A porous membrane of electrospun nanofibers for protective clothing

Abstract

The present invention relates to the technical field of nanofiber porous membranes, and particularly to an electrospun nanofiber porous membrane for protective clothing. The electrospun nanofiber porous membrane for protective clothing has raw materials in parts by mass including: 5-15 parts of polyvinylidene fluoride, 1-2 parts of zirconium chloride, 5-15 parts of titanium dioxide aerogel, 0.5-1.5 parts of 2-aminoterephthalic acid, 1-3 parts of glacial acetic acid, 1-5 parts of collagen, and 1-2 parts of carbon nanotubes. The titanium dioxide aerogel is prepared by the following steps: adding tetrabutyl titanate and graphene oxide into ethanol, stirring evenly, adjusting the pH value of the system to 3-4, stirring for 10-20 min, standing at 60-70 °C for 1-2 h, filtering, washing, drying, pulverizing, mixing with carboxyl-terminated polyamidoamine, adding into water for ultrasonic treatment, freezing, vacuum drying, and pulverizing. The structure of the present invention has excellent stability, good barrier property, high puncture resistance strength, and excellent moisture permeability.

Description

Technical Field

[0001] The present invention relates to the technical field of nanofiber porous membranes, and particularly to an electrospun nanofiber porous membrane for protective clothing. Background Art

[0002] The air permeability of existing protective clothing is poor, and the bodies of the staff wearing medical protective clothing for a long time will feel uncomfortable. This discomfort is significantly related to the air permeability, moisture permeability, thermal and moisture resistance, etc. of the materials used for the protective clothing. However, comfort is usually contrary to the protective performance. Therefore, it is necessary to improve the comfort of the protective clothing fabric as much as possible on the premise of meeting the protective performance of the protective clothing.

[0003] The porous structure of fibers can also greatly improve the water absorption and air permeability of textiles. Therefore, constructing fibers with a porous structure can be an effective means. Polyvinylidene fluoride (PVDF) has good chemical stability due to its own properties, and has advantages such as acid and alkali resistance, oxidation resistance, and anti-aging. Electrospinning has good air permeability due to its unique three-dimensional stacked structure and can be used to improve the wearing comfort of protective clothing. Preparing PVDF nanofiber porous membranes by electrospinning for application in protective clothing has excellent research prospects.

[0004] CN 103263856 A discloses a preparation method of an electrospun hydrophobic nanofiber porous membrane for membrane distillation, including: dissolving a hydrophobic functional polymer material in a solvent to obtain a polymer spinning solution of 1-35 wt%, performing electrospinning to obtain a hydrophobic nanofiber porous membrane, and then performing heat treatment to obtain the electrospun hydrophobic nanofiber porous membrane for membrane distillation. It can improve the defects of low water flux and easy wetting of membrane pores of traditional membranes for membrane distillation, but has poor stability.

[0005] Electrospinning can prepare nano or submicron fibers, and the pore size of the obtained nanofiber porous membrane is between dozens of nanometers and dozens of microns, and the pores have good connectivity. However, the porous membrane structure has poor stability, and it is easy to rupture in terms of puncture strength when applied in protective clothing, which greatly limits its development and application and urgently needs to be solved. Summary of the Invention

[0006] The purpose of the present invention is to solve the defects existing in the prior art, and to propose an electrospun nanofiber porous membrane for protective clothing.

[0007] An electrospun nanofiber porous membrane for protective clothing, the raw materials of which include, by mass: 5-15 parts of polyvinylidene fluoride, 1-2 parts of zirconium chloride, 5-15 parts of titanium dioxide aerogel, 0.5-1.5 parts of 2-aminoterephthalic acid, 1-3 parts of glacial acetic acid, 1-5 parts of collagen, and 1-2 parts of carbon nanotubes.

[0008] Preferably, the porosity of the electrospun nanofiber porous membrane for protective clothing is 75 - 82.4%, and the thickness is 150 - 210 μm.

[0009] Preferably, the titanium dioxide aerogel is prepared by the following steps: adding tetrabutyl titanate and graphene oxide to ethanol, stirring evenly, adjusting the pH value of the system to 3 - 4, stirring for 10 - 20 min, standing at 60 - 70 °C for 1 - 2 h, filtering, washing, drying, pulverizing, mixing with carboxyl - terminated polyamidoamine, adding to water and performing ultrasonic treatment for 1 - 2 h, freezing at - 60 to - 40 °C for 1 - 3 h, and vacuum drying and pulverizing.

[0010] Preferably, the mass ratio of tetrabutyl titanate, graphene oxide, and carboxyl - terminated polyamidoamine is 5 - 15:1 - 2:1 - 3; the generation number of carboxyl - terminated polyamidoamine is 2.0 - 4.0.

[0011] Preferably, the ultrasonic frequency is 10 - 15 kHz.

