A method for preparing a sensing antibacterial coaxial fiber membrane by coaxial electrospinning

Abstract

The invention discloses a method for preparing a sensing antibacterial coaxial fiber membrane by a coaxial electrospinning method, comprising the steps of: dissolving gelatin and ethyl cellulose in a mixed solution of water, ethanol and acetic acid, and completely dissolving to obtain a shell spinning solution; dissolving polyurethane in N, N-dimethylformamide and tetrahydrofuran, and completely dissolving as a core spinning solution; slowly adding Ti3AlC2 to a lithium fluoride / hydrochloric acid mixed solution to react and ultrasonicate to obtain a few-layer MXene; adding MXene and PVP to a copper sulfate solution and stirring, adding HHA solution, continuing stirring, and freeze-drying the product to obtain MXene / Cu2O; adding to the shell spinning solution and stirring evenly; electrostatically spinning the above solution to obtain an electrostatically spun fiber membrane. The method has mild reaction conditions and is easy to operate, and can prepare a gelatin / polyurethane-based fiber membrane with good sensing performance and antibacterial performance, and can make the fiber membrane have moisture absorption, moisture permeability and air permeability.

Description

Technical Field

[0001] The invention belongs to the field of nanofiber and fiber membrane manufacturing, and relates to a process for preparing sensing antibacterial core-shell structure fibers by coaxial electrostatic spinning. Background Art

[0002] Electrospinning is a highly efficient nanofiber manufacturing technique in which a polymer solution or melt is jet-spun in a strong electric field. This method can produce fibers with diameters ranging from a few nanometers to several hundred nanometers by adjusting the spinning voltage and liquid feed rate. It offers the advantages of mild experimental conditions, low cost, and rapid and convenient processing. Electrospun products exhibit high porosity, large specific surface area, diverse composition, and uniform diameter distribution, holding great potential for application in fields such as biomedicine, environmental engineering, and textiles.

[0003] Fiber membranes produced by electrospinning are nonwoven materials, and nonwoven fabrics offer significant advantages over traditional fabrics. Traditional fabrics are constructed by crossing, entangled, and connected yarns, requiring analysis of the yarn composition, direction of yarn movement, and the relationship between yarn movement and formation. Nonwoven fabrics, on the other hand, are a new type of fiber product that can be formed without spinning or weaving. Instead, they simply form a web by aligning or randomly arranging short fibers or filaments. These fabrics offer rapid production, high yield, and low cost.

[0004] Coaxial electrospinning is a modified version of electrospinning. Its basic principle is to inject a core-plasma solution and a chitin solution into two coaxial capillaries of different inner diameters. The two solutions converge at the end of the nozzle and solidify into composite nanofibers under the action of an electric field. Coaxial electrospinning overcomes the limitation of the spinning solution requiring a homogeneous system. The resulting coaxial fibers are superior in uniformity and continuity to fibers obtained by other methods. Coaxial electrospinning can also produce hollow fibers and nanocomposite fibers.

[0005] MXene possesses excellent electrical conductivity (reaching 6500 S / cm) and mechanical properties (Young's modulus approximately 0.33 TPa). During its preparation, it incorporates abundant oxygen- and fluorine-containing functional groups and active sites, enabling it to interact with and stabilize functional groups on various polymer chains. Its incorporation into flexible films enhances their conductivity, promising broad applications in flexible sensing, wearable devices, and other fields. Furthermore, the synergistic antimicrobial effect of Cu2O reduces bacterial growth on fiber membranes, extending their lifespan. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for preparing a sensing antibacterial coaxial fiber membrane by a coaxial electrospinning method, and to apply the method to spandex fabrics to enrich the functionality of traditional polyurethane fabrics.

[0007] To achieve the above object, the technical solution used in the present invention is:

[0008] A method for preparing a sensing antibacterial coaxial fiber membrane by coaxial electrospinning, comprising the following steps:

[0009] Step 1: Preparation of solution A, gelatin-ethyl cellulose solution and solution B, polyurethane solution:

[0010] Water, anhydrous ethanol, and acetic acid were prepared into a solution with a volume ratio of 2:2:6, and then 15-25 wt% of gelatin and ethyl cellulose were dissolved in the solution with a mass ratio of 1:2-2:1. The solution was stirred magnetically at 35°C for 4 hours to obtain a gelatin-ethyl cellulose spinning solution.

