A self-adhesive unidirectional hydrophobic silica fiber membrane, its preparation method and application

Abstract

This invention relates to the field of flexible insulating materials technology, specifically a self-adhesive unidirectional hydrophilic silicone fiber membrane, its preparation method, and its applications. The preparation method provided by this invention, in order to match the high viscosity coefficients of liquid silicone and the sacrificial layer fluid material, designs a corresponding electrospinning platform for thermosetting polymer fiber forming, constructing an all-silicone flexible spun material framework; patterned exposure is performed on one side of the film using plasma with a template design, followed by self-assembly of a hydrophilic film at the exposed area, solidifying the hydrophilic groups on and inside the silicone fiber surface, thus achieving the unidirectional hydrophilic function and long-term stability of the final membrane material; the self-adhesive function under the all-silicone fiber framework is achieved by spinning core-shell structure fibers onto a base membrane; providing a new realization path for wearable bioelectronics and high-intensity exercise physiological detection substrates.

Description

Technical Field

[0001] This invention relates to the field of flexible insulating materials technology, specifically to a self-adhesive unidirectional hydrophilic silicone fiber membrane, its preparation method, and its application. Background Technology

[0002] Silicone materials are widely used in the biomedical and optical fields due to their excellent chemical stability, electrical insulation, thermal stability, flexibility, water resistance, oxidation resistance, biocompatibility, sterilizability, and optical transparency. Traditional methods for preparing silicone films (taking highly transparent polydimethylsiloxane PDMS as an example) mainly include spin coating, hang coating, and spray coating, forming dense, non-porous films with controllable thickness.

[0003] With the development of wearable electronics, this dense material cannot meet the needs of breathable substrates for long-term wear and various functional porous support materials. Chemical foaming and template methods have been developed to prepare stretchable porous silicone substrates. Examples include (i) polymer microparticles (e.g., polystyrene), then dissolving the polystyrene beads with toluene; (ii) liquid mixtures (e.g., water and ethanol), then forming pores through evaporation; (iii) water-soluble solutes (e.g., sugars), then dissolving the solute in water; and (iv) chemical foaming. For example, a method using citric acid crystallization and dissolution in PDMS to form small-sized foam pores was reported in a well-known international journal (npj Flexible Electronics (2023) 7:49). All of these methods are suitable for preparing silicone foam materials, but the total thickness is difficult to control precisely. It is difficult to achieve precise control and preparation of porous structures in ultra-compliant stretchable substrates and functional silicone materials (thickness on the order of 10 μm and below).

[0004] One-way water wicking is a technology centered around breathable, sweat-wicking flexible substrate materials. With the development of wearable devices, prolonged wear leads to sweat retention on the skin's surface, affecting overall device performance, reducing comfort, and even triggering skin inflammation. In recent years, methods focusing on breathable, sweat-wicking, and one-way water wicking have been reported extensively. Breathable perspiration strategies include adding biphasic polymers to one side of the material (Mater. Today Phys., 2020, 12, 100191) – self-assembling a layer of thiol molecules on the surface of gold nanowires to increase perspiration rate; one-way hydrophoresis strategies include: (i) using Janus biphasic microspheres dispersed inside the fabric (Adv. Mater. Technol. 2022, 7, 2200040) to allow sweat to be expelled against gravity across a substrate of a certain thickness; (ii) a paper published in the top international journal Nature describes using plasma technology to pattern and etch the surface of commercially available textiles with a thickness of hundreds of micrometers (Nature, 2024, 628, 84-92) to generate hydrophilic permeable groups, thereby achieving sweat expulsion against gravity. Both of these one-way hydrophoresis technologies are prepared on relatively thick substrates, resulting in insufficient skin adhesion. Furthermore, due to the presence of gravity, further fixation to the skin still requires the addition of other adhesive materials such as medical tape, which significantly reduces the perspiration effect. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a self-adhesive unidirectional hydrophilic silica fiber membrane, its preparation method and application. The preparation method provided by the present invention can prepare a unidirectional hydrophilic porous silica fiber membrane with an ultra-thin thickness that is adjustable, and can achieve self-adhesion function under a full silica fiber framework.

