A near-infrared light-responsive nanofiber Janus membrane and its preparation method and application

Abstract

The present invention discloses a near-infrared light-responsive nanofiber Janus membrane and a preparation method and application thereof. By introducing amino groups into a carboxylated nanocellulose fiber matrix, and then introducing phenolic hydroxyl groups, a near-infrared light-stimulated responsive nanofiber is prepared, and then using it as a matrix for divinylbenzene free radical polymerization to prepare a super-hydrophobic nanofiber; then the super-hydrophobic nanofiber is exposed to ultraviolet light to obtain a hydrophilic nanofiber; then hydroxymethyl cellulose is copolymerized with N-isopropylacrylamide to obtain a nanofiber with temperature phase transition performance; finally, a partition is used to block the mold into four compartments, which are regions Ⅰ, Ⅱ, Ⅲ, and Ⅳ, respectively, and the prepared materials are poured into the molds respectively, and the membranes are filtered to prepare near-infrared light-responsive nanofiber Janus membranes. The material has excellent near-infrared light intelligent switching hydrophilicity and pus self-removal performance, and can be used for healing of diabetic ulcer wounds.

Description

Technical Field

[0001] The invention belongs to the technical field of biomass fiber modification, and specifically relates to a near-infrared light responsive nanofiber Janus membrane and a preparation method and application thereof. Background Art

[0002] Diabetic ulcer wounds are often accompanied by tissue edema and a large amount of exudate, which will compress the local blood vessels and lymphatic system of the wound and have an adverse effect on wound healing. Therefore, improving wound drainage is of great significance for the treatment of diabetic ulcers. However, the traditional strong hydrophilic wound edema gauze has limited ability to absorb fluid and is easy to stick to the wound and cause secondary damage; hydrophobic dressings are difficult to quickly absorb exudate due to their hydrophobicity, so negative pressure wound therapy (NPWT) technology is often required for treatment, which may cause secondary problems such as pain and wound tearing. The Janus membrane composed of hydrophilic and hydrophobic membranes can be assembled into a self-pumping dressing due to its wetting gradient force and spontaneous unidirectional water transport function, which can transport excess biological fluids from its hydrophobic side to prevent biological fluids from wetting the wound. The chemical gradient of the Janus membrane plays a vital role in driving fluid transport to overcome the surface contact angle hysteresis in the bulk collection process, significantly enhancing fluid absorption and may lead to rapid and autonomous removal of exudate from the wound. However, the excess wound pus still has a large number of untapped bioactive molecules, so there is still a need to design bidirectional fluid transport properties to allow some drugs and bioactive molecules to flow back while transporting a large amount of fluid from the wound to the Janus membrane. Summary of the invention

[0003] The purpose of the present invention is to provide a near-infrared light responsive nanofiber Janus membrane and a preparation method and application thereof. The material has clear hydrophobic and hydrophilic regions, and the hydrophobic region has super hydrophobic properties, and the hydrophilic region has super hydrophilic properties; it also has excellent near-infrared light stimulation response performance and intelligent hydrophilicity and hydrophobicity adjustment characteristics, and is used for self-clearing of wound pus, while allowing some drugs to flow back.

[0004] The above-mentioned purpose of the present invention is achieved by the following technical solutions:

[0005] A near-infrared light-responsive nanofiber Janus membrane is divided into four adjacent connected regions, wherein the upper left side is region I, the upper right side is region II, the lower left side is region III, and the lower right side is region IV, region I is composed of hydrophilic nanofibers, regions III and IV are both composed of super-hydrophobic nanofibers, and region II is composed of nanofibers with temperature phase transition performance;

[0006] The preparation of the super-hydrophobic nanofiber comprises: using carboxylated nanocellulose fibers as a matrix, grafting polyethyleneimine on the surface of the carboxylated nanocellulose fibers through an amidation reaction to prepare amino-modified nanocellulose fibers, and then using the amino groups of the nanocellulose fibers to react with the carboxyl groups of 3,4-dihydroxybenzoic acid to introduce phenolic hydroxyl groups to prepare near-infrared light stimulus responsive nanofibers; using the near-infrared light stimulus responsive nanofibers as a matrix, free radical polymerizing divinylbenzene on the near-infrared light stimulus responsive nanofibers to in-situ synthesize polydivinylbenzene with super-hydrophobic properties to prepare super-hydrophobic nanofibers;

[0007] The preparation of the hydrophilic nanofibers comprises: exposing super-hydrophobic nanofibers to ultraviolet light to obtain hydrophilic nanofibers;

[0008] The preparation of the nanofiber with temperature phase transition performance comprises: copolymerizing hydroxymethyl cellulose and N-isopropyl acrylamide to prepare the nanofiber with temperature phase transition performance.