[0011] 5-20 wt% of polyurethane was dissolved in a mixed solution of N,N-dimethylformamide and tetrahydrofuran in a volume ratio of 4:1-1:1, and magnetically stirred at 55°C for 4 hours to obtain a polyurethane spinning solution;

[0012] Step 2: Preparation of MXene / Cu2O:

[0013] Lithium fluoride and hydrochloric acid are mixed and stirred, and Ti3AlC2 is slowly added to the lithium fluoride / hydrochloric acid mixed solution and reacted for 24-72 hours. The reaction temperature is controlled at 35-38°C to produce multilayer MXene. The multilayer MXene is washed with ultrapure water and ultrasonically treated with inert gas. After centrifugation, the supernatant is freeze-dried to obtain a few-layer MXene for subsequent use.

[0014] Add 5 mg of few-layer MXene nanosheets and 0.5 g of polyvinylpyrrolidone (PVP) to 10–20 mL of 0.01 mol / L copper sulfate solution and stir. Then, add 10–15 μL of hydrazine hydrate (HHA) solution and continue stirring. The resulting MXene / Cu2O product is freeze-dried before use.

[0015] Step 3: Preparation of coaxial electrospinning fiber membrane:

[0016] 0.5-2.5 wt% MXene / Cu2O was added to the gelatin-ethyl cellulose solution prepared in step 1 and stirred to mix evenly to obtain solution C. Solution C was drawn into a syringe and connected to the coaxial needle shell tube. The syringe containing solution B was then connected to the coaxial needle core tube and connected to the electrospinning device. The voltage between the coaxial needle and the flat receiver was controlled to be 9-15 kV and the distance was 5-15 cm. The propulsion speeds of the core layer spinning solution and the shell layer spinning solution were controlled. Electrospinning was performed at a temperature of 30-35°C and a relative humidity of 30-40% to obtain an electrospun fiber membrane. The fiber membrane was then dried in a vacuum oven for 24 h to obtain a fiber membrane sample.

[0017] In the step 2, the mass ratio of lithium fluoride to Ti3AlC2 is 1.6:1 to 2:1.

[0018] In the step 2, the multilayer MXene solution should be washed with water to a pH of about 6 before ultrasonic treatment. The ultrasonic treatment time is 0.5 to 1 h, and the centrifugal conditions are a speed of 3500 r / min and a time of 15 min.

[0019] In step 3, the stirring time of MXene and copper sulfate solution is not less than 30 min, and the stirring time after adding HHA is not less than 10 min.

[0020] In the step 3, the supply rate of the gelatin-ethyl cellulose solution is 0.00010-0.0060 mm / s, and the supply rate of the polyurethane solution is 0.0010-0.0040 mm / s.

[0021] The present invention has the following advantages and effects:

[0022] The fiber shell obtained by this method is made of ethyl cellulose-modified gelatin, which improves gelatin's water resistance and poor mechanical properties, imparting a certain degree of water resistance and strength. Simultaneously, the polyurethane in the core layer enhances the fiber's strength and elasticity, thereby improving the practicality of hygroscopic fabrics. The electrical conductivity of MXene and its synergistic antibacterial effect with Cu2O not only enrich the fabric's functionality but also reduce bacterial growth, extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a test chart of the antibacterial performance of the sample prepared in Example 1. DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to specific examples. These examples are intended to illustrate the present invention but are not intended to limit its scope. The implementation conditions used in the examples may be further adjusted according to specific experimental circumstances. Numerous variations and modifications may be made without departing from the scope of the present invention. Unspecified implementation conditions are generally those used in routine experiments.

