Method for modifying polyacrylonitrile-based activated carbon fiber cloth and application thereof

Abstract

The application provides a polyacrylonitrile-based activated carbon fiber cloth modification method and application thereof, and the preparation method comprises the following steps: performing ultrasonic treatment on polyacrylonitrile-based activated carbon fiber cloth; and performing modification treatment on the polyacrylonitrile-based activated carbon fiber cloth after the ultrasonic treatment, wherein the modification treatment mode at least comprises one of ultraviolet light modification treatment, medium microwave modification treatment, so as to obtain an ultraviolet light modified ACF sheet, a medium microwave modified ACF sheet or a composite modified ACF sheet. The polyacrylonitrile-based activated carbon fiber cloth modification method provided by the application adopts a series of composite treatments such as ultrasonic treatment, microwave treatment and ultraviolet light treatment to prepare modified ACF, so that the ACF-SO2 adsorption capacity is further improved, and the whole composite modification treatment process does not require any chemical reagent and high-temperature reaction device, the experimental operation is simple, the time consumption is short, and the material can be better applied to the application of wardrobe activated carbon adsorption filter elements.

Description

Technical Field

[0001] This invention relates to the field of carbon fiber material modification technology, and in particular to a method for modifying polyacrylonitrile-based activated carbon fiber cloth and its application. Background Technology

[0002] With the rapid development of modern society, women's pursuit of clothing has become more refined, and the prices of clothing they purchase continue to rise. Because luxury clothing is high-end, its materials are expensive and its workmanship is exquisite. For these reasons, luxury clothing often cannot be easily washed; even dry cleaning often results in wrinkles and irreversible damage such as deformation. Therefore, washing should be reduced or avoided altogether. However, clothing easily absorbs various odors in daily life, which can easily develop in the closed environment of a wardrobe. Currently, the most common solution is to place activated charcoal or mothballs in the wardrobe to remove odors. However, mothballs, whose main components are naphthalene or dichlorobenzene, themselves produce an odor upon evaporation. Activated charcoal particles are large, resulting in poor adsorption and limited reusability.

[0003] Activated carbon fiber (ACF) is a porous adsorbent material with abundant micropores, exceeding 90% micropore content. This abundance of micropores significantly increases the specific surface area of ​​ACF. Furthermore, adsorbate molecules do not need to pass through mesopores or macropores for adsorption; they can directly contact the microporous adsorption sites on the ACF surface. Therefore, it greatly improves the adsorption capacity and rate of ACF. Besides specific surface area, the pore size within the ACF, as well as the molecular diameter of the adsorbate or the kinematic diameter of gas molecules, also directly affect its adsorption performance. Through certain modification techniques, the adsorption capacity of ACF for odorous gases such as SO2 can be further enhanced. However, current traditional modification techniques involve high-temperature heat treatment, strong acid or strong alkali soaking, etc. These methods are time-consuming, energy-intensive, and prone to generating difficult-to-treat wastewater, increasing the difficulty of industrial production. Summary of the Invention

[0004] Based on this, the purpose of this invention is to propose a modification method for polyacrylonitrile-based activated carbon fiber cloth and its application, aiming to solve the problem of poor adsorption effect of existing polyacrylonitrile activated carbon fibers on odor gases such as SO2, so as to prepare fiber materials with excellent adsorption capacity for odor gases such as SO2, which can be better applied to wardrobe activated carbon fiber filter materials.

[0005] On one hand, this invention proposes a method for modifying polyacrylonitrile-based activated carbon fiber cloth, the preparation method comprising:

[0006] The polyacrylonitrile-based activated carbon fiber cloth was ultrasonically treated.

[0007] The ultrasonically treated polyacrylonitrile-based activated carbon fiber cloth is modified by at least one of ultraviolet light modification and medium-heat microwave modification to obtain ultraviolet light modified ACF sheet, medium-heat microwave modified ACF sheet, or composite modified ACF sheet.