[0012] The preparation method of the above - mentioned electrospun nanofiber porous membrane for protective clothing includes the following steps:

[0013] S1. Add zirconium chloride to N,N - dimethylformamide and stir evenly, add titanium dioxide aerogel to it and perform ultrasonic treatment for 2 - 4 h, add 2 - aminoterephthalic acid and glacial acetic acid to it, perform solvothermal reaction at 90 - 100 °C for 5 - 15 h, cool to room temperature, wash, and vacuum dry to obtain titanium dioxide - loaded material;

[0014] S2. Add polyvinylidene fluoride and titanium dioxide - loaded material to hexafluoroisopropanol and stir evenly to obtain a pre - formed shell - layer mixture;

[0015] S3. Add collagen and carbon nanotubes to hexafluoroisopropanol and stir evenly to obtain a pre - formed core - layer mixture;

[0016] S4. Coaxially electrospin the pre - formed shell - layer mixture and the pre - formed core - layer mixture onto the surface of a metal drum, with an electrospinning voltage of 18 - 20 kV, a distance between the spinning nozzle and the metal drum of 10 - 12 cm; perform heat treatment at 70 - 80 °C for 10 - 15 h.

[0017] Preferably, in S1, the ultrasonic frequency is 10 - 15 kHz.

[0018] Preferably, in S4, during the coaxial electrospinning process, inject the pre - formed shell - layer mixture into the outer needle of the coaxial electrospinning needle, inject the pre - formed core - layer mixture into the inner needle of the coaxial electrospinning needle, the inner diameter of the outer needle is 1 - 1.2 mm, the inner diameter of the inner needle is 0.6 - 0.8 mm, control the inner - layer liquid feeding speed to be 0.1 - 0.4 mL / min, and the outer - layer liquid feeding speed to be 1 - 1.5 mL / min.

[0019] A protective clothing, which sequentially includes from inside to outside: a polyester fabric, the electrospun nanofiber porous membrane for the protective clothing, a non-woven fabric, the electrospun nanofiber porous membrane for the protective clothing, and a polyester / propylene fabric.

[0020] Preferably, the mass ratio of polyester to polypropylene in the polyester / propylene fabric is 50:50, and the areal density of the polyester / propylene fabric is 120 - 140 g / m 2 .

[0021] Preferably, the areal density of the polyester fabric is 90 - 110 g / m 2 .

[0022] Preferably, the areal density of the non-woven fabric is 50 - 70 g / m 2 .

[0023] Beneficial effects:

[0024] In the present invention, graphene oxide is doped into titanium dioxide, and then combined with carboxyl-terminated polyamidoamine to form an aerogel. The graphene oxide has a hydrophilic lamellar structure and cooperates with the dendritic macromolecule polyamidoamine. The obtained aerogel structure not only has good air permeability, but also has excellent heat and moisture conduction effects. At the same time, MOFs are in-situ grown on the aerogel through a solvothermal reaction, and the growth of MOFs is effectively inhibited in cooperation with the structure of the titanium dioxide aerogel, so that the loaded titanium dioxide has good stability, a large specific surface area and a high porosity. The fabric formed by compounding with polyvinylidene fluoride not only has good softness, but also can ensure excellent mechanical strength and high tear resistance.

[0025] In the present invention, polyvinylidene fluoride and loaded titanium dioxide are compounded as the shell layer, while collagen and carbon nanotubes are compounded as the core layer. Through coaxial electrospinning, on the basis of ensuring that the porous membrane has good uniformity, high porosity and good air permeability, a porous network structure is formed to promote the effective diffusion of air and moisture from the skin to the environment, and the moisture permeability is excellent; at the same time, it has a low thermal resistance and can effectively transfer the heat generated by the human body through the fabric to the environment, and the wearing comfort is good.

[0026] The porous membrane obtained in the present invention has excellent structural stability, good barrier property, high puncture resistance, excellent moisture permeability, can effectively reduce the stuffy feeling during wearing, and has excellent dressing comfort, and is particularly suitable for medical clothing and protective clothing. Description of the Drawings

[0027] Figure 1 It is a comparison chart of the rigidity of the electrospun nanofiber porous membranes for the protective clothing obtained in Example 5 and Comparative Examples 1 - 3.

[0028] Figure 2 It is a comparison chart of the air permeability and moisture permeability of the electrospun nanofiber porous membranes for the protective clothing obtained in Example 5 and Comparative Examples 1 - 3.

[0029] Figure 3 It is a comparison chart of the tear strength and breaking strength of the protective clothing prepared from the electrospun nanofiber porous membrane obtained in Example 5 and Comparative Examples 1-3.

[0030] Figure 4 It is a comparison chart of the puncture resistance and thermal resistance of the protective clothing prepared from the electrospun nanofiber porous membrane obtained in Example 5 and Comparative Examples 1-3. Detailed implementation manners

[0031] The present invention will be further explained below in conjunction with specific embodiments.