[0025] Example 1

[0026] Step 1:

[0027] Preparation of gelatin-ethyl cellulose solution: Water, anhydrous ethanol and acetic acid were prepared into a solution with a volume ratio of 2:2:6. Then, gelatin and ethyl cellulose were dissolved in the solution with a mass ratio of 2:1. The solution was magnetically stirred at 35°C for 4 h to obtain a 15 wt% gelatin-ethyl cellulose spinning solution (solution A).

[0028] Preparation of polyurethane solution: Polyurethane was dissolved in a mixed solution of N,N-dimethylformamide and tetrahydrofuran with a volume ratio of 4:1, and magnetically stirred at 55°C for 4 h to obtain a 5 wt% polyurethane spinning solution (solution B).

[0029] Step 2:

[0030] Preparation of few-layer MXene: 0.32 g of lithium fluoride was dissolved in 4 mL of 9 mol / L hydrochloric acid and stirred evenly. Then 0.2 g of Ti3AlC2 was slowly added to the lithium fluoride / hydrochloric acid mixed solution and reacted for 24 h. The reaction temperature was controlled at 35 °C to obtain multi-layer MXene. The multi-layer MXene was washed with ultrapure water to a pH of 6 and ultrasonically treated with inert gas. After centrifugation, the supernatant was freeze-dried for subsequent use. The ultrasonic treatment time was 0.5 h, and the centrifugation conditions were a speed of 3500 r / min and a time of 15 min.

[0031] Preparation of MXene / Cu2O: 5 mg of MXene nanosheets and 0.5 g of PVP were added to 10 mL of 0.01 mol / L copper sulfate solution and stirred for 30 min. Then, 10 μL of HHA (hydrazine hydrate) solution was added and stirred for another 10 min. The resulting product was freeze-dried before use.

[0032] Step 3:

[0033] Preparation of coaxial electrospun fiber membranes: 0.5 wt% MXene / Cu2O was added to Solution A prepared in Step 1 and stirred to mix thoroughly to obtain Solution C. Solution C was drawn into a syringe and connected to the shell tube of the coaxial needle. A syringe containing Solution B was then connected to the core tube of the coaxial needle and connected to the electrospinning apparatus. The voltage between the coaxial needle and the flat-plate receiver was controlled at 9 kV and the distance was 5 cm. The feed rates of Solution C and Solution B were controlled at 0.00020 mm / s and 0.00020 mm / s, respectively. Electrospinning was performed at 30°C and 30% relative humidity to obtain electrospun fiber membranes. The fiber membranes were then dried in a vacuum oven for 24 hours to obtain the fiber membrane samples.

[0034] Example 2

[0035] Step 1:

[0036] Preparation of gelatin-ethyl cellulose solution: Water, anhydrous ethanol and acetic acid were prepared into a solution with a volume ratio of 2:2:6. Then, gelatin and ethyl cellulose were dissolved in the solution with a mass ratio of 1:1. The solution was magnetically stirred at 35°C for 4 h to obtain a 20 wt% gelatin-ethyl cellulose spinning solution (solution A).

[0037] Preparation of polyurethane solution: Polyurethane was dissolved in a mixed solution of N,N-dimethylformamide and tetrahydrofuran with a volume ratio of 2:1, and magnetically stirred at 55°C for 4 h to obtain a 15 wt% polyurethane spinning solution (solution B).

[0038] Step 2:

[0039] Preparation of few-layer MXene: 0.36 g lithium fluoride was dissolved in 4 mL 9 mol / L hydrochloric acid and stirred evenly, and then 0.2 g Ti3AlC2 was slowly added to the lithium fluoride / hydrochloric acid mixed solution to react for 24 h. The reaction temperature was controlled at 35 °C to obtain multi-layer MXene; the multi-layer MXene was washed with ultrapure water to a pH of 6, and ultrasonic treatment was performed by passing inert gas. After centrifugation, the supernatant was freeze-dried for subsequent use. The ultrasonic treatment time was 0.5 h, and the centrifugation conditions were a speed of 3500 r / min and a time of 15 min.

[0040] Preparation of MXene / Cu2O: 10 mg of MXene nanosheets and 0.5 g of PVP were added to 15 mL of 0.01 mol / L copper sulfate solution and stirred for 40 min. Then, 12 μL of HHA (hydrazine hydrate) solution was added and stirred for another 10 min. The resulting product was freeze-dried before use.