[0008] In a preferred embodiment of the present invention, the modification treatment of the ultrasonically treated polyacrylonitrile-based activated carbon fiber cloth includes:

[0009] The ultrasonically treated polyacrylonitrile-based activated carbon fiber cloth was placed in a UV analyzer and irradiated with a UV lamp to obtain UV-modified ACF sheets.

[0010] In a preferred embodiment of the present invention, the modification treatment of the ultrasonically treated polyacrylonitrile-based activated carbon fiber cloth includes:

[0011] The ultrasonically treated polyacrylonitrile-based activated carbon fiber cloth was placed in a porcelain crucible, and the porcelain crucible containing the polyacrylonitrile-based activated carbon fiber cloth was placed in a microwave oven for medium-heat microwave treatment to obtain medium-heat microwave modified ACF sheets.

[0012] In a preferred embodiment of the present invention, the modification treatment of the ultrasonically treated polyacrylonitrile-based activated carbon fiber cloth includes:

[0013] The microwave-modified ACF sheet was placed in an ultraviolet analyzer and irradiated with an ultraviolet lamp to obtain a composite modified ACF sheet.

[0014] Alternatively, the UV-modified ACF sheet can be placed in a porcelain crucible, and the crucible containing the UV-modified ACF sheet can be microwaved in a microwave oven at medium heat to obtain the composite modified ACF sheet.

[0015] In a preferred embodiment of the present invention, the ultrasonic treatment of the polyacrylonitrile-based activated carbon fiber cloth includes:

[0016] Cut the polyacrylonitrile-based activated carbon fiber cloth into pieces, place the cut polyacrylonitrile-based activated carbon fiber cloth into a beaker containing deionized water, and then sonicate the beaker containing the polyacrylonitrile-based activated carbon fiber cloth for 25-35 minutes.

[0017] In a preferred embodiment of the present invention, the wavelength of the ultraviolet light is 254 nm.

[0018] In a preferred embodiment of the present invention, the power of the microwave treatment is 400-600W.

[0019] In a preferred embodiment of the present invention, the drying temperature of the oven is 100-140°C and the drying time is 2-3 hours.

[0020] In a preferred embodiment of the present invention, the formula for calculating the SO2 absorption content of the prepared UV-modified ACF sheet, citric acid-impregnated modified ACF sheet, or composite modified ACF sheet is as follows:

[0021]

[0022] Where K represents the SO2 content adsorbed by the activated carbon fiber, mg / g; C0 represents the concentration of injected SO2, mg / ml; V nd The volume of SO2 injected is represented in ml; C(1 / 2I2) represents the concentration of the iodine standard solution in mol / L; V1 represents the volume of iodine standard solution consumed by the remaining SO2 after adsorption by the activated carbon fiber in ml; 32.0 is the mass of sulfur dioxide equivalent to 1 ml of 1 mol / L iodine standard solution in mg; m ACF The mass of activated carbon fiber is expressed in grams (g).

[0023] On the other hand, the present invention also provides the application of modified polyacrylonitrile-based activated carbon fiber cloth obtained by a modification method of polyacrylonitrile-based activated carbon fiber cloth in SO2 adsorption.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. Traditional methods require high-temperature reaction treatment, which is time-consuming, energy-intensive, and time-consuming. Alternatively, different modifying reagents may be needed, potentially causing problems in industrial production such as wastewater discharge. This method combines microwave heat treatment with ultraviolet light treatment. The modification process does not involve any high-temperature reactions or reagents, has a short modification time, low energy consumption, and is completely green and emission-free.

[0026] 2. Traditional modification methods involve expensive large-scale instruments, and high-temperature reactors also pose operational risks. This modification method only requires a regular microwave oven and ultraviolet analyzer, and the operation is very safe, with no pollutants generated and no dangerous operations.

[0027] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by means of embodiments of the invention. Attached Figure Description

[0028] Figure 1 The adsorption capacity of ACF-SO2 after 254nm UV light modification is shown in the figure.

