A filter material with high-efficiency emulsified water coalescence separation and antibacterial properties, and its preparation method and application

Abstract

The present invention discloses a filter material with high-efficiency emulsified water coalescence separation and antibacterial properties, as well as a preparation method and application thereof. The present invention disperses inorganic particles with hydroxyl groups on the surface in ethanol, adds a silane coupling agent with epoxy groups, and heats the mixture for reaction to prepare a dispersion of inorganic particles with epoxy groups on the surface; then adds polyethyleneimine with a branched structure, reacts to prepare a polyethyleneimine-coated modified inorganic particle dispersion; then adds a silane coupling agent with epoxy groups, reacts to prepare an organic-inorganic composite material dispersion; and then immerses a porous filter substrate in the diluted organic-inorganic composite material dispersion, takes it out, dries it, and solidifies it to obtain a filter material with high-efficiency emulsified water coalescence separation and antibacterial properties. The preparation method of the present invention is simple, and the prepared filter material has excellent coalescence separation performance for emulsified water in fuel, and has a lasting antibacterial effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of filtration and separation materials, and in particular relates to a filter material with high-efficiency emulsified water coalescence separation and antibacterial properties, and a preparation method and application thereof. Background Art

[0002] Water contamination in fuels such as diesel and jet fuel is a key indicator of fuel quality and a major cause of engine failure. Water in fuel can decompose certain additives, forming acids that corrode the engine's injection system and the engine itself. Furthermore, the presence of water accelerates oil oxidation, creating a thick sludge that can easily clog microporous components such as nozzles and filters. Furthermore, at low temperatures, water in the fuel can freeze and clog engine oil lines, impacting fuel delivery. Water in the fuel can also reduce its calorific value and increase pollutant emissions. Therefore, separating water from the fuel is crucial. However, with the development of ultra-low sulfur fuel and biofuel, the amount of surfactants added to the fuel is increasing to ensure adequate lubricity. These surfactants adsorb at the oil-water interface, reducing interfacial tension, reducing the size of water droplets in the diesel fuel, and increasing their stability, making water separation more difficult.

[0003] Currently, coalescing materials are primarily used to separate contaminated water from fuel. Coalescing separation utilizes interwoven fibers within the filter media to capture water droplets. Under the influence of the fluid, the droplets migrate downstream, where they continuously collide and coalesce with droplets attached to the fibers, causing them to gradually increase in size. Once the droplets reach a certain size, they can collide with each other, coalescing further. Finally, under the influence of gravity and fluid drag, the droplets detach from the outlet surface of the material and self-sediment. Coalescing separation offers high separation efficiency, low energy consumption, and a high throughput rate, meeting the complexities of the oil-water systems required for filtration in real-world fuel applications. Therefore, it is a widely used method. However, its efficiency needs to be further improved. Furthermore, the demulsification and coalescence of emulsified water by the coalescing material results in a high water content within the material, making it susceptible to bacterial growth and proliferation on its surface. Bacterial growth on the surface can adhere to or damage the surface, potentially leading to material failure. Therefore, in addition to having good coalescing properties, the surface of the coalescing material should also have good antibacterial properties to avoid the negative impact of bacterial growth. However, current emulsified water coalescing materials rarely have both efficient coalescing and separation properties and excellent long-lasting antibacterial properties. Summary of the Invention

[0004] In order to overcome the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a filter material with high-efficiency emulsified water coalescence separation and antibacterial properties, as well as its preparation method and application; the filter material obtained by the present invention not only has high-efficiency water coalescence separation performance, but also has excellent antibacterial properties; and the preparation method is simple and can be used for different porous fiber substrates.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A method for preparing a filter material with high-efficiency emulsified water coalescence separation and antibacterial properties, comprising the following steps:

[0007] Step 1: Dispersing inorganic particles with hydroxyl groups on the surface in 20-30 times the mass of ethanol, adding a silane coupling agent with epoxy groups, heating to 60-70° C. and reacting for 3-5 hours to prepare a dispersion of inorganic particles with epoxy groups on the surface; the average particle size of the inorganic particles is 0.3-3.0 μm;

[0008] Step 2: Continue adding branched polyethyleneimine and react at 60-70° C. for 2-4 hours to prepare a polyethyleneimine-coated modified inorganic particle dispersion; the polyethyleneimine has a molecular weight of 1800-10000; and the weight of the polyethyleneimine is 200-400% of the inorganic particles;

[0009] Step 3, continue to add a silane coupling agent with an epoxy group, react at 70-75° C. for 2-4 hours to prepare an organic-inorganic composite material dispersion; the mass of the silane coupling agent is 25-45% of the inorganic particles;

[0010] Step 4: immerse the porous filter substrate in the diluted organic-inorganic composite material dispersion for 10 to 60 minutes, take it out, dry it, and solidify it to obtain a filter material with high-efficiency emulsified water agglomeration separation and antibacterial properties.

