WO2022147860A1 - Method for preparing superhydrophobic filter material of bag-type dust collector and use thereof - Google Patents

Abstract

A method for preparing a superhydrophobic filter material of a bag-type dust collector and the use thereof, belonging to the field of the preparation of filter bags of bag-type dust collectors. The preparation method comprises: firstly preparing a titanium dioxide sol by means of a sol-gel method, then subjecting the prepared titanium dioxide sol to hydrophobic modification with a γ-methacryloyloxypropyltrimethoxy silane to obtain a hydrophobic sol for coating, and finally spray-coating the prepared modified titanium dioxide sol onto the surface of a filter material by means of a spray gun to obtain a filter material of a bag-type dust collector, which has a superhydrophobic property. The titanium dioxide sol prepared by the method constructs a rough structure and a silane coupling agent reduces the surface energy thereof, such that both good hydrophobic performance and a regular rough structure are obtained, and the coating will not block gaps among fibers of the filter material, such that the filtering efficiency of the filter material is improved, the filtering resistance is reduced, the preparation process is simple, and the coating stability is good.

Description

A kind of preparation method and application of super-hydrophobic bag filter material technical field

The invention belongs to the field of preparation of filter bags for bag-type dust collectors, and particularly relates to a method and application for preparing super-hydrophobic filter material by modifying titanium dioxide sol with a silane coupling agent.

Background technique

With the rapid development of industrialization and urbanization in modern society, a large amount of dust will be generated in various production processes of steel, cement, mining, building materials and other industries. Atmospheric pollution levels are rising at alarming rates in many parts of the world, posing potential risks to life forms on Earth. Air quality in most cities around the world is severely polluted, which has a huge impact on the health of humans, animals, and plants. It affects economic efficiency, reduces agricultural productivity, destroys property and alters the ecology of the region, thereby increasing the risk of environmental disaster.

The bag filter is more used in various production processes because of its convenient operation, simple structure and high dust removal efficiency. However, when the bag filter handles dust with high moisture content in areas with high humidity, the filter material is easy The phenomenon of bag sticking and clogging occurs, thereby increasing the pressure drop of the filter material, reducing the filtration efficiency of the dust collector, resulting in increased operation and maintenance costs and reduced service life.

After searching, the Chinese patent application number 201410356080.4, the application date is July 24, 2014, and the name of the invention is: a preparation method of titanium dioxide super-hydrophobic film; the application adopts the "photosol-gel microfabrication" technology in titanium dioxide A micron-scale lattice rough structure was constructed on the surface of the film, and then the surface of the micro-patterned roughened titanium dioxide film was chemically modified with 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane to obtain a titanium dioxide film with superhydrophobic properties. . However, in this application, the rough structure is prepared by photosensitive sol-gel microfabrication technology, and then modified with fluorosilane. Complicated manufacturing processes and expensive and toxic fluorine-containing low-surface-energy reagents are required to reduce the surface energy, which is not economical and environmentally friendly.

SUMMARY OF THE INVENTION

In order to overcome the deficiencies of the prior art, the problem to be solved by the present invention is to provide an economical and environmentally friendly method for preparing a filter material for a super-hydrophobic bag filter, in order to solve the problem of dust when the bag filter is dealing with high-humidity dust. Problems such as sticking bags, blockages, etc.

The present invention is achieved by the following schemes.

A method for preparing a super-hydrophobic filter material and a surface hydrophobic coating thereof. First, a sol-gel method is used to prepare a titanium dioxide sol; to obtain the hydrophobic sol to be coated; finally, the prepared modified titanium dioxide sol is sprayed onto the surface of the filter material with a spray gun to obtain a bag filter material with super-hydrophobic properties. Specifically include the following steps:

(1) Preparation of titanium dioxide sol: a certain amount of tetrabutyl titanate and glacial acetic acid are uniformly mixed by magnetic stirring; the absolute ethanol solution of 2/3 of the total amount is poured into the above-mentioned mixed solution and stirred at a uniform speed, denoted as A solution; Mix the remaining anhydrous ethanol solution and deionized water evenly, add nitric acid to adjust the pH to 2~3, record as B solution; use a constant pressure dropping funnel to add B solution to A solution, and then drop nitric acid into the mixture, The pH was adjusted to 2-3, and the mixture was uniformly stirred to obtain a titanium dioxide sol.

