Modified cotton fiber for adsorbing alkaline peculiar smell gas as well as preparation method and application of modified cotton fiber

Abstract

The invention provides a modified cotton fiber for adsorbing alkaline peculiar smell gas as well as a preparation method and application of the modified cotton fiber. According to the preparation method of the modified cotton fiber for adsorbing the alkaline odorous gas, the surface of the cotton fiber modified by the citric acid, the mesoporous silicon and the tetra (4-hydroxyphenyl) porphyrin has more active sites, the specific surface area is increased, the adsorption performance on ammonia gas is remarkably improved, 90% of ammonia gas in a system is adsorbed within 10 minutes, and the adsorption efficiency is greatly improved. And the unmodified fiber only adsorbs 20% of ammonia gas in the system. After 40 minutes, ammonia gas in the system is basically completely adsorbed, and the adsorption capacity is improved by 3.6 times compared with that of unmodified cotton. Due to the fact that the tetra (4-hydroxyphenyl) porphyrin can achieve antibiosis through the double functions of photodynamic antibiosis and metal ion chelation, the antibiosis performance of the modified cotton fiber is greatly improved. In a first photosensitive antibacterial test, the bactericidal rate on staphylococcus aureus reaches up to 98.83%, and excellent antibacterial activity is shown.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of cotton fiber modification, and particularly relates to modified cotton fiber for adsorbing alkaline odor gas and a preparation method and application thereof. BACKGROUND

[0002] Cotton fiber is composed of cellulose macromolecules, and a large number of hydroxyl groups (-OH) exist on the molecular chain of the cotton fiber. These hydroxyl groups endow the cotton fiber with certain hydrophilicity and weak adsorption capacity. However, the adsorption performance of natural cotton fiber on alkaline gas such as ammonia is relatively limited, and it is difficult to meet the demand for high-efficiency adsorption of ammonia in actual application.

[0003] Therefore, it is necessary to modify the cotton fiber to improve its adsorption performance on alkaline gas such as ammonia. SUMMARY

[0004] In order to solve the defects in the prior art, the present application provides a preparation method and application of modified cotton fiber for adsorbing alkaline odor gas. The present application uses citric acid, mesoporous silica and tetra(4-hydroxyphenyl) porphyrin to modify the cotton fiber. The modified cotton fiber contains a large number of carboxyl groups and has a larger specific surface area, so that the adsorption effect of the modified cotton fiber on ammonia is significantly enhanced. In addition, the porphyry tetrahydrazine has photodynamic antibacterial activity, so that the modified cotton fiber has good antibacterial performance.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0006] In a first aspect, the present application provides a preparation method of modified cotton fiber for adsorbing alkaline odor gas, comprising the following steps:

[0007] The cotton fiber is added to a mixed solution containing NaOH, Triton X-100 and citric acid, soaked, and activated cotton fiber is obtained;

[0008] The mesoporous silica is dispersed in an ethanol solution of APTES, refluxed, and filtered to obtain amino-functionalized mesoporous silica;

[0009] The amino-functionalized mesoporous silica, citric acid and tetra(4-hydroxyphenyl) porphyrin are added to anhydrous ethanol to obtain a modification solution;

[0010] The activated cotton fiber is added to the modification solution, soaked, dried, and carboxylated to obtain modified cotton fiber for adsorbing alkaline odor gas.

[0011] Preferably, the cotton fiber is added to a mixed solution containing NaOH, Triton X-100 and citric acid, soaked at 80-100℃ for 0.5-1h, and then washed with water until the pH is 8-9 to obtain the activated cotton fiber.

[0012] Preferably, the mixed solution containing NaOH, Triton X-100 and citric acid has a NaOH mass concentration of 0.5-1%, a Triton X-100 mass concentration of 0.1-0.3%, and a citric acid mass concentration of 0.2-0.25%.

[0013] The mass-to-volume ratio of cotton fiber to a mixed solution containing NaOH, Triton X-100 and citric acid is 1 g:(30-50) mL.

[0014] Preferably, mesoporous silica is dispersed in an ethanol solution of APTES, and in the reflux step, the reflux temperature is 60-80°C and the reflux time is 6-12 hours.

[0015] Preferably, the volume concentration of APTES in the ethanol solution of APTES is 5-6%;

[0016] The mass-to-volume ratio of mesoporous silica to APTES ethanol solution is 1 g:(50-60) mL;

[0017] The mesoporous silica is mesoporous silica MCM-41.

