A cleanable flexible multifunctional coaxial electrospun fiber membrane and preparation and application thereof

Abstract

The application discloses a washable flexible multifunctional coaxial electrospun fiber membrane and a preparation and application thereof. The fiber membrane adopts a coaxial electrospun composite membrane, silver nanoparticles are loaded on the coaxial electrospun composite membrane, and PDMS is coated on a surface layer, wherein the PDMS is polydimethylsiloxane; a core layer component of the coaxial electrospun composite membrane comprises polymer one and conductive particles; a shell layer component of the coaxial electrospun composite membrane comprises polymer two and magnetic particles; the polymer one and the polymer two are independently selected from polymers containing benzene rings or polar groups; and the polymer one and the polymer two have compatibility. The wearable electronic textile based on the high-performance coaxial electrospun fiber has stability and multifunctionality, and has great application potential in future pregnant woman protective clothing.

Description

Technical Field

[0001] This invention relates to a flexible fiber membrane, specifically to a washable flexible multifunctional coaxial electrospun fiber membrane and its preparation and application. Background Technology

[0002] Today, public concern about electromagnetic radiation pollution is growing. Electromagnetic radiation pollution seriously threatens people's health, causing nausea, headaches, eye problems, and even cancer, and is particularly harmful to the developing brains of infants. For pregnant women, it would be invaluable if their protective clothing could also serve more valuable functions, such as not only protecting the fetus from electromagnetic radiation (electromagnetic shielding), but also providing heat to their injured joints, keeping them warm during heat treatment (thermotherapy), and monitoring their activities and fetal movements (human body sensing).

[0003] Currently, some materials can achieve the above functions, such as introducing nanosheets into electrospun thermoplastic polyurethane (TPU) fiber membranes (Journal of Materials Chemistry A 2021, 9(11), 7238-7247), or using carbon nanotubes (CNTs) and MXene, as well as two Ag adsorption-reduction processes, to create multifunctional electrospun polyurethane films with unique multidimensional conductive networks, which have tensile sensing, thermotherapy, and electromagnetic interference shielding properties (Advanced Electronic Materials 2020, 7(1)). Although these fabrics achieve a certain degree of multifunctionality, the following problems still exist:

[0004] (1) Although the performance of these wearable devices has been significantly improved, the comfort, performance stability and washability of maternity protective clothing still need to be further improved in order to achieve seamless integration and sensitivity with the therapeutic functions of textiles and clothing.

[0005] (2) Since the fabrics obtained by using existing fabrics or by electrospinning, wet spinning and other methods are basically pure polymer fabrics with very simple existing structures, in order to increase the functionality, it is necessary to carry out complex modifications on the original fabrics or superimpose multiple conductive materials, which makes the synthesis very complicated and time-consuming.

[0006] Furthermore, washability presents a significant challenge for wearable electronics based on electronic fabrics to achieve success in a broader market. In the case of personal protective equipment for pregnant women, hygiene requirements make washing essential. However, traditional electronic components are often rigid, uncomfortable, and difficult to integrate with the complex structure of a pregnant woman's body, which greatly limits their practical application.

[0007] Currently, the most common method for preparing multifunctional electrospun fiber membranes is uniaxial electrospinning, followed by modification of the electrospun fibers with functional particles, or blending functional particles with polymers and then coating them onto the surface of the fiber membrane. This method is not only time-consuming, but also difficult to control the content of functional particles and fiber membranes, thus failing to simultaneously meet the requirements of washability and multifunctionality. Summary of the Invention

[0008] The purpose of this invention is to provide a washable, flexible, multifunctional coaxial electrospun fiber membrane, its preparation and application, which solves the problem of poor washability of existing fiber membranes. It has hydrophobicity and washability, as well as stability and multifunctionality, and has great potential for future application in protective clothing for pregnant women.

[0009] To achieve the above objectives, this invention provides a washable, flexible, multifunctional coaxial electrospun fiber membrane. This membrane is a coaxial electrospun composite membrane on which silver nanoparticles are loaded, and a surface layer is coated with PDMS (polydimethylsiloxane). The core layer of the coaxial electrospun composite membrane comprises polymer one and conductive particles; the particle size of the conductive particles is <100 nm. The shell layer of the coaxial electrospun composite membrane comprises polymer two and magnetic particles; the particle size of the magnetic particles is <100 nm. Polymer one and polymer two are independently selected from polymers containing benzene rings or polar groups; polymer one and polymer two are compatible. The particle size of the conductive and magnetic particles must be below 100 nm to be electrospun; particles larger than 100 nm will clog the needles, preventing spinning.