[0011] Preferably, in step 1, the inorganic particles are at least one of silicon dioxide and titanium dioxide;

[0012] Preferably, in step 1, the average particle size of the inorganic particles is 0.5-2.0 μm.

[0013] Preferably, in step 1, the silane coupling agent is at least one of 3-glycidyloxypropyltrimethoxysilane, 3-(2,2-epoxypropylene)propyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltriethoxysilane;

[0014] Preferably, in step 1, the mass of the silane coupling agent is 10-30 wt % of the inorganic particles.

[0015] Further preferably, in step 1, the mass of the silane coupling agent is 15-25 wt % of the inorganic particles.

[0016] Preferably, in step 2, the molecular weight of the polyethyleneimine is 3000-7000;

[0017] Preferably, in step 2, the mass of the polyethyleneimine is 200-350% of the inorganic particles.

[0018] Preferably, in step 3, the silane coupling agent is at least one of 3-glycidyloxypropyltrimethoxysilane, 3-(2,2-epoxypropylene)propyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltriethoxysilane;

[0019] Preferably, in step 3, the mass of the silane coupling agent is 30-40% of the inorganic particles.

[0020] Preferably, in step 4, the porous filter substrate is a porous fiber substrate.

[0021] Preferably, in step 4, the porous filter substrate is one of filter paper and non-woven fabric.

[0022] Preferably, in step 4, the mass concentration of the diluted organic-inorganic composite material dispersion is 2-8%.

[0023] More preferably, the mass concentration of the diluted organic-inorganic composite material dispersion is 3-5%.

[0024] Preferably, in step 4, the drying temperature is 50-100°C and the time is 20-60 minutes;

[0025] Further preferably, the drying temperature is 50-80°C and the drying time is 30-60 minutes;

[0026] Preferably, in step 4, the curing temperature is 120-150° C. and the curing time is 10-30 min.

[0027] More preferably, the curing temperature is 120-130° C. and the curing time is 20-40 minutes.

[0028] The filter material prepared by the above preparation method has high-efficiency emulsified water coalescence separation and antibacterial properties.

[0029] Preferably, the filter material with high-efficiency emulsified water coalescence separation and antibacterial properties includes a porous filter substrate and an organic-inorganic composite material, the organic-inorganic composite material is loaded on the porous filter substrate, and the mass ratio of the porous filter substrate to the organic-inorganic composite material is 95:5-85:15.

[0030] Further preferably, the mass ratio of the porous filter substrate to the organic-inorganic composite material is 95:5-90:10.

[0031] The application of the above-mentioned filter material with high efficiency emulsified water coalescence separation and antibacterial properties in oil-water separation.

[0032] Preferably, the oil-water separated from the oil-water contains a surfactant, that is, an oil liquid containing emulsified water.

[0033] The present invention first uses a silane coupling agent to modify the surface of inorganic particles to introduce epoxy groups, then further grafts and modifies them using polyethyleneimine to form organic polyethyleneimine-coated inorganic particles. Finally, the surface of the organic-coated inorganic particles is further modified using a silane coupling agent to introduce siloxane groups with self-crosslinking functionality, thereby preparing the target organic-inorganic composite material. A porous fiber substrate is immersed in the organic-inorganic composite material diluted to an appropriate concentration, removed, dried, and cured to prepare a filter material with high-efficiency emulsified water coalescence separation and antibacterial properties (coalescence separation filter material obtained after treatment with the organic-inorganic composite material).