[0006] This invention provides a method for preparing a self-adhesive unidirectional hydrophobic silica fiber membrane, comprising the following steps:

[0007] S1) On an insulating material, PVP solution and PDMS dilution are coaxially electrospun and cured to obtain a base film;

[0008] S2) A patterned surface is constructed on one side of the base film obtained in step S1), and the PVA solution is cured on the patterned surface of the base film to obtain a unidirectional hydrophobic base film.

[0009] S3) The patterned surface of the unidirectional hydrophilic base membrane obtained in step S2) is subjected to coaxial electrospinning of PVP solution and PDMS dilution containing silicone pressure-sensitive adhesive, and after curing, a self-adhesive unidirectional hydrophilic silicone fiber membrane is obtained.

[0010] In steps S1) and S3), the receiving end of the coaxial electrospinning is located directly below the exit end of the coaxial electrospinning, the exit end is loaded with a positive high voltage of 15 kV to 28 kV, and the receiving end is loaded with a negative high voltage of 6 kV to 10 kV.

[0011] In step S1) of this invention, a PVP solution and a PDMS diluent are first coaxially electrospun on an insulating material, and a base film is obtained after curing. Specifically, in this invention, the insulating material is placed on the electrode plate at the receiving end of the coaxial electrospinning process, with the PVP solution as the shell component spinning solution (also known as the sacrificial layer component spinning solution) and the PDMS diluent as the core component spinning solution. The PVP solution and the PDMS diluent are coaxially electrospun using a coaxial needle, which is placed at the exit end of the coaxial electrospinning process. The receiving end of the coaxial electrospinning process is located directly below the exit end of the coaxial electrospinning process. The exit end is directly connected to the coaxial needle with a positive high voltage of 15 kV to 28 kV, preferably 15 kV to 25 kV. The receiving end is directly connected to the electrode plate with a negative high voltage of 6 kV to 10 kV, preferably 6 kV to 9 kV, so that the insulating material is in a negative high voltage electric field. In some embodiments of the present invention, the insulating material is selected from high-temperature resistant release paper, specifically fluorinated release paper.

[0012] To match the high viscosity coefficients of liquid silicone and sacrificial layer fluid materials, this invention designs a corresponding electrospinning platform for thermosetting polymer fiber forming. Coaxial electrospinning with positive and negative high-voltage power supplies is performed in the vertical direction. Positive voltage is applied to the coaxial needle head, while negative high voltage is applied to a metal heat-conducting plate electrode of a specific shape and size, perpendicular to the nozzle of the coaxial needle head. By uniformly arranging the negative high voltage on the shape-controlling electrode plates, the problems of flyaway fibers and spinning pad formation can be effectively controlled, resulting in a uniform, fully perforated product. This achieves precise coverage of the electric field tension within a limited pattern in this direction, ultimately forming a uniform and controllable fiber membrane structure on the insulating material.

[0013] The temperature of the receiving end of the coaxial electrospinning process described in this invention is 100℃~140℃. This invention further heats the bicomponent spinning solution ejected from the outlet end through a hot plate at the receiving end, causing the micron-sized fibers to solidify rapidly and form a loose, porous structure with good air permeability.

[0014] The PVP solution mentioned in step S1) of this invention is specifically an alcoholic solution of PVP, more specifically a methanolic solution of PVP; the weight-volume ratio of PVP in the PVP solution is 15% (w / v) to 20% (w / v)%. The PVP solution of this invention serves as the spinning solution for the sacrificial layer component, and the sacrificial layer material is selected based on mechanical property matching using a high-viscosity polymer hydrogel material. In some embodiments of this invention, the PVP is high-polymerization-degree polyvinylpyrrolidone PVP (K90).