[0009] Furthermore, the preparation of the super-hydrophobic nanofibers is mainly performed as follows: deionized water is added to the carboxylated nanocellulose fibers, ultrasonically dispersed to make them uniform, and then 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are added in sequence, and then polyethyleneimine is added, mixed evenly, and stirred at room temperature for reaction, after the reaction is completed, the product is centrifuged, the supernatant is poured out, and the precipitate is repeatedly washed with deionized water until the washing liquid is neutral, and the resulting product is amino-modified nanocellulose fibers; the obtained amino-modified nanocellulose fibers are mixed with water, ultrasonically dispersed to make them uniform, and then 3,4-dihydroxybenzoic acid is added, and then 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are added in sequence, mixed evenly, and stirred at room temperature for reaction, after the reaction is completed, the product is centrifuged, the supernatant is removed .... until the washing liquid is neutral, the obtained product is a near-infrared light stimulus responsive nanofiber, which can be heated to 42-50°C under irradiation of 980nm near-infrared light; the mass ratio of the carboxylated nanocellulose fiber, polyethyleneimine, and 3,4-dihydroxybenzoic acid is 1:2:1; deionized water is added to the obtained near-infrared light stimulus responsive nanofiber, and ultrasonic dispersion is performed to make it uniform, a solution containing divinylbenzene is added to the near-infrared light stimulus responsive nanofiber dispersion, 2,2-azobisisobutyronitrile is added as a free radical initiator, and the mixture is stirred at 30-50°C for 3-5h, and then the mixture is heat-treated at 100-150°C for 48-72h, the product is centrifuged, the supernatant is poured out, and the precipitate is repeatedly washed with deionized water until the washing liquid is neutral, and the obtained product is a superhydrophobic nanofiber; the mass ratio of the near-infrared light stimulus responsive nanofiber to divinylbenzene is 1:2.5-20.

[0010] Furthermore, the preparation of the hydrophilic nanofibers mainly involves placing the obtained super-hydrophobic nanofibers in an ultraviolet ray atmosphere with a wavelength of 360 nm for 0.5 to 5 hours to prepare the hydrophilic nanofibers in situ.

[0011] Furthermore, the preparation of the nanofiber with temperature phase transition performance mainly comprises the following steps: adding deionized water to hydroxymethyl cellulose, dissolving for 24 to 48 hours, then adding N-isopropyl acrylamide, and subsequently adding potassium persulfate, the reaction temperature is 45 to 55°C, the stirring rate is 400 to 600 rpm, and stirring is performed for 1 to 4 hours under a nitrogen atmosphere, the reaction mixture is dialyzed in water, and dried to obtain the nanofiber with temperature phase transition performance; the mass ratio of the hydroxymethyl cellulose to the N-isopropyl acrylamide is 1:1 to 2.

[0012] Furthermore, the preparation of the near-infrared light responsive nanofiber Janus membrane mainly comprises the following steps: using a partition to separate the mold into four compartments, namely, the upper left side is region I, the upper right side is region II, the lower left side is region III, and the lower right side is region IV; the prepared superhydrophobic nanofiber is poured into region III and region IV of the mold, filtered and dried to form a film; the prepared hydrophilic nanofiber is poured into region I of the mold, filtered and dried to form a film, and the prepared nanofiber with temperature phase transition performance is poured into region II of the mold, filtered and dried to form a film; when each region is dried to a state of not being completely dried, the partition is removed, and the regions are combined together and dried to a state of being completely dried, hydrogen bonds, van der Waals forces, and electrostatic interactions are formed between adjacent regions to form a close fit together, thereby obtaining a near-infrared light responsive nanofiber Janus membrane.