The molar ratio of tetrabutyl titanate:glacial acetic acid:deionized water:absolute ethanol is 1:3:9.5-38:64.5.

(2) Preparation of silane coupling agent-modified titania sol: adding silane coupling agents of different mass fractions dropwise to the titania sol prepared in step (1), and vigorously stirring to obtain a modified titania sol.

The amount of the silane coupling agent added is that the mass fraction of the titanium dioxide sol is 0.25% to 6%, and the stirring temperature is 50°C.

(3) Preparation of super-hydrophobic filter material: First, pre-process the fiber filter material, use absolute ethanol to ultrasonically clean the filter material at room temperature, and use deionized water to clean the surface of the filter material to neutrality; repeat the above operation twice Then, drying is performed; the modified titanium dioxide sol prepared in step (2) is coated on the surface of the treated fiber filter material, and then dried to obtain the target product: superhydrophobic filter material.

Further, in step (2), the silane coupling agent is γ-methacryloyloxypropyltrimethoxysilane.

Further, in step (2), the stirring temperature is 50°C.

Further, in step (3), the drying temperature is 60°C.

Further, in step (3), the modified titanium dioxide sol is coated on the surface of the filter material by spraying with a spray gun.

Further, in step (3), the drying temperature is 60°C.

The super-hydrophobic bag filter material obtained by the above preparation method can be applied in the treatment of dust with high moisture content.

The chemical reaction formula of the superhydrophobic coating obtained by the present invention is as follows:

Adopting the technical scheme provided by the present invention, compared with the existing known technology, has the following remarkable effects:

1. A super-hydrophobic filter material of the present invention and a method for preparing a surface silane coupling agent modified titanium dioxide sol hydrophobic coating, wherein the main body of the hydrophobic sol is titanium dioxide, which has excellent performance, low cost, easy acquisition, high stability and non-toxicity etc. It is hydrophobically modified with silane coupling agent γ-methacryloyloxypropyltrimethoxysilane and applied to the filter material of bag filter to prepare non-toxic, non-polluting, super-hydrophobic It is a new attempt to improve the filtration performance of the filter material.

2. The preparation process of the present invention is simple, and a simple sol-gel method is used to generate a titanium dioxide nano-sol by using tetrabutyl titanate in the presence of anhydrous ethanol, and then a silane coupling agent γ-methacryloyloxy is used. The titanium dioxide sol is modified with low surface energy by propyltrimethoxysilane to obtain the sol to be coated, and the modified titanium dioxide sol is sprayed onto the surface of the filter material by a spray gun to obtain a superhydrophobic fiber filter material. It improves the sticking phenomenon of filter media when dealing with sticky dust with high moisture content, prolongs the service life of filter media and reduces operation and maintenance costs.

3. Carry out stability test on the obtained filter material. A 40g weight was placed on the obtained super-hydrophobic filter material on a 1000-mesh sandpaper along the horizontal and vertical directions of 10 cm as a cycle. After 50 cycles of wear, the filter material still had super-hydrophobicity. The hydrophobically modified filter material was soaked in strong acid and alkali solution for 24 hours, and the filter material still had super-hydrophobicity. It shows that the superhydrophobic filter material obtained by the present invention has excellent mechanical and chemical stability.

4. Place the high-humidity dust on the surface of the filter material, and use the aqueous solution of dimethyl blue to test the self-cleaning performance of the filter material. It is found that the high-humidity dust adheres to the surface of the untreated filter material, and the high-humidity dust on the surface of the treated filter material is taken away with the rolling of the methylene blue aqueous solution, that is, the modified filter material of the present invention has stable self-cleaning. performance.