[0018] Preferably, the modified solution contains 1-3% by mass of aminated mesoporous silica, 5-10% by mass of citric acid, and 0.1-0.3% by mass of tetrakis(4-hydroxyphenyl)porphyrin.

[0019] Preferably, activated cotton fibers are added to a modification solution, soaked for 1-2 hours, dried at 80-90°C for 5-10 minutes, then cured and carboxylated at 110-130°C for 30-60 minutes, washed, and dried to obtain modified cotton fibers that adsorb alkaline odor gases.

[0020] The mass-to-volume ratio of cotton fiber to modified solution is 1g:(30~60)mL.

[0021] Secondly, the present invention also provides a modified cotton fiber that adsorbs alkaline odor gases, which is prepared by the preparation method described above.

[0022] Thirdly, the present invention also provides a modified cotton fiber prepared by the preparation method described above, or the application of the modified cotton fiber described above in adsorbing alkaline odor gases, inhibiting bacterial growth, and preparing dyed fibers.

[0023] Preferably, the application of modified cotton fiber in the preparation of dyed fiber specifically includes: dyeing the modified cotton fiber to obtain dyed fiber.

[0024] The preparation method and application of the modified cotton fiber for adsorbing alkaline odor gases of the present invention have the following advantages compared with the prior art:

[0025] 1. The method for preparing modified cotton fibers for adsorbing alkaline odor gases according to the present invention, wherein the cotton fibers modified with citric acid, mesoporous silica, and tetrakis(4-hydroxyphenyl)porphyrin have more active sites on their surface and an increased specific surface area, resulting in a significant improvement in ammonia adsorption performance. After 10 minutes, the modified fibers have adsorbed 90% of the ammonia in the system, while unmodified fibers only adsorb 20%. After 40 minutes, the fibers have essentially completely adsorbed the ammonia, representing a 3.6-fold increase in adsorption capacity compared to unmodified cotton. This high ammonia adsorption performance is due to the multi-carboxyl active groups on the surface resulting from carboxyl modification. Simultaneously, the mesoporous silica, with its high specific surface area, regularly tunable pore size, and rich surface chemical properties, enhances the adsorption effect on gases.

[0026] 2. The modified cotton fiber prepared by this invention exhibits excellent desorption and cyclic adsorption performance. After five cycles, it can still adsorb up to 98% of the ammonia gas in the system. The modified fiber basically does not release gas after adsorption, demonstrating good adsorption retention performance for ammonia. Since tetrakis(4-hydroxyphenyl)porphyrin can achieve antibacterial activity through a dual action of photodynamic antibacterial and metal ion chelation, the antibacterial performance of the modified cotton fiber is significantly improved. In the initial photosensitized antibacterial test, its bactericidal rate against Staphylococcus aureus reached 98.83%, demonstrating excellent antibacterial activity. After five alcohol washes, it still maintained a 70.14% inhibition rate. In contrast, the unmodified cotton fiber only showed a 29.43% inhibition rate in the initial test, and only 10.79% after five washes. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 Scanning electron microscope images of the cotton fibers used in Example 1 and the modified cotton fibers prepared in Example 1;

[0029] Figure 2 The infrared absorption spectra of the cotton fibers used in Example 1 and the modified cotton fibers prepared in Example 1 are shown.

[0030] Figure 3 The graph shows the specific surface area test results of the cotton fiber used in Example 1 and the modified cotton fiber prepared in Example 1.

[0031] Figure 4 Diagram of a gas adsorption device;

[0032] Figure 5 The relative concentration change of ammonia in the odor detection system when the cotton fiber used in Example 1 and the modified cotton fiber prepared in Example 1 adsorb gases;

[0033] Figure 6 The amount of ammonia released by the cotton fiber used in Example 1 and the modified cotton fiber prepared in Example 1 within 60 minutes;

[0034] Figure 7 The modified cotton fiber prepared in Example 1 exhibits ammonia adsorption performance over five cycles. Detailed Implementation

[0035] To facilitate understanding of the present invention, a more comprehensive description of the invention will be provided below in conjunction with specific embodiments. Preferred embodiments of the invention are given in the specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0036] The order in which the embodiments are described below is not intended to limit the preferred order of the embodiments. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". Various embodiments of the invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any referenced number (fraction or integer) within the indicated range.