[0029] Figure 2 The graph shows the adsorption capacity of ACF-SO2 after microwave modification treatment.

[0030] Figure 3This is a graph showing the adsorption capacity of ACF-SO2 under combined treatment.

[0031] Figure 4 FT-IR spectra of ACF materials prepared by different modification methods.

[0032] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0033] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] Polyacrylonitrile-based activated carbon fiber (ACF) is a carbon fiber material with excellent adsorption properties. It can be made into adsorption boxes and placed in wardrobes to effectively adsorb odor gases such as SO2 from inside the wardrobe and on clothes, keeping the wardrobe clean.

[0036] Examples 1-5

[0037] The polyacrylonitrile activated carbon fiber cloth (hereinafter referred to as ACF) was cut into pieces of 7.5cm*3cm, approximately 1g per piece. The cut ACF was then placed in a beaker containing 250ml of deionized water, and the beaker was placed in an ultrasonic cleaner for ultrasonic treatment for 30 minutes. Finally, the ACF pieces were placed in an oven and dried at 120℃ for 2 hours.

[0038] The ultrasonically treated ACF sheets were placed in a UV analyzer and irradiated with a 254nm UV lamp for 1h, 2h, 3h, 4h, and 5h, respectively, to obtain five ACF sheets modified by 254nm UV light treatment for different times. The prepared UV-modified ACF sheets were then subjected to SO2 adsorption tests.

[0039] Examples 6-10

[0040] The polyacrylonitrile activated carbon fiber cloth (hereinafter referred to as ACF) was cut into pieces of 7.5cm*3cm, approximately 1g / piece. The cut ACF was then placed in a beaker containing 250ml of deionized water, and the beaker was placed in an ultrasonic cleaner for ultrasonic treatment for 30 minutes. The ACF pieces were then placed in an oven at 120℃ for 2 hours to dry.

[0041] The ultrasonically treated ACF sheets were placed in a 100ml porcelain crucible and microwaved at medium heat for 2 min, 4 min, 6 min, 8 min, and 10 min, respectively, to obtain five ACF sheets modified by medium-heat microwave treatment for different times. SO2 adsorption tests were then performed on the prepared medium-heat microwave modified ACF sheets.

[0042] Examples 11-15

[0043] The polyacrylonitrile activated carbon fiber cloth (hereinafter referred to as ACF) was cut into pieces of 7.5cm*3cm, approximately 1g / piece. The cut ACF was then placed in a beaker containing 250ml of deionized water, and the beaker was placed in an ultrasonic cleaner for ultrasonic treatment for 30 minutes. The ACF pieces were then placed in an oven at 120℃ for 2 hours to dry.

[0044] The ultrasonically treated ACF tablets were placed in a 100ml porcelain crucible and microwaved on medium heat for 2 min, 4 min, 6 min, 8 min, and 10 min, respectively. The resulting five ACF tablets were then irradiated with 254nm UV light for 3 hours in a UV analyzer. SO2 adsorption tests were then performed on the five composite modified ACF tablets.

[0045] Examples 16-20

[0046] The polyacrylonitrile activated carbon fiber cloth (hereinafter referred to as ACF) was cut into pieces of 7.5cm*3cm, approximately 1g / piece. The cut ACF was then placed in a beaker containing 250ml of deionized water, and the beaker was placed in an ultrasonic cleaner for ultrasonic treatment for 30 minutes. The ACF pieces were then placed in an oven at 120℃ for 2 hours to dry.

[0047] Five ACF sheets, after ultrasonic treatment, were placed in a UV analyzer and treated with 254nm UV light for 3 hours. Then, each sheet was placed in a 100ml porcelain crucible and microwaved on medium heat for 2 minutes, 4 minutes, 6 minutes, 8 minutes, and 10 minutes, respectively. Five composite modified ACF sheets were then prepared for SO2 adsorption testing.

