Photocatalyst functionalized nylon fabric and preparation method thereof

Abstract

This invention discloses a photocatalytic functionalized nylon fabric and its preparation method. The method includes the following steps: (1) mixing carbon quantum dots with nano-titanium dioxide to prepare photocatalytic nanomaterials, and mixing the photocatalytic nanomaterials with a composite emulsion to obtain a composite photocatalytic sizing solution; (2) applying the composite photocatalytic sizing solution to nylon yarn by padding or single-yarn sizing, and drying and curing to obtain nylon sizing yarn with a composite photocatalytic sizing film; (3) weaving the nylon sizing yarn to obtain nylon fabric with a composite photocatalytic sizing film; (4) desizing the nylon fabric, washing and drying it to obtain nylon fabric loaded with a photocatalytic film layer; (5) plasma treating the nylon fabric to form dispersed hydrophilic and hydrophobic regions on the surface of the nylon fabric to obtain the finished product of photocatalytic functionalized nylon fabric. The nylon fabric of this invention has excellent VOC gas degradation efficiency and antibacterial rate.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of functional fiber preparation, and particularly relates to a photocatalyst functionalized nylon fabric and a preparation method thereof. BACKGROUND

[0002] Nylon fibers are widely used due to their high strength, high wear resistance and excellent resilience. However, it is challenging to endow nylon fabric with persistent antibacterial and photocatalytic self-cleaning functions. This is because nylon has surface inertness, which is not only smooth, but also lacks active groups, and has weak binding force with functional nanomaterials. If traditional finishing methods such as immersion adsorption method are used, the load firmness of functional nanomaterials on nylon fibers is poor. In addition, there are differences in chemical structure between nylon fibers and cotton fibers. Unlike the strong hydrophilicity of cotton fibers, nylon molecular chains mainly contain amide groups (-CONH-) and methylene groups (-CH2-), which are hydrophobic. For example, if starch sizing material is used to load functional nanomaterials, the adhesion is also poor, and only a small amount of functional nanomaterials is loaded on nylon after desizing. If a strong polar chemical crosslinking agent is added to the sizing material, although the firmness can be improved, the mechanical properties of nylon fibers may be damaged, and it does not meet the development trend of green chemistry.

[0003] Therefore, it is of great significance to develop a processing method that can not only strongly combine with nylon fibers, but also firmly load functional nanomaterials without affecting the performance of the fibers themselves. SUMMARY

[0004] To solve the above technical problems, the present application provides a photocatalyst functionalized nylon fabric and a preparation method thereof.

[0005] The technical solution adopted by the present application is as follows: In a first aspect, the present application provides a preparation method of a photocatalyst functionalized nylon fabric, comprising the following steps: (1) mixing carbon quantum dots with nano-titanium dioxide to prepare photocatalyst nanomaterials, and mixing the photocatalyst nanomaterials with a composite emulsion to obtain a composite photocatalyst sizing liquid; (2) applying the composite photocatalyst sizing liquid obtained in step (1) to nylon yarn by padding or single yarn sizing, and drying and curing to obtain nylon sized yarn with a composite photocatalyst sizing film; (3) weaving the nylon sized yarn obtained in step (2) to obtain nylon fabric with a composite photocatalyst sizing film; (4) desizing the nylon fabric obtained in step (3), and washing and drying to obtain nylon fabric loaded with a photocatalyst film layer; (5) The nylon fabric obtained in step (4) is subjected to plasma treatment to expose part of the nylon fabric, and a dispersed hydrophilic and hydrophobic area is formed on the surface of the nylon fabric to obtain the finished functional nylon fabric loaded with photocatalyst.

[0006] Furthermore, in step (1), the mass ratio of carbon quantum dots to nano-titanium dioxide in the photocatalytic nanomaterial is 1:10~20.

[0007] Furthermore, the mass percentage of photocatalytic nanomaterials in the composite photocatalytic slurry of step (1) is 1-15%.

[0008] Further, the composite emulsion in step (1) includes a main binder, an auxiliary binder and an etching aid, and the dry weight ratio of the main binder, the auxiliary binder and the etching aid is 3~8:1:0.01~0.1.