[0010] Preferably, polymer one and polymer two are independently selected from any one or more of polyacrylonitrile (PAN), polyurethane (PU), polyvinyl alcohol (PVA), polyvinylidene fluoride (PVDF), and polystyrene (PS). Coaxial electrospinning can be performed using these materials, while materials such as polyacrylic acid (PAA) cannot be electrospinned. More preferably, the molecular weight of polymer one and polymer two is independently between 150,000 and 350,000.

[0011] Preferably, the conductive particles are selected from any one or more of carbon nanotubes, graphene oxide, and MXene.

[0012] Preferably, the magnetic particles are selected from any one or more of MOF, Fe3O4, and Fe2O3.

[0013] Preferably, the thickness of the PDMS is 10–15 μm.

[0014] Preferably, the mass ratio of polymer one to conductive particles and polymer two to magnetic particles is independently (8-5):(2-5).

[0015] More preferably, the mass ratio of polymer one to conductive particles and polymer two to magnetic particles is independently (8-7):(2-3).

[0016] Preferably, the mass ratio of the conductive particles to the magnetic particles is (1-5):1.

[0017] More preferably, the mass ratio of the conductive particles to the magnetic particles is (4-5):1.

[0018] Another object of the present invention is to provide a method for preparing the aforementioned washable flexible multifunctional coaxial electrospun fiber membrane, the method comprising:

[0019] (1) Preparation of coaxial electrospinning solution

[0020] Polymer I and Polymer II were dissolved in the same polar solvent to obtain solutions of Polymer I and Polymer II, respectively; wherein the concentrations of Polymer I and Polymer II in the obtained solutions were independently 10–20 wt%.

[0021] Conductive particles and magnetic particles are dispersed in the polar solvent to obtain conductive particle dispersion and magnetic particle dispersion, respectively; the polar solvent is selected to dissolve polymer one and polymer two, but not conductive particles and magnetic particles.

[0022] The polymer solution is mixed with the conductive particle dispersion to obtain the inner core spinning solution;

[0023] The polymer solution and the magnetic particle dispersion were mixed to obtain the shell spinning solution;

[0024] (2) Preparation of coaxial electrospun fiber membrane

[0025] The inner core spinning solution and the outer shell spinning solution are loaded into a coaxial conduit and sprayed onto silicone paper through an electrospinning machine. The silicone paper is then peeled off from under the roller to obtain a coaxial electrospinning composite film.

[0026] (3) Silver nanoparticle loading

[0027] Ammonia was added dropwise to a 5-20 wt% silver nitrate aqueous solution. The coaxial electrospun composite membrane was then added to a dispersed AgNO3 solution. A glucose solution was added to react and reduce AgNO3 to AgNPs. The resulting membrane was rinsed clean and dried to obtain a fiber membrane loaded with silver nanoparticles.

[0028] (4) Surface PDMS coating

[0029] PDMS and silicone curing agent are mixed, and PDMS is sprayed onto a fiber membrane loaded with silver nanoparticles at a pressure of about 1 MPa using a spray gun equipped with an air compressor. Then, it is crosslinked and cured at 70-80°C.

[0030] Preferably, the coaxial electrospinning time is 1 to 10 hours, and the voltage used is 18 to 25 kV.

[0031] Preferably, the ammonia concentration is 25 wt%.

[0032] Preferably, the concentrations of polymer one and polymer two in the resulting solution are independently 13–20 wt%.

[0033] Preferably, a glucose solution is added for the reaction, and the reduction time is 1 to 8 hours.

[0034] Preferably, the polar solvent is selected from any one or more of N,N-dimethylformamide (DMF), water, and ethanol.

[0035] Another object of the present invention is to provide the application of the washable flexible multifunctional coaxial electrospun fiber membrane in maternity protective clothing.