[0034] The preparation mechanism of the organic-inorganic composite material of the present invention is as follows:

[0035]

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention prepares an organic-inorganic composite material and can endow various porous fiber substrates with excellent emulsified water aggregation and separation performance and antibacterial performance through a simple impregnation and drying solidification method. The polyethyleneimine in the organic-inorganic composite material has good hydrophilic and lipophilic properties, which can give the material surface excellent emulsified water aggregation properties, and at the same time provide the material with high-efficiency and broad-spectrum antibacterial properties, and can inactivate and inhibit a variety of bacteria including Escherichia coli and Staphylococcus aureus; in addition, due to the presence of siloxane groups with self-crosslinking function in the organic-inorganic composite material, a polymer network structure can be formed during the curing process, thereby improving the adhesion performance and oil resistance of the organic-inorganic composite material on the filter material fiber; and the inorganic particle components in the organic-inorganic composite material can be permanently and firmly attached to the surface of the porous substrate and form a protrusion structure through chemical bonding and fixation with the organic polymer phase, which can make the emulsified water pass through the interior of the porous substrate. The protrusion structure on the surface of the material can increase the probability of capturing water droplets, thereby further improving the aggregation and separation performance of the material; in addition, the protrusion structure on the surface of the filter material fiber and the polyethyleneimine structure with antibacterial properties can further enhance the antibacterial properties of the filter material. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the oil-water separation test bench of the present invention.

[0039] Figure 2 This is an SEM image of the glass fiber substrate of the agglomerated material of the present invention.

[0040] Figure 3 This is a SEM image of the agglomerated material after treatment of the organic-inorganic composite material according to Example 1 of the present invention. DETAILED DESCRIPTION

[0041] The present invention will be described in further detail below with reference to examples and drawings, but the embodiments of the present invention are not limited thereto.

[0042] Unless otherwise specified, the experimental methods described in the examples of the present invention are conventional methods; the raw materials and reagents used in the examples are all commercially available unless otherwise specified.

[0043] The glass fiber substrates of the following examples were prepared by the following method: the base paper weight was controlled at 80 g / m 2 Glass wool fiber 19°SR (purchased from Yulin Tianshengyuan Glass Fiber Technology Co., Ltd.) and glass fiber (purchased from Shenzhen Xinxian Technology Co., Ltd.) were weighed in a mass ratio of 4:6. Dilute sulfuric acid was added to adjust the pH of the mixture in the container to 2-3. The fibers were then transferred to a deflaking machine for deflaking. Once the fibers were dispersed, the deflaked slurry was transferred to an automatic sheeter. Finally, the water was drained, the paper was peeled off, and the wet paper web was dried on a flatbed dryer at 105°C to a constant weight.

[0044] Example 1

[0045] A filter material with high-efficiency emulsified water coalescence separation and antibacterial properties and a preparation method thereof are prepared according to the following steps based on the following formula:

[0046] Step 1: Disperse 10 g of silica powder (average particle size 1.2 μm) in 240 g of ethanol, add 2.0 g of silane coupling agent 3-glycidyloxypropyltrimethoxysilane, and heat to 65°C for 3 h.

[0047] Step 2: Add 30 g of branched polyethyleneimine (molecular weight 3000), heat to 70° C. and react for 2 h to prepare a polyethyleneimine-coated modified inorganic particle dispersion;

[0048] Step 3: Continue to add 3.5g of silane coupling agent 3-glycidyloxypropyltrimethoxysilane, raise the temperature to 75°C and react for 2h to prepare an organic-inorganic composite material dispersion;

[0049] Step 4: Immerse the circular filter glass fiber substrate with a diameter of 20 cm obtained by papermaking into 200 mL of the organic-inorganic composite material dispersion prepared in step 3 (diluted to 3.0 wt% with ethanol solvent) for 30 minutes; take it out and dry it at 60°C for 60 minutes, and then cure it at 120°C for 15 minutes to obtain a filter material with high-efficiency emulsified water agglomeration separation and antibacterial properties.

[0050] Example 2

[0051] A filter material with high-efficiency emulsified water coalescence separation and antibacterial properties and a preparation method thereof are prepared according to the following steps based on the following formula:

[0052] Step 1: Disperse 15g of titanium dioxide powder (average particle size of about 2.3μm) in 300g of ethanol, add 2.5g of silane coupling agent β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and heat to 62°C for 4h.