[0009] Furthermore, the main adhesive is a polyacrylate emulsion and / or an amide-modified waterborne polyurethane emulsion, the auxiliary adhesive is polyvinyl alcohol, and the etching aid is polyvinylpyrrolidone.

[0010] Furthermore, the sizing process parameters in step (2) are: sizing temperature of 40~60℃, and sizing rate of 6~12%; The drying temperature in step (2) is 100~120℃.

[0011] Furthermore, in step (4), the desizing treatment uses hot water at 80~95℃ or a weakly alkaline oxidative desizing solution; the weakly alkaline oxidative desizing solution is a mixed solution of hydrogen peroxide and sodium hydroxide, with a pH of 8~10.

[0012] Furthermore, the plasma treatment in step (5) is divided into two steps: First, the nylon fabric is pretreated with nitrogen plasma to decompose and etch the continuous film layer on the surface of the nylon fabric, exposing part of the nylon fabric. At the same time, amino active sites are generated on the surface of the exposed nylon fabric, forming a hydrophilic region. Secondly, the nylon fabric is treated with fluorocarbon gas plasma to form a hydrophobic protective layer in the unetched area on the surface of the nylon fabric, thus forming a hydrophobic region.

[0013] Furthermore, when pretreating nylon fabrics with nitrogen plasma, the power is 50~100W and the time is 40~80s; When treating nylon fabrics with fluorocarbon gas plasma, the power is 100~150W and the time is 20~40s.

[0014] Secondly, the present invention provides a photocatalytic functionalized nylon fabric, which is prepared using the above method.

[0015] The beneficial effects of this invention are as follows: (1) The preparation method of photocatalytic functionalized nylon fabric proposed in this invention uses polyacrylate and / or modified polyurethane as the main binder in the sizing solution. It is compatible with the molecular structure of nylon and can form a strong bond with nylon yarn through intermolecular forces, which significantly improves the load fastness of the photocatalyst and has excellent wash resistance. At the same time, polyvinyl alcohol is used as an auxiliary binder to improve the permeability and film-forming properties of the sizing solution. It can form an interpenetrating network with the main binder and provide stable support for the photocatalyst before desizing. After desizing, the main binder undertakes the main fixing role. In addition, a small amount of etching aid is added to the sizing solution, which can be preferentially decomposed during subsequent plasma treatment to form initial etching points, thereby guiding the directional generation of fragmented morphology of subsequent polyacrylate and / or modified polyurethane. (2) The method for preparing photocatalytic functionalized nylon fabric proposed in this invention involves two-step plasma treatment after desizing. The resulting nylon fabric has dispersed hydrophilic and hydrophobic regions on its surface. The hydrophilic regions can adsorb VOC gases and bacteria, which diffuse to the hydrophobic regions and are degraded by photocatalysis after adsorption, thereby improving the VOC gas degradation efficiency and antibacterial rate. Under visible light, the antibacterial rate against common bacteria (such as Staphylococcus aureus and Escherichia coli) exceeds 99%, and it has a significant photocatalytic degradation ability against air pollutants (such as formaldehyde and toluene), with a degradation rate of over 80% in 12 hours. At the same time, the hydrophobic regions make it difficult for pollutants to adhere, improving the anti-fouling ability of the nylon fabric itself. Moreover, the fluorocarbon layer deposited in the hydrophobic regions can reduce the peeling off of unetched fragments during friction, preserving the photocatalytic nanomaterials as much as possible. Detailed Implementation

[0016] This invention provides a photocatalytically functionalized nylon fabric and its preparation method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0017] Unless otherwise specified, the experimental methods described in the following examples are generally performed under standard conditions or as recommended by the manufacturer.

[0018] This invention provides a method for preparing photocatalytic functionalized nylon fabric, comprising the following steps: (1) Photocatalytic nanomaterials were prepared by mixing carbon quantum dots with nano-titanium dioxide, and the photocatalytic nanomaterials were mixed with composite emulsion to obtain composite photocatalytic slurry; (2) The composite photocatalyst sizing solution obtained in step (1) is applied to nylon yarn by padding or single yarn sizing and then dried and cured to obtain nylon sizing yarn with composite photocatalyst sizing film. (3) The nylon sizing yarn obtained in step (2) is woven using conventional processes to obtain a nylon fabric with a composite photocatalytic sizing film. (4) The nylon fabric obtained in step (3) is desized, washed and dried to obtain the nylon fabric loaded with photocatalytic film layer. (5) The nylon fabric obtained in step (4) is subjected to plasma treatment to expose part of the nylon fabric, and a dispersed hydrophilic and hydrophobic area is formed on the surface of the nylon fabric to obtain the finished functional nylon fabric loaded with photocatalyst.