[0032] Example 1

[0033] An electrospun nanofiber porous membrane for protective clothing, the raw materials thereof comprising: 50 g of polyvinylidene fluoride, 10 g of zirconium chloride, 50 g of titanium dioxide aerogel, 5 g of 2-aminoterephthalic acid, 10 g of glacial acetic acid, 10 g of collagen, and 10 g of carbon nanotubes.

[0034] The titanium dioxide aerogel is prepared by the following steps: adding 50 g of tetrabutyl titanate and 10 g of graphene oxide to 300 g of ethanol, stirring evenly, adjusting the pH value of the system to 3-4 with a nitric acid solution, stirring at a speed of 1000 r / min for 10 min, standing at a temperature of 60 °C for 1 h, filtering, washing, drying at a temperature of 100 °C, pulverizing, mixing with 10 g of 2.0-generation carboxyl-terminated polyamidoamine, adding to 400 g of water, performing ultrasonic treatment for 1 h, with an ultrasonic frequency of 10 kHz, freezing at a temperature of -60 °C for 1 h, and performing vacuum drying and pulverizing.

[0035] The preparation method of the above electrospun nanofiber porous membrane for protective clothing comprises the following steps:

[0036] S1. Adding zirconium chloride to 500 g of N,N-dimethylformamide, stirring evenly, adding the titanium dioxide aerogel thereto, performing ultrasonic treatment for 2 h, with an ultrasonic frequency of 10 kHz, adding 2-aminoterephthalic acid and glacial acetic acid thereto, performing a solvothermal reaction at a temperature of 90 °C for 5 h, cooling to room temperature, washing once with ethanol, and performing vacuum drying to obtain the titanium dioxide-loaded product;

[0037] S2. Adding polyvinylidene fluoride and the titanium dioxide-loaded product to 200 g of hexafluoroisopropanol, stirring evenly to obtain a prefabricated shell layer mixture;

[0038] S3. Adding collagen and carbon nanotubes to 50 g of hexafluoroisopropanol, stirring evenly to obtain a prefabricated core layer mixture;

[0039] S4. Inject the prefabricated shell layer mixture into the outer needle of the coaxial electrospinning needle, and inject the prefabricated core layer mixture into the inner needle of the coaxial electrospinning needle. The inner diameter of the outer needle is 1 mm, and the inner diameter of the inner needle is 0.6 mm. Control the inner layer liquid feeding speed at 0.1 mL / min and the outer layer liquid feeding speed at 1 mL / min; perform electrospinning treatment, with the electrospinning voltage at 18 kV, the distance between the spinning nozzle and the metal roller at 10 cm, and the rotation speed of the metal roller at 200 r / min; remove the film from the surface of the metal roller and perform heat treatment at 70 °C for 10 h.

[0040] Example 2

[0041] An electrospun nanofiber porous membrane for protective clothing, the raw materials of which include: 150 g of polyvinylidene fluoride, 20 g of zirconium chloride, 150 g of titanium dioxide aerogel, 15 g of 2-aminoterephthalic acid, 30 g of glacial acetic acid, 50 g of collagen, and 20 g of carbon nanotubes.

[0042] The titanium dioxide aerogel is prepared by the following steps: Add 150 g of tetrabutyl titanate and 20 g of graphene oxide to 600 g of ethanol and stir evenly. Adjust the pH value of the system to 3 - 4 with a nitric acid solution, stir at a speed of 2000 r / min for 20 min, stand at 70 °C for 2 h, filter, wash, dry at 110 °C, crush, mix with 30 g of 4.0-generation carboxyl-terminated polyamidoamine, add to 1000 g of water and perform ultrasonic treatment for 2 h with an ultrasonic frequency of 15 kHz, freeze at -40 °C for 3 h, and perform vacuum drying and crushing.

[0043] The preparation method of the above electrospun nanofiber porous membrane for protective clothing includes the following steps:

[0044] S1. Add zirconium chloride to 1000 g of N,N-dimethylformamide and stir evenly. Add the titanium dioxide aerogel to it and perform ultrasonic treatment for 4 h with an ultrasonic frequency of 15 kHz. Add 2-aminoterephthalic acid and glacial acetic acid to it, perform solvothermal reaction at 100 °C for 15 h, cool to room temperature, wash 3 times with ethanol, and perform vacuum drying to obtain the titanium dioxide-loaded product;

[0045] S2. Add polyvinylidene fluoride and the titanium dioxide-loaded product to 300 g of hexafluoroisopropanol and stir evenly to obtain the prefabricated shell layer mixture;

[0046] S3. Add collagen and carbon nanotubes to 150 g of hexafluoroisopropanol and stir evenly to obtain the prefabricated core layer mixture;

[0047] S4. Inject the prefabricated shell layer mixture into the outer needle of the coaxial electrospinning needle, and inject the prefabricated core layer mixture into the inner needle of the coaxial electrospinning needle. The inner diameter of the outer needle is 1.2 mm, and the inner diameter of the inner needle is 0.8 mm. Control the inner layer liquid feeding speed at 0.4 mL / min and the outer layer liquid feeding speed at 1.5 mL / min; conduct electrospinning treatment with an electrospinning voltage of 20 kV, a distance of 12 cm between the spinning nozzle and the metal roller, and a metal roller rotation speed of 450 r / min; remove the film from the surface of the metal roller and conduct heat treatment at 80 °C for 15 h.