[0053] Step 2: Add 45 g of branched polyethyleneimine (molecular weight 7000), raise the temperature to 68° C. and react for 2.5 hours to prepare a polyethyleneimine-coated modified inorganic particle dispersion;

[0054] Step 3: Continue to add 5.0g of silane coupling agent β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, raise the temperature to 75°C and react for 2h to prepare an organic-inorganic composite material dispersion;

[0055] Step 4: Immerse the circular filter glass fiber substrate with a diameter of 20 cm obtained by papermaking into 200 mL of the organic-inorganic composite material dispersion prepared in step 3 (diluted to 3.0 wt% with ethanol solvent) for 30 minutes; take it out and dry it at 60°C for 30 minutes, and then cure it at 120°C for 15 minutes to obtain a filter material with high-efficiency emulsified water agglomeration separation and antibacterial properties.

[0056] Example 3

[0057] A filter material with high-efficiency emulsified water coalescence separation and antibacterial properties and a preparation method thereof are prepared according to the following steps based on the following formula:

[0058] Step 1: Disperse 10g of silica powder (average particle size of about 0.8μm) in 250g of ethanol, add 2.8g of silane coupling agent β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, and heat to 64°C for 4h.

[0059] Step 2: Add 32 g of branched polyethyleneimine (molecular weight 7000), heat to 70° C. and react for 2 h to prepare a polyethyleneimine-coated modified inorganic particle dispersion;

[0060] Step 3: Continue to add 4.3 g of silane coupling agent β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, raise the temperature to 75° C. and react for 2 hours to prepare an organic-inorganic composite material dispersion;

[0061] Step 4: Immerse the circular filter glass fiber substrate with a diameter of 20 cm obtained by papermaking into 200 mL of the organic-inorganic composite material dispersion prepared in step 3 (diluted to 3.0 wt% with ethanol solvent) for 15 minutes; take it out and dry it at 60°C for 40 minutes, and then cure it at 120°C for 15 minutes to obtain a filter material with high-efficiency emulsified water agglomeration separation and antibacterial properties.

[0062] Comparative Example 1

[0063] The process formula of Comparative Example 1 is basically the same as that of Example 1, except that the amount of silicon dioxide in step 1 is reduced from 10 g to 2.5 g.

[0064] Comparative Example 2

[0065] The process formula of Comparative Example 2 is basically the same as that of Example 2, except that the amount of titanium dioxide in step 1 is adjusted from 10 g to 25.0 g.

[0066] Comparative Example 3

[0067] The process formula of Comparative Example 3 is basically the same as that of Example 1, except that the molecular weight of polyethyleneimine in step 2 is increased to 70000. The product prepared in step 3 has high viscosity and forms a gel in the late reaction stage of step 4, making it unusable.

[0068] Comparative Example 4

[0069] The process formula of Comparative Example 4 is basically the same as that of Example 1, except that the molecular weight of polyethyleneimine in step 2 is only 1000.

[0070] Comparative Example 5

[0071] The process formula of Comparative Example 5 is basically the same as that of Example 1, except that the amount of silane coupling agent in step 3 is 1.0 g.

[0072] Comparative Example 6

[0073] The process formula of Comparative Example 6 was basically the same as that of Example 1, except that the amount of silane coupling agent in step 3 was 6.0 g too high. The product prepared by the reaction in step 3 was highly viscous and formed a gel at the end of the reaction in step 4, making it unusable.

[0074] Comparative Example 7

[0075] The process formula of Comparative Example 7 is basically the same as that of Example 1, except that the average particle size of the silicon dioxide in step 1 is 100 nm.

[0076] Comparative Example 8

[0077] Disperse the silica particles in ethanol without adding any organic components for reaction and directly use it to soak the glass fiber substrate. The details are as follows:

[0078] Step 1: Disperse 10 g of silica powder (average particle size of 1.2 μm) in 240 g of ethanol to prepare an inorganic material dispersion;

[0079] Step 2: Immerse the paper-made circular filter glass fiber substrate with a diameter of 20 cm into 200 mL of the inorganic material dispersion prepared in step 1 (diluted to 3.0 wt% with ethanol solvent) for 30 minutes; take it out and dry it at 60°C for 60 minutes, and then cure it at 120°C for 15 minutes to obtain the filter material.

