0154] The test method is as follows: Measure 25 ml of a pre-prepared 40 mg / L simulated organic pollutant wastewater solution. Add 30 mg of the diatomaceous earth-based composite material modified lacquer preservative material from Example 1 to a 50 ml wide-mouth opaque plastic vial. Then, according to batches, add the above simulated wastewater solution to the vial. Place all vials in a chilled water bath constant temperature shaker, adjust the temperature and rotation speed to 120 rpm / min, and set the shaking time (6 vials, shaking for 10, 20, 30, 40, 50, and 60 minutes respectively). After shaking, take out the samples one by one and filter them through a 0.45 μm filter membrane. Measure the absorbance at the maximum absorption wavelength using a spectrophotometer, calculate the concentration of pollutants in the residual filtrate, and obtain the adsorption amount. Perform three parallel tests and take the average value.

[0155] The above steps were repeated for the testing of the diatomaceous earth-based composite material modified raw lacquer materials in Examples 2-4.

[0156] Figure 6 The graph shows the adsorption performance of organic pollutants in the diatomaceous earth-based composite modified lacquer materials in Examples 1-4, with the horizontal axis representing the oscillation time.

[0157] The results showed that the diatomaceous earth-based composite materials modified with raw lacquer in Examples 1-4 all exhibited good adsorption capacity, and the adsorption capacity of the diatomaceous earth-based composite material modified with raw lacquer in Example 2 was significantly improved compared to the materials in the other examples. Gene editing introduced new genes or modified genes related to adsorption, which explains the stronger adsorption performance of the materials in Examples 1-4.

[0158] Table 1 Physical and mechanical properties

[0159]

[0160] Table 2 Corrosion Resistance Test

[0161]

[0162] Table 3 shows the environmentally relevant tests (LAC).

[0163]

[0164] Table 4 shows the environmentally relevant tests (LAC).

[0165]

Claims

1. A method for preparing a diatomaceous earth-based composite material modified raw lacquer anticorrosive coating, characterized in that, The preparation method includes the following steps: Step (1) Gene editing of diatoms: Select genes in diatoms that are related to the adsorption of small organic carbon molecules and organic compounds as target genes, and use gene editing technology CRISPR-Cas9 to knock in, knock out or mutate the above target genes, and design gRNA sequences to be compounded into specific sites of the target genes. The target genes are silaffin-1A and silaffin-1B; The specific operation of step (1) is as follows: CRISPR-Cas9 is used to perform gene knock-in, knock-out, or point mutation to change the gene sequence of an organism. The designed gRNA will pair with the target gene sequence, guide the Cas9 protein to cut, and then introduce the desired gene mutation through the cell's repair mechanism. Step (2): Cultivating gene-edited diatoms: First, prepare the "BG11" culture medium: Inorganic salts and trace elements are mixed with water to obtain "BG11" culture medium. The contents of each component in "BG11" culture medium are as follows: sodium nitrate 1-3 g / L, dipotassium hydrogen phosphate 0.02-0.06 g / L, magnesium sulfate heptahydrate 0.05-0.07 g / L, boric acid 2-4 mg / L, and manganese chloride 1-3 mg / L. The gene-edited diatoms from step (1) were then cultured in the "BG11" medium under the following conditions: temperature 20-30℃, light intensity 50-150 μmol photons / (m²). 2 s), culture time 8-16 hours, pH 7.3-7.5, to obtain disc-shaped diatoms; collect water samples to obtain diatoms, filter, wash, dry to remove water, and obtain diatomaceous earth; Step (3), Preparation of diatomaceous earth-based composite materials: Select diatomite with a particle size of 20-30μm and a pore size of 200-300nm from step (2), load magnesium aluminum hydrotalcite onto the diatomite, and then load an external corrosion inhibitor to obtain a diatomite-based composite material. The external corrosion inhibitor is sodium phosphate; Step (4), Modification: The diatomite-based composite material obtained in step (3) is modified to be oleophilic to obtain an oleophilic diatomite-based composite material; Step (5), Mixing: Add the oleophilic diatomaceous earth-based composite material obtained in step (4) to the raw lacquer to prepare a diatomaceous earth-based composite material modified raw lacquer anti-corrosion coating.

2. The preparation method according to claim 1, characterized in that, The process of loading magnesium aluminum hydrotalcite onto diatomite obtained from diatoms and then loading an external corrosion inhibitor in step (3) specifically includes the following steps: Magnesium nitrate, aluminum nitrate, and urea were added to the diatomaceous earth aqueous solution in step (3), and the mixture was stirred again to obtain a mixture, wherein Mg 2+ / Al 3+ The molar ratio is 1:1 to 4:1, and the total molar ratio of urea to cations is 5:1 to 1:1; Then, the above mixture is reacted at 100℃-160℃ for 8-16 hours. After the reaction is cooled to room temperature, it is washed and the material is dried under vacuum to obtain the composite material. The above-mentioned composite material, external corrosion inhibitor sodium phosphate, and water are mixed and stirred, and then dried to obtain the diatomaceous earth-based composite material.

3. The preparation method according to claim 1, characterized in that, The specific operation of step (4) is as follows: The diatomaceous earth-based composite material obtained in step (3) is dispersed in an ethanol solution and subjected to alcoholysis reaction with alkylsiloxanes to branch the fatty acid linkers on the surface of the diatomaceous earth-based composite material, so that it changes from hydrophilic to lipophilic, and thus obtains an lipophilic diatomaceous earth-based composite material.

4. The preparation method according to claim 1, characterized in that, The specific operation of step (5) is as follows: the oleophilic diatomaceous earth-based composite material obtained in step (4) is dispersed in a solvent to prepare a filler, and then added to the raw lacquer at a mass ratio of 4% to 10% to obtain a diatomaceous earth-based composite material modified raw lacquer anti-corrosion coating.

Images