[0048] Example 3

[0049] An electrospun nanofiber porous membrane for protective clothing, the raw materials of which include: 80 g of polyvinylidene fluoride, 18 g of zirconium chloride, 80 g of titanium dioxide aerogel, 12 g of 2-aminoterephthalic acid, 15 g of glacial acetic acid, 40 g of collagen, and 13 g of carbon nanotubes.

[0050] The titanium dioxide aerogel is prepared by the following steps: Add 120 g of tetrabutyl titanate and 13 g of graphene oxide to 500 g of ethanol and stir evenly. Adjust the pH value of the system to 3-4 with a nitric acid solution, stir at a speed of 1200 r / min for 18 min, let it stand at a temperature of 64 °C for 100 min, filter, wash, dry at a temperature of 102 °C, pulverize, mix with 25 g of 3.0-generation carboxyl-terminated polyamidoamine, add it to 600 g of water and conduct ultrasonic treatment for 100 min with an ultrasonic frequency of 11 kHz, freeze at a temperature of -45 °C for 1.5 h, and conduct vacuum drying and pulverization.

[0051] The preparation method of the above-mentioned electrospun nanofiber porous membrane for protective clothing includes the following steps:

[0052] S1. Add zirconium chloride to 900 g of N,N-dimethylformamide and stir evenly. Add the titanium dioxide aerogel to it and conduct ultrasonic treatment for 2.5 h with an ultrasonic frequency of 13 kHz. Add 2-aminoterephthalic acid and glacial acetic acid to it, conduct solvothermal reaction at a temperature of 92 °C for 12 h, cool to room temperature, wash 2 times with ethanol, and conduct vacuum drying to obtain the titanium dioxide-loaded product;

[0053] S2. Add polyvinylidene fluoride and the titanium dioxide-loaded product to 220 g of hexafluoroisopropanol and stir evenly to obtain the prefabricated shell layer mixture;

[0054] S3. Add collagen and carbon nanotubes to 120 g of hexafluoroisopropanol and stir evenly to obtain the prefabricated core layer mixture;

[0055] S4. Inject the prefabricated shell layer mixture into the outer needle of the coaxial electrospinning needle, and inject the prefabricated core layer mixture into the inner needle of the coaxial electrospinning needle. The inner diameter of the outer needle is 1.1 mm, and the inner diameter of the inner needle is 0.7 mm. Control the inner layer liquid feeding speed at 0.2 mL / min and the outer layer liquid feeding speed at 1.4 mL / min; perform electrospinning treatment with an electrospinning voltage of 18.5 kV, a distance of 11.5 cm between the spinning nozzle and the metal roller, and a metal roller rotation speed of 300 r / min; remove the film from the surface of the metal roller and perform heat treatment at 77 °C for 11 h.

[0056] Example 4

[0057] An electrospun nanofiber porous membrane for protective clothing, the raw materials of which include: 120 g of polyvinylidene fluoride, 12 g of zirconium chloride, 120 g of titanium dioxide aerogel, 8 g of 2-aminoterephthalic acid, 25 g of glacial acetic acid, 20 g of collagen, and 17 g of carbon nanotubes.

[0058] The titanium dioxide aerogel is prepared by the following steps: Add 80 g of tetrabutyl titanate and 17 g of graphene oxide to 400 g of ethanol and stir evenly. Adjust the pH value of the system to 3 - 4 with a nitric acid solution, stir at a speed of 1800 r / min for 12 min, let stand at 66 °C for 80 min, filter, wash, dry at 108 °C, pulverize, mix with 15 g of 3.0-generation carboxyl-terminated polyamidoamine, add to 800 g of water and perform ultrasonic treatment for 80 min with an ultrasonic frequency of 13 kHz, freeze at -55 °C for 2.5 h, and perform vacuum drying and pulverization.

[0059] The preparation method of the above-mentioned electrospun nanofiber porous membrane for protective clothing includes the following steps:

[0060] S1. Add zirconium chloride to 700 g of N,N-dimethylformamide and stir evenly. Add titanium dioxide aerogel to it and perform ultrasonic treatment for 3.5 h with an ultrasonic frequency of 11 kHz. Add 2-aminoterephthalic acid and glacial acetic acid to it, and perform solvothermal reaction at 98 °C for 8 h. Cool to room temperature, wash twice with ethanol, and perform vacuum drying to obtain titanium dioxide-loaded material;

[0061] S2. Add polyvinylidene fluoride and the titanium dioxide-loaded material to 280 g of hexafluoroisopropanol and stir evenly to obtain a prefabricated shell layer mixture;

[0062] S3. Add collagen and carbon nanotubes to 80 g of hexafluoroisopropanol and stir evenly to obtain a prefabricated core layer mixture;

[0063] S4. Inject the prefabricated shell layer mixture into the outer needle of the coaxial electrospinning needle, and inject the prefabricated core layer mixture into the inner needle of the coaxial electrospinning needle. The inner diameter of the outer needle is 1.1 mm, and the inner diameter of the inner needle is 0.7 mm. Control the inner layer liquid feeding speed at 0.3 mL / min and the outer layer liquid feeding speed at 1.2 mL / min; perform electrospinning treatment, with the electrospinning voltage at 19.5 kV, the distance between the spinning nozzle and the metal roller at 10.5 cm, and the rotation speed of the metal roller at 400 r / min; remove the film from the surface of the metal roller and perform heat treatment at 73 °C for 13 h.

[0064] Example 5

[0065] An electrospun nanofiber porous membrane for protective clothing, the raw materials of which include: 100 g of polyvinylidene fluoride, 15 g of zirconium chloride, 100 g of titanium dioxide aerogel, 10 g of 2-aminoterephthalic acid, 20 g of glacial acetic acid, 30 g of collagen, and 15 g of carbon nanotubes.

[0066] The titanium dioxide aerogel is prepared by the following steps: Add 100 g of tetrabutyl titanate and 15 g of graphene oxide to 450 g of ethanol and stir evenly. Adjust the pH value of the system to 3 - 4 with a nitric acid solution, stir at a speed of 1500 r / min for 15 min, let stand at 65 °C for 90 min, filter, wash, dry at 105 °C, pulverize, mix with 20 g of 3.0-generation carboxyl-terminated polyamidoamine, add to 700 g of water and perform ultrasonic treatment for 90 min with an ultrasonic frequency of 12 kHz, freeze at -40 °C for 2 h, and perform vacuum drying and pulverization.

[0067] The preparation method of the above-mentioned electrospun nanofiber porous membrane for protective clothing includes the following steps:

[0068] S1. Add zirconium chloride to 800 g of N,N-dimethylformamide and stir evenly. Add titanium dioxide aerogel to it and perform ultrasonic treatment for 3 h with an ultrasonic frequency of 12 kHz. Add 2-aminoterephthalic acid and glacial acetic acid to it, perform solvothermal reaction at 95 °C for 10 h, cool to room temperature, wash 2 times with ethanol, and perform vacuum drying to obtain titanium dioxide-loaded material;

[0069] S2. Add polyvinylidene fluoride and the titanium dioxide-loaded material to 250 g of hexafluoroisopropanol and stir evenly to obtain a prefabricated shell layer mixture;

[0070] S3. Add collagen and carbon nanotubes to 100 g of hexafluoroisopropanol and stir evenly to obtain a prefabricated core layer mixture;

[0071] S4. Inject the prefabricated shell layer mixture into the outer needle of the coaxial electrospinning needle, and inject the prefabricated core layer mixture into the inner needle of the coaxial electrospinning needle. The inner diameter of the outer needle is 1.1 mm, and the inner diameter of the inner needle is 0.7 mm. Control the inner layer liquid feeding speed at 0.25 mL / min and the outer layer liquid feeding speed at 1.3 mL / min; conduct electrospinning treatment with an electrospinning voltage of 19 kV, a distance of 11 cm between the spinning nozzle and the metal roller, and a metal roller rotation speed of 350 r / min; remove the film from the surface of the metal roller and conduct heat treatment at 75 °C for 12 h.

[0072] Comparative Example 1

[0073] An electrospun nanofiber porous membrane for protective clothing, the raw materials thereof comprising: 100 g of polyvinylidene fluoride, 145 g of titanium dioxide aerogel, 30 g of collagen, and 15 g of carbon nanotubes.

[0074] The titanium dioxide aerogel is prepared by the following steps: Add 100 g of tetrabutyl titanate and 15 g of graphene oxide to 450 g of ethanol, stir evenly, adjust the pH value of the system to 3 - 4 with a nitric acid solution, stir at a speed of 1500 r / min for 15 min, stand at 65 °C for 90 min, filter, wash, dry at 105 °C, pulverize, mix with 20 g of 3.0-generation carboxyl-terminated polyamidoamine, add to 700 g of water, conduct ultrasonic treatment for 90 min with an ultrasonic frequency of 12 kHz, freeze at -40 °C for 2 h, and conduct vacuum drying and pulverization.