[0036] The washable flexible multifunctional coaxial electrospun fiber membrane of the present invention, its preparation and application, have the following advantages:

[0037] This invention differs from traditional thinking by proposing a novel design concept for a washable, flexible, multifunctional coaxial electrospun membrane. Through ingenious structural design, two functional particles are introduced into the fiber in a single coaxial electrospinning process for electromagnetic shielding. Since the core and shell use the same or highly compatible polymer, the two layers have excellent compatibility and are firmly bonded together without peeling.

[0038] This unique material combines these properties with waterproof, stain-resistant, and machine-washable capabilities. Through ingenious structural design, the coaxial electrospun fiber membrane matrix not only endows smart devices with high breathability (water vapor transmission rate (WVTR, g·cm³) but also... -2 ·h -1 The value is 0.0125 g·cm⁻¹ -2 ·h -1The film exhibits ultra-flexibility (tensile deformation exceeding 200%), with conductive particles in the core providing a stable and continuous conductive network, while magnetic particles in the outer shell not only help the fibers provide abundant attachment sites for silver nanoparticles but also provide magnetic loss and increase absorption of electromagnetic waves. In a silver nitrate solution, the coaxial electrospun fiber membrane is reduced by silver ions, resulting in uniformly loaded silver nanoparticles on the surface of each fiber, forming a robust biphasic conductive channel within the material and improving the film's conductivity (650 S / cm). Then, a 10–15 μm PDMS coating is sprayed onto the upper and lower surfaces of the composite membrane, which not only improves the mechanical strength and performance stability of the composite fiber membrane but also imparts high hydrophobicity and washability. The composite fiber membrane possesses a high conductivity (over 400 S / cm) due to the presence of a double-layer conductive network of conductive particles within the coaxial electrospun fiber core and silver nanoparticles. Because of the high impedance mismatch, some electromagnetic waves are immediately reflected upon encountering the silver nanoparticles in the conductive material. Then, some of the incoming electromagnetic waves interact with the magnetic and conductive particles in the coaxial fibers as they pass through the composite membrane. This interaction of electron carriers generates abundant polarization and losses at interfaces, defects, and terminal groups, thus giving the membrane electromagnetic shielding properties (X-band electromagnetic shielding performance exceeding 110.0 dB at a thickness of 0.3 mm). Furthermore, the composite membrane also exhibits advantages such as thermal therapy (temperature rise to 40–70°C within 20 seconds when 1.5V is applied), good sensing performance (high sensing sensitivity within a 0–230% tensile range), and high mechanical strength (tensile deformation exceeding 200%). It also possesses extremely high stability, maintaining these functions even after 10 water washes, with a water contact angle of 140–150°. This high-performance wearable electronic textile based on coaxial electrospun fiber membrane has stability and multifunctionality, and has broad applications in maternity protective clothing, electromagnetic shielding, and other fields in the future. Attached Figure Description

[0039] Figure 1 The TEM morphology of the flexible multifunctional coaxial electrospun fiber membrane in Example 1 is shown.

[0040] Figure 2 The image shows the SEM morphology of the flexible multifunctional coaxial electrospun fiber membrane in Example 1. Detailed Implementation

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Example 1

[0043] A flexible multifunctional coaxial electrospun fiber membrane of PAN@CNT-PAN@Fe2O3 is prepared by the following steps:

[0044] (1) Preparation of coaxial electrospinning solution

[0045] Two portions of PAN powder (molecular weight of 150,000 to 300,000) were dissolved in N,N-dimethylformamide (DMF) solution respectively, and the resulting solution concentration was 13 wt%. The solution was stirred for 20 h to obtain PAN solution.

[0046] CNT (carbon nanotube) powder and Fe2O3 particles were dispersed in DMF and stirred evenly to obtain functional particle CNT dispersion and functional particle Fe2O3 dispersion, respectively.

[0047] After degassing, PAN solution was mixed with functional particle CNT dispersion and functional particle Fe2O3 dispersion to obtain inner core spinning solution PAN / CNT and outer shell spinning solution PAN / Fe2O3. The mass ratio of polymer to functional particles in both inner core spinning solution and outer shell spinning solution was 8:2, and the mass ratio of CNT to Fe2O3 was 5:1. The voltage was 20KV and the electrospinning time was 4 hours.

[0048] (2) Preparation of coaxial electrospun fiber membrane

[0049] The prepared spinning solutions for the inner core and outer shell are loaded into a coaxial conduit and sprayed onto silicone paper through an electrospinning machine. After 2 hours, the silicone paper is peeled off from under the roller to obtain a coaxial electrospinned fiber membrane.