[0037] This invention provides a method for preparing modified cotton fibers that adsorb alkaline odor gases, comprising the following steps:

[0038] S1. Add cotton fibers to a mixed solution containing NaOH, Triton X-100 and citric acid, soak, and obtain activated cotton fibers;

[0039] S2. Disperse mesoporous silica in an ethanol solution of APTES (i.e., 3-aminopropyltriethoxysilane, silane coupling agent KH-550), reflux, and filter to obtain aminated mesoporous silica.

[0040] S3. Aminated mesoporous silica, citric acid and tetrakis(4-hydroxyphenyl)porphyrin were added to anhydrous ethanol to obtain a modified solution;

[0041] S4. Add the activated cotton fiber to the modification solution, soak, dry, and solidify carboxylation to obtain modified cotton fiber that adsorbs alkaline odor gases.

[0042] In some embodiments, cotton fibers are added to a mixed solution containing NaOH, Triton X-100 and citric acid, soaked at 80-100°C for 0.5-1 h, removed, squeezed dry, and washed with deionized water until the pH reaches 8-9 to obtain activated cotton fibers.

[0043] In some embodiments, the mixed solution containing NaOH, Triton X-100, and citric acid has a NaOH mass concentration of 0.5-1%, a Triton X-100 mass concentration of 0.1-0.3%, and a citric acid mass concentration of 0.2-0.25%.

[0044] The mass-to-volume ratio of cotton fiber to a mixed solution containing NaOH, Triton X-100 and citric acid is 1 g:(30-50) mL.

[0045] In some embodiments, mesoporous silica is dispersed in an ethanol solution of APTES, and in the reflux step, the reflux temperature is 60–80°C and the reflux time is 6–12 h.

[0046] In some embodiments, the volume concentration of APTES in the ethanol solution of APTES is 5-6%;

[0047] The mass-to-volume ratio of mesoporous silica to APTES ethanol solution is 1 g:(50-60) mL;

[0048] The mesoporous silica is mesoporous silica MCM-41.

[0049] In some embodiments, the modified solution contains 1-3% by mass of aminated mesoporous silica, 5-10% by mass of citric acid, and 0.1-0.3% by mass of tetrakis(4-hydroxyphenyl)porphyrin.

[0050] In some embodiments, activated cotton fibers are added to a modification solution and soaked for 1–2 hours. Then, they are dried at 80–90°C for 5–10 minutes to remove ethanol from the fibers. Next, they are cured and carboxylated at 110–130°C for 30–60 minutes. During the curing process, the carboxyl groups (-COOH) of citric acid first undergo esterification with the hydroxyl groups (-OH) on the cellulose molecular chain to form cellulose-citric acid monoester. Further esterification occurs between the carboxyl groups of citric acid and the hydroxyl groups of adjacent cellulose chains, forming a cellulose-citric acid-cellulose three-dimensional network, which improves the stability and carboxyl group retention rate of the modified cellulose. After curing, the fibers are washed to remove unreacted raw materials from the fiber surface and dried to obtain modified cotton fibers that adsorb alkaline odor gases.

[0051] The mass-to-volume ratio of cotton fiber to modified solution is 1g:(30~60)mL.

[0052] The method for preparing modified cotton fibers that adsorb alkaline odor gases according to the present invention first activates cotton fibers using a mixed solution containing NaOH, Triton X-100 and citric acid to obtain activated cotton fibers; then prepares a modification solution containing aminated mesoporous silica, citric acid and tetrakis(4-hydroxyphenyl)porphyrin; and modifies the activated cotton fibers using the modification solution to obtain modified cotton fibers that adsorb alkaline odor gases.

[0053] The cotton fiber used in this invention has a wide planting range, huge output, wide availability, low cost, good mechanical properties, is environmentally friendly, contains abundant hydroxyl groups, and is easy to chemically modify.

[0054] The cotton fibers modified with citric acid, mesoporous silica, and tetra(4-hydroxyphenyl)porphyrin exhibit a greater number of active sites and an increased specific surface area, resulting in a significant improvement in ammonia adsorption performance. After 10 minutes, the modified fibers adsorbed 90% of the ammonia in the system, compared to only 20% for the unmodified fibers. After 40 minutes, the fibers had essentially completely adsorbed the ammonia, representing a 3.6-fold increase in adsorption capacity compared to the unmodified cotton. This high ammonia adsorption performance is attributed to the increased carboxyl group activity on the surface resulting from carboxyl modification. Furthermore, the high specific surface area, regularly tunable pore size, and rich surface chemical properties of mesoporous silica enhance the gas adsorption effect.

[0055] The modified cotton fiber prepared by this invention exhibits excellent desorption and cyclic adsorption performance. Even after five cycles, it can still adsorb up to 98% of the ammonia gas in the system. The modified fiber releases virtually no gas after adsorption, demonstrating good ammonia adsorption retention performance. Because tetrakis(4-hydroxyphenyl)porphyrin achieves antibacterial activity through a dual action of photodynamic antibacterial and metal ion chelation, the antibacterial performance of the modified cotton fiber is significantly improved. In the initial photosensitized antibacterial test, it showed a bactericidal rate of up to 98.83% against Staphylococcus aureus, demonstrating excellent antibacterial activity. After five alcohol washes, it still maintained a 70.14% inhibition rate. In contrast, unmodified cotton fiber showed only a 29.43% inhibition rate in the initial test, and only 10.79% after five washes.

[0056] Based on the same inventive concept, the present invention also provides a modified cotton fiber for adsorbing alkaline odor gases, which is prepared by the preparation method described above.

[0057] Based on the same inventive concept, the present invention also provides a modified cotton fiber prepared by the preparation method described above, or the application of the modified cotton fiber described above in adsorbing alkaline odor gases (such as ammonia) and inhibiting bacterial growth.

[0058] The modified cotton fiber for adsorbing alkaline odor gases, its preparation method, and its application are further illustrated below with specific embodiments. This section further illustrates the content of the present invention in conjunction with specific embodiments, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0059] In the following examples, the cotton fibers used were provided by Winner Medical (Wuhan) Co., Ltd.

[0060] In the following examples, mesoporous silica MCM-41, brand Sigma-Aldrich, CAS 7631-86-9, item number 643645, is used.

[0061] In the following examples, Triton X-100 was purchased from Maclean's Reagents, specifically T6328 Triton X-100, CAS No.: 9002-93-1.

[0062] Example 1

[0063] This embodiment provides a method for preparing modified cotton fibers that adsorb alkaline odor gases, including the following steps:

[0064] S1. Add 1g of cotton fiber to 50mL of a mixed solution containing NaOH, Triton X-100 and citric acid, soak at 80℃ for 0.5h, remove and squeeze out the water, wash with deionized water until pH is 9 to obtain activated cotton fiber; the mixed solution containing NaOH, Triton X-100 and citric acid has a mass concentration of 1% NaOH, a mass concentration of 0.1% Triton X-100 and a mass concentration of 0.2% citric acid.

[0065] S2. Disperse 10g of mesoporous silica MCM-41 in 500mL of ethanol solution of APTES with a volume concentration of 5%, reflux at 70℃ for 10h, and filter to obtain aminated mesoporous silica.

[0066] S3. Add 1.5g of aminated mesoporous silica, 5g of citric acid and 0.15g of tetrakis(4-hydroxyphenyl)porphyrin to 50mL of anhydrous ethanol to obtain a modified solution.

[0067] S4. Add the activated cotton fiber from S1 to the modified solution in S3 and soak for 1 hour (soaking at room temperature of 25°C). Then dry at 90°C for 10 minutes, and then solidify and carboxylate at 130°C for 30 minutes. Wash with deionized water and dry to obtain modified cotton fiber (denoted as CA-cotton) that adsorbs alkaline odor gases.

[0068] Performance testing

[0069] The microstructure of the cotton fiber (i.e., the original cotton fiber) used in Example 1 and the modified cotton fiber (CA-cotton) prepared in Example 1 were observed using a scanning electron microscope (JEOL-7800F, Nippon Electronics Co., Ltd.). The test results are shown in [Figure number missing]. Figure 1 .

[0070] Figure 1 (a) is a SEM image of the original cotton fiber, and (b) is a SEM image of the modified cotton fiber (CA-cotton) prepared in Example 1.

[0071] from Figure 1 As can be seen, the original cotton fiber surface is smooth and the fiber is flat and curled, but the modified cotton fiber surface is significantly rougher and the curl is reduced. This is because the cellulose swelling causes it to become coarser, the introduced groups on the surface make the surface rough, and the surface is loaded with a certain number of silica spheres.

[0072] The infrared absorption spectra of the cotton fiber used in Example 1 (i.e., the original cotton fiber) and the modified cotton fiber (CA-cotton) prepared in Example 1 were tested using Fourier transform infrared spectroscopy (Nicoletis 50, Thermo Fisher Scientific, USA). The results are shown in the figure. Figure 2 .

[0073] Figure 2 In this, cotton is the original cotton fiber, and CA-cotton is the modified cotton fiber prepared in Example 1.

[0074] From Figure 2 it can be seen that the modified cotton fiber (CA-cotton) shows an obvious absorption peak at 1708.1 cm -1 , corresponding to the stretching vibration of the carbonyl group (C=O) in the carboxyl group, which confirms that the carboxyl group has been successfully grafted onto the cotton fiber. In addition, the newly emerged characteristic peak at 1552.4 cm -1 belongs to the stretching vibration of the C=N bond, which is the characteristic absorption peak of the porphyrin molecule, clearly proving the successful loading of the porphyrin molecule onto the modified cotton fiber (CA-cotton).

[0075] The specific surface areas of the four fibers were tested by a reverse-phase gas chromatography-surface energy analyzer. Using methane as the dead volume correction probe and n-octane as the non-polar probe, the BET of the cotton fiber (i.e., the original cotton fiber) used in Example 1 and the modified cotton fiber (CA-cotton) prepared in Example 1 were measured, and the results are as Figure 3 shown.

[0076] Figure 3 In this, Cotton is the original cotton fiber, and CA-cotton is the modified cotton fiber prepared in Example 1.

[0077] From Figure 3 it can be seen that the specific surface area of the modified cotton fiber is 1.36 m 2 ·g -1 , and the specific surface area of the original cotton fiber is 1.25 m 2 ·g -1 . Compared with the original cotton fiber, the specific surface area of the modified cotton fiber has increased. This is because during the treatment process, citric acid will destroy the crystalline region of cellulose, making the originally tight structure become loose, exposing more surface areas, and loading mesoporous silica spheres. A larger specific surface area can provide more adsorption sites, which helps to enhance the gas adsorption performance of the fiber.

[0078] Ammonia adsorption performance of the modified cotton fiber

[0079] The ammonia adsorption performances of the cotton fiber (i.e., the original cotton fiber) used in Example 1 and the modified cotton fiber (CA-cotton) prepared in Example 1 were tested using the gas detection system set up in the laboratory (see Figure 4 ). This odor detection system consists of a gas circulation pump ( Figure 4 Gas pump in Figure 4 ), a sample chamber ( Figure 4 Sample chamber in ), an infrared spectrometer (Figure 4 FTIRgas analyzer), data acquisition device ( Figure 4 The experiment consisted of a data collector. The specific experimental procedure was as follows: all test samples (i.e., the original cotton fiber used in Example 1 and the modified cotton fiber (CA-cotton) prepared in Example 1) were left to stand for 48 hours at (20±2℃, relative humidity 65±2%) before testing. Adsorption experiments were conducted at room temperature in a fume hood. Two grams of each test sample were placed in the sample chamber of the gas detection system. The sample chamber was completely sealed, and 10 μL of ammonia gas was injected into the gas pump using a microsyringe. The ammonia gas was rapidly vaporized and circulated in the odor detection system. The real-time concentration change of ammonia gas was detected using time-resolved infrared spectroscopy. The desorption experiment was conducted as follows: 2 g of the test sample and 80 μL of ammonia gas were placed together in a sealed container (5L). The container was first placed in a 50℃ oven for 30 min, and then at 20℃ for 8 hours to allow gas adsorption saturation. The sample was then quickly placed into the sample chamber and sealed. The gas release process was monitored using an infrared spectrometer. The cyclic testing process is as follows: After each gas adsorption test, the cotton fiber used in Example 1 (i.e., the original cotton fiber, cotton) and the modified cotton fiber (CA-cotton) prepared in Example 1 are placed in a laboratory environment at a temperature of 20±2℃ for at least 12 hours to restore their adsorption capacity before the next round of cyclic testing. The cyclic test is repeated 5 times.

[0080] The adsorption, desorption, and cyclic adsorption effects of the cotton fiber (i.e., the original cotton fiber) used in Example 1 and the modified cotton fiber (CA-cotton) prepared in Example 1 are shown in the figure. Figures 5-7 .

[0081] Specifically, Figure 5 The relative concentration change of ammonia in the odor detection system when cotton fiber and modified cotton fiber (CA-cotton) adsorb gases, where C t Ct represents the real-time concentration of ammonia in the system, and C0 represents the initial concentration of ammonia.

[0082] Figure 6 The amount of ammonia released by cotton fiber and modified cotton fiber (CA-cotton) within 60 minutes;

[0083] Figure 7 The adsorption performance of modified cotton fiber (CA-cotton) for ammonia in five cycles was measured.

[0084] Depend on Figure 5It can be seen that at 10 minutes, the modified cotton fiber (CA-cotton) had adsorbed 90% of the ammonia in the system, while the unmodified cotton fiber (cotton) only adsorbed 20% of the ammonia in the system; at 40 minutes, the modified cotton fiber (CA-cotton) had almost completely adsorbed the ammonia in the system, which was 3.6 times higher than that of the unmodified cotton. This high adsorption performance for ammonia is due to the surface polycarboxyl active groups caused by carboxyl modification. At the same time, mesoporous silica has an enhanced adsorption effect on gases due to its high specific surface area, regular and adjustable pore size and rich surface chemical properties.

[0085] Depend on Figure 6 It is known that cotton fiber releases approximately 25 ppm of gas within one hour after adsorbing ammonia, while modified cotton fiber (CA-cotton) releases virtually no gas after adsorption, demonstrating superior ammonia adsorption performance. In the study of the fiber's cyclic adsorption capacity, it was found that modified cotton fiber (CA-cotton) could still adsorb up to 98% of the ammonia in the system after 5 cycles. Figure 7 The modified cotton fiber (CA-cotton) exhibits good adsorption cycle stability, indicating that it has good adsorption potential in complex adsorption scenarios.

[0086] Photodynamic antibacterial properties of modified cotton fibers

[0087] The photosensitizing antibacterial properties of the modified cotton fiber (CA-cotton) and cotton fiber (i.e., the original cotton fiber) prepared in Example 1 were evaluated according to AATCC 100—2012, "Evaluation Methods for Antimicrobial Textiles". Dry cotton fiber and modified cotton fiber (CA-cotton) were used as blank control and experimental samples, respectively. Several uniformly shaped and thick circular samples were cut from each sample and laid flat in a 24-well plate. 0.1 mL of a 1×10⁻⁶ solution was taken. 8 ~3×10 8 CFU / mL bacterial suspension was inoculated onto each sample. Each sample was divided into two groups and incubated under light for 30 min. Subsequently, the original bacterial suspension and the bacterial suspension on the sample were serially diluted 10⁻⁶ CFU / mL in centrifuge tubes. 6 To create a 10-fold dilution series, take 10 μL of solution from each centrifuge tube of the dilution series and inject it into a Petri dish containing agar medium. Incubate at 37°C for 24 hours.

[0088] Finally, the colony count was measured, and the inhibition rate r was calculated using the following formula to evaluate the antibacterial effect. The test results are shown in Table 1.

[0089]

[0090] In the formula: N0, Ni These represent the number of bacteria that grew on the plate as is and the number of colonies remaining after the sample was sterilized, respectively.

[0091] Table 1 - Bactericidal effects of modified cotton fiber (CA-cotton) and cotton fiber (cotton) on Staphylococcus aureus under light conditions.

[0092] Alcohol washes Cotton germicidal rate / % Modified cotton (CA-cotton) germicidal rate / % 1 29.43±4.17 98.83±1.17 2 17.25±7.41 87.95±4.63 5 10.79±5.92 70.14±3.26

[0093] Note: In Table 1, both the modified cotton fiber (CA-cotton) and cotton fiber (cotton) underwent antibacterial testing after being washed with alcohol for different numbers of times. Alcohol washing refers to cleaning the fiber samples with alcohol. Its main purpose is to simulate the washing and loss scenarios that the materials may experience during actual use, in order to examine the binding stability and antibacterial durability of the porphyrin photosensitizer loaded on the surface of the modified cotton fiber (CA-cotton) after washing.

[0094] As shown in Table 1, the modified cotton fiber (CA-cotton) exhibits significant photosensitizing antibacterial properties. In the initial photosensitizing antibacterial test, it achieved a bactericidal rate of 98.83% against Staphylococcus aureus, demonstrating excellent antibacterial activity. After five alcohol washes, although some porphyrin photosensitizer may have detached, leading to a slight decrease in antibacterial effect, it still maintained a 70.14% inhibition rate, indicating that porphyrin molecules are stably bound to the fiber surface through covalent bonds. In contrast, the unmodified cotton fiber showed only a 29.43% inhibition rate in the initial test, which further decreased to 10.79% after five washes, indicating that the modified cotton fiber (CA-cotton) achieved durable photodynamic antibacterial properties through carboxylation modification and porphyrin loading.

[0095] It is understood that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0096] The above are merely preferred embodiments of this application, and only specifically describe the technical principles of this application. These descriptions are only for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, as well as other specific embodiments of this application that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of this application.

Claims

1. A method for preparing modified cotton fiber that adsorbs alkaline odor gases, characterized in that, Includes the following steps: Cotton fibers were soaked in a mixed solution containing NaOH, Triton X-100 and citric acid to obtain activated cotton fibers. Mesoporous silica was dispersed in an ethanol solution of APTES, refluxed, and filtered to obtain aminated mesoporous silica. Aminated mesoporous silica, citric acid, and tetrakis(4-hydroxyphenyl)porphyrin were added to anhydrous ethanol to obtain a modified solution. Activated cotton fibers are added to a modification solution, soaked, dried, and cured with carboxylation to obtain modified cotton fibers that adsorb alkaline odor gases.

2. The method for preparing modified cotton fiber for adsorbing alkaline odor gases as described in claim 1, characterized in that, Cotton fibers are added to a mixed solution containing NaOH, Triton X-100 and citric acid, and soaked at 80-100℃ for 0.5-1h. Then, they are washed with dewatering water until the pH reaches 8-9 to obtain activated cotton fibers.

3. The method for preparing modified cotton fiber for adsorbing alkaline odor gases as described in claim 1, characterized in that, The mixed solution containing NaOH, Triton X-100, and citric acid has a NaOH mass concentration of 0.5–1%, a Triton X-100 mass concentration of 0.1–0.3%, and a citric acid mass concentration of 0.2–0.25%. The mass-to-volume ratio of cotton fiber to a mixed solution containing NaOH, Triton X-100 and citric acid is 1 g:(30-50) mL.

4. The method for preparing modified cotton fiber for adsorbing alkaline odor gases as described in claim 1, characterized in that, Mesoporous silica is dispersed in an ethanol solution of APTES, and the reflux step is performed at a temperature of 60–80 °C for 6–12 h.

5. The method for preparing modified cotton fiber for adsorbing alkaline odor gases as described in claim 1, characterized in that, The volume concentration of APTES in the ethanol solution is 5-6%; The mass-to-volume ratio of mesoporous silica to APTES in ethanol solution is 1 g:(50-60) mL; The mesoporous silica is mesoporous silica MCM-41.

6. The method for preparing modified cotton fiber for adsorbing alkaline odor gases as described in claim 1, characterized in that, The modified solution contains 1-3% aminated mesoporous silica, 5-10% citric acid, and 0.1-0.3% tetrakis(4-hydroxyphenyl)porphyrin by mass.

7. The method for preparing modified cotton fiber for adsorbing alkaline odor gases as described in claim 1, characterized in that, The activated cotton fibers were added to the modification solution and soaked for 1-2 hours. Then, they were dried at 80-90℃ for 5-10 minutes and then cured and carboxylated at 110-130℃ for 30-60 minutes. After washing and drying, the modified cotton fibers that adsorb alkaline odor gases were obtained.

8. The method for preparing modified cotton fiber for adsorbing alkaline odor gases as described in claim 1, characterized in that, The mass-to-volume ratio of cotton fiber to modified solution is 1 g:(30-60) mL.

9. A modified cotton fiber for adsorbing alkaline odor gases, characterized in that, It is prepared by any one of the preparation methods described in claims 1 to 8.

10. The application of a modified cotton fiber prepared by any one of the preparation methods described in claims 1 to 8, or the modified cotton fiber described in claim 9, in adsorbing alkaline odor gases and inhibiting bacterial growth.

Images