[0019] Specifically, in step (1) above, the mass ratio of carbon quantum dots to nano-titanium dioxide in the photocatalytic nanomaterial is 1:10~20, and the mass percentage of the photocatalytic nanomaterial in the composite photocatalyst slurry is 1~15%.

[0020] The carbon quantum dots and nano-titanium dioxide in the above-mentioned photocatalytic nanomaterials work synergistically to improve the antibacterial rate and the degradation efficiency of VOC gases. Especially under visible light, the antibacterial rate reaches more than 99%, and the VOC gas degradation rate can reach more than 80%.

[0021] Specifically, the composite emulsion in step (1) above includes a main binder, an auxiliary binder, and an etching aid, and the dry weight ratio of the main binder, the auxiliary binder, and the etching aid is 3~8:1:0.01~0.1; wherein, the main binder is a polyacrylate emulsion and / or an amide-modified waterborne polyurethane emulsion, and the solid content of the polyacrylate emulsion is 10~25wt%, the solid content of the amide-modified waterborne polyurethane emulsion is 30~50wt%, the auxiliary binder is polyvinyl alcohol, the etching aid is polyvinylpyrrolidone, and the auxiliary binder and the etching aid are added to the main binder in the form of solid powder to form a composite emulsion.

[0022] In the above composite emulsion, the main adhesive has groups that can form hydrogen bonds or van der Waals forces with the amide groups of nylon, thereby improving the adhesion strength between the nylon yarn and the slurry; the auxiliary adhesive can work synergistically with the main adhesive to enhance film-forming properties and adhesion strength to the nylon yarn; when the etching aid is used in the plasma treatment in step (5), it can be preferentially decomposed by the plasma to form initial etching points, thereby guiding the directional generation of subsequent polyacrylate and / or modified polyurethane fragmentation morphology.

[0023] Specifically, the sizing process parameters in step (2) are: sizing temperature of 40~60℃ and sizing rate of 6~12%; The drying temperature in step (2) is 100~120℃.

[0024] In step (2) above, the sizing temperature is controlled at 40~60℃ to avoid excessive temperature causing changes in nylon thermal stress; the sizing rate is controlled at 6~12% to ensure that the sizing liquid adheres evenly to the surface of the nylon yarn and to prevent the subsequent film layer from being too thick.

[0025] Specifically, in step (4) above, the desizing treatment uses hot water at 80~95℃ or a weakly alkaline oxidizing desizing solution; the weakly alkaline oxidizing desizing solution is a mixed solution of hydrogen peroxide and sodium hydroxide, with a pH of 8~10.

[0026] During the desizing process in step (4) above, most of the PVA that serves as a temporary skeleton and some of the free polyacrylate or modified polyurethane polymer can be removed, as well as a very small amount of PVP. Most of the main adhesive and PVP are firmly bonded to the nylon and are selectively retained on the surface of the nylon fabric to form a continuous film. At the same time, the photocatalytic nanomaterials wrapped by the main adhesive are also retained on the surface of the nylon fabric.

[0027] Specifically, the plasma treatment in step (5) above is divided into two steps: The first step is to pretreat the nylon fabric with nitrogen plasma, which decomposes and etches the continuous film layer on the surface of the nylon fabric, exposing part of the nylon fabric. At the same time, amino active sites are generated on the surface of the exposed nylon fabric, forming a hydrophilic region. The second step involves performing fluorocarbon gas plasma deposition on the nylon fabric to form a hydrophobic protective layer on the unetched areas of the nylon fabric surface, thus creating a hydrophobic region.

[0028] Specifically, when pretreating nylon fabrics with nitrogen plasma, the power is 50~100W, the time is 40~80s, and the vacuum degree is 10~50Pa; when pretreating nylon fabrics with fluorocarbon gas plasma, the power is 100~150W, the time is 20~40s, and the vacuum degree is 10~50Pa.