[0050] (3) Silver nanoparticle loading

[0051] Silver nitrate was dissolved in water to a concentration of 10 wt%. Ammonia (25 wt%) was added dropwise to the solution, and the coaxial electrospun membrane obtained in step (1) was added to a dispersed AgNO3 solution. Glucose solution was added to the above solution, and after reacting for 4 hours, AgNO3 was reduced to AgNPs. The resulting membrane was rinsed clean and then dried in a vacuum oven at 60 °C to obtain a silver-loaded fiber membrane.

[0052] (4) Surface PDMS coating

[0053] PDMS and silicone curing agent at a mass ratio of 10:1 were mixed in ethyl acetate under magnetic stirring. The concentration of PDMS in ethyl acetate was 20 wt%. The mixture was magnetically stirred for 0.5 h. PDMS was then sprayed onto a fiber membrane loaded with silver nanoparticles under pressure using a spray gun equipped with an air compressor. The composite membrane was then placed in an oven at 80 °C for crosslinking for 4 h. The resulting flexible multifunctional coaxial electrospun fiber membrane was designated as flexible membrane 1.

[0054] Example 2

[0055] A flexible multifunctional coaxial electrospun fiber membrane of PU@CNT-PU@Fe3O4 is prepared by a method that is basically the same as that in Example 1, except that:

[0056] In step (1), PU powder (molecular weight of 200,000) is used to replace PAN powder, and the resulting solution concentration is 20wt%. The mass ratio of the polymer in the inner core spinning solution and the outer shell spinning solution to the functional particles they are mixed with is 7:3, and the mass ratio of CNT and Fe3O4 is 4:1.

[0057] In step (2), the silicone paper is peeled off from under the roller after 3 hours;

[0058] In step (3), the concentration of the silver nitrate aqueous solution used is 5 wt%; after 6 h of reaction, AgNO3 is reduced to AgNPs.

[0059] Example 3

[0060] A flexible multifunctional coaxial electrospun fiber membrane based on PU@graphene oxide-PU@Fe3O4 is prepared using a method basically the same as that in Example 1, with the difference being:

[0061] In step (1), PU powder (molecular weight of 200,000) is used instead of PAN powder, and the resulting solution concentration is 20wt%; the two functional particles are Fe3O4 and graphene oxide, respectively; the mass ratio of graphene oxide to Fe3O4 is 5:1.

[0062] In step (3), the concentration of the silver nitrate aqueous solution used is 20 wt%; after reacting for 2 h, AgNO3 is reduced to AgNPs.

[0063] Example 4

[0064] A flexible multifunctional coaxial electrospun fiber membrane of PS@MXene-PU@Fe3O4 is prepared by a method that is basically the same as that in Example 1, except that:

[0065] In step (1), one part PS powder (molecular weight of 350,000) and one part PU powder (molecular weight of 200,000) are used to replace two parts PAN powder, and the resulting solution concentration is 20wt%; the two functional particles are MXene and Fe3O4, respectively; the PS solution and MXene are mixed to obtain the inner core spinning solution PS / MXene, and the PU solution and Fe3O4 dispersion are mixed to obtain the outer shell spinning solution PU / Fe3O4; the mass ratio of MXene to Fe3O4 is 4:1;

[0066] In step (3), the concentration of the silver nitrate aqueous solution used is 20 wt%; after a reaction time of 2 h, AgNO3 is reduced to AgNPs.

[0067] Example 5

[0068] A flexible multifunctional coaxial electrospun fiber membrane of PU@CNT-PVDF@Fe2O3 is prepared by a method that is basically the same as that in Example 1, except that:

[0069] In step (1), one part of PVDF powder (molecular weight of 350,000) and one part of PU powder (molecular weight of 200,000) are used to replace two parts of PAN powder. The solvent used is ethanol solution, and the concentration of the resulting solution is 18wt%. The solvent used for the functional particle CNT dispersion and the functional particle Fe2O3 dispersion is also ethanol solution. The PU solution and the functional particle CNT dispersion are mixed to obtain the inner core spinning solution PU / CNT. The PVDF solution and the functional particle Fe2O3 dispersion are mixed to obtain the outer shell spinning solution PVDF / Fe2O3. The mass ratio of any polymer to the functional particles it is mixed with is 7:3, and the mass ratio of CNT to Fe3O4 is 4.6:1.