5. After the filter material is sprayed with a hydrophobic coating, the titanium dioxide modified by the silane coupling agent is evenly attached to the surface of the fiber, so that the surface of the filter material has excellent hydrophobic properties and a regular rough structure, and the coating will not block the gaps between fibers. The filtering efficiency of the filtering material is improved, the filtering resistance is reduced, the preparation process is simple, and the coating stability is good. The invention can better improve the filtering performance of the filter material of the bag filter when the dust with high moisture content is processed.

Description of drawings

Fig. 1 is the SEM photograph of the superhydrophobic filter material obtained in Example 4 of the present invention.

2 is a photo of the water contact angle of the superhydrophobic filter material obtained in Example 4 of the present invention.

3 is a photograph of the mechanical stability analysis of the superhydrophobic filter material obtained in Example 4 of the present invention.

4 is a photo of chemical stability analysis of the superhydrophobic filter material obtained in Example 4 of the present invention.

Fig. 5 is the filtration performance analysis photograph of the superhydrophobic filter material obtained in Example 4 of the present invention.

6 is a comparison photo of the self-cleaning process of the superhydrophobic filter material obtained in Example 4 of the present invention and the original filter material (a, c, e are the original filter material, b, d, f are the superhydrophobic filter material).

Detailed ways

In order to further understand the content of the present invention, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments. However, the present invention is not limited to the following examples.

Example 1

Step 1: Preparation of Titanium Dioxide Sol

(1) 3mL of tetrabutyl titanate and 1.5mL of glacial acetic acid were uniformly mixed by magnetic stirring for 30min at room temperature;

(2) pour the dehydrated alcohol solution of 22mL into the above-mentioned mixed solution and stir at a constant speed for 10min, denoted as A solution;

(3) Mix 11 mL of absolute ethanol solution with 1.5 mL of deionized water, add nitric acid to adjust pH, and denote it as B solution;

(4) Use a constant pressure dropping funnel to add solution B to A dropwise, drop nitric acid into the mixed solution of AB, adjust the pH again, and stir evenly to obtain a light yellow transparent titanium dioxide sol.

Step 2: Preparation of Silane Coupling Agent Modified Titanium Dioxide Sol

The gamma-methacryloyloxypropyltrimethoxysilane with a mass fraction of 0.25% was added dropwise to the titanium dioxide sol, and vigorously stirred to obtain a modified titanium dioxide sol.

Step 3: Preparation of Hydrophobic Filter Media

(1) First, pretreat the fiber filter material, use absolute ethanol to ultrasonically clean the filter material at room temperature for 30 minutes, and use deionized water to clean the filter material to neutrality. Repeat the above operation twice and then place it in a blast drying oven at 60°C for drying;

(2) The modified titanium dioxide sol is sprayed onto the surface of the treated fiber filter material with a spray gun, and then the modified titanium dioxide sol floating on the surface is washed with absolute ethanol, and then dried in a blast drying oven at 60 °C to obtain superhydrophobicity. filter material.

Example 2

Step 1: Preparation of Titanium Dioxide Sol

(1) 3mL of tetrabutyl titanate and 1.5mL of glacial acetic acid were uniformly mixed by magnetic stirring for 30min at room temperature;

(2) pour the dehydrated alcohol solution of 22mL into the above-mentioned mixed solution and stir at a constant speed for 10min, denoted as A solution;

(3) Mix 11 mL of absolute ethanol solution with 1.5 mL of deionized water, add nitric acid to adjust pH, and denote it as B solution;

(4) adopt constant pressure dropping funnel to add B solution dropwise in A, in the mixed solution of AB, drip nitric acid, adjust pH again, uniformly stir, obtain pale yellow transparent titanium dioxide sol.

Step 2: Preparation of Silane Coupling Agent Modified Titanium Dioxide Sol

The gamma-methacryloyloxypropyltrimethoxysilane with a mass fraction of 0.5% was added dropwise to the titanium dioxide sol, and vigorously stirred to obtain a modified titanium dioxide sol.