[0013] Application of the near-infrared light responsive nanofiber Janus membrane of the present invention in self-clearing of pus from wounds: the near-infrared light responsive nanofiber Janus membrane is placed in a diabetic ulcer wound to achieve rapid removal of pus from the diabetic ulcer wound, and each gram of the near-infrared light responsive nanofiber Janus membrane can collect 3.2 to 4.2 g of pus, and after the collection is completed, near-infrared light is applied externally to close the self-clearing channels of pus in regions II and IV of the near-infrared light responsive nanofiber Janus membrane, and the pus enriched in region IV and refluxed due to gravity can be collected up to 0.7 to 3.3 g, with a reflux rate of 17.9 to 24.4%.

[0014] The present invention has the following beneficial effects:

[0015] (1) The near-infrared light-responsive nanofiber Janus membrane prepared by the present invention has clear hydrophobic and hydrophilic regions, and the hydrophobic region has super hydrophobic properties, and the hydrophilic region has super hydrophilic properties. The difference between super hydrophobicity and hydrophilicity can enhance the chemical gradient characteristics of the Janus membrane and further enhance its application in self-clearing of wound pus.

[0016] (2) The present invention cleverly integrates a near-infrared switch into the material to control the hydrophilic and hydrophobic properties of the material. While the material can maintain the self-clearing property of the Janus membrane, it can also give the material the ability to turn off the self-clearing property of the pus at any time, so that the wound to which it is applied will not be hindered from healing due to excessive moisture or dryness. At the same time, it can also reflux the loaded active molecular drugs to avoid the problem of excessive loss. In addition, the use of near-infrared light as a switch also avoids time and space limitations.

[0017] (3) In the near-infrared response performance of the near-infrared light stimulus responsive nanofiber of the present invention, the regulation of the degree of amino reaction of polyethyleneimine is the key, and the regulated addition ratio of 3,4-dihydroxybenzoic acid is an important means to achieve effective regulation of near-infrared photothermal performance, and the temperature stage of its heating temperature response can reach 42 to 50°C. Therefore, a lot of experimental exploration is needed to achieve controllable synthesis. The regulation of the lower critical solution temperature (LCST) of the nanofiber with temperature phase transition performance of the present invention, the regulation of the degree of copolymerization of hydroxymethyl cellulose and N-isopropyl acrylamide is the key, and the regulated addition ratio of hydroxymethyl cellulose and N-isopropyl acrylamide is an important means, so a lot of experimental exploration is needed to achieve controllable synthesis. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of a near-infrared light-responsive nanofiber Janus membrane of the present invention.

[0019] Explanation of the reference numerals: 1 - region I, 2 - region II, 3 - region III, 4 - region IV. DETAILED DESCRIPTION

[0020] like Figure 1 As shown, a near-infrared light responsive nanofiber Janus membrane of the present invention is divided into four adjacent connected regions, wherein the upper left side is region Ⅰ1, the upper right side is region Ⅱ2, the lower left side is region Ⅲ3, and the lower right side is region Ⅳ4, region Ⅰ1 is composed of hydrophilic nanofibers, region Ⅲ3 and region Ⅳ4 are both composed of superhydrophobic nanofibers, and region Ⅱ2 is composed of nanofibers with temperature phase transition properties.

[0021] Example 1

[0022] The preparation method of a near-infrared light-responsive nanofiber Janus membrane of the present invention is as follows:

[0023] S1. Preparation of near-infrared light stimulus responsive nanofibers: deionized water was added to 1.0 g of carboxylated nanocellulose fibers, and the fibers were dispersed evenly by ultrasound. Then, 1.0 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 1.0 g of N-hydroxysuccinimide were added in sequence, and then 2.0 g of polyethyleneimine was added. After mixing evenly, the mixture was stirred at room temperature for reaction. After the reaction was completed, the product was centrifuged, the supernatant was poured out, and the precipitate was repeatedly washed with deionized water until the washing liquid was neutral. The obtained product was amino-modified nanocellulose fibers. The amino-modified nanocellulose fibers are mixed with water and dispersed evenly by ultrasound. Then, 1.0 g of 3,4-dihydroxybenzoic acid is added, and then 1.0 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 1.0 g of N-hydroxysuccinimide are added in sequence. After mixing evenly, the mixture is stirred at room temperature for reaction. After the reaction is completed, the product is centrifuged, the supernatant is removed, and the precipitate is repeatedly washed with deionized water until the washing liquid is neutral. The obtained product is near-infrared light stimulus responsive nanofibers, which can be heated to 42°C under 980 nm near-infrared light irradiation.