[0070] In step (2), the silicone paper is peeled off from under the roller after 4 hours.

[0071] Comparative Example 1

[0072] The preparation method of a PAN / Ag / PDMS composite membrane (composite membrane 1) is basically the same as that in Example 1, except that:

[0073] In step (1), two portions of PAN powder (molecular weight of 150,000) were dissolved in DMF solution, and the resulting solution concentration was 13wt%. After stirring for 24 hours, the spinning solution was obtained after degassing.

[0074] Comparative Example 2

[0075] The preparation method of a PAN-CNT / PAN-Fe2O3 / PDMS composite membrane (composite membrane 2) is basically the same as that in Example 1, except that:

[0076] No step (3).

[0077] Experimental Example 1: Microstructure of the flexible multifunctional coaxial electrospun fiber membrane of the present invention

[0078] 1. Test Methods

[0079] The composite film prepared in Example 1 was used to observe the structure of the coaxial fibers and the morphology of the composite film surface using transmission electron microscopy and scanning electron microscopy. Before observation with transmission electron microscopy, the coaxial fiber filaments were sprayed onto a copper mesh. Before observation with scanning electron microscopy, the composite film was sputtered with gold.

[0080] 2. Test Results

[0081] TEM images of coaxial fibers, such as Figure 1 As shown, the fibers exhibit a distinct core-shell structure, with an inner layer of CNTs and an outer layer of Fe3O4. The aerogel prepared by slow freezing can form a micron-scale porous structure inside, such as... Figure 2 (A and B are SEM morphologies of the flexible multifunctional coaxial electrospun membrane of Example 1 at different magnifications) This shows that the electrospun nanofibers are loaded with a high content of silver nanoparticles, resulting in a large number of conductive particles in the composite membrane, which in turn brings about high conductivity.

[0082] Experimental Example 2: Determination of the air permeability and flexibility of the coaxial electrospun fiber membrane of the present invention.

[0083] 1. Breathability

[0084] (1) Test methods

[0085] The water vapor transmission rate (WVTR) of the coaxial electrospun fiber membrane prepared in Example 1 of this invention is as follows: -2 ·h -1 The test involved sealing the bottle opening with the flexible multi-functional coaxial electrospun membrane of Example 1, then heating it in a hot pan at 35°C. The change in the mass of the water in the bottle over time was calculated using the following formula:

[0086] WVTR = M / At

[0087] Where M represents the mass loss of water (g), and A represents the area of ​​the container pores (cm²). 2 ), where t represents the time (h) required for the water mass to be lost.

[0088] (2) Test Results

[0089] The results showed that the water vapor transmission rate (WVTR) of the coaxial electrospun fiber membrane prepared in Example 1 of the present invention was 0.0125 g·cm⁻¹. -2 ·h -1 .

[0090] Experimental Example 3: Determination of the conductivity of the silver-loaded fiber membrane and the flexible multifunctional coaxial electrospun fiber membrane of the present invention.

[0091] 1. Test Methods

[0092] The conductivity of the silver-loaded fiber membrane and the flexible multifunctional coaxial electrospun fiber membrane of Example 1 of the present invention was measured using an insulation resistance tester (6487, Keith). Each sample was tested three times, and the conductivity of the three tests was calculated as follows:

[0093] σ=l / Rwt

[0094] Where l, R, w, and t represent the length, resistance, width, and thickness of the sample, respectively.

[0095] 2. Test Results

[0096] The results showed that the conductivity of the silver-loaded fiber membrane prepared in Example 1 of the present invention was 650 S / cm, and the conductivity of the flexible multifunctional coaxial electrospun fiber membrane obtained after spraying PDMS coating was higher than 400 S / cm.