[0029] In the aforementioned plasma treatment, during the first step of plasma pretreatment, the etching agent polyvinylpyrrolidone on the surface of the nylon fabric is preferentially decomposed, forming initial etching points. Then, by controlling the plasma treatment power and time, various fragment patterns such as honeycomb, crack, and island shapes can be achieved (in the unetched fragment areas). The exposed nylon areas generate amino active sites under nitrogen plasma treatment, improving the hydrophilicity and water absorption of the nylon, which is beneficial for adsorbing VOC gases. In the second step of plasma treatment, fluorocarbon compound gas is used for plasma deposition treatment, which can deposit a fluorocarbon layer on the surface of the unetched fragment areas. This fluorocarbon layer is hydrophobic, making it difficult for pollutants to adhere and improving the stain resistance of the nylon fabric itself. At the same time, the deposited fluorocarbon layer can also reduce the peeling off of unetched fragments during friction, retain photocatalytic nanomaterials as much as possible, and simultaneously maintain a yarn strength retention rate of ≥95%.

[0030] After plasma treatment, the nylon fabric of the present invention has dispersed hydrophilic and hydrophobic regions on its surface. The hydrophilic regions can adsorb VOC gases and bacteria, which diffuse to the hydrophobic regions and are degraded by photocatalysis, thereby improving the VOC gas degradation efficiency and antibacterial rate.

[0031] Example 1 This embodiment provides a photocatalytically functionalized nylon fabric, the preparation process of which is as follows: (1) 2g of CQDs / TiO2 composite photocatalyst nanomaterial (the mass ratio of carbon quantum dots to nano titanium dioxide is 1:15) is dispersed in 150g of composite emulsion (the dry weight ratio of polyacrylate, polyvinyl alcohol and polyvinylpyrrolidone is 5:1:0.04, and the solid content of polyacrylate emulsion is 20wt%), and stirred evenly to obtain composite photocatalyst slurry; (2) Place the composite photocatalyst sizing solution obtained in step (1) into the sizing tank, pass the nylon FDY filament through the sizing tank, sizing at 50°C with a roll-off rate of 80% and a sizing rate of 10%, and then dry and cure in a hot air oven at 110°C to obtain nylon sizing yarn with a composite photocatalyst sizing film. (3) The nylon sizing yarn obtained in step (2) is woven into a plain weave fabric on a water jet loom to obtain a nylon fabric with a composite photocatalytic sizing film. (4) The nylon fabric obtained in step (3) is placed in hot water at 90°C for desizing treatment for 30 minutes, and mechanical stirring is added. Then, it is washed with hot water, washed with cold water, and dried to obtain the nylon fabric loaded with photocatalytic film layer. (5) The nylon fabric obtained in step (4) is subjected to two-step plasma treatment. The first step is to pre-treat the nylon fabric with plasma in the atmosphere of nitrogen, a vacuum of 20 Pa, a power of 80 W, a time of 60 s, and a temperature below 80 °C. This decomposes and etches the continuous film layer on the surface of the nylon fabric, exposing part of the nylon fabric. At the same time, amino active sites are generated on the surface of the exposed nylon fabric, forming a hydrophilic region. The remaining unexposed area is wrapped by dispersed fragments, which is the unetched area. The second step is to perform plasma deposition treatment on the nylon fabric with a fluorocarbon gas (C4F8), a vacuum of 20 Pa, a power of 120 W, a time of 30 s, and a temperature below 80 °C. This forms a hydrophobic protective layer on the surface of the unetched area of ​​the nylon fabric.

[0032] The functional nylon fabric loaded with photocatalyst prepared by the above method has a surface with dispersed hydrophilic and hydrophobic regions. The hydrophilic region accounts for 19% of the area and has a water contact angle of 45°. The hydrophobic region accounts for 81% of the area and has a water contact angle of 155°.

[0033] The functional nylon fabric with photocatalyst loading obtained in this embodiment was tested for antibacterial rate, VOC degradation rate, oil removal rate, and anti-pilling grade. The test results are as follows: When nylon fabrics are unwashed, the inhibition rate against Escherichia coli reaches 99.5%, and after 12 hours of exposure to visible light, the degradation rate of toluene vapor (initial concentration of 10 ppm) reaches 91%. After 30 standard household washes, nylon fabrics showed a 92% inhibition rate against E. coli. After five standard household washes, nylon fabrics showed a 98% oil stain removal rate. Anti-pilling level: 4~5.