[0024] S2. Preparation of superhydrophobic nanofibers: add 50 mL of deionized water to 0.1 g of the obtained near-infrared light stimulus responsive nanofibers, and disperse them evenly by ultrasound. Add 80 mL of a solution containing 2.0 g of divinylbenzene to the near-infrared light stimulus responsive nanofiber dispersion, add 80 mL of 2,2-azobisisobutyronitrile as a free radical initiator, stir at 30°C for 3 h, and then heat-treat the mixture at 100°C for 48 h. Centrifuge the product, pour out the supernatant, and repeatedly wash the precipitate with deionized water until the washing liquid is neutral. The resulting product is superhydrophobic nanofibers.

[0025] S3. Preparation of hydrophilic nanofibers: The obtained super-hydrophobic nanofibers were placed in an ultraviolet light atmosphere with a wavelength of 360 nm for 0.5 h to obtain hydrophilic nanofibers in situ.

[0026] S4. Preparation of nanofibers with temperature phase transition properties: Add 50 mL of deionized water to 0.1 g of hydroxymethyl cellulose and dissolve it for 24 hours. Then add 0.1 g of N-isopropylacrylamide, followed by 0.01 g of potassium persulfate. The reaction temperature is 45°C, the stirring rate is 400 rpm, and the mixture is stirred for 1 hour under a nitrogen atmosphere. The reaction mixture is dialyzed in water and dried to obtain nanofibers with temperature phase transition properties.

[0027] S5. Preparation of near-infrared light responsive nanofiber Janus membrane: Use partitions to separate the mold into four compartments, upper, lower, left and right, with the upper left side being region I, the upper right side being region II, the lower left side being region III, and the lower right side being region IV; pour the prepared superhydrophobic nanofibers into regions III and IV of the mold, filter and dry to form a membrane; pour the prepared hydrophilic nanofibers into region I of the mold, filter and dry to form a membrane; pour the prepared nanofibers with temperature phase transition properties into region II of the mold, filter and dry to form a membrane; when each region is dried to a state of not being completely dry, remove the partitions, combine them together and dry them to a state of being completely dry; hydrogen bonds, van der Waals forces, and electrostatic interactions are formed between adjacent regions to form a close fit together to obtain a near-infrared light responsive nanofiber Janus membrane.

[0028] The near-infrared light responsive nanofiber Janus membrane (1.0 g) prepared in Example 1 was placed in a diabetic ulcer wound to collect pus from the diabetic ulcer wound. The materials before and after collection were weighed, and the collected pus could reach 3.2 g. After the collection was completed, near-infrared light was applied externally to close the self-clearing channels of the pus in regions II and IV of the near-infrared light responsive nanofiber Janus membrane. The pus enriched in region IV and refluxed due to gravity could reach 0.7 g, and the reflux rate was 17.9%.

[0029] Example 2

[0030] The preparation method of a near-infrared light-responsive nanofiber Janus membrane of the present invention is as follows:

[0031] S1. Preparation of near-infrared light stimulus responsive nanofibers: deionized water was added to 2.0 g of carboxylated nanocellulose fibers, and the fibers were dispersed evenly by ultrasound. Then, 2.0 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 2.0 g of N-hydroxysuccinimide were added in sequence, and then 4.0 g of polyethyleneimine was added. After mixing evenly, the mixture was stirred at room temperature for reaction. After the reaction was completed, the product was centrifuged, the supernatant was poured out, and the precipitate was repeatedly washed with deionized water until the washing liquid was neutral. The obtained product was amino-modified nanocellulose fibers. The amino-modified nanocellulose fibers are mixed with water and dispersed evenly by ultrasound. Then, 2.0 g of 3,4-dihydroxybenzoic acid is added, and then 2.0 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 2.0 g of N-hydroxysuccinimide are added in sequence. After mixing evenly, the mixture is stirred at room temperature for reaction. After the reaction is completed, the product is centrifuged, the supernatant is removed, and the precipitate is repeatedly washed with deionized water until the washing liquid is neutral. The obtained product is near-infrared light stimulus responsive nanofibers, which can be heated to 48°C under 980 nm near-infrared light irradiation.