[0015] The PDMS diluent in step S1 of this invention comprises PDMS and a diluent in a weight ratio of (4~6):1. Specifically, the PDMS diluent is obtained by diluting PDMS with a diluent; wherein, the PDMS is a thermosetting silicone spinning material; in some embodiments of this invention, the PDM diluent S is selected from Sylgard-184 diluent. The diluent is selected from one or more of n-hexane and cyclohexane. This invention dilutes thermosetting silicone in a liquid state, thereby reducing the tensile load on the sacrificial layer fiber material at the high-pressure nozzle.

[0016] Before coaxial electrospinning, the PDMS diluent is heat-treated at 60°C to 80°C for 15 to 50 minutes, preferably 30 to 40 minutes, and more preferably 38 minutes. This heat treatment allows for partial pre-crosslinking of the PDMS diluent before coaxial electrospinning, thereby increasing the molding speed.

[0017] In step S1) of this invention, the volume ratio of the coaxial electrospinning speed of the PVP solution and the PDMS dilution is (7~9):3. This invention uses PVP as a sacrificial layer to encapsulate the diluted pre-crosslinked PDMS precursor to form a core-shell structure. A flexible, stretchable, ultrathin thermosetting silicone fiber base film with an adjustable thickness of 5 μm to 50 μm can be achieved by washing with solutions such as ethanol.

[0018] After the coaxial electrospinning of the present invention is completed, the obtained spun material is cured at 60°C to 80°C for 10 to 14 hours to obtain a base film. In some embodiments of the present invention, the entire spun pad formed on the insulating material is transferred to an oven for further curing to obtain a base film.

[0019] After obtaining the base film, this invention constructs a patterned surface on one side of the base film, and then cures a PVA solution on the patterned surface of the base film to obtain a unidirectional hydrophilic base film. Specifically, this invention peels the obtained base film from the insulating material, attaches one side of the base film to a patterned template, encapsulates the other side, then subjectes the base film to vacuum plasma treatment for 90 to 120 seconds to construct a patterned surface, then coats the patterned surface of the base film with a PVA solution, allows it to stand for 8 to 12 minutes, and then cures it at 80°C to 120°C for 3 to 4 hours. After washing, a unidirectional hydrophilic base film is obtained; wherein, the PVA solution comprises 2 wt% to 5 wt% PVA and 5 wt% to 10 wt% glycerol, specifically an aqueous solution comprising 2 wt% to 5 wt% PVA and 5 wt% to 10 wt% glycerol. This invention uses a template design to pattern the exposure of a thin film on one side using plasma, and then uses a self-assembled hydrophilic film at the exposed area to solidify the hydrophilic groups on the surface and inside of the silicone fiber, thereby achieving the unidirectional hydrophilic function and long-term stability of the final membrane material.

[0020] After obtaining the unidirectional hydrophilic membrane, this invention performs coaxial electrospinning of a PVP solution and a PDMS diluent containing a silicone pressure-sensitive adhesive on the patterned surface of the membrane. After curing, a self-adhesive unidirectional hydrophilic silicone fiber membrane is obtained. The coaxial electrospinning in step S3) is the same as in step S1) and will not be repeated. The PVP solution in step S3) is the same as in step S1) and will not be repeated. The PDMS diluent containing a silicone pressure-sensitive adhesive in step S3) comprises PDMS, silicone pressure-sensitive adhesive, and a diluent in a weight ratio of (1.5~2.5):3:3. It is obtained by thoroughly mixing PDMS and silicone pressure-sensitive adhesive, adding the diluent, and then heat-treating at 60℃~80℃ for 50 min~70 min. The PDMS and diluent are the same as in step S1) and will not be repeated. Based on the electrospinning platform for thermosetting polymer fiber forming, this invention uses a homogeneous silicone pressure-sensitive material, after dilution to reduce its viscosity coefficient, to be further mixed with a silicone substrate. The mixture is then spun into a core-shell structure and laid flat on the base film, thereby achieving self-adhesion under a full silicone fiber framework, resulting in a self-adhesive unidirectional hydrophilic silicone fiber membrane.