[0034] Example 2 This embodiment provides a photocatalytically functionalized nylon fabric, the preparation process of which is as follows: (1) 2.5g of CQDs / TiO2 composite photocatalyst nanomaterial (the mass ratio of carbon quantum dots to nano titanium dioxide is 1:10) is dispersed in 150g of composite emulsion (the dry weight ratio of polyacrylate, polyvinyl alcohol and polyvinylpyrrolidone is 4:1:0.02, and the solid content of polyacrylate emulsion is 15wt%), and stirred evenly to obtain composite photocatalyst slurry; (2) Place the composite photocatalyst sizing solution obtained in step (1) into the sizing tank, pass the nylon FDY filament through the sizing tank, sizing at 45°C with a roll-off rate of 70% and a sizing rate of 7%, and then dry and cure in a hot air oven at 100°C to obtain nylon sizing yarn with a composite photocatalyst sizing film. (3) The nylon sizing yarn obtained in step (2) is woven into a plain weave fabric on a water jet loom to obtain a nylon fabric with a composite photocatalytic sizing film. (4) The nylon fabric obtained in step (3) is placed in hot water at 90°C for desizing treatment for 30 minutes, and mechanical stirring is added. Then, it is washed with hot water, washed with cold water, and dried to obtain the nylon fabric loaded with photocatalytic film layer. (5) The nylon fabric obtained in step (4) is subjected to two-step plasma treatment. The first step is to pre-treat the nylon fabric with plasma in the atmosphere of nitrogen, a vacuum of 10 Pa, a power of 60 W, a time of 80 s, and a temperature below 80 °C. This decomposes and etches the continuous film layer on the surface of the nylon fabric, exposing part of the nylon fabric. At the same time, amino active sites are generated on the surface of the exposed nylon fabric, forming a hydrophilic region. The remaining unexposed area is wrapped by dispersed fragments, which is the unetched area. The second step is to perform plasma deposition treatment on the nylon fabric with a fluorocarbon gas (C4F8), a vacuum of 10 Pa, a power of 110 W, a time of 40 s, and a temperature below 80 °C. This forms a hydrophobic protective layer on the surface of the unetched area of ​​the nylon fabric.

[0035] The functional nylon fabric loaded with photocatalyst prepared by the above method has a surface with dispersed hydrophilic and hydrophobic regions. The hydrophilic region accounts for 15% of the area and has a water contact angle of 46°. The hydrophobic region accounts for 85% of the area and has a water contact angle of 153°.

[0036] The functional nylon fabric with photocatalyst loading obtained in this embodiment was tested for antibacterial rate, VOC degradation rate, oil removal rate, and anti-pilling grade. The test results are as follows: When nylon fabrics are unwashed, the inhibition rate of Escherichia coli reaches 98.7%, and after 12 hours of visible light irradiation, the degradation rate of toluene vapor (initial concentration of 10 ppm) reaches 91.2%. After 30 standard household washes, nylon fabrics showed a 91.5% inhibition rate against E. coli. After five standard household washes, the oil stain removal rate of nylon fabrics was 97.5%. Anti-pilling level: 4~5.