[0080] Comparative Example 9

[0081] The process formula of Comparative Example 9 is basically the same as that of Example 1, except that Steps 1 and 2 are omitted, that is, only the organic component of the silane coupling agent-modified polyethyleneimine is generated for soaking the glass fiber substrate. The details are as follows:

[0082] Step 1: Disperse 30 g of branched polyethyleneimine (molecular weight 3000) in 240 g of ethanol, add 3.5 g of silane coupling agent 3-glycidyloxypropyltrimethoxysilane, heat to 75° C. and react for 2 h to prepare an organic material dispersion;

[0083] Step 2: Immerse the paper-made circular filter glass fiber substrate with a diameter of 20 cm into 200 mL of the organic material dispersion prepared in step 1 (diluted to 3.0 wt% with ethanol solvent) for 30 minutes; take it out and dry it at 60°C for 60 minutes, and then cure it at 120°C for 15 minutes to obtain the filter material.

[0084] Comparative Example 10

[0085] The silica particles of Comparative Example 8 and the silane coupling agent-modified polyethyleneimine of Comparative Example 9 are directly blended. The details are as follows:

[0086] Step 1: Disperse 10 g of silica powder (average particle size 1.2 μm) in 240 g of ethanol to prepare an inorganic material dispersion;

[0087] Step 2: Disperse 30 g of branched polyethyleneimine (molecular weight 3000) in 240 g of ethanol, add 3.5 g of silane coupling agent 3-glycidyloxypropyltrimethoxysilane, raise the temperature to 75° C. and react for 2 h to prepare an organic material dispersion;

[0088] Step 3: mixing the inorganic material dispersion of step 1 and the organic material dispersion of step 2 to obtain a blended dispersion of the inorganic material and the organic material;

[0089] Step 4: Immerse the paper-made circular filter glass fiber substrate with a diameter of 20 cm into 200 mL of the blended dispersion of the inorganic material and organic material in step 3 (diluted to 3.0 wt% with ethanol solvent) for 30 minutes; take out and dry at 60°C for 60 minutes, and then cure at 120°C for 15 minutes to obtain the filter material.

[0090] The water separation performance and antibacterial performance of the filter materials with high-efficiency emulsified water coalescence separation and antibacterial performance of Examples 1-3 and Comparative Examples 1, 2, 4, 5, 7, 9, and 10 were tested by the water separation test method and antibacterial performance test method described below.

[0091] Antibacterial performance test: The antibacterial performance of the filter material was tested according to the standard method of GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles Part 3: Oscillation method". 5 mL of bacterial solution with a concentration of 1×10 8 cfu / mL-5×10 8 The experimental bacterial solution (cfu / mL) was placed in a conical flask containing 70mL of 0.03mol / L PBS buffer (2.84g disodium hydrogen phosphate, 1.36g potassium dihydrogen phosphate, 1000mL water), and 0.75g of the shredded filter material was added. The conical flask was placed in a constant temperature water bath shaker and incubated at (24±1)°C at 150rpm for different time periods. After the specified time, the experimental mixture was diluted to the appropriate multiple with 0.03mol / L PBS buffer, transferred to nutrient agar medium, and incubated at (37±1)°C for 24h-48h. After that, the counts were counted and the antibacterial rate was calculated. The test bacteria included Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli).

[0092] Water separation test method: Using the oil-water separation test bench (such as Figure 1The water separation performance of the filter material was tested (as shown). First, different types of surfactants were dissolved in a measured mixture of diesel and tap water (the oil-water ratio was 90:10 by weight, with No. 0 diesel as the oil). In this experiment, the nonionic surfactant nonylphenol polyoxyethylene ether (NP-10) was added at 0.1 wt% of the oil-water mixture. The mixture was then emulsified using a high-speed disperser at 5000 rpm for 30 minutes to produce an oil-water emulsion. After the filter material sample was placed in a fixture, the emulsion was pumped through the filter material sample at a set flow rate. Samples taken from the upstream and downstream ports were tested for water content using a Karl Fischer titrator (C20, METTLER TOLEDO, Switzerland). Samples were taken every 15 minutes, and the test was terminated after 1 hour. The average of these samples was the total upstream and downstream water content. The water separation efficiency was calculated using the formula: Water separation efficiency (%) = (upstream water content - downstream water content) / (upstream water content) * 100%. After the filter material sample test is completed, continue to immerse it in the tested oil-water mixture. After leaving it at room temperature for one month, continue to test the water separation efficiency, which is recorded as the water separation performance after one month. Observe whether there is any bacterial plaque on the surface of the filter material.

[0093] The water separation and antibacterial performance test results of the filter materials of the embodiment and the comparative example are shown in Table 1 below:

[0094] Table 1 Performance measurement results of various embodiments and comparative examples

[0095]

[0096] The water separation test data in Table 1 demonstrates that the filter materials prepared using Examples 1-3 of the present invention exhibit excellent coalescence and separation performance for emulsified water in oil. Furthermore, the materials maintain high water separation performance even after being immersed in an oil-water mixture for one month. Furthermore, the filter materials exhibit excellent antibacterial properties, achieving antibacterial efficiencies exceeding 99% against both Stenotrophomonas aureus and Escherichia coli. No bacterial plaque was observed after one month of immersion in an oil-water mixture.

[0097] Compared with the untreated glass fiber substrate ( Figure 2 ), the filter material after the treatment of the organic-inorganic composite material in Example 1 ( Figure 3 ) fibers are covered with inorganic particles, which can further enhance the capture and aggregation of emulsified water droplets on the filter material fibers, thus achieving excellent aggregation effects.

[0098] Comparative Example 1 lacks sufficient inorganic particles, resulting in a limited number of raised structures on the filter material's fiber surface. Consequently, its agglomeration and separation performance is significantly lower than that of Example 1. Furthermore, the antibacterial performance of the filter material in Comparative Example 1 is also significantly lower than that of Example 1, further demonstrating that surface nanoparticles can significantly enhance the filter material's antibacterial properties, in addition to improving its water separation performance.

[0099] The proportion of inorganic particle components in Comparative Example 2 is too high, resulting in the organic phase component failing to fully modify the surface of the inorganic particles and stably bond and fix them, causing some organic-inorganic composite materials to swell and fall off due to oil during testing and long-term immersion, thereby resulting in a significant decrease in the agglomeration performance and antibacterial performance of the filter material.

[0100] In Comparative Example 3, since the molecular weight of the polyethyleneimine used was too large, the viscosity of the product during the reaction was high, and gel was formed in the later stage of the reaction, making it unusable.

[0101] In Comparative Example 4, since the molecular weight of the polyethyleneimine used was too small, the reinforced glass fiber filter material was brittle and had low strength. The filter material broke during the water separation test, and therefore the full process test of the water separation performance could not be performed.

[0102] In Comparative Example 5, due to the low amount of silane coupling agent added in Step 3, the crosslink density of the organic-inorganic composite system was low. In water separation and antimicrobial performance tests, the resin dissolved, resulting in low agglomeration separation and antimicrobial performance. During long-term immersion in the oil-water mixture, the resin dissolved, causing the filter material to become loose and significantly weakened in strength, failing to meet the water separation performance test requirements. Furthermore, the resin dissolution also caused the filter material to lose its antimicrobial properties, resulting in the appearance of bacterial plaque.

[0103] In Comparative Example 6, since the amount of silane coupling agent added in step 3 was too high, the product during the reaction had high viscosity and formed a gel in the later stage of the reaction, making it unusable.

[0104] In Comparative Example 7, the inorganic particles are too small and are completely covered by the organic phase, resulting in unclear protrusions on the surface of the filter material fibers. Therefore, the agglomeration and separation performance and antibacterial performance are much lower than those in Example 1.

[0105] Comparative Example 8, which only contained inorganic particles, had poor binding strength with the glass fiber substrate and could not enhance the filter material. Consequently, when immersed in an oil-water mixture for water separation testing, the filter material fibers fell off, causing the entire filter material structure to fall apart, making it unsuitable for testing or application.

[0106] Since the product of Comparative Example 9 is only polyethyleneimine modified by a silane coupling agent, after being applied to the glass fiber filter material, the agglomeration separation performance and antibacterial performance are low; at the same time, since it is not an organic-inorganic composite system, the oil resistance is reduced, and part of the resin is dissolved after long-term immersion in an oil-water mixture, resulting in a significant decrease in the water separation performance of the filter material after one month, and the antibacterial performance is also reduced, resulting in the appearance of plaque.