[0021] This invention provides a self-adhesive unidirectional hydrophobic silicone fiber membrane prepared by the above-described method. The self-adhesive unidirectional hydrophobic silicone fiber membrane of this invention is an electrospun porous insulating material and also an electronic material. The finished membrane has a thickness of only 5 μm to 30 μm, with mesopores that allow for air permeability, sweat wicking, and water blocking. Based on a constructed thermoplastic electrospinning platform, the fineness and pore size of the silicone fibers can be adjusted.

[0022] This invention also provides the application of the self-adhesive unidirectional hydrophobic silicone fiber membrane obtained by the above preparation method in the fabrication of wearable electronic devices. The self-adhesive unidirectional hydrophobic silicone fiber membrane of this invention, because it can be prepared from highly transparent silicone, exhibits colorless polarized light transmittance after passing through optical matching oil. By mixing homogeneous silicone pressure-sensitive adhesive, a self-adhesive all-fiber silicone film substrate is achieved, providing a new realization path for wearable bioelectronics and high-intensity exercise physiological detection substrates.

[0023] This invention provides a self-adhesive unidirectional hydrophilic silicone fiber membrane, its preparation method, and its applications. The preparation method provided by this invention, in order to match the high viscosity coefficients of liquid silicone and the sacrificial layer fluid material, designs a corresponding electrospinning platform for thermosetting polymer fiber forming, and constructs an all-silicone flexible spun material framework. Through template-designed plasma, patterned exposure is performed on one side of the film, followed by self-assembly of a hydrophilic film at the exposed site to solidify the hydrophilic groups on and inside the silicone fiber surface, achieving the unidirectional hydrophilic function and long-term stability of the final membrane material. The self-adhesive function under the all-silicone fiber framework is achieved by spinning core-shell structure fibers onto a base membrane. This provides a new realization path for wearable bioelectronics and high-intensity exercise physiological detection substrates. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the electrospinning platform for thermosetting polymer material fiber forming according to the present invention;

[0025] Figure 2 SEM image of PDMS silicone fibers;

[0026] Figure 3 These are a series of images illustrating the anti-gravity unidirectional hydrophobic effect of the silicone fiber material film with unidirectional hydrophobic function obtained in step 3) of Embodiment 1 of the present invention.

[0027] Figure 4 An optical photograph of the self-adhesive ultrathin stretchable porous silicone fiber base film described in Embodiment 1 of the present invention;

[0028] Figure 5 This is a front scanning electron microscope image of the self-adhesive ultrathin stretchable porous silicone fiber substrate membrane described in Embodiment 1 of the present invention.

[0029] Figure 6 This is a side scanning electron microscope image of the self-adhesive ultrathin stretchable porous silicone fiber substrate membrane described in Embodiment 1 of the present invention;

[0030] Figure 7 The image shows the peel force test results between the self-adhesive ultrathin stretchable porous silicone fiber base film obtained in Example 1 of the present invention and pigskin.

[0031] Figure 8The image shows the 24-hour water permeability test results of the self-adhesive ultrathin stretchable porous silicone fiber base membrane described in Example 1 of this invention. Detailed Implementation

[0032] This invention discloses a self-adhesive one-way hydrophobic silica fiber membrane, its preparation method, and its applications. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments, and those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0033] The present invention will be further described below with reference to the embodiments:

[0034] Example 1

[0035] 1) Constructing an electrospinning platform:

[0036] This paper first constructs an electrospinning platform for silicone, a difficult-to-spin thermosetting molding material, and then uses this platform for spinning, such as... Figure 1 As shown, Figure 1 This is a schematic diagram of the electrospinning platform for thermosetting polymer fiber forming according to the present invention. The electrospinning platform consists of a bicomponent coaxial spinning system, a vertical fully insulated heating device, and a power supply system. The bicomponent coaxial spinning system includes a flow control pump and a coaxial needle connected to the flow control pump. The vertical fully insulated heating device includes a negative high-voltage electrode plate and a fully enclosed insulating heating plate placed on the negative high-voltage electrode plate, and the vertical fully insulated heating device is located directly below the coaxial needle. The power supply system includes a positive high-voltage DC power supply and a negative high-voltage DC power supply. The positive high-voltage DC power supply is connected to the coaxial needle, and the negative high-voltage DC power supply is connected to the negative high-voltage electrode plate.