[0032] S2. Preparation of superhydrophobic nanofibers: add 250 mL of deionized water to 1.0 g of the obtained near-infrared light stimulus responsive nanofibers, and disperse them evenly by ultrasound. Add 100 mL of a solution containing 3.5 g of divinylbenzene to the near-infrared light stimulus responsive nanofiber dispersion, add 120 mL of 2,2-azobisisobutyronitrile as a free radical initiator, stir at 40°C for 4 h, and then heat-treat the mixture at 125°C for 60 h. Centrifuge the product, pour out the supernatant, and repeatedly wash the precipitate with deionized water until the washing liquid is neutral. The resulting product is superhydrophobic nanofibers.

[0033] S3. Preparation of hydrophilic nanofibers: The obtained super-hydrophobic nanofibers were placed in an ultraviolet light atmosphere with a wavelength of 360 nm for 2.5 h to obtain hydrophilic nanofibers in situ.

[0034] S4. Preparation of nanofibers with temperature phase transition properties: Add 250 mL of deionized water to 1.0 g of hydroxymethyl cellulose and dissolve it for 36 hours. Then add 1.5 g of N-isopropylacrylamide, followed by 0.05 g of potassium persulfate. The reaction temperature is 50°C, the stirring rate is 500 rpm, and the mixture is stirred for 3 hours under a nitrogen atmosphere. The reaction mixture is dialyzed in water and dried to obtain nanofibers with temperature phase transition properties.

[0035] S5. Preparation of near-infrared light responsive nanofiber Janus membrane: Use partitions to separate the mold into four compartments, upper, lower, left and right, with the upper left side being region I, the upper right side being region II, the lower left side being region III, and the lower right side being region IV; pour the prepared superhydrophobic nanofibers into regions III and IV of the mold, filter and dry to form a membrane; pour the prepared hydrophilic nanofibers into region I of the mold, filter and dry to form a membrane; pour the prepared nanofibers with temperature phase transition properties into region II of the mold, filter and dry to form a membrane; when each region is dried to a state of not being completely dry, remove the partitions, combine them together and dry them to a state of being completely dry; hydrogen bonds, van der Waals forces, and electrostatic interactions are formed between adjacent regions to form a close fit together to obtain a near-infrared light responsive nanofiber Janus membrane.

[0036] The near-infrared light responsive nanofiber Janus membrane (2.0 g) prepared in Example 2 was placed in a diabetic ulcer wound to collect pus from the diabetic ulcer wound. The materials before and after collection were weighed, and the collected pus could reach 8.4 g. After the collection was completed, near-infrared light was applied externally to close the self-clearing channels of the pus in regions II and IV of the near-infrared light responsive nanofiber Janus membrane. The pus enriched in region IV and refluxed due to gravity could reach 1.9 g, and the reflux rate was 18.4%.

[0037] Example 3

[0038] The preparation method of a near-infrared light-responsive nanofiber Janus membrane of the present invention is as follows:

[0039] S1. Preparation of near-infrared light stimulus responsive nanofibers: deionized water was added to 5.0 g of carboxylated nanocellulose fibers, and the fibers were dispersed evenly by ultrasound. Then, 5.0 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 5.0 g of N-hydroxysuccinimide were added in sequence, and then 10.0 g of polyethyleneimine was added. After mixing evenly, the mixture was stirred at room temperature for reaction. After the reaction was completed, the product was centrifuged, the supernatant was poured out, and the precipitate was repeatedly washed with deionized water until the washing liquid was neutral. The obtained product was amino-modified nanocellulose fibers. The amino-modified nanocellulose fibers are mixed with water and dispersed evenly by ultrasound. Then, 5.0 g of 3,4-dihydroxybenzoic acid is added, and then 5.0 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 5.0 g of N-hydroxysuccinimide are added in sequence. After mixing evenly, the mixture is stirred at room temperature for reaction. After the reaction is completed, the product is centrifuged, the supernatant is removed, and the precipitate is repeatedly washed with deionized water until the washing liquid is neutral. The obtained product is near-infrared light stimulus responsive nanofibers, which can be heated to 50°C under 980 nm near-infrared light irradiation.

[0040] S2. Preparation of superhydrophobic nanofibers: add 500 mL of deionized water to 2.0 g of the obtained near-infrared light stimulus responsive nanofibers, and disperse them evenly by ultrasound. Add 150 mL of a solution containing 5.0 g of divinylbenzene to the near-infrared light stimulus responsive nanofiber dispersion, add 150 mL of 2,2-azobisisobutyronitrile as a free radical initiator, stir at 50°C for 5 h, and then heat-treat the mixture at 150°C for 72 h. Centrifuge the product, pour out the supernatant, and repeatedly wash the precipitate with deionized water until the washing liquid is neutral. The resulting product is superhydrophobic nanofibers.