[0075] The preparation method of the above electrospun nanofiber porous membrane for protective clothing comprises the following steps:

[0076] S1. Add polyvinylidene fluoride and titanium dioxide aerogel to 250 g of hexafluoroisopropanol, stir evenly to obtain a prefabricated shell layer mixture;

[0077] S3. Add collagen and carbon nanotubes to 100 g of hexafluoroisopropanol, stir evenly to obtain a prefabricated core layer mixture;

[0078] S4. Inject the prefabricated shell layer mixture into the outer needle of the coaxial electrospinning needle, and inject the prefabricated core layer mixture into the inner needle of the coaxial electrospinning needle. The inner diameter of the outer needle is 1.1 mm, and the inner diameter of the inner needle is 0.7 mm. Control the inner layer liquid feeding speed at 0.25 mL / min and the outer layer liquid feeding speed at 1.3 mL / min; conduct electrospinning treatment with an electrospinning voltage of 19 kV, a distance of 11 cm between the spinning nozzle and the metal roller, and a metal roller rotation speed of 350 r / min; remove the film from the surface of the metal roller and conduct heat treatment at 75 °C for 12 h.

[0079] Comparative Example 2

[0080] An electrospun nanofiber porous membrane for protective clothing, the raw materials of which include: 100 g of polyvinylidene fluoride, 15 g of zirconium chloride, 100 g of titanium dioxide aerogel, 10 g of 2-aminoterephthalic acid, 20 g of glacial acetic acid, 30 g of collagen, and 15 g of carbon nanotubes.

[0081] The titanium dioxide aerogel is prepared by the following steps: Add 100 g of tetrabutyl titanate to 450 g of ethanol and stir evenly. Adjust the pH value of the system to 3 - 4 with a nitric acid solution, stir at a speed of 1500 r / min for 15 min, stand at a temperature of 65 °C for 90 min, filter, wash, dry at a temperature of 105 °C, crush, mix with 20 g of 3.0-generation carboxyl-terminated polyamidoamine, add to 700 g of water and perform ultrasonic treatment for 90 min, with an ultrasonic frequency of 12 kHz, freeze at a temperature of -40 °C for 2 h, vacuum dry, crush, and add 15 g of graphene oxide and mix evenly.

[0082] The preparation method of the above-mentioned electrospun nanofiber porous membrane for protective clothing includes the following steps:

[0083] S1. Add zirconium chloride to 800 g of N,N-dimethylformamide and stir evenly. Add the titanium dioxide aerogel to it and perform ultrasonic treatment for 3 h, with an ultrasonic frequency of 12 kHz. Add 2-aminoterephthalic acid and glacial acetic acid to it, and perform solvothermal reaction at a temperature of 95 °C for 10 h. Cool to room temperature, wash twice with ethanol, and vacuum dry to obtain titanium dioxide supported.

[0084] S2. Add polyvinylidene fluoride and titanium dioxide supported to 250 g of hexafluoroisopropanol and stir evenly to obtain a prefabricated shell layer mixture.

[0085] S3. Add collagen and carbon nanotubes to 100 g of hexafluoroisopropanol and stir evenly to obtain a prefabricated core layer mixture.

[0086] S4. Inject the prefabricated shell layer mixture into the outer needle of a coaxial electrospinning needle, and inject the prefabricated core layer mixture into the inner needle of the coaxial electrospinning needle. The inner diameter of the outer needle is 1.1 mm, and the inner diameter of the inner needle is 0.7 mm. Control the inner layer liquid feeding speed at 0.25 mL / min and the outer layer liquid feeding speed at 1.3 mL / min; perform electrospinning treatment, with an electrospinning voltage of 19 kV, the distance between the spinning nozzle and the metal roller is 11 cm, and the rotation speed of the metal roller is 350 r / min; remove the film from the surface of the metal roller and perform heat treatment at 75 °C for 12 h.

[0087] Comparative Example 3

[0088] An electrospun nanofiber porous membrane for protective clothing, the raw materials of which include: 100 g of polyvinylidene fluoride, 15 g of zirconium chloride, 100 g of titanium dioxide aerogel, 10 g of 2-aminoterephthalic acid, 20 g of glacial acetic acid, 30 g of collagen, and 15 g of carbon nanotubes.

[0089] The titanium dioxide aerogel is prepared by the following steps: Add 100 g of tetrabutyl titanate and 15 g of graphene oxide to 450 g of ethanol and stir evenly. Adjust the pH value of the system to 3 - 4 with a nitric acid solution, stir at a speed of 1500 r / min for 15 min, let it stand at 65 °C for 90 min, filter, wash, dry at 105 °C, crush, add it to 700 g of water and perform ultrasonic treatment for 90 min with an ultrasonic frequency of 12 kHz, freeze at -40 °C for 2 h, perform vacuum drying, crush, and mix evenly with 20 g of 3.0-generation carboxyl-terminated polyamidoamine.