[0037] This invention employs the aforementioned coaxial spinning system, spinning based on the core-shell structure of the spun fibers. A bicomponent liquid is converged at the needle, and the shell component (sacrificial layer) and the auxiliary core component (silicone) are stretched and jetted under an applied DC electric field, thus forming a spun fiber structure. Secondly, to expedite the curing of the thermosetting polymer in the fibrous state, the following vertical, fully insulated heating device is designed: ① The thermosetting silicone in liquid state is diluted to reduce the tensile load on the sacrificial layer fiber material at the high-pressure nozzle; ② After sealing, it is placed in an oven for partial pre-crosslinking to improve the molding speed; ③ The jetted bicomponent liquid is further heated at high temperature by a lower hot plate, causing the micron-sized fibers to rapidly solidify, forming a porous microporous structure with good air permeability. Finally, to match the high viscosity coefficients of the liquid silicone and the sacrificial layer fluid material, a vertically designed positive and negative high-voltage power supply system is implemented. A positive voltage is applied to the needle, and a negative high voltage is applied to a metal heat-conducting plate of a specific shape and size perpendicular to the nozzle, thereby achieving precise coverage of the electric field tension within a limited pattern in this direction, ultimately forming a uniform and controllable fiber membrane structure.

[0038] 2) The specific steps for making an ultra-thin, stretchable, porous silicone fiber base film are as follows:

[0039] ① The sacrificial layer material for spinning is selected based on the matching of mechanical properties, using a high-viscosity polymeric hydrogel material. Here, the solute is high-polymerization-degree polyvinylpyrrolidone (PVP) (K90), the solvent is methanol, and the solution weight-volume ratio is 19% (w / v)%.

[0040] ② Taking thermosetting PDMS (Sylgard-184) as an example, the spun silica gel material is first thoroughly mixed with its AB components at a weight ratio of A:B = 10:1 to obtain a silica gel liquid. Hexane and cyclohexane are selected as diluents and diluted at a weight ratio of 5:1 (silica gel liquid: diluent). After sealing, it is placed in a 70℃ oven for partial pre-crosslinking for 48 minutes.

[0041] ③ The colloidal solutions prepared in steps ① and ② are added to the assembled spinning platform. The lower hot plate is preheated to 120℃ and kept at a constant temperature. High-temperature resistant release paper (fluorine release paper) is placed on the negative electrode plate. The sacrificial layer in step ① is the shell component, and the core component in step ② is the core component. Coaxial needles are preferably G22-G17 / G23-G17. Spinning is carried out according to the feed speed ratio ①:② is 7:3. The positive voltage is 15kV~25kV, and the negative voltage is 6kV~9kV, forming a spinning pad on the release paper.

[0042] ④ After spinning, the spinning pad is transferred to a 70℃ oven through release paper for further curing for about 12 hours.

[0043] 3) The specific preparation steps for the patterned unidirectional hydrophilic function of silicone fiber materials are as follows:

[0044] ① Peel the spinning pad obtained in step 2) off the release paper, attach one side to the patterned template, and seal the other side.

[0045] ② Place in a plasma cleaner and vacuum process for approximately 150 seconds;

[0046] ③ Coat the template surface with a layer of polyvinyl alcohol (PVA) aqueous solution—2 wt% low viscosity PVA + 5 wt% glycerol, let stand for 10 min, and then place it on a hot plate at 100℃ to cure for 3 hours.

[0047] ④ After washing away any remaining liquid from the surface, remove the film. Perform scanning electron microscopy (SEM) imaging on the resulting film, such as... Figure 2 As shown, Figure 2 This is a scanning electron microscope (SEM) image of PDMS silicone fibers.