Step 3: Preparation of Hydrophobic Filter Media

(1) First, pretreat the fiber filter material, use absolute ethanol to ultrasonically clean the filter material at room temperature for 30 minutes, and use deionized water to clean the filter material to neutrality. Repeat the above operation twice and then place it in a blast drying oven at 60°C for drying;

(2) The modified titanium dioxide sol is sprayed onto the surface of the treated fiber filter material with a spray gun, and then the modified titanium dioxide sol floating on the surface is washed with absolute ethanol, and then dried in a blast drying oven at 60 °C to obtain superhydrophobicity. filter material.

Example 3

Step 1: Preparation of Titanium Dioxide Sol

(1) 3mL of tetrabutyl titanate and 1.5mL of glacial acetic acid were uniformly mixed by magnetic stirring for 30min at room temperature;

(2) pour the dehydrated alcohol solution of 22mL into the above-mentioned mixed solution and stir at a constant speed for 10min, denoted as A solution;

(3) Mix 11 mL of absolute ethanol solution with 1 mL of deionized water, add nitric acid to adjust pH, and denote it as B solution;

(4) Use a constant pressure dropping funnel to add solution B to A dropwise, drop nitric acid into the mixed solution of AB, adjust the pH again, and stir evenly to obtain a pale yellow solution, which is a colorless solution after aging, and a sol The phenomenon is not obvious.

Step 2: Preparation of Silane Coupling Agent Modified Titanium Dioxide Sol

The γ-methacryloyloxypropyltrimethoxysilane with a mass fraction of 1% was added dropwise to the titanium dioxide sol, and vigorously stirred to obtain a modified titanium dioxide sol.

Step 3: Preparation of Hydrophobic Filter Media

(1) at first the fiber filter material is pretreated, and the filter material is ultrasonically cleaned 30min under room temperature using absolute ethanol, and the filter material is cleaned with deionized water to neutrality. Repeat the above operation twice and then place it in a blast drying oven at 60°C for drying;

(2) The modified titanium dioxide sol is sprayed onto the surface of the treated fiber filter material with a spray gun, and then the modified titanium dioxide sol floating on the surface is washed with absolute ethanol, and then dried in a blast drying oven at 60 °C to obtain superhydrophobicity. filter material.

Example 4

Step 1: Preparation of Titanium Dioxide Sol

(1) 3mL of tetrabutyl titanate and 1.5mL of glacial acetic acid were uniformly mixed by magnetic stirring for 30min at room temperature;

(2) pour the dehydrated alcohol solution of 22mL into the above-mentioned mixed solution and stir at a constant speed for 10min, denoted as A solution;

(3) Mix 11 mL of absolute ethanol solution with 1.5 mL of deionized water, add nitric acid to adjust pH, and denote it as B solution;

(4) Use a constant pressure dropping funnel to add solution B to A dropwise, drop nitric acid into the mixed solution of AB, adjust the pH again, and stir evenly to obtain a light yellow transparent titanium dioxide sol.

Step 2: Preparation of Silane Coupling Agent Modified Titanium Dioxide Sol

The γ-methacryloyloxypropyltrimethoxysilane with a mass fraction of 1% was added dropwise to the titanium dioxide sol, and vigorously stirred to obtain a modified titanium dioxide sol.

Step 3: Preparation of Hydrophobic Filter Media

(1) First, pretreat the fiber filter material, use absolute ethanol to ultrasonically clean the filter material at room temperature for 30 minutes, and use deionized water to clean the filter material to neutrality. Repeat the above operation twice and then place it in a blast drying oven at 60°C for drying;

(2) The modified titanium dioxide sol is sprayed onto the surface of the treated fiber filter material with a spray gun, and then the modified titanium dioxide sol floating on the surface is washed with absolute ethanol, and then dried in a blast drying oven at 60 °C to obtain superhydrophobicity. filter material.

The SEM of the hydrophobic filter material tested by field emission scanning electron microscopy is shown in Figure 1. The _TiO2 nanoparticles are uniformly dispersed. After the filter material is sprayed with a hydrophobic coating, the silane coupling agent-modified titanium dioxide is evenly attached to the surface of the fiber, making the filter material uniform. The surface of the material has excellent hydrophobic properties and a regular rough structure, and the coating will not block the gaps between fibers.

Using a contact angle tester to test the wettability of the hydrophobic filter material is shown in Figure 2, and its water contact angle is 156.29°.

The abrasion resistance of the filter media was tested by using sandpaper abrasion cycles as shown in Figure 3. A cycle of 10 cm in the horizontal and vertical directions on sandpaper with a particle size of 1000 mesh was used to measure the water contact angle of the filter media within 50 cycles. The superhydrophobicity remained after 50 cycles of abrasion.

The acid and alkali resistance of the filter material was tested by soaking in acid-base solution as shown in Figure 4. The water contact angle of the filter material was measured by soaking in different pH (1-13) solutions for 24h. The superhydrophobicity remained after being soaked in different pH solutions for 24 h.

The filtration performance of the filter material was tested by the filter material test bench as shown in Figure 5. The filtration efficiency and pressure drop of the filter material were tested at different wind speeds (0.043-0.127m/s), and the quality factor was used to comprehensively evaluate the filter material. Filtration performance. Compared with the original filter material, the modified filter material improves the filtration efficiency, and the quality factor also increases, indicating that the silane coupling agent-modified titanium dioxide is evenly attached to the fiber surface, and the modified filter material makes the filtration efficiency and pressure drop reach the highest level. A better balance improves the filtration performance of the filter material.

The self-cleaning performance of the modified filter media was tested by using pulverized coal with a humidity of 4% and an aqueous methylene blue solution. , b, d, and f are superhydrophobic filter media).

Example 5

Step 1: Preparation of Titanium Dioxide Sol

(1) 3mL of tetrabutyl titanate and 1.5mL of glacial acetic acid were uniformly mixed by magnetic stirring for 30min at room temperature;

(2) pour the dehydrated alcohol solution of 22mL into the above-mentioned mixed solution and stir at a constant speed for 10min, denoted as A solution;

(3) Mix 11 mL of absolute ethanol solution and 3 mL of deionized water, add nitric acid to adjust pH, and denote it as B solution;

(4) Use a constant pressure dropping funnel to add solution B to A dropwise, drop nitric acid into the mixed solution of AB, adjust the pH again, and stir evenly to obtain a light blue solution with Tyndall phenomenon, after aging Tyndall phenomenon disappeared.

Step 2: Preparation of Silane Coupling Agent Modified Titanium Dioxide Sol

The γ-methacryloyloxypropyltrimethoxysilane with a mass fraction of 1% was added dropwise to the titanium dioxide sol, and vigorously stirred to obtain a modified titanium dioxide sol.

Step 3: Preparation of Hydrophobic Filter Media

(1) First, pretreat the fiber filter material, use absolute ethanol to ultrasonically clean the filter material at room temperature for 30 minutes, and use deionized water to clean the filter material to neutrality. Repeat the above operation twice and then place it in a blast drying oven at 60°C for drying;

(2) The modified titanium dioxide sol is sprayed onto the surface of the treated fiber filter material with a spray gun, and then the modified titanium dioxide sol floating on the surface is washed with absolute ethanol, and then dried in a blast drying oven at 60 °C to obtain superhydrophobicity. filter material.

Example 6

Step 1: Preparation of Titanium Dioxide Sol

(1) 3mL of tetrabutyl titanate and 1.5mL of glacial acetic acid were uniformly mixed by magnetic stirring for 30min at room temperature;

(2) pour the dehydrated alcohol solution of 22mL into the above-mentioned mixed solution and stir at a constant speed for 10min, denoted as A solution;

(3) Mix 11 mL of absolute ethanol solution with 4.5 mL of deionized water, add nitric acid to adjust pH, and denote it as B solution;

(4) Using a constant pressure dropping funnel, add solution B to A dropwise, add nitric acid dropwise to the mixed solution of AB, adjust the pH again, and stir evenly to obtain a blue solution without Tyndall phenomenon.

Step 2: Preparation of Silane Coupling Agent Modified Titanium Dioxide Sol

The γ-methacryloyloxypropyltrimethoxysilane with a mass fraction of 1% was added dropwise to the titanium dioxide sol, and vigorously stirred to obtain a modified titanium dioxide sol.

Step 3: Preparation of Hydrophobic Filter Media

(1) at first the fiber filter material is pretreated, and the filter material is ultrasonically cleaned 30min under room temperature using absolute ethanol, and the filter material is cleaned with deionized water to neutrality. Repeat the above operation twice and then place it in a blast drying oven at 60°C for drying;

(2) The modified titanium dioxide sol is sprayed onto the surface of the treated fiber filter material with a spray gun, and then the modified titanium dioxide sol floating on the surface is washed with absolute ethanol, and then dried in a blast drying oven at 60 °C to obtain superhydrophobicity. filter material.

Example 7

Step 1: Preparation of Titanium Dioxide Sol

(1) 3mL of tetrabutyl titanate and 1.5mL of glacial acetic acid were uniformly mixed by magnetic stirring for 30min at room temperature;

(2) pour the dehydrated alcohol solution of 22mL into the above-mentioned mixed solution and stir at a constant speed for 10min, denoted as A solution;

(3) Mix 11 mL of absolute ethanol solution with 1.5 mL of deionized water, add nitric acid to adjust pH, and denote it as B solution;

(4) Use a constant pressure dropping funnel to add solution B to A dropwise, drop nitric acid into the mixed solution of AB, adjust the pH again, and stir evenly to obtain a light yellow transparent titanium dioxide sol.

Step 2: Preparation of Silane Coupling Agent Modified Titanium Dioxide Sol

The γ-methacryloyloxypropyltrimethoxysilane with a mass fraction of 2% was added dropwise to the titanium dioxide sol, and vigorously stirred to obtain a modified titanium dioxide sol.

Step 3: Preparation of Hydrophobic Filter Media

(1) First, pretreat the fiber filter material, use absolute ethanol to ultrasonically clean the filter material at room temperature for 30 minutes, and use deionized water to clean the filter material to neutrality. Repeat the above operation twice and then place it in a blast drying oven at 60°C for drying;

(2) The modified titanium dioxide sol is sprayed onto the surface of the treated fiber filter material with a spray gun, and then the modified titanium dioxide sol floating on the surface is washed with absolute ethanol, and then dried in a blast drying oven at 60 °C to obtain superhydrophobicity. filter material.

Example 8

Step 1: Preparation of Titanium Dioxide Sol

(1) 3mL of tetrabutyl titanate and 1.5mL of glacial acetic acid were uniformly mixed by magnetic stirring for 30min at room temperature;

(2) pour the dehydrated alcohol solution of 22mL into the above-mentioned mixed solution and stir at a constant speed for 10min, denoted as A solution;

(3) Mix 11 mL of absolute ethanol solution with 1.5 mL of deionized water, add nitric acid to adjust pH, and denote it as B solution;

(4) Use a constant pressure dropping funnel to add solution B to A dropwise, drop nitric acid into the mixed solution of AB, adjust the pH again, and stir evenly to obtain a light yellow transparent titanium dioxide sol.

Step 2: Preparation of Silane Coupling Agent Modified Titanium Dioxide Sol

The γ-methacryloyloxypropyltrimethoxysilane with a mass fraction of 3% was added dropwise to the titanium dioxide sol, and the modified titanium dioxide sol was obtained by vigorously stirring uniformly.

Step 3: Preparation of Hydrophobic Filter Media

(1) First, pretreat the fiber filter material, use absolute ethanol to ultrasonically clean the filter material at room temperature for 30 minutes, and use deionized water to clean the filter material to neutrality. Repeat the above operation twice and then place it in a blast drying oven at 60°C for drying;

(2) The modified titanium dioxide sol is sprayed onto the surface of the treated fiber filter material with a spray gun, and then the modified titanium dioxide sol floating on the surface is washed with absolute ethanol, and then dried in a blast drying oven at 60 °C to obtain superhydrophobicity. filter material.