[0041] Step 3:

[0042] Preparation of coaxial electrospun fiber membranes: 1.5 wt% MXene / Cu2O was added to Solution A prepared in Step 1 and stirred to mix thoroughly to obtain Solution C. Solution C was drawn into a syringe and connected to the shell tube of the coaxial needle. A syringe containing Solution B was then connected to the core tube of the coaxial needle and connected to the electrospinning apparatus. The voltage between the coaxial needle and the flat-plate receiver was controlled at 12 kV and a distance of 10 cm. The feed rates of Solution C and Solution B were controlled at 0.00040 mm / s and 0.00040 mm / s, respectively. Electrospinning was performed at 32°C and 35% relative humidity to obtain electrospun fiber membranes. The membranes were then dried in a vacuum oven for 24 hours to obtain the membrane samples.

[0043] Example 3

[0044] Step 1:

[0045] Preparation of gelatin-ethyl cellulose solution: Water, anhydrous ethanol and acetic acid were prepared into a solution with a volume ratio of 2:2:6. Then, gelatin and ethyl cellulose were dissolved in the solution with a mass ratio of 1:2. The solution was magnetically stirred at 35°C for 4 h to obtain a 25 wt% gelatin-ethyl cellulose spinning solution (solution A).

[0046] Preparation of polyurethane solution: polyurethane was dissolved in a mixed solution of N,N-dimethylformamide and tetrahydrofuran in a volume ratio of 1:1, and magnetically stirred at 55°C for 4 h to obtain a 20 wt% polyurethane spinning solution (solution B).

[0047] Step 2:

[0048] Preparation of few-layer MXene: 0.4 g lithium fluoride was dissolved in 4 mL 9 mol / L hydrochloric acid and stirred evenly, and then 0.2 g Ti3AlC2 was slowly added to the lithium fluoride / hydrochloric acid mixed solution and reacted for 24 h. The reaction temperature was controlled at 35 °C to obtain multi-layer MXene; the multi-layer MXene was washed with ultrapure water to a pH of 6, and ultrasonic treatment was carried out by passing inert gas. After centrifugation, the supernatant was freeze-dried for subsequent use. The ultrasonic treatment time was 0.5 h, and the centrifugation conditions were a speed of 3500 r / min and a time of 15 min.

[0049] Preparation of MXene / Cu2O: 5 mg of MXene nanosheets and 1 g of PVP were added to 20 mL of 0.01 mol / L copper sulfate solution and stirred for 1 h. Then, 15 μL of HHA (hydrazine hydrate) solution was added and stirring continued for 10 min. The resulting product was freeze-dried before use.

[0050] Step 3:

[0051] Preparation of coaxial electrospun fiber membranes: 2.5 wt% MXene / Cu2O was added to Solution A prepared in Step 1 and stirred to mix thoroughly to obtain Solution C. Solution C was drawn into a syringe and connected to the shell tube of the coaxial needle. A syringe containing Solution B was then connected to the core tube of the coaxial needle and connected to the electrospinning apparatus. The voltage between the coaxial needle and the flat-plate receiver was controlled at 15 kV and the distance was 15 cm. The feed rates of Solution C and Solution B were controlled at 0.00060 mm / s and 0.00030 mm / s, respectively. Electrospinning was performed at 35°C and 40% relative humidity to obtain electrospun fiber membranes. The fiber membranes were then dried in a vacuum oven for 24 hours to obtain the fiber membrane samples.

[0052] The present invention tested the mechanical properties of the samples according to the method mentioned in GB / T 3923-2013 (Tensile Properties of Textile Fabrics), tested the antibacterial properties of the samples according to the method mentioned in GB / T 20944.3-2007 (Evaluation of Antibacterial Properties of Textiles Part 3: Oscillation Method), and tested and calculated the water resistance of the samples (the remaining mass fraction after immersion in pure water for 24 hours is the water resistance data) and sweat resistance (the remaining mass fraction after immersion in artificial sweat for 24 hours is the sweat resistance data) using the immersion method.