[0097] Experimental Example 4: Electromagnetic Shielding of the Flexible Multifunctional Coaxial Electrospun Fiber Membrane of the Present Invention

[0098] 1. Test Methods

[0099] The flexible multifunctional coaxial electrospun membrane of Example 1 (flexible membrane 1) and comparative examples 1 and 2 (composite membrane 1 and composite membrane 2) were used. The electromagnetic parameters of the films (13 mm in diameter, 0.3 mm in thickness) in the X-band were measured at room temperature using a network analyzer (Agilent Technologies N5247). The X-band scattering parameters (S0) were recorded. 11 and S 21 To obtain reflectivity (R), absorptivity (A), transmittance (T), and total electromagnetic shielding effectiveness (SE) T Electromagnetic wave reflection efficiency (SE) R ) and electromagnetic wave absorption efficiency (SE) A The coefficients of ) are calculated using the following formulas:

[0100] R = |S 11 | 2 (1)

[0101] A = 1 - RT (2)

[0102] T = |S 21 | 2 (3)

[0103] SE T =-10·log 10 (T) (4)

[0104] SE R =-10·log 10 (1-R) ​​(5)

[0105] SE A =-10·log 10 [(T / 1-R)] (6)

[0106] 2. Test Results

[0107] Table 1 Electromagnetic shielding performance of composite fiber membranes in embodiments and comparative examples of the present invention.

[0108]

[0109] The test results are shown in Table 1. It can be seen that only by forming a double conductive network and adding magnetic loss can the composite fiber membrane achieve high electromagnetic shielding.

[0110] Experimental Example 5: Strain Sensing Test of the Flexible Multifunctional Coaxial Electrospun Fiber Membrane of the Present Invention

[0111] 1. Test Methods

[0112] Strain induction tests were conducted on the flexible multifunctional coaxial electrospun membrane and coaxial electrospun fiber membrane of Example 1 of the present invention, respectively, using a high-precision electronic universal testing machine (INSTRO 5967, USA), which is equipped with a tensile controller and software system. A constant voltage was applied to them using an electrochemical workstation (PARSTAT 2273, Princeton Applied Research Corporation), and the resistance change was measured.

[0113] The Joule heating performance test of the flexible multifunctional coaxial electrospun membrane (flexible membrane 1) of Example 1 was conducted using a DC power supply (UTP 1306S, UNI-T) charged at a specific voltage, and a thermal imager (E60, FLIR) was used to detect temperature changes in real time.

[0114] 2. Test Results

[0115] When 1.5V is applied, the flexible multifunctional coaxial electrospun membrane of Example 1 heats up to 40–70°C within 20 seconds, exhibiting high sensing sensitivity within a stretching range of 0–230%. The stretching deformation of the coaxial electrospun fiber membrane of Example 1 can exceed 200%.

[0116] Experimental Example 6: Washability and Contact Angle Measurement of the Flexible Multifunctional Coaxial Electrospun Membrane of the Present Invention

[0117] 1. Washability

[0118] (1) Test methods

[0119] The washability of the flexible multifunctional coaxial electrospun membrane (flexible membrane 1) of Example 1 and the samples of Comparative Examples 1 and 2 (composite membrane 1 and composite membrane 2) was simulated by accelerated water washing according to the AATCC TM 61-1A standard.

[0120] (2) Test Results

[0121] The test results are shown in Table 2. In Comparative Example 2, the composite fiber membrane, lacking the protection of a PDMS layer, experienced a sharp decline in performance due to the shedding of silver nanoparticles from the fiber surface during the washing process. However, the flexible membrane 1 of Example 1, a novel composite membrane, not only exhibits high performance but also maintains its original performance after up to ten water washes.

[0122] Table 2. Washability of composite fiber membranes in the embodiments and comparative examples of the present invention.

[0123]

[0124] 2. Contact angle

[0125] The water contact angle of the flexible multifunctional coaxial electrospun membrane in Example 1 was measured to be 140-150° using a contact angle measuring instrument.

[0126] In summary, the water vapor transmission rate (WVTR) of the coaxial electrospun fiber membrane of the present invention is 0.0125 g·cm⁻¹. -2 ·h -1 The tensile deformation can exceed 200%, and the conductivity of the silver-loaded fiber membrane is 650 S / cm. Spraying a PDMS coating onto the coaxial electrospun fiber membrane not only improves its washability but also enhances the mechanical strength and performance stability of the composite fiber membrane, imparting high hydrophobicity. After spraying the PDMS coating, the conductivity of the flexible multifunctional coaxial electrospun membrane exceeds 400 S / cm. The flexible multifunctional coaxial electrospun membrane of this invention also possesses thermotherapy properties; when 1.5V is applied, the temperature rises to 40–70°C within 20 seconds, exhibiting high sensing sensitivity within a tensile range of 0–230%, and the composite membrane's water contact angle can reach 140–150°.