[0090] The preparation method of the above electrospun nanofiber porous membrane for protective clothing includes the following steps:

[0091] S1. Add zirconium chloride to 800 g of N,N-dimethylformamide and stir evenly. Add the titanium dioxide aerogel to it and perform ultrasonic treatment for 3 h with an ultrasonic frequency of 12 kHz. Add 2-aminoterephthalic acid and glacial acetic acid to it, and perform solvothermal reaction at 95 °C for 10 h. Cool to room temperature, wash twice with ethanol, and perform vacuum drying to obtain titanium dioxide-loaded material;

[0092] S2. Add polyvinylidene fluoride and the titanium dioxide-loaded material to 250 g of hexafluoroisopropanol and stir evenly to obtain a prefabricated shell layer mixture;

[0093] S3. Add collagen and carbon nanotubes to 100 g of hexafluoroisopropanol and stir evenly to obtain a prefabricated core layer mixture;

[0094] S4. Inject the prefabricated shell layer mixture into the outer needle of a coaxial electrospinning needle, and inject the prefabricated core layer mixture into the inner needle of the coaxial electrospinning needle. The inner diameter of the outer needle is 1.1 mm, and the inner diameter of the inner needle is 0.7 mm. Control the inner layer liquid feeding speed to be 0.25 mL / min and the outer layer liquid feeding speed to be 1.3 mL / min; Perform electrospinning treatment, with an electrospinning voltage of 19 kV, the distance between the spinning nozzle and the metal roller is 11 cm, and the rotation speed of the metal roller is 350 r / min; Take the film off the surface of the metal roller and perform heat treatment at 75 °C for 12 h.

[0095] Use the Kawabata evaluation system (KES-FB) to test the softness of the electrospun nanofiber porous membranes for protective clothing obtained in Example 5 and Comparative Examples 1 - 3.

[0096] As Figure 1As shown, the electrospun nanofiber porous membrane of the protective clothing obtained in Example 5 has the lowest rigidity, only 0.2267 gf·cm 2 / cm, that is, the highest softness, which is better than Comparative Examples 1-3 (P < 0.05).

[0097] Referring to GB / T 24218.15-2018 "Textiles - Test methods for nonwovens - Part 15: Determination of air permeability", the air permeability of the electrospun nanofiber porous membranes of the protective clothing obtained in Example 5 and Comparative Examples 1-3 was measured by the differential pressure method (100 Pa).

[0098] Referring to GB / T 12704.1-2009 "Textiles - Test methods for fabric water vapor permeability - Part 1: Moisture absorption method", the water vapor permeability of the electrospun nanofiber porous membranes of the protective clothing obtained in Example 5 and Comparative Examples 1-3 was measured.

[0099] As Figure 2 shown, the air permeability and water vapor permeability of the electrospun nanofiber porous membrane of the protective clothing obtained in Example 5 are both the highest, which is better than Comparative Examples 1-3 (P < 0.05).

[0100] Using the electrospun nanofiber porous membranes of the protective clothing obtained in Example 5 and Comparative Examples 1-3 to prepare protective clothing, each group of protective clothing includes, from the inside out in turn: polyester fabric with a surface density of 100 g / m 2 , the electrospun nanofiber porous membranes of each group of protective clothing, non-woven fabric with a surface density of 60 g / m 2 , the electrospun nanofiber porous membranes of each group of protective clothing, polyester / propylene (mass ratio 50 / 50) fabric with a surface density of 130 g / m 2 .

[0101] Referring to GB 19082-2023 "Medical disposable protective clothing", the tear strength, breaking strength and puncture resistance of the above-mentioned groups of protective clothing were measured. Referring to GB / T 11048-2018 "Textiles - Physiological comfort - Determination of thermal and water vapor resistance under steady-state conditions (evaporative hotplate method)", the thermal resistance of the above-mentioned groups of protective clothing was measured.

[0102] As Figure 3 and Figure 4 shown, the protective clothing prepared with the electrospun nanofiber porous membrane of the protective clothing obtained in Example 5 has the highest tear strength, breaking strength and puncture resistance, and has a small thermal resistance, indicating that the protective clothing prepared with the electrospun nanofiber porous membrane of the protective clothing obtained in Example 5 has excellent mechanical properties and can effectively transfer the heat generated by the human body through the fabric to the environment.