[0041] S3. Preparation of hydrophilic nanofibers: The obtained super-hydrophobic nanofibers were placed in an ultraviolet light atmosphere with a wavelength of 360 nm for 5 hours to obtain hydrophilic nanofibers in situ.

[0042] S4. Preparation of nanofibers with temperature phase transition properties: Add 500 mL of deionized water to 2.0 g of hydroxymethyl cellulose and dissolve it for 48 hours. Then add 4.0 g of N-isopropylacrylamide, followed by 0.1 g of potassium persulfate. The reaction temperature is 55°C, the stirring rate is 600 rpm, and the mixture is stirred for 4 hours under a nitrogen atmosphere. The reaction mixture is dialyzed in water and dried to obtain nanofibers with temperature phase transition properties.

[0043] S5. Preparation of near-infrared light responsive nanofiber Janus membrane: Use partitions to separate the mold into four compartments, upper, lower, left and right, with the upper left side being region I, the upper right side being region II, the lower left side being region III, and the lower right side being region IV; pour the prepared superhydrophobic nanofibers into regions III and IV of the mold, filter and dry to form a membrane; pour the prepared hydrophilic nanofibers into region I of the mold, filter and dry to form a membrane; pour the prepared nanofibers with temperature phase transition properties into region II of the mold, filter and dry to form a membrane; when each region is dried to a state of not being completely dry, remove the partitions, combine them together and dry them to a state of being completely dry; hydrogen bonds, van der Waals forces, and electrostatic interactions are formed between adjacent regions to form a close fit together to obtain a near-infrared light responsive nanofiber Janus membrane.

[0044] The near-infrared light responsive nanofiber Janus membrane (3.0 g) prepared in Example 3 was placed in a diabetic ulcer wound to collect pus from the diabetic ulcer wound. The materials before and after collection were weighed, and the collected pus could reach 10.2 g. After the collection was completed, near-infrared light was applied externally to close the self-clearing channels of the pus in regions II and IV of the near-infrared light responsive nanofiber Janus membrane. The pus enriched in region IV and refluxed due to gravity could reach 3.3 g, and the reflux rate was 24.4%.

Claims

1. A near-infrared light-responsive nanofiber Janus membrane, characterized in that: It is divided into four adjacent connected areas, where the upper left side is area I, the upper right side is area II, the lower left side is area III, and the lower right side is area IV. Area I is composed of hydrophilic nanofibers, areas III and IV are both composed of super-hydrophobic nanofibers, and area II is composed of nanofibers with temperature phase transition properties. The preparation of the super-hydrophobic nanofiber comprises: using carboxylated nanocellulose fibers as a matrix, sequentially adding 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, and then adding polyethyleneimine, grafting polyethyleneimine on the surface of the carboxylated nanocellulose fibers through an amidation reaction, preparing amino-modified nanocellulose fibers, and then using the amino groups of the nanocellulose fibers to react with the carboxyl groups of 3,4-dihydroxybenzoic acid to introduce phenolic hydroxyl groups to prepare near-infrared light stimuli-responsive nanofibers; using the near-infrared light stimuli-responsive nanofibers as a matrix, free radically polymerizing divinylbenzene on the near-infrared light stimuli-responsive nanofibers to in-situ synthesize polydivinylbenzene with super-hydrophobic properties, and preparing the super-hydrophobic nanofibers; The preparation of the hydrophilic nanofibers comprises: exposing super-hydrophobic nanofibers to ultraviolet light to obtain hydrophilic nanofibers; The preparation of the nanofiber with temperature phase transition performance comprises: copolymerizing hydroxymethyl cellulose and N-isopropyl acrylamide to prepare the nanofiber with temperature phase transition performance.