[0048] Comparative Example

[0049] The comparison example is a standard activated carbon fiber cloth (raw sheet) that has not undergone any of the following treatments: ultrasonic treatment, ultraviolet light treatment, or citric acid soaking.

[0050] Please refer to Table 1 below, which shows the adsorption capacity of ACF-SO2 after UV modification treatment at 254 nm wavelength. As can be seen from Table 1, the ACF modification effect after 3 hours of UV irradiation is the best, with an ACF-SO2 adsorption capacity of 6.573 mg / g, representing an increase of 35.91%.

[0051] Table 1. Adsorption capacity of ACF-SO2 after UV modification treatment at 254 nm wavelength

[0052]

[0053] Please see Figure 1 The graph shows the adsorption capacity of ACF-SO2 after 254nm UV light modification. Figure 1 It can be clearly seen that after ultraviolet light treatment, the adsorption capacity of ACF-SO2 is significantly improved compared with the original sheet. However, when the ultraviolet light is irradiated for too long, ACF will show obvious aging, which will cause the adsorption capacity of the material for SO2 to decrease significantly. After irradiation with 254nm ultraviolet light for 5 hours, the adsorption capacity of ACF-SO2 is close to that of the original sheet.

[0054] Please refer to Table 2 below, which shows the adsorption capacity of ACF-SO2 after ultrasonic and medium-heat microwave modification. As can be seen from Table 2, the adsorption capacity of ACF-SO2 is significantly improved after medium-heat microwave modification, especially after 6 min of medium-heat microwave treatment, the adsorption capacity reaches 6.718 mg / g, an increase of 38.90%.

[0055] Table 2. ACF-SO2 adsorption capacity after microwave modification treatment

[0056]

[0057] Please see Figure 2 The graph shows the adsorption capacity of ACF-SO2 after microwave modification treatment over medium heat. Figure 2 It can be clearly seen that after microwave treatment, the adsorption capacity of ACF-SO2 is significantly increased compared with the original tablet. The modification effect is best after 6 min of microwave treatment. After 6 min, the adsorption capacity of ACF-SO2 decreases significantly.

[0058] Please refer to Table 3 below for ACF-SO2 adsorption data after different composite treatments. As shown in Table 3, the ACF-SO2 adsorption effect after the combined treatment of microwave and ultraviolet light was far from ideal, with a significant antagonistic effect between ultraviolet light irradiation and microwave treatment. However, the data for ultraviolet light + microwave treatment were very good, showing a significant improvement compared to single microwave and single ultraviolet light irradiation treatments. Among them, the ACF-SO2 adsorption capacity of the 254nm ultraviolet light 3h + 8min microwave treatment reached 7.615mg / g, with an adsorption rate increase of 48.16%, exhibiting the best composite modification effect.

[0059] Table 3. ACF-SO2 adsorption capacity after different composite treatments (UV light treatment: 254nm irradiation for 3h)

[0060]

[0061]

[0062] Please see Figure 3 The graph shows the adsorption capacity of ACF-SO2 under combined treatment. Figure 3 It is clearly evident that treating ACF with microwaves over medium heat followed by UV irradiation produces a significant antagonistic effect, resulting in a marked decrease in ACF-SO2 adsorption capacity, even falling short of the capacity of UV treatment alone. However, after UV irradiation followed by microwave treatment, the modification effect of ACF significantly improves with increasing microwave time, reaching its optimal value at 8 minutes, except for a slight decrease at 2 minutes. Subsequently, with further microwave time, the ACF material is severely damaged, and its modification performance shows a significant decline.

[0063] Please see Figure 4 The images show the FT-IR spectra of ACF materials prepared by different modification methods. Figure 4 As can be seen, after being treated with microwave at medium heat, ACF, compared to the original film, shows a difference in thickness between 1205-1266 cm⁻¹. -1 A distinct absorption peak appears, which is the CO stretching vibration peak of -COOH. Two strong peaks appear in the 3300-3500 cm⁻¹ range, indicating the presence of C-NH₂ primary amine groups. This indicates that after single microwave treatment, the material surface is oxidized, producing obvious -COOH and amine groups. After 3 hours of 254 nm ultraviolet irradiation followed by 6 minutes of medium-heat microwave composite treatment, the ACF at 3300-3400 cm⁻¹... -1 The strong dimer peak at 1205-1266 cm⁻¹ disappears and becomes a large peak, indicating that the amine group has been further oxidized to form a C-NH-O secondary amine group. -1The absorption peaks observed were significantly stronger than those of ACF modified by microwave heating alone. This indicates that after composite modification, the oxygen-containing and nitrogen-containing functional groups of ACF were further enhanced compared to single modification methods, thus further improving ACF's adsorption capacity for SO2.

[0064] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0065] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for modifying polyacrylonitrile-based activated carbon fiber cloth, characterized in that, The modification method includes: The polyacrylonitrile-based activated carbon fiber cloth was ultrasonically treated. The ultrasonically treated polyacrylonitrile-based activated carbon fiber cloth is modified by first performing ultraviolet light modification treatment and then performing medium-heat microwave modification treatment to obtain a composite modified ACF sheet. The wavelength of the ultraviolet light is 254 nm; The power of microwave processing is 400-600W.

2. The method for modifying polyacrylonitrile-based activated carbon fiber cloth according to claim 1, characterized in that, The modification treatment of the ultrasonically treated polyacrylonitrile-based activated carbon fiber cloth includes: The ultrasonically treated polyacrylonitrile-based activated carbon fiber cloth was placed in a UV analyzer and irradiated with a UV lamp to obtain UV-modified ACF sheets.

3. The method for modifying polyacrylonitrile-based activated carbon fiber cloth according to claim 1, characterized in that, The modification treatment of the ultrasonically treated polyacrylonitrile-based activated carbon fiber cloth includes: The UV-modified ACF sheet was placed in a porcelain crucible, and the porcelain crucible containing the UV-modified ACF sheet was placed in a microwave oven for medium-heat microwave treatment to obtain the composite modified ACF sheet.

4. The method for modifying polyacrylonitrile-based activated carbon fiber cloth according to any one of claims 1-3, characterized in that, The ultrasonic treatment of the polyacrylonitrile-based activated carbon fiber cloth includes: Cut the polyacrylonitrile-based activated carbon fiber cloth into pieces, place the cut polyacrylonitrile-based activated carbon fiber cloth into a beaker containing deionized water, and then sonicate the beaker containing the polyacrylonitrile-based activated carbon fiber cloth for 25-35 minutes.

5. The method for modifying polyacrylonitrile-based activated carbon fiber cloth according to any one of claims 1, characterized in that, The ultrasonically treated polyacrylonitrile-based activated carbon fiber cloth is placed in an oven for drying. The oven drying temperature is 100-140℃, and the drying time is 2-3 hours.

6. The method for modifying polyacrylonitrile-based activated carbon fiber cloth according to claim 1, characterized in that, The formula for calculating the SO2 absorption content of the prepared composite modified ACF tablets is as follows: Where K represents the SO2 content adsorbed by the activated carbon fiber, mg / g; C0 represents the concentration of injected SO2, mg / ml; V nd The volume of SO2 injected is represented in ml; C(1 / 2I2) represents the concentration of the iodine standard solution in mol / L; V1 represents the volume of iodine standard solution consumed by the remaining SO2 after adsorption by the activated carbon fiber in ml; 32.0 is the mass of sulfur dioxide equivalent to 1 ml of 1 mol / L iodine standard solution in mg; m ACF The mass of activated carbon fiber is expressed in grams (g).

7. The application of the modified polyacrylonitrile-based activated carbon fiber cloth obtained by the modification method of the polyacrylonitrile-based activated carbon fiber cloth according to any one of claims 1-6 in SO2 adsorption.

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