[0103] This is because in the present invention, graphene oxide is doped into titanium dioxide and then combined with carboxyl-terminated polyamidoamine to form an aerogel. The graphene oxide has a hydrophilic lamellar structure and cooperates with the dendritic macromolecule polyamidoamine. The obtained aerogel structure not only has good air permeability, but also has excellent heat and moisture conduction effects. At the same time, MOFs are in-situ grown on the aerogel through a solvothermal reaction, and the growth of MOFs is effectively inhibited in cooperation with the structure of the titanium dioxide aerogel, so that the loaded titanium dioxide has good stability, a large specific surface area and a high porosity. The fabric formed by compounding with polyvinylidene fluoride has both good softness and excellent mechanical strength and high tear resistance. In the present invention, polyvinylidene fluoride and loaded titanium dioxide are compounded as the shell layer, while collagen and carbon nanotubes are compounded as the core layer. Through coaxial electrospinning, on the basis of ensuring that the porous membrane has good uniformity, a high porosity and good air permeability, a porous network structure is formed to promote the effective diffusion of air and moisture from the skin to the environment, and the moisture permeability is excellent; at the same time, it has a low thermal resistance and can effectively transfer the heat generated by the human body through the fabric to the environment, and the wearing comfort is good.

[0104] As mentioned above, the above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes should be covered by the protection scope of the present invention.

Claims

1. An electrostatic spinning nanofiber porous membrane for protective clothing, characterized in that, The raw materials include, by mass: 5-15 parts of polyvinylidene fluoride, 1-2 parts of zirconium chloride, 5-15 parts of titanium dioxide aerogel, 0.5-1.5 parts of 2-aminoterephthalic acid, 1-3 parts of glacial acetic acid, 1-5 parts of collagen, and 1-2 parts of carbon nanotubes; Titanium dioxide aerogel is prepared by the following steps: adding butyl titanate and graphene oxide to ethanol and stirring evenly, adjusting the pH value of the system to 3-4, stirring for 10-20 minutes, standing at 60-70°C for 1-2 hours, filtering, washing, drying, crushing, mixing with carboxyl-terminated polyamidoamine, adding to water for ultrasonic treatment for 1-2 hours, freezing at -60 to -40°C for 1-3 hours, vacuum drying, and crushing; The mass ratio of butyl titanate, graphene oxide and carboxyl-terminated polyamidoamine is 5-15:1-2:1-3; the generation number of carboxyl-terminated polyamidoamine is 2.0-4.

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2. The electrospun nanofiber porous membrane for protective clothing according to claim 1, wherein Its porosity is 75-82.4% and its thickness is 150-210μm.

3. The electrospun nanofiber porous membrane for protective clothing according to claim 1, wherein Ultrasonic frequency 10-15kHz.

4. A method for preparing an electrospun nanofiber porous membrane for protective clothing according to any one of claims 1-3, characterized in that, The steps include: S1, adding zirconium chloride to N,N-dimethylformamide and stirring evenly, adding titanium dioxide aerogel thereto and ultrasonically treating for 2-4 hours, adding 2-aminoterephthalic acid and glacial acetic acid thereto, solvent thermally reacting at 90-100°C for 5-15 hours, cooling to room temperature, washing, and vacuum drying to obtain loaded titanium dioxide; S2, adding polyvinylidene fluoride and loaded titanium dioxide into hexafluoroisopropanol and stirring evenly to obtain a prefabricated shell mixture; S3, adding collagen and carbon nanotubes into hexafluoroisopropanol and stirring evenly to obtain a prefabricated core layer mixture; S4. Coaxially electrospin the prefabricated shell layer mixture and the prefabricated core layer mixture onto the surface of a metal drum, the electrospinning voltage is 18-20 kV, and the distance between the spinning nozzle and the metal drum is 10-12 cm; heat treatment at 70-80° C. for 10-15 h.

5. The preparation method of the electrospun nanofiber porous membrane for protective clothing according to claim 4, characterized in that, In S1, the ultrasound frequency is 10-15kHz.

6. The preparation method of the electrospun nanofiber porous membrane for protective clothing according to claim 4, characterized in that, In S4, during the coaxial electrospinning process, the prefabricated shell layer mixture is injected into the outer needle of the coaxial electrospinning needle, and the prefabricated core layer mixture is injected into the inner needle of the coaxial electrospinning needle. The inner diameter of the outer needle is 1-1.2 mm, and the inner diameter of the inner needle is 0.6-0.8 mm. The inner layer liquid inlet speed is controlled to be 0.1-0.4 mL / min, and the outer layer liquid inlet speed is 1-1.5 mL / min.

7. A protective suit, characterized in that, From the inside out, they include: polyester fabric, the electrospun nanofiber porous membrane for protective clothing as described in any one of claims 1 to 3, non-woven fabric, the electrospun nanofiber porous membrane for protective clothing as described in any one of claims 1 to 3, and polyester / polypropylene fabric.

8. The protective clothing according to claim 7, wherein The mass ratio of polyester to polypropylene in the polyester / polypropylene fabric is 50:50; the areal density of the polyester fabric is 90 - 110 g / m 2 , the areal density of the non-woven fabric is 50 - 70 g / m 2 , the areal density of the polyester / polypropylene fabric is 120 - 140 g / m 2 .

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