[0037] Example 3 This embodiment provides a photocatalytically functionalized nylon fabric, the preparation process of which is as follows: (1) 2g of CQDs / TiO2 composite photocatalyst nanomaterial (the mass ratio of carbon quantum dots to nano titanium dioxide is 1:10) is dispersed in 150g of composite emulsion (the dry weight ratio of amide-modified waterborne polyurethane, polyvinyl alcohol and polyvinylpyrrolidone is 8:1:0.1, and the solid content of amide-modified waterborne polyurethane is 40wt%), and stirred evenly to obtain composite photocatalyst slurry; (2) Place the composite photocatalyst sizing solution obtained in step (1) into the sizing tank, pass the nylon FDY filament through the sizing tank, sizing at 45°C with a roll-off rate of 80% and a sizing rate of 12%, and then dry and cure in a hot air oven at 100°C to obtain nylon sizing yarn with a composite photocatalyst sizing film. (3) The nylon sizing yarn obtained in step (2) is woven into a plain weave fabric on a water jet loom to obtain a nylon fabric with a composite photocatalytic sizing film. (4) The nylon fabric obtained in step (3) is placed in a weakly alkaline oxidative desizing solution (a mixed solution of hydrogen peroxide and sodium hydroxide) with pH 9 for desizing treatment for 30 minutes, and mechanical stirring is added. Then, it is washed with hot water, washed with cold water, and dried to obtain the nylon fabric loaded with photocatalytic film layer. (5) The nylon fabric obtained in step (4) is subjected to two-step plasma treatment. The first step is to pre-treat the nylon fabric with plasma in the atmosphere of nitrogen, a vacuum of 40 Pa, a power of 100 W, a time of 50 s, and a temperature below 80 °C. This decomposes and etches the continuous film layer on the surface of the nylon fabric, exposing part of the nylon fabric. At the same time, amino active sites are generated on the surface of the exposed nylon fabric, forming a hydrophilic region. The remaining unexposed area is wrapped by dispersed fragments, which is the unetched area. The second step is to perform plasma deposition treatment on the nylon fabric with a fluorocarbon gas (C4F8), a vacuum of 30 Pa, a power of 145 W, a time of 20 s, and a temperature below 80 °C. This forms a hydrophobic protective layer on the surface of the unetched area of ​​the nylon fabric.

[0038] The functional nylon fabric loaded with photocatalyst prepared by the above method has a surface with dispersed hydrophilic and hydrophobic regions. The hydrophilic region accounts for 16% of the area and has a water contact angle of 48°. The hydrophobic region accounts for 84% of the area and has a water contact angle of 161°.

[0039] The functional nylon fabric with photocatalyst loading obtained in this embodiment was tested for antibacterial rate, VOC degradation rate, oil removal rate, and anti-pilling grade. The test results are as follows: When nylon fabrics are unwashed, the inhibition rate of Escherichia coli reaches 99.8%, and after 12 hours of visible light irradiation, the degradation rate of toluene vapor (initial concentration of 10 ppm) reaches 91.3%. After 30 standard household washes, nylon fabrics showed a 92.8% inhibition rate against E. coli. After five standard household washes, the oil stain removal rate of nylon fabrics was 98.2%. Anti-pilling level: 4~5.

[0040] Comparative Example 1 This comparative example provides a photocatalytically functionalized nylon fabric, the preparation process of which is as follows: (1) 2g of CQDs / TiO2 composite photocatalyst nanomaterial (the mass ratio of carbon quantum dots to nano titanium dioxide is 1:15) is dispersed in 150g of composite emulsion (the dry weight ratio of polyacrylate, polyvinyl alcohol and polyvinylpyrrolidone is 5:1:0.04), and stirred evenly to obtain composite photocatalyst slurry. (2) Place the composite photocatalyst sizing solution obtained in step (1) into the sizing tank, pass the nylon FDY filament through the sizing tank, sizing at 50°C with a roll-off rate of 80% and a sizing rate of 10%, and then dry and cure in a hot air oven at 110°C to obtain nylon sizing yarn with a composite photocatalyst sizing film. (3) The nylon sizing yarn obtained in step (2) is woven into a plain weave fabric on a water jet loom to obtain a nylon fabric with a composite photocatalytic sizing film. (4) The nylon fabric obtained in step (3) is placed in hot water at 90°C for desizing treatment for 30 minutes, and mechanical stirring is added. Then, it is washed with hot water, washed with cold water, and dried to obtain the nylon fabric loaded with photocatalytic film layer.

[0041] The surface of the finished functional nylon fabric loaded with photocatalyst prepared by the above method is basically covered with a continuous polyacrylate film layer. The film layer encapsulates photocatalyst nanomaterials. In the polyacrylate film layer, the polyacrylate film covers part of the fiber surface, increasing hydrophobicity. However, the PVA and PVP that were not completely removed during desizing, as well as the hydroxyl groups on the nylon surface, are still exposed, so that the surface maintains hydrophilic properties, making the fabric generally neutral to slightly hydrophilic. The water contact angle of the fabric surface is 68°.