[0127] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A washable flexible multifunctional coaxial electrospun fiber membrane, characterized in that, The fiber membrane adopts a coaxial electrospun composite membrane, silver nanoparticles are loaded on the coaxial electrospun composite membrane, and PDMS is coated on the surface layer, wherein the PDMS is polydimethylsiloxane; The core layer component of the coaxial electrospun composite membrane comprises polymer one and conductive particles; the particle size of the conductive particles is <100 nm; The shell layer component of the coaxial electrospun composite membrane comprises polymer two and magnetic particles; the particle size of the magnetic particles is <100 nm; The polymer one and the polymer two are independently selected from polymers containing benzene rings or polar groups; The polymer one and the polymer two have compatibility.

2. The washable flexible multi-functional coaxial electrospun fiber membrane according to claim 1, wherein, The polymer one and the polymer two are independently selected from any one or more than two of polyacrylonitrile, polyurethane, polyvinyl alcohol, polyvinylidene fluoride and polystyrene.

3. The washable flexible multi-functional coaxial electrospun fiber membrane according to claim 2, wherein, The molecular weight of the polymer one and the polymer two is independently 150-350 thousand.

4. The washable flexible multi-functional concentric electrospun fiber membrane according to claim 1, wherein, The conductive particles are selected from any one or more than two of carbon nanotubes, graphene oxide and MXene.

5. The washable flexible multi-functional concentric electrospun fiber membrane according to claim 1, wherein, The magnetic particles are selected from any one or more than two of MOF, Fe3O4 and Fe2O3.

6. The washable flexible multi-functional concentric electrospun fiber membrane according to claim 1, wherein, The thickness of the PDMS is 10-15 μm.

7. The washable flexible multi-functional concentric electrospun fiber membrane according to claim 1, wherein, The mass ratio of the polymer one and the conductive particles, the polymer two and the magnetic particles is independently (8-5):(2-5).

8. The washable flexible multi-functional concentric electrospun fiber membrane according to claim 1, wherein, The mass ratio of the conductive particles and the magnetic particles is (1-5):

1.

9. The method of claim 1-8, wherein the washable flexible multifunctional co-axial electrospun fiber membrane is prepared by, The method comprises: (1) Preparation of coaxial electrospinning solution The polymer one and the polymer two are respectively dissolved in the same polar solvent to obtain a polymer one solution and a polymer two solution; wherein the concentration of the polymer one and the polymer two in the obtained solution is independently 10-20 wt%; The conductive particles and the magnetic particles are respectively dispersed in the polar solvent to obtain a conductive particle dispersion liquid and a magnetic particle dispersion liquid; the polar solvent is selected to be a solvent capable of dissolving the polymer one and the polymer two but not capable of dissolving the conductive particles and the magnetic particles; The polymer one solution and the conductive particle dispersion liquid are mixed to obtain an inner core spinning solution; The polymer two solution and the magnetic particle dispersion liquid are mixed to obtain an outer shell spinning solution; (2) Preparation of coaxial electrospun fiber membrane The inner core spinning solution and the outer shell spinning solution are loaded into a coaxial catheter, sprayed onto a silicone oil paper through an electrospinning machine, and the silicone oil paper is taken off from the roller to obtain a coaxial electrospun composite membrane; (3) Silver nanoparticle loading Ammonia water is added dropwise into a silver nitrate aqueous solution with a concentration of 5-20 wt%, the coaxial electrospun composite membrane is added into the dispersed AgNO3 solution, a glucose solution is added for reaction, AgNO3 is reduced into AgNPs, the obtained membrane is washed clean, dried, and a fiber membrane loaded with silver nanoparticles is obtained; (4) Surface layer PDMS coating The PDMS and a silicone curing agent are mixed, the PDMS is sprayed onto the fiber membrane loaded with silver nanoparticles under the pressure of 1 MPa by using an air compressor-equipped spray gun, and then cross-linked and cured at 70-80℃.

10. The method of claim 9, wherein, The coaxial electrospinning time is 1-10 h, and the voltage used is 18-25 kV.

11. Application of the washable flexible multifunctional coaxial electrospun fiber membrane according to any one of claims 1-8 in a protective garment for pregnant women.

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