[0053] The mechanical properties, water resistance and sweat resistance test results of the samples prepared in Example 1 are as follows: Figure 1 As shown:

[0054]

[0055] The content of the present invention is not limited to the embodiments listed. Any equivalent transformation of the technical solution of the present invention made by ordinary technicians in this field after reading the description of the present invention is covered by the claims of the present invention.

Claims

1. A method for preparing a sensing antibacterial coaxial fiber membrane by coaxial electrospinning, characterized in that: The steps include: Step 1: Preparation of solution A, gelatin-ethyl cellulose solution and solution B, polyurethane solution: Water, anhydrous ethanol, and acetic acid were prepared into a solution with a volume ratio of 2:2:6, and then 15-25 wt% of gelatin and ethyl cellulose were dissolved in the solution with a mass ratio of 1:2-2:

1. The solution was stirred magnetically at 35°C for 4 hours to obtain a gelatin-ethyl cellulose spinning solution. 5-20 wt% of polyurethane was dissolved in a mixed solution of N,N-dimethylformamide and tetrahydrofuran in a volume ratio of 4:1-1:1, and magnetically stirred at 55°C for 4 hours to obtain a polyurethane spinning solution; Step 2: Preparation of MXene / Cu2O: Lithium fluoride and hydrochloric acid are mixed and stirred, and Ti3AlC2 is slowly added to the lithium fluoride / hydrochloric acid mixed solution to react for 24-72 hours, and the reaction temperature is controlled at 35-38°C to obtain multi-layer MXene; the multi-layer MXene is washed with ultrapure water and ultrasonically treated with inert gas, and the supernatant is obtained after centrifugation and freeze-dried to obtain a few-layer MXene for subsequent use; 5 mg of few-layer MXene nanosheets and 0.5 g of polyvinylpyrrolidone (PVP) were added to 10-20 mL of 0.01 mol / L copper sulfate solution and stirred. Then, 10-15 μL of HHA (hydrazine hydrate) solution was added to the solution and stirred continuously. The obtained product MXene / Cu2O was freeze-dried and used. Step 3: Preparation of coaxial electrospinning fiber membrane: 0.5-2.5 wt% MXene / Cu2O was added to the gelatin-ethyl cellulose solution prepared in step 1 and stirred to mix evenly to obtain solution C. Solution C was drawn into a syringe and connected to the coaxial needle shell tube. The syringe containing solution B was then connected to the coaxial needle core tube and connected to the electrospinning device. The voltage between the coaxial needle and the flat receiver was controlled to be 9-15 kV and the distance was 5-15 cm. The propulsion speeds of the core layer spinning solution and the shell layer spinning solution were controlled. Electrospinning was performed at a temperature of 30-35°C and a relative humidity of 30-40% to obtain an electrospun fiber membrane. The fiber membrane was then dried in a vacuum oven for 24 h to obtain a fiber membrane sample.

2. The method for preparing a sensing antibacterial coaxial fiber membrane by coaxial electrospinning according to claim 1, characterized in that: In the step 2, the mass ratio of lithium fluoride to Ti3AlC2 is 1.6:1 to 2:

1.

3. The method for preparing a sensing antibacterial coaxial fiber membrane by coaxial electrospinning according to claim 1, characterized in that: In the step 2, the multilayer MXene solution should be washed with water to a pH of about 6 before ultrasonic treatment. The ultrasonic treatment time is 0.5 to 1 h, and the centrifugal conditions are a speed of 3500 r / min and a time of 15 min.

4. The method for preparing a sensing antibacterial coaxial fiber membrane by coaxial electrospinning according to claim 1, characterized in that: In step 3, the stirring time of MXene and copper sulfate solution is not less than 30 min, and the stirring time after adding HHA is not less than 10 min.

5. The method for preparing a sensing antibacterial coaxial fiber membrane by coaxial electrospinning according to claim 1, characterized in that: In the step 3, the supply rate of the gelatin-ethyl cellulose solution is 0.00010-0.0060 mm / s, and the supply rate of the polyurethane solution is 0.0010-0.0040 mm / s.

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