[0042] The antibacterial rate, VOC degradation rate, oil removal rate, and anti-pilling grade of the functional nylon fabric with photocatalyst loading obtained in this comparative example were tested. The test results are as follows: When nylon fabrics are unwashed, the inhibition rate against Escherichia coli reaches 96.1%, and after 12 hours of exposure to visible light, the degradation rate of toluene vapor (initial concentration of 10 ppm) reaches 77.2%. After 30 standard household washes, nylon fabrics showed a 78.8% inhibition rate against E. coli. After five standard household washes, the oil stain removal rate of nylon fabric was 43.7%. Anti-pilling level: 3~4.

[0043] Comparative Example 2 This comparative example provides a photocatalytically functionalized nylon fabric, the preparation process of which is as follows: (1) 2g of CQDs / TiO2 composite photocatalyst nanomaterial (the mass ratio of carbon quantum dots to nano titanium dioxide is 1:15) is dispersed in 150g of composite emulsion (the dry weight ratio of polyacrylate, polyvinyl alcohol and polyvinylpyrrolidone is 5:1:0.04), and stirred evenly to obtain composite photocatalyst slurry. (2) Place the composite photocatalyst sizing solution obtained in step (1) into the sizing tank, pass the nylon FDY filament through the sizing tank, sizing at 50°C with a roll-off rate of 80% and a sizing rate of 10%, and then dry and cure in a hot air oven at 110°C to obtain nylon sizing yarn with a composite photocatalyst sizing film. (3) The nylon sizing yarn obtained in step (2) is woven into a plain weave fabric on a water jet loom to obtain a nylon fabric with a composite photocatalytic sizing film. (4) The nylon fabric obtained in step (3) is placed in hot water at 90°C for desizing treatment for 30 minutes, and mechanical stirring is added. Then, it is washed with hot water, washed with cold water, and dried to obtain the nylon fabric loaded with photocatalytic film layer. (5) The nylon fabric obtained in step (4) is subjected to a one-step plasma treatment, that is, the nylon fabric is subjected to plasma pretreatment. The gas atmosphere is nitrogen, the vacuum degree is 20Pa, the power is 80W, the time is 60s, and the temperature is below 80℃. The continuous film layer on the surface of the nylon fabric is decomposed and etched, exposing part of the nylon fabric. At the same time, amino active sites are generated on the surface of the exposed nylon fabric, that is, hydrophilic regions are formed. The polyacrylate film layer forms a dispersed fragment structure and is in a neutral to hydrophobic state.

[0044] The surface of the functional nylon fabric loaded with photocatalyst prepared by the above method has dispersed hydrophilic and weakly hydrophobic regions. The hydrophilic region accounts for 17% of the area and has a water contact angle of 46°; the weakly hydrophobic region accounts for 83% and has a water contact angle of 75°.

[0045] The antibacterial rate, VOC degradation rate, oil removal rate, and anti-pilling grade of the functional nylon fabric with photocatalyst loading obtained in this comparative example were tested. The test results are as follows: When nylon fabrics are unwashed, the inhibition rate against Escherichia coli reaches 97.6%, and after 12 hours of exposure to visible light, the degradation rate of toluene vapor (initial concentration of 10 ppm) reaches 86.4%. After 30 standard household washes, nylon fabrics showed an E. coli inhibition rate of 86.7%. After five standard household washes, the oil stain removal rate of nylon fabric was 56.2%. Anti-pilling rating: Level 4.

[0046] By comparing the nylon fabrics obtained in Examples 1-3 and Comparative Examples 1 and 2 above in terms of water contact angle, antibacterial rate, VOC gas degradation rate, oil stain removal rate, and anti-pilling grade, it can be found that: After two-step plasma treatment, the nylon fabrics in Examples 1-3 have dispersed hydrophilic and hydrophobic regions on their surface, exhibiting high VOC degradation efficiency and antibacterial rate. At the same time, the hydrophobic regions not only make it difficult for pollutants to adhere, giving the nylon fabric its own anti-fouling ability, but the fluorocarbon layer deposited in the hydrophobic regions can also reduce the peeling off of unetched fragments during friction, retaining photocatalytic nanomaterials as much as possible, and ensuring that it still has high VOC degradation efficiency and antibacterial rate after multiple washes. In Comparative Example 1, without plasma treatment, the nylon fabric was generally in a neutral to slightly hydrophilic state. Before washing, its VOC degradation efficiency and antibacterial rate were slightly low. After multiple washes, the antibacterial rate was significantly reduced, indicating that the surface film layer was partially detached during the washing process. In addition, its stain resistance was poor. Comparative Example 2 only underwent one plasma treatment. The nylon fabric was generally in a neutral to slightly hydrophobic state. Although it had high VOC gas degradation efficiency and antibacterial rate before washing, the antibacterial rate decreased significantly after multiple washes, indicating that the surface film layer was partially detached during the washing process. In addition, its stain resistance was also poor.