[0048] The obtained thin film was subjected to a unidirectional hydrophobicity test, and the test results were captured using a surface contact angle optical lens, such as... Figure 3 As shown, Figure 3 This is a series of images showing the anti-gravity unidirectional hydrophobic effect of the silicone fiber material film with unidirectional hydrophobic function obtained in step 3) of Embodiment 1 of the present invention. Under an optical microscope, it can be seen that water droplets are transported in the reverse direction against gravity from below (closer to the skin) of the silicone fiber material film with unidirectional hydrophobic function described in this invention.

[0049] 4) The specific steps for making a self-adhesive ultrathin stretchable porous silicone fiber base film are as follows:

[0050] ① Based on step 2), firstly, the two components of Sylgard-184 are thoroughly mixed at a weight ratio of 10:1 to obtain Sylgard-184 adhesive solution. Then, the obtained Sylgard-184 adhesive solution is mixed with silicone pressure-sensitive adhesive, and n-hexane diluent is added for dilution. The weight ratio of Sylgard-184 adhesive solution, silicone pressure-sensitive adhesive and diluent is 2:3:3.

[0051] ② After placing the mixture from ① in a 70 ℃ oven for about 1 hour, use the same PVP solution as in step 2) and the mixture from ① to spin the mixture according to the same process as in step 2) to obtain a self-adhesive ultrathin stretchable porous silicone fiber base film.

[0052] The obtained self-adhesive ultrathin stretchable porous silicone fiber substrate film was photographed using optical microscopy, scanning electron microscopy (SEM) frontal imaging, and SEM side imaging. The results are as follows: Figures 4-6 As shown, Figure 4 This is an optical photograph of the self-adhesive ultrathin stretchable porous silicone fiber base film described in Embodiment 1 of the present invention. Figure 5This is a front scanning electron microscope image of the self-adhesive ultrathin stretchable porous silicone fiber substrate membrane described in Embodiment 1 of the present invention. Figure 6 This is a side scanning electron microscope image of the self-adhesive ultrathin stretchable porous silicone fiber base film described in Embodiment 1 of the present invention.

[0053] Peel force tests were performed on the obtained self-adhesive ultrathin stretchable porous silicone fiber-based film, and the results are as follows: Figure 7 As shown, Figure 7 The figure shows the peel force test results between the self-adhesive ultrathin stretchable porous silicone fiber base film obtained in Example 1 of the present invention and pigskin, where F1~F3 represent three repeated experimental curves.

[0054] The obtained self-adhesive ultrathin stretchable porous silicone fiber substrate (denoted as PDMS spinning substrate) was subjected to a 24-hour water permeability test. Commercial nonwoven substrates (i.e., nonwoven medical adhesive tape) and commercial PU substrates (i.e., PU medical adhesive tape) were used as comparisons. The results are as follows: Figure 8 As shown, Figure 8 The image shows the 24-hour water permeability test results of the self-adhesive ultrathin stretchable porous silicone fiber base membrane described in Example 1 of this invention.

[0055] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a self-adhesive unidirectional hydrophobic silica fiber membrane, characterized in that, Includes the following steps: S1) On an insulating material, PVP solution and PDMS dilution are coaxially electrospun and cured to obtain a base film; The propulsion velocity ratio of the PVP solution to the PDMS diluent is (7~9):3; the weight-volume ratio of PVP in the PVP solution is 15 w / v%~20 w / v%; the PDMS diluent comprises PDMS and a diluent in a weight ratio of (4~6):

1. S2) A patterned surface is constructed on one side of the base film obtained in step S1), and a PVA solution is cured on the patterned surface of the base film to obtain a unidirectional hydrophobic base film; the PVA solution includes 2 wt%~5 wt% PVA and 5 wt%~10 wt% glycerol; S3) On the patterned surface of the unidirectional hydrophobic membrane obtained in step S2), a PVP solution and a PDMS diluent containing silicone pressure-sensitive adhesive are coaxially electrospun, and after curing, a self-adhesive unidirectional hydrophobic silicone fiber membