A carbon fiber-based polymer filter material and its preparation method

Abstract

The present invention discloses a carbon fiber-based polymer filtration material and a preparation method thereof, relating to the technical field of filter materials. The carbon fiber-based polymer filtration material prepared by the present invention is obtained by mixing modified polystyrene and modified carbon fibers and then preparing a film through a template leaching method; the modified polystyrene is obtained by grafting and modifying calixarene on polystyrene and then carrying out acyl chlorination and hydrazide formation; the modified carbon fibers are obtained by polymerizing benzidine and tris(tetraphenylbenzaldehyde)phosphine on the surface of amino-functionalized carbon fibers and then reacting with 4-(2-bromoethyl)acetophenone; the carbon fiber-based polymer filtration material prepared by the present invention has good adsorption properties, photocatalytic degradation performance and mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of filter materials, and specifically to a carbon fiber-based polymer filter material and a preparation method thereof. Background Art

[0002] Water treatment is of extremely important significance in modern society. It not only concerns human health but also directly affects environmental protection and sustainable development. Common water treatment filter materials include activated carbon, ceramic filter elements, polymer membranes, etc.

[0003] Traditional filter membranes mainly rely on physical interception mechanisms to remove suspended solids and macromolecular organic matter in water, but they have poor removal effects on dissolved small molecular organic matter and heavy metal ions, and often need to be combined with other treatment processes. To solve these problems, methods of introducing various adsorption mechanisms and functionalized functional groups can be adopted to improve the comprehensive performance of the membrane material. For example, introducing hydrophilic functional groups into the polymer matrix can improve the hydrophilicity of the membrane surface and reduce membrane fouling; by grafting or embedding functional groups with specific adsorption capabilities (such as carboxyl groups, amino groups, sulfonic acid groups, etc.), the selective adsorption of specific pollutants can be enhanced. In addition, photocatalytic degradation technology has also been widely applied in the field of water treatment. By introducing photocatalysts (such as titanium dioxide, zinc oxide, etc.) into the membrane material, strongly oxidizing free radicals can be generated under light irradiation conditions to completely decompose organic pollutants into harmless small molecular substances, thereby achieving deep purification.

[0004] As a high-performance material, carbon fiber has excellent mechanical strength, electrical conductivity, and chemical stability, and has been widely used in the field of water treatment in recent years. However, the application of pure carbon fiber in water treatment still has limitations, such as a relatively small specific surface area and limited adsorption capacity. To overcome these deficiencies, researchers have proposed a new idea of compounding polymer materials with carbon fiber. By blending and modifying polymer materials such as polystyrene with carbon fiber, not only can the specific surface area and adsorption performance of the material be significantly improved, but also new functional characteristics can be imparted to it, which is expected to become an ideal choice for a new generation of high-efficiency water treatment filter materials. Summary of the Invention

[0005] The purpose of the present invention is to provide a carbon fiber-based polymer filter material and a preparation method thereof to solve the problems existing in the prior art.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] A preparation method of a carbon fiber-based polymer filter material, comprising the following preparation steps:

[0008] (1) Reacting sodium 4-sulfonylcalix[4]arene with 3-butenoyl chloride to obtain modified calixarene;

[0009] (2) React polystyrene and vinyl calixarene to obtain pre-modified polystyrene; react the pre-modified polystyrene, bis(trichloromethyl) carbonate, and N,N-dimethylformamide for 2 - 3 h to obtain a pre-cursor of modified polystyrene;

[0010] (3) React hydrazine hydrate and the pre-cursor of modified polystyrene to obtain modified polystyrene;

[0011] (4) Immerse carbon fiber in acetone and then oxidize it in acid to obtain oxidized carbon fiber, and mix the oxidized carbon fiber and p-aminophenyltrimethoxysilane to obtain amino-functionalized carbon fiber;

[0012] (5) React the amino-functionalized carbon fiber, tris(tetraphenylbenzaldehyde)phosphine, and benzidine to obtain pre-modified carbon fiber; react the pre-modified carbon fiber and 4-(2-bromoethyl)acetophenone to obtain modified carbon fiber;

[0013] (6) Mix the modified polystyrene, modified carbon fiber, starch, and L-tyrosine to obtain a casting solution, spin-coat the casting solution on a glass slide to obtain a modified polystyrene film, and immerse the modified polystyrene film in nitric acid for treatment to obtain a carbon fiber-based polymer filtration material.

[0014] As an optimization, the preparation method of the modified calixarene in step (1) is: mix sodium 4-sulfonylcalix[4]arene, N,N-dimethylformamide, 3-butenoyl chloride, and triethylamine at 0 - 4 °C for 50 - 60 min, raise the temperature to room temperature and react for 50 - 60 min, and obtain the modified calixarene through reduced-pressure rotary evaporation, washing, and drying; the molar ratio of sodium 4-sulfonylcalix[4]arene to 3-butenoyl chloride is 1:(1.3 - 1.5), and the mass ratio of sodium 4-sulfonylcalix[4]arene, N,N-dimethylformamide, and triethylamine is 1:(10 - 12):(1.5 - 2.0).

[0015] As an optimization, the preparation method of the pre-cursor of modified polystyrene in step (2) is: mix polystyrene, vinyl calixarene, xylene, and benzoyl peroxide according to the mass ratio of 1:(0.5 - 0.6):(20 - 30):(0.001 - 0.002), raise the temperature to 100 - 110 °C and react for 2 - 3 h, then cool down to 40 - 50 °C, and obtain the pre-modified polystyrene through precipitation with acetone, filtration, washing, and drying; mix the pre-modified polystyrene, toluene, bis(trichloromethyl) carbonate, and N,N-dimethylformamide according to the mass ratio of 1:(10 - 12):(0.2 - 0.3):(0.2 - 0.3), raise the temperature to 83 - 85 °C and reflux for 2 - 3 h, after the reaction is completed, obtain the pre-cursor of modified polystyrene through reduced-pressure rotary evaporation, washing with dichloromethane, and drying; the polystyrene model is Styron 685D - 26W.

[0016] As an optimization, the preparation method of the modified polystyrene in step (3) is as follows: Mix 85 wt% hydrazine hydrate and N,N-dimethylformamide and cool down to -5°C. After adding the modified polystyrene precursor and mixing for 3 - 5 min, heat up to room temperature and stir for 3 - 4 h. Precipitate with pure water, and obtain the modified polystyrene after filtration, washing, and drying; the mass ratio of the modified polystyrene precursor, N,N-dimethylformamide, and 85 wt% hydrazine hydrate is 1:(15 - 17):(0.3 - 0.5).

[0017] As an optimization, the preparation method of the amino-functionalized carbon fiber in step (4) is as follows: Immerse the carbon fiber in acetone for 48 h, take it out, wash, and dry. Then immerse it in 98 wt% concentrated nitric acid at 80°C for 4 h, wash, and dry to obtain the oxidized carbon fiber. Mix the oxidized carbon fiber, ethanol, water, and p-aminophenyltrimethoxysilane according to the mass ratio of 1:(50 - 60):(5 - 6):(5 - 6), heat up to 80°C, reflux and react for 8 h, and obtain the amino-functionalized carbon fiber after filtration, washing, and drying.

[0018] As an optimization, the preparation method of the modified carbon fiber in step (5) is as follows: Ultrasonically disperse the amino-functionalized carbon fiber in N,N-dimethylacetamide. After adding tris(tetraphenylbenzylidene)phosphorane and 6 M acetic acid solution and ultrasonically treating for 30 min, add benzidine and continue ultrasonically treating for 30 min. Under the protection of argon, heat up to 120°C and react for 72 h. After filtration, wash with tetrahydrofuran, and then dry to obtain the pre-modified carbon fiber; the mass ratio of the amino-functionalized carbon fiber, tris(tetraphenylbenzylidene)phosphorane, benzidine, N,N-dimethylacetamide, and 6 M acetic acid solution is 1:(1 - 1.5):(2.5 - 3.0):(20 - 30):(0.1 - 0.2); Mix the pre-modified carbon fiber, 4-(2-bromoethyl)acetophenone, and acetone according to the mass ratio of 1:(2 - 3):(20 - 30), heat up to 55 - 60°C, reflux and react for 20 - 24 h, and obtain the modified carbon fiber after filtration, washing, and drying.

[0019] As an optimization, the preparation method of the carbon fiber-based polymer filtration material in step (6) is as follows: Mix the modified polystyrene, modified carbon fiber, starch, and toluene according to the mass ratio of 1:(0.03 - 0.05):1:(20 - 30), ultrasonically treat for 40 - 50 min, then add L-tyrosine with a mass 0.01 times that of the modified polystyrene to obtain a casting solution. Spin-coat the casting solution on a glass slide and dry at 80 - 90°C to obtain a modified polystyrene membrane. The spin-coating speed is 1900 r / min. Immerse the modified polystyrene membrane in 2 mol / L nitric acid and treat for 2 h to obtain the carbon fiber-based polymer filtration material.

[0020] The present invention also provides a carbon fiber-based polymer filtration material prepared according to the above preparation method of the carbon fiber-based polymer filtration material.

[0021] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0022] The carbon fiber-based polymer filtration material prepared by the present invention is obtained by mixing modified polystyrene and modified carbon fiber and then preparing a film through a template leaching method; the modified polystyrene is obtained by grafting modified calixarene onto polystyrene and then subjecting it to acyl chlorination and hydrazide formation; the modified carbon fiber is obtained by polymerizing benzidine and tris(tetraphenylbenzaldehyde)phosphine on the surface of amino-functionalized carbon fiber and then reacting with 4-(2-bromoethyl)acetophenone.

[0023] First, 4-sulfonylcalix[4]arene sodium salt is reacted with but-3-enoyl chloride to graft a double bond onto the calixarene. Then, in the presence of benzoyl peroxide, 4-sulfonylcalix[4]arene sodium salt is grafted onto the side chain of polystyrene. The sulfonate functional group on 4-sulfonylcalix[4]arene sodium salt undergoes acyl chlorination and then reacts with hydrazine hydrate to become a sulfonylhydrazide functional group. The cup-shaped cavity structure of calixarene can accommodate guest molecules, and this unique molecular recognition ability enables calixarene to achieve efficient adsorption. In addition, calixarene and the sulfonic acid groups on calixarene can interact with compounds through various non-covalent bonds such as hydrogen bonds, van der Waals forces, π-π interactions, and electrostatic interactions, further enhancing its adsorption performance and showing excellent performance in removing heavy metal ions and organic pollutants.

[0024] Second, benzidine and tris(4-formylphenyl)phosphine are polymerized on the surface of amino-functionalized carbon fiber to coat a conjugated porous organic polymer on the surface of amino-functionalized carbon fiber, and then reacted with 4-(2-bromoethyl)acetophenone to generate a quaternary phosphonium salt and introduce a carbonyl group. Carbon fiber itself is a material with good adsorption properties, and the addition of carbon fiber can also improve the mechanical properties of the material. Benzidine and tris(tetraphenylbenzaldehyde)phosphine are polymerized through a Schiff base reaction, and the presence of the Schiff base can further improve the adsorption performance of the material for metal ions. In addition, its porous structure can be used to selectively intercept pollutants of different sizes, thereby improving the filtration efficiency. The aromatic ring structure and conjugated system in the conjugated porous organic polymer are beneficial to the photocatalytic degradation process and can generate strongly oxidizing free radicals under light irradiation to decompose organic pollutants into harmless small molecule substances, realizing the photocatalytic degradation of pollutants.

[0025] Finally, a porous polystyrene film, i.e., the carbon fiber-based polymer filtration material of the present invention, is prepared by a template leaching method using polystyrene and carbon fiber as the matrix, starch as the leaching agent, and an acid solution as the solvent for the leachable substance. The sulfonylhydrazide group on the side chain of polystyrene and the carbonyl group on the carbon fiber are crosslinked through the formation of a sulfonylhydrazone functional group in the presence of the catalyst L-tyrosine during the film-forming process. The presence of the crosslinked network can further enhance the mechanical properties of the material, and the formation of the sulfonylhydrazone functional group can endow the material with good antibacterial and antioxidant properties and enhance the service life of the material. Detailed implementation mode

[0026] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present invention.

[0027] The polystyrene models used in the following examples and comparative examples are Styron 685D-26W, purchased from Trinseo Corporation, USA; the starch is corn starch, purchased from Shijiazhuang Tangtian Starch Co., Ltd.; the carbon fiber has a diameter of 150-200 nm and a length of 10-20 μm; purchased from Zhongke Leiming (Beijing) Technology Co., Ltd.

[0028] Example 1:

[0029] A preparation method of a carbon fiber-based polymer filter material, the preparation method of the carbon fiber-based polymer filter material includes the following preparation steps:

[0030] (1) Mix sodium 4-sulfonylcalix[4]arene, N,N-dimethylformamide, but-3-enoyl chloride, and triethylamine at 4°C for 60 min, raise the temperature to room temperature and react for 60 min, and obtain modified calixarene through reduced pressure rotary evaporation, washing and drying; the molar ratio of sodium 4-sulfonylcalix[4]arene to but-3-enoyl chloride is 1:1.3, and the mass ratio of sodium 4-sulfonylcalix[4]arene, N,N-dimethylformamide, and triethylamine is 1:10:1.5;

[0031] (2) Mix polystyrene, vinyl calixarene, xylene, and benzoyl peroxide in a mass ratio of 1:0.5:20:0.001, raise the temperature to 110°C and react for 3 h, then cool down to 50°C, and obtain pre-modified polystyrene through acetone precipitation, filtration, washing and drying; mix pre-modified polystyrene, toluene, bis(trichloromethyl) carbonate, and N,N-dimethylformamide in a mass ratio of 1:10:0.2:0.2, raise the temperature to 85°C and reflux for 3 h, after the reaction is completed, obtain a modified polystyrene precursor through reduced pressure rotary evaporation, washing and drying with dichloromethane;

[0032] (3) Mix 85 wt% hydrazine hydrate and N,N-dimethylformamide and cool down to -5°C, add the modified polystyrene precursor and mix for 5 min, then raise the temperature to room temperature and stir for 4 h, precipitate with pure water, and obtain modified polystyrene through filtration, washing and drying; the mass ratio of the modified polystyrene precursor, N,N-dimethylformamide, and 85 wt% hydrazine hydrate is 1:15:0.3;

[0033] (4) Immerse the carbon fiber in acetone for 48 h, then take it out, wash and dry it. Then immerse it in concentrated nitric acid at 80 °C and 98 wt% for 4 h, wash and dry it to obtain oxidized carbon fiber. Mix the oxidized carbon fiber, ethanol, water, and p-aminophenyltrimethoxysilane in a mass ratio of 1:50:5:5, heat up to 80 °C and reflux for 8 h, and obtain amino-functionalized carbon fiber after filtration, washing, and drying.

[0034] (5) Ultrasonically disperse the amino-functionalized carbon fiber in N,N-dimethylacetamide. Add tris(tetraphenylporphyrinato)phosphorus and 6 M acetic acid solution, and ultrasonicate for 30 min. Then add benzidine and ultrasonicate for another 30 min. Under the protection of argon, heat up to 120 °C and react for 72 h. After filtration, wash with tetrahydrofuran and then dry to obtain pre-modified carbon fiber; the mass ratio of amino-functionalized carbon fiber, tris(tetraphenylporphyrinato)phosphorus, benzidine, N,N-dimethylacetamide, and 6 M acetic acid solution is 1:1:2.5:20:0.1; mix the pre-modified carbon fiber, 4-(2-bromoethyl)acetophenone, and acetone in a mass ratio of 1:2:20, heat up to 60 °C and reflux for 24 h, and obtain modified carbon fiber after filtration, washing, and drying.

[0035] (6) Mix modified polystyrene, modified carbon fiber, starch, and toluene in a mass ratio of 1:0.03:1:20 and ultrasonicate for 50 min. Then add L-tyrosine which is 0.01 times the mass of modified polystyrene to obtain a casting solution. Spin-coat the casting solution on a glass slide and dry it at 90 °C to obtain a modified polystyrene membrane. The spin-coating speed is 1900 r / min. Immerse the modified polystyrene membrane in 2 mol / L nitric acid for 2 h to obtain a carbon fiber-based polymer filtration material.

[0036] Example 2:

[0037] A preparation method of a carbon fiber-based polymer filtration material, the preparation method of the carbon fiber-based polymer filtration material includes the following preparation steps:

[0038] (1) Mix sodium 4-sulfonylcalix[4]arene, N,N-dimethylformamide, but-3-enoyl chloride, and triethylamine at 2 °C for 55 min, heat up to room temperature and react for 55 min, and obtain modified calixarene after reduced pressure rotary evaporation, washing, and drying; the molar ratio of sodium 4-sulfonylcalix[4]arene to but-3-enoyl chloride is 1:1.4, and the mass ratio of sodium 4-sulfonylcalix[4]arene, N,N-dimethylformamide, and triethylamine is 1:11:1.7;

[0039] (2) Mix polystyrene, vinyl calixarene, xylene, and benzoyl peroxide in a mass ratio of 1:0.55:25:0.001. After heating to 105 °C and reacting for 2.5 h, cool to 45 °C, precipitate with acetone, filter, wash, and dry to obtain pre-modified polystyrene; Mix pre-modified polystyrene, toluene, bis(trichloromethyl) carbonate, and N,N-dimethylformamide in a mass ratio of 1:11:0.25:0.27, heat to 84 °C and reflux for 2.5 h. After the reaction, perform rotary evaporation under reduced pressure, wash with dichloromethane, and dry to obtain a modified polystyrene precursor;

[0040] (3) Mix 85 wt% hydrazine hydrate and N,N-dimethylformamide and cool to -5 °C. Add the modified polystyrene precursor and mix for 4 min, then heat to room temperature and stir for 3.5 h. Precipitate with pure water, filter, wash, and dry to obtain modified polystyrene; The mass ratio of the modified polystyrene precursor, N,N-dimethylformamide, and 85 wt% hydrazine hydrate is 1:16:0.4;

[0041] (4) Immerse carbon fiber in acetone for 48 h, take it out, wash, and dry. Then immerse it in concentrated nitric acid at 80 °C and 98 wt% for 4 h, wash, and dry to obtain oxidized carbon fiber. Mix oxidized carbon fiber, ethanol, water, and p-aminophenyltrimethoxysilane in a mass ratio of 1:52:5.5:5.7, heat to 80 °C and reflux for 8 h, filter, wash, and dry to obtain amino-functionalized carbon fiber;

[0042] (5) Ultrasonically disperse amino-functionalized carbon fiber in N,N-dimethylacetamide. Add tris(tetraphenylbenzaldehyde)phosphine and 6 M acetic acid solution, ultrasonically treat for 30 min, then add benzidine and continue ultrasonically treating for 30 min. Under argon protection, heat to 120 °C and react for 72 h. Filter, wash with tetrahydrofuran, and dry to obtain pre-modified carbon fiber; The mass ratio of amino-functionalized carbon fiber, tris(tetraphenylbenzaldehyde)phosphine, benzidine, N,N-dimethylacetamide, and 6 M acetic acid solution is 1:1.7:2.7:25:0.15; Mix pre-modified carbon fiber, 4-(2-bromoethyl)acetophenone, and acetone in a mass ratio of 1:2.5:25, heat to 57 °C and reflux for 22 h, filter, wash, and dry to obtain modified carbon fiber;

[0043] (6) Mix modified polystyrene, modified carbon fiber, starch, and toluene in a mass ratio of 1:0.04:1:25, ultrasonically treat for 45 min, then add L-tyrosine at 0.01 times the mass of modified polystyrene to obtain a casting solution. Spin-coat the casting solution on a glass slide and dry at 85 °C to obtain a modified polystyrene film. The spin-coating speed is 1900 r / min. Immerse the modified polystyrene film in 2 mol / L nitric acid and treat for 2 h to obtain a carbon fiber-based polymer filtration material.

[0044] Example 3:

[0045] A preparation method of a carbon fiber-based polymer filter material, the preparation method of the carbon fiber-based polymer filter material comprising the following preparation steps:

[0046] (1) Mix sodium 4-sulfonylcalix[4]arene, N,N-dimethylformamide, but-3-enoyl chloride, and triethylamine at 4°C for 50 min, then raise the temperature to room temperature and react for 50 min. After rotary evaporation under reduced pressure, washing, and drying, a modified calixarene is obtained; the molar ratio of sodium 4-sulfonylcalix[4]arene to but-3-enoyl chloride is 1:1.5, and the mass ratio of sodium 4-sulfonylcalix[4]arene, N,N-dimethylformamide, and triethylamine is 1:12:2.0;

[0047] (2) Mix polystyrene, vinyl calixarene, xylene, and benzoyl peroxide in a mass ratio of 1:0.6:30:0.002. After raising the temperature to 100°C and reacting for 2 h, lower the temperature to 40°C. After precipitation with acetone, filtration, washing, and drying, pre-modified polystyrene is obtained; mix the pre-modified polystyrene, toluene, bis(trichloromethyl) carbonate, and N,N-dimethylformamide in a mass ratio of 1:12:0.3:0.3. Raise the temperature to 83°C and reflux for 2 h. After the reaction is completed, rotary evaporation under reduced pressure, washing with dichloromethane, and drying are carried out to obtain a modified polystyrene precursor;

[0048] (3) Mix 85 wt% hydrazine hydrate and N,N-dimethylformamide and cool to -5°C. Add the modified polystyrene precursor and mix for 3 min, then raise the temperature to room temperature and stir for 3 h. Precipitate with pure water, and after filtration, washing, and drying, modified polystyrene is obtained; the mass ratio of the modified polystyrene precursor, N,N-dimethylformamide, and 85 wt% hydrazine hydrate is 1:17:0.5;

[0049] (4) Immerse carbon fiber in acetone for 48 h, then take it out, wash, and dry. Then immerse it in concentrated nitric acid at 80°C and 98 wt% for 4 h, wash, and dry to obtain oxidized carbon fiber. Mix the oxidized carbon fiber, ethanol, water, and p-aminophenyltrimethoxysilane in a mass ratio of 1:60:6:6. Raise the temperature to 80°C and reflux for 8 h. After filtration, washing, and drying, amino-functionalized carbon fiber is obtained;

[0050] (5) Ultrasonically disperse the aminated carbon fiber in N,N-dimethylacetamide. Add tris(tetraphenylphosphine) and 6 M acetic acid solution, and ultrasonicate for 30 min. Then add benzidine and ultrasonicate for another 30 min. Under argon protection, heat to 120 °C and react for 72 h. After filtration, wash with tetrahydrofuran and then dry to obtain the pre-modified carbon fiber; the mass ratio of aminated carbon fiber, tris(tetraphenylphosphine), benzidine, N,N-dimethylacetamide, and 6 M acetic acid solution is 1:1.5:3.0:30:0.2; Mix the pre-modified carbon fiber, 4-(2-bromoethyl)acetophenone, and acetone in a mass ratio of 1:3:30, heat to 55 °C and reflux for 20 h, and obtain the modified carbon fiber after filtration, washing, and drying;

[0051] (6) Mix modified polystyrene, modified carbon fiber, starch, and toluene in a mass ratio of 1:0.05:1:30 and ultrasonicate for 40 min. Then add L-tyrosine at 0.01 times the mass of modified polystyrene to obtain the casting solution. Spin-coat the casting solution on a glass slide and dry at 80 °C to obtain the modified polystyrene film. The spin-coating speed is 1900 r / min. Immerse the modified polystyrene film in 2 mol / L nitric acid for 2 h to obtain the carbon fiber-based polymer filtration material.

[0052] Comparative Example 1:

[0053] The preparation method of the carbon fiber-based polymer filtration material in Comparative Example 1 is different from that in Example 2 in that polystyrene is not modified. Specifically, steps (1) to (3) are not included, and step (6) is modified as follows: Mix polystyrene, modified carbon fiber, starch, and toluene in a mass ratio of 1:0.04:1:25 and ultrasonicate for 45 min. Then add L-tyrosine at 0.01 times the mass of modified polystyrene to obtain the casting solution. Spin-coat the casting solution on a glass slide and dry at 85 °C to obtain the modified polystyrene film. The spin-coating speed is 1900 r / min. Immerse the modified polystyrene film in 2 mol / L nitric acid for 2 h to obtain the carbon fiber-based polymer filtration material. The remaining steps are the same as in Example 2.

[0054] Comparative Example 2:

[0055] The preparation method of the carbon fiber-based polymer filtration material of Comparative Example 2 is different from that of Example 2 in that the carbon fiber is not modified. Specifically, steps (4) to (5) are not included, and step (6) is modified as follows: Mix modified polystyrene, carbon fiber, starch, and toluene at a mass ratio of 1:0.04:1:25 and ultrasonicate for 45 min, then add L-tyrosine at 0.01 times the mass of the modified polystyrene to obtain a casting solution. Spin-coat the casting solution on a glass slide and dry it at 85 °C to obtain a modified polystyrene membrane. The spin-coating speed is 1900 r / min. Immerse the modified polystyrene membrane in 2 mol / L nitric acid for 2 h to obtain the carbon fiber-based polymer filtration material. The remaining steps are the same as those in Example 2.

[0056] Comparative Example 3:

[0057] The preparation method of the carbon fiber-based polymer filtration material of Comparative Example 3 is different from that of Example 2 in that the catalyst L-tyrosine is not added. Specifically, step (6) is modified as follows: Mix modified polystyrene, modified carbon fiber, starch, and toluene at a mass ratio of 1:0.04:1:25 and ultrasonicate for 45 min to obtain a casting solution. Spin-coat the casting solution on a glass slide and dry it at 85 °C to obtain a modified polystyrene membrane. The spin-coating speed is 1900 r / min. Immerse the modified polystyrene membrane in 2 mol / L nitric acid for 2 h to obtain the carbon fiber-based polymer filtration material. The remaining steps are the same as those in Example 2.

[0058] Test Example 1:

[0059] Test of photocatalytic degradation performance:

[0060] Test method: Mix 15 mg of the filtration materials prepared in the examples and comparative examples with 150 mL of a 5 mg / mL methylene blue aqueous solution. After reaching adsorption equilibrium under dark conditions, carry out photocatalytic degradation under the irradiation of an ultraviolet lamp with a wavelength of 365 nm and a power of 36 W for 2 h. Measure the concentrations of methylene blue before and after, and calculate the removal rate of methylene blue. The results are shown in Table 1.

[0061] Table 1

[0062] ;

[0063] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 1, it can be found that the materials prepared by the present invention have good photocatalytic degradation performance.

[0064] In Comparative Example 2, the carbon fiber was not modified. The photo-degradation performance of Examples 1 to 3 was better than that of Comparative Example 2, indicating that benzidine and tris(tetraphenylbenzaldehyde)phosphine were polymerized through Schiff base reaction. The presence of Schiff base could further improve the adsorption performance of the material for metal ions, and its porous structure could also be used to selectively intercept pollutants of different sizes, thereby improving the filtration efficiency. The aromatic ring structure and conjugated system in the conjugated porous organic polymer were beneficial to the photocatalytic degradation process. Under light illumination conditions, strongly oxidizing free radicals could be generated to decompose organic pollutants into harmless small molecule substances, realizing the photocatalytic degradation of pollutants.

[0065] Test Example 2:

[0066] Test for adsorption performance:

[0067] Test method: Mix 1 g of the water treatment filter material with 40 g of 50 mg / L copper sulfate pentahydrate solution; oscillate at a speed of 120 rpm / min at 30 °C for 120 min, then take out the filter material, measure the concentration of copper ions, and calculate the adsorption rate of copper ions. The results are shown in Table 2.

[0068] Table 2

[0069] ;

[0070] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 2, it can be found that the filter material prepared by the present invention has good adsorption performance.

[0071] In Comparative Example 1, polystyrene was not modified, and in Comparative Example 2, carbon fiber was not modified. The adsorption performance of Examples 1 to 3 was better than that of Comparative Examples 1 and 2, indicating that 4-sulfonylcalix[4]arene sodium salt was reacted with but-3-enoyl chloride to graft a double bond onto the calixarene, and then 4-sulfonylcalix[4]arene sodium salt was grafted onto the side chain of polystyrene in the presence of benzoyl peroxide; the cup-shaped cavity structure of calixarene and the sulfonic acid groups on calixarene both had good adsorption properties for metal cations; secondly, benzidine and tris(aldehyde group)triphenylphosphine were polymerized on the surface of amino-functionalized carbon fiber to coat a conjugated porous organic polymer on the surface of amino-functionalized carbon fiber; benzidine and tris(tetraphenylbenzaldehyde)phosphine were polymerized through Schiff base reaction. The presence of Schiff base could further improve the adsorption performance of the material for metal ions.

[0072] Test Example 3:

[0073] Test for mechanical properties:

[0074] Test method: The materials prepared in the examples and comparative examples were tested for tensile strength according to standard ASTM D 822-97. The results are shown in Table 3.

[0075] Table 3

[0076] ;

[0077] From the comparison of the experimental data of Examples 1-3 and Comparative Examples 1-3 in Table 3, it can be found that the materials prepared by the present invention have good mechanical properties.

[0078] The mechanical properties of Examples 1-3 are superior to those of Comparative Examples 1-3; in Comparative Example 1, polystyrene is not modified, in Comparative Example 2, carbon fiber is not modified; in Comparative Example 3, L-tyrosine is not contained; none of Comparative Examples 1-3 contain crosslinking sites. In addition, due to the lack of calixarene structure in the side chain of polystyrene in Comparative Example 1, the mechanical properties will be further reduced; it shows that the sulfonylhydrazide group on the side chain of polystyrene and the carbonyl group on the carbon fiber crosslink through the formation of sulfonylhydrazone functional groups in the presence of the catalyst L-tyrosine during the film-forming process. The existence of the crosslinked network can further enhance the mechanical properties of the material, and the formation of sulfonylhydrazone functional groups can endow the material with good antibacterial and antioxidant properties and enhance the service life of the material.

[0079] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be construed as limiting the claimed claim.

Claims

1. A preparation method of a carbon fiber-based polymer filter material, characterized in that, It includes the following preparation steps: (1) Mix sodium 4-sulfonylcalix[4]arene, N,N-dimethylformamide, but-3-enoyl chloride, and triethylamine at 0 - 4 °C for 50 - 60 min, then raise the temperature to room temperature and react for 50 - 60 min to obtain modified calixarene; (2) Mix polystyrene, modified calixarene, xylene, and benzoyl peroxide, raise the temperature to 100 - 110 °C and react for 2 - 3 h, then cool down to 40 - 50 °C to obtain pre-modified polystyrene; Mix pre-modified polystyrene, toluene, bis(trichloromethyl) carbonate, and N,N-dimethylformamide, raise the temperature to 83 - 85 °C and reflux for 2 - 3 h to obtain a modified polystyrene precursor; (3) Mix 85 wt% hydrazine hydrate and N,N-dimethylformamide and cool down to -5 °C, add the modified polystyrene precursor and mix for 3 - 5 min, then raise the temperature to room temperature and stir for 3 - 4 h to obtain modified polystyrene; (4) Immerse carbon fiber in acetone and then oxidize it in acid to obtain oxidized carbon fiber, and mix oxidized carbon fiber and p-aminophenyltrimethoxysilane to obtain aminated carbon fiber; (5) Ultrasonically disperse aminated carbon fiber in N,N-dimethylacetamide, add tris(tetraphenylbenzaldehyde)phosphine and 6M acetic acid solution and ultrasonic for 30 min, then add benzidine and ultrasonic for another 30 min, under argon protection, raise the temperature to 120 °C and react for 72 h to obtain pre-modified carbon fiber; Mix pre-modified carbon fiber, 4-(2-bromoethyl)acetophenone, and acetone, raise the temperature to 55 - 60 °C and reflux for 20 - 24 h to obtain modified carbon fiber; (6) Mix modified polystyrene, modified carbon fiber, starch, and L-tyrosine to obtain a casting solution, spin-coat the casting solution on a glass slide to obtain a modified polystyrene film, and immerse the modified polystyrene film in nitric acid for treatment to obtain a carbon fiber-based polymer filtration material.

2. The preparation method of a carbon fiber-based polymer filter material according to claim 1, characterized in that, The preparation method of the modified calixarene described in step (1) is: Mix sodium 4-sulfonylcalix[4]arene, N,N-dimethylformamide, but-3-enoyl chloride, and triethylamine at 0 - 4 °C for 50 - 60 min, then raise the temperature to room temperature and react for 50 - 60 min, and obtain modified calixarene through reduced pressure rotary evaporation, washing, and drying; The molar ratio of sodium 4-sulfonylcalix[4]arene to but-3-enoyl chloride is 1:(1.3 - 1.5), and the mass ratio of sodium 4-sulfonylcalix[4]arene, N,N-dimethylformamide, and triethylamine is 1:(10 - 12):(1.5 - 2.0).

3. The preparation method of a carbon fiber-based polymer filter material according to claim 1, characterized in that, The preparation method of the modified polystyrene precursor described in step (2) is as follows: Mix polystyrene, modified calixarene, xylene, and benzoyl peroxide in a mass ratio of 1:(0.5 - 0.6):(20 - 30):(0.001 - 0.002). After heating to 100 - 110 °C and reacting for 2 - 3 h, cool to 40 - 50 °C, precipitate with acetone, filter, wash, and dry to obtain pre-modified polystyrene; Mix pre-modified polystyrene, toluene, bis(trichloromethyl) carbonate, and N,N-dimethylformamide in a mass ratio of 1:(10 - 12):(0.2 - 0.3):(0.2 - 0.3), heat to 83 - 85 °C and reflux for 2 - 3 h. After the reaction, perform rotary evaporation under reduced pressure, wash with dichloromethane, and dry to obtain the modified polystyrene precursor; The polystyrene model is Styron 685D-26W.

4. The preparation method of a carbon fiber-based polymer filter material according to claim 1, characterized in that, The preparation method of the modified polystyrene described in step (3) is as follows: Mix 85 wt% hydrazine hydrate and N,N-dimethylformamide and cool to -5 °C. Add the modified polystyrene precursor and mix for 3 - 5 min, then heat to room temperature and stir for 3 - 4 h. Precipitate with pure water, filter, wash, and dry to obtain modified polystyrene; The mass ratio of the modified polystyrene precursor, N,N-dimethylformamide, and 85 wt% hydrazine hydrate is 1:(15 - 17):(0.3 - 0.5).

5. The preparation method of a carbon fiber-based polymer filter material according to claim 1, characterized in that, The preparation method of the amino-functionalized carbon fiber described in step (4) is as follows: Immerse the carbon fiber in acetone for 48 h, then take it out, wash, and dry. Then immerse it in 98 wt% concentrated nitric acid at 80 °C for 4 h, wash, and dry to obtain oxidized carbon fiber. Mix oxidized carbon fiber, ethanol, water, and p-aminophenyltrimethoxysilane in a mass ratio of 1:(50 - 60):(5 - 6):(5 - 6), heat to 80 °C and reflux for 8 h, filter, wash, and dry to obtain amino-functionalized carbon fiber.

6. The preparation method of a carbon fiber-based polymer filter material according to claim 1, characterized in that, The preparation method of the modified carbon fiber described in step (5) is as follows: Ultrasonically disperse the amino-functionalized carbon fiber in N,N-dimethylacetamide, add tris(tetraphenylphosphine) and 6 M acetic acid solution, and ultrasonically treat for 30 min. Then add benzidine and ultrasonically treat for another 30 min. Under argon protection, heat to 120 °C and react for 72 h. After filtration, wash with tetrahydrofuran, and then dry to obtain pre-modified carbon fiber; The mass ratio of amino-functionalized carbon fiber, tris(tetraphenylphosphine), benzidine, N,N-dimethylacetamide, and 6 M acetic acid solution is 1:(1 - 1.5):(2.5 - 3.0):(20 - 30):(0.1 - 0.2); Mix pre-modified carbon fiber, 4-(2-bromoethyl)acetophenone, and acetone in a mass ratio of 1:(2 - 3):(20 - 30), heat to 55 - 60 °C and reflux for 20 - 24 h, filter, wash, and dry to obtain modified carbon fiber.

7. The preparation method of a carbon fiber-based polymer filtration material according to claim 1, characterized in that, The preparation method of the carbon fiber-based polymer filter material described in step (6) is as follows: Mix modified polystyrene, modified carbon fiber, starch, and toluene according to a mass ratio of 1:(0.03 - 0.05):1:(20 - 30), and ultrasonicate for 40 - 50 minutes. Then, add L-tyrosine which is 0.01 times the mass of the modified polystyrene to obtain a casting solution. Spin-coat the casting solution on a glass slide and dry it at 80 - 90 °C to obtain a modified polystyrene membrane. The spin-coating speed is 1900 r / min. Immerse the modified polystyrene membrane in 2 mol / L nitric acid for 2 hours to obtain the carbon fiber-based polymer filter material.

8. A carbon fiber-based polymer filter material prepared by the preparation method of the carbon fiber-based polymer filter material according to any one of claims 1 - 7.