[0107] In Comparative Example 10, due to the direct blending of inorganic particles and organic components, phase separation occurred between the inorganic components and the organic components during the application process, and the inorganic components agglomerated, failing to form uniform protrusions on the surface of the glass fiber filter material, resulting in low agglomeration and separation performance and antibacterial performance. In addition, the organic components and the inorganic components did not form a good chemical bond coating combination, and their oil resistance was poor. After long-term immersion in an oil-water mixture, part of the resin was dissolved, resulting in a significant decrease in the water separation performance of the filter material after one month, and the antibacterial performance also decreased, leading to the appearance of plaque.

Claims

1. A method for preparing a filter material with high-efficiency emulsified water coalescence separation and antibacterial properties, characterized in that: The following steps are involved: Step 1: Dispersing inorganic particles with hydroxyl groups on the surface in 20-30 times the mass of ethanol, adding a silane coupling agent with epoxy groups, heating to 60-70° C. and reacting for 3-5 hours to prepare a dispersion of inorganic particles with epoxy groups on the surface; the average particle size of the inorganic particles is 0.3-3.0 μm; Step 2: Continue adding branched polyethyleneimine and react at 60-70° C. for 2-4 hours to prepare a polyethyleneimine-coated modified inorganic particle dispersion; the polyethyleneimine has a molecular weight of 1800-10000; and the weight of the polyethyleneimine is 200-400% of the inorganic particles; Step 3, continue to add a silane coupling agent with an epoxy group, react at 70-75° C. for 2-4 hours to prepare an organic-inorganic composite material dispersion; the mass of the silane coupling agent is 25-45% of the inorganic particles; Step 4: immerse the porous filter substrate in the diluted organic-inorganic composite material dispersion for 10 to 60 minutes, take it out, dry it, and solidify it to obtain a filter material with high-efficiency emulsified water agglomeration separation and antibacterial properties.

2. The method for preparing a filter material with high-efficiency emulsified water coalescence separation and antibacterial properties according to claim 1, characterized in that: In step 1, the inorganic particles are at least one of silicon dioxide and titanium dioxide; In step 1, the average particle size of the inorganic particles is 0.5-2.0 μm.

3. The method for preparing a filter material with high-efficiency emulsified water coalescence separation and antibacterial properties according to claim 1, characterized in that: In step 1, the silane coupling agent is at least one of 3-glycidyloxypropyltrimethoxysilane, 3-(2,2-epoxypropylene)propyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltriethoxysilane; In step 1, the mass of the silane coupling agent is 10-30 wt % of the inorganic particles.

4. The method for preparing a filter material with high-efficiency emulsified water coalescence separation and antibacterial properties according to claim 3, characterized in that: In step 1, the mass of the silane coupling agent is 15-25 wt % of the inorganic particles.

5. The method for preparing a filter material with high-efficiency emulsified water coalescence separation and antibacterial properties according to claim 1, characterized in that: In step 2, the molecular weight of the polyethyleneimine is 3000-7000; In step 2, the mass of the polyethyleneimine is 200-350% of the inorganic particles.

6. The method for preparing a filter material with high-efficiency emulsified water coalescence separation and antibacterial properties according to claim 1, characterized in that: In step 3, the silane coupling agent is at least one of 3-glycidyloxypropyltrimethoxysilane, 3-(2,2-epoxypropylene)propyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltriethoxysilane; In step 3, the mass of the silane coupling agent is 30-40% of the inorganic particles.

7. The method for preparing a filter material with high-efficiency emulsified water coalescence separation and antibacterial properties according to claim 1, characterized in that: In step 4, the porous filter substrate is one of filter paper and non-woven fabric; In step 4, the mass concentration of the diluted organic-inorganic composite material dispersion is 2-8%; In step 4, the drying temperature is 50-100°C and the time is 20-60 minutes; In step 4, the curing temperature is 120-150° C. and the curing time is 10-30 minutes.

8. A filter material having high-efficiency emulsified water coalescence separation and antibacterial properties, prepared by the preparation method according to any one of claims 1 to 7.

9. The filter material with high-efficiency emulsified water coalescence separation and antibacterial properties according to claim 8, characterized in that: The filter material with high-efficiency emulsified water coalescence separation and antibacterial properties includes a porous filter substrate and an organic-inorganic composite material. The organic-inorganic composite material is loaded on the porous filter substrate, and the mass ratio of the porous filter substrate to the organic-inorganic composite material is 95:5-85:

15.

10. Use of the filter material with high-efficiency emulsified water coalescence separation and antibacterial properties according to any one of claims 8 to 9 in oil-water separation.

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