[0047] It should be noted that any parts not mentioned in this invention can be achieved by using or referencing existing technologies.

[0048] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for preparing photocatalytic functionalized nylon fabric, characterized in that, Including the following steps: (1) Photocatalytic nanomaterials were prepared by mixing carbon quantum dots with nano-titanium dioxide, and the photocatalytic nanomaterials were mixed with composite emulsion to obtain composite photocatalytic slurry; (2) The composite photocatalyst sizing solution obtained in step (1) is applied to nylon yarn by padding or single yarn sizing and then dried and cured to obtain nylon sizing yarn with composite photocatalyst sizing film. (3) The nylon sizing yarn obtained in step (2) is woven to obtain a nylon fabric with a composite photocatalytic sizing film; (4) The nylon fabric obtained in step (3) is desized, washed and dried to obtain the nylon fabric loaded with photocatalytic film layer. (5) The nylon fabric obtained in step (4) is subjected to plasma treatment to expose part of the nylon fabric, and a dispersed hydrophilic and hydrophobic area is formed on the surface of the nylon fabric to obtain the finished functional nylon fabric loaded with photocatalyst.

2. The method for preparing a photocatalytic functionalized nylon fabric according to claim 1, characterized in that, In step (1), the mass ratio of carbon quantum dots to nano-titanium dioxide in the photocatalytic nanomaterial is 1:10~20.

3. The method for preparing a photocatalytically functionalized nylon fabric according to claim 1, characterized in that, The mass percentage of photocatalytic nanomaterials in the composite photocatalytic slurry of step (1) is 1-15%.

4. The method for preparing a photocatalytically functionalized nylon fabric according to claim 1, characterized in that, The composite emulsion in step (1) includes a main binder, an auxiliary binder, and an etching aid, and the dry weight ratio of the main binder, the auxiliary binder, and the etching aid is 3~8:1:0.01~0.

1.

5. The method for preparing a photocatalytically functionalized nylon fabric according to claim 4, characterized in that, The main adhesive is a polyacrylate emulsion and / or an amide-modified waterborne polyurethane emulsion, the auxiliary adhesive is polyvinyl alcohol, and the etching aid is polyvinylpyrrolidone.

6. The method for preparing a photocatalytically functionalized nylon fabric according to claim 1, characterized in that, The sizing process parameters in step (2) are: sizing temperature of 40~60℃ and sizing rate of 6~12%; The drying temperature in step (2) is 100~120℃.

7. The method for preparing a photocatalytically functionalized nylon fabric according to claim 1, characterized in that, In step (4), the desizing treatment uses hot water at 80~95℃ or a weakly alkaline oxidative desizing solution; the weakly alkaline oxidative desizing solution is a mixed solution of hydrogen peroxide and sodium hydroxide with a pH of 8~10.

8. The method for preparing a photocatalytically functionalized nylon fabric according to claim 1, characterized in that, The plasma treatment in step (5) consists of two steps: First, the nylon fabric is pretreated with nitrogen plasma to decompose and etch the continuous film layer on the surface of the nylon fabric, exposing part of the nylon fabric. At the same time, amino active sites are generated on the surface of the exposed nylon fabric, forming a hydrophilic region. Secondly, the nylon fabric is treated with fluorocarbon gas plasma to form a hydrophobic protective layer in the unetched area on the surface of the nylon fabric, thus forming a hydrophobic region.

9. The method for preparing a photocatalytically functionalized nylon fabric according to claim 8, characterized in that, When performing nitrogen plasma pretreatment on nylon fabrics, the power is 50~100W and the time is 40~80s; When treating nylon fabrics with fluorocarbon gas plasma, the power is 100~150W and the time is 20~40s.

10. A photocatalytic functionalized nylon fabric, prepared by the method according to any one of claims 1-9.