2. The near-infrared light-responsive nanofiber Janus membrane according to claim 1, characterized in that: The preparation of the super-hydrophobic nanofibers is mainly performed as follows: deionized water is added to the carboxylated nanocellulose fibers, ultrasonically dispersed to make them uniform, then 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are added in sequence, and then polyethyleneimine is added, mixed evenly, stirred at room temperature for reaction, and after the reaction is completed, the product is centrifuged, the supernatant is poured out, and the precipitate is repeatedly washed with deionized water until the washing liquid is neutral, and the obtained product is amino-modified nanocellulose fibers; the obtained amino-modified nanocellulose fibers are mixed with water, ultrasonically dispersed to make them uniform, and then 3,4-dihydroxybenzoic acid is added, and then 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are added in sequence, mixed evenly, and stirred at room temperature for reaction, and after the reaction is completed, the product is centrifuged, the supernatant is removed, and the precipitate is repeatedly washed with deionized water until the washing liquid is neutral, and the obtained product is amino-modified nanocellulose fibers; The washing liquid is neutral, and the obtained product is a near-infrared light stimulus responsive nanofiber, which can be heated to 42-50°C under irradiation of 980nm near-infrared light; the mass ratio of the carboxylated nanocellulose fiber, polyethyleneimine, and 3,4-dihydroxybenzoic acid is 1:2:1; deionized water is added to the obtained near-infrared light stimulus responsive nanofiber, and ultrasonic dispersion is performed to make it uniform, a solution containing divinylbenzene is added to the near-infrared light stimulus responsive nanofiber dispersion, 2,2-azobisisobutyronitrile is added as a free radical initiator, and the mixture is stirred at 30-50°C for 3-5h, and then the mixture is heat-treated at 100-150°C for 48-72h, the product is centrifuged, the supernatant is poured out, and the precipitate is repeatedly washed with deionized water until the washing liquid is neutral, and the obtained product is a superhydrophobic nanofiber; the mass ratio of the near-infrared light stimulus responsive nanofiber to divinylbenzene is 1:2.5-20.

3. The near-infrared light-responsive nanofiber Janus membrane according to claim 1, characterized in that: The main operation of preparing the hydrophilic nanofibers is: placing the obtained super-hydrophobic nanofibers in an ultraviolet ray atmosphere with a wavelength of 360 nm for 0.5 to 5 hours to prepare the hydrophilic nanofibers in situ.

4. The near-infrared light-responsive nanofiber Janus membrane according to claim 1, characterized in that: The main operation of preparing the nanofiber with temperature phase transition performance is: adding deionized water to hydroxymethyl cellulose, dissolving for 24 to 48 hours, then adding N-isopropyl acrylamide, and then adding potassium persulfate, the reaction temperature is 45 to 55°C, the stirring rate is 400 to 600 rpm, and stirring is carried out for 1 to 4 hours under a nitrogen atmosphere, the reaction mixture is dialyzed in water, and dried to obtain the nanofiber with temperature phase transition performance; the mass ratio of the hydroxymethyl cellulose to the N-isopropyl acrylamide is 1:1 to 2.

5. The near-infrared light-responsive nanofiber Janus membrane according to claim 1, characterized in that: The preparation of the near-infrared light-responsive nanofiber Janus membrane is mainly performed as follows: a mold is separated into four compartments, upper, lower, left and right, by a partition, with the upper left side being region I, the upper right side being region II, the lower left side being region III, and the lower right side being region IV; the prepared super-hydrophobic nanofiber is poured into regions III and IV of the mold, and filtered and dried to form a membrane; The prepared hydrophilic nanofibers are poured into area I of the mold, filtered and dried to form a film, and the prepared nanofibers with temperature phase change properties are poured into area II of the mold, filtered and dried to form a film. When each area is dried to a state that is not completely dry, the partitions are removed, and the areas are combined together and dried to a state that is completely dry. Hydrogen bonds, van der Waals forces, and electrostatic interactions are formed between adjacent areas to form a close fit together to obtain a near-infrared light responsive nanofiber Janus membrane.

6. An application of the near-infrared light responsive nanofiber Janus membrane according to any one of claims 1 to 5 as a self-clearing dressing for wound pus; each gram of the near-infrared light responsive nanofiber Janus membrane can collect 3.2 to 4.2 g of pus, and after the collection is completed, the near-infrared light is applied externally to close the self-clearing channels of pus in regions II and IV of the near-infrared light responsive nanofiber Janus membrane, and the pus enriched in region IV and refluxed due to gravity can be collected up to 0.7 to 3.3 g, with a reflux rate of 17.9 to 24.4%.

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