Example 9

Step 1: Preparation of Titanium Dioxide Sol

(1) 3mL of tetrabutyl titanate and 1.5mL of glacial acetic acid were uniformly mixed by magnetic stirring for 30min at room temperature;

(2) pour the dehydrated alcohol solution of 22mL into the above-mentioned mixed solution and stir at a constant speed for 10min, denoted as A solution;

(3) Mix 11 mL of absolute ethanol solution with 1.5 mL of deionized water, add nitric acid to adjust pH, and denote it as B solution;

(4) adopt constant pressure dropping funnel to add B solution dropwise in A, drip nitric acid in the mixed solution of AB, adjust pH again, uniformly stir, obtain pale yellow transparent titanium dioxide sol.

Step 2: Preparation of Silane Coupling Agent Modified Titanium Dioxide Sol

The γ-methacryloyloxypropyltrimethoxysilane with a mass fraction of 6% was added dropwise to the titanium dioxide sol, and vigorously stirred to obtain a modified titanium dioxide sol.

Step 3: Preparation of Hydrophobic Filter Media

(1) First, pretreat the fiber filter material, use absolute ethanol to ultrasonically clean the filter material at room temperature for 30 minutes, and use deionized water to clean the filter material to neutrality. Repeat the above operation twice and then place it in a blast drying oven at 60°C for drying;

(2) The modified titanium dioxide sol is sprayed onto the surface of the treated fiber filter material with a spray gun, and then the modified titanium dioxide sol floating on the surface is washed with absolute ethanol, and then dried in a blast drying oven at 60 °C to obtain superhydrophobicity. filter material.

Claims (7)

1. A method for preparing a filter material for a super-hydrophobic bag filter, comprising the following steps:

   (1) Preparation of titanium dioxide sol: a certain amount of tetrabutyl titanate and glacial acetic acid are uniformly mixed by magnetic stirring; the absolute ethanol solution of 2/3 of the total amount is poured into the above mixed solution and stirred at a uniform speed, denoted as A solution; Mix the remaining anhydrous ethanol solution and deionized water evenly, add nitric acid to adjust the pH to 2~3, record as B solution; use a constant pressure dropping funnel to add B solution to A solution, and then drop nitric acid into the mixture, Adjust pH to 2-3, stir evenly to obtain titanium dioxide sol;

   The molar ratio of tetrabutyl titanate: glacial acetic acid: deionized water: absolute ethanol is 1:3:9.5-38:64.5;

   (2) Preparation of silane coupling agent-modified titania sol: adding silane coupling agents of different mass fractions dropwise to the titania sol prepared in step (1), and vigorously stirring to obtain a modified titania sol;

   The added amount of the silane coupling agent is 0.25% to 6% of the mass fraction of the titanium dioxide sol;

   (3) Preparation of super-hydrophobic filter material: firstly, the fiber filter material is pretreated, and the filter material is ultrasonically cleaned at room temperature with absolute ethanol, and the surface of the filter material is washed with deionized water until neutral; the above operation is repeated twice After drying, the modified titanium dioxide sol prepared in step (2) is coated on the surface of the treated fiber filter material, and then dried.
2. The method for preparing a filter material for a super-hydrophobic bag filter according to claim 1, wherein in step (2), the silane coupling agent is γ-methacryloyloxypropyl Trimethoxysilane.
3. The method for preparing a filter material for a super-hydrophobic bag filter according to claim 1, wherein in step (2), the stirring temperature is 50°C.
4. The method for preparing a filter material for a super-hydrophobic bag filter according to claim 1, wherein in step (3), the drying temperature is 60°C.
5. The method for preparing a filter material for a super-hydrophobic bag filter according to claim 1, wherein in step (3), the modified titanium dioxide sol is applied to the surface of the filter material by spraying with a spray gun.
6. The method for preparing a filter material for a super-hydrophobic bag filter according to claim 1, wherein in step (3), the drying temperature is 60°C.
7. Application of the super-hydrophobic bag filter filter material obtained by the preparation method as claimed in claim 1 in the treatment of dust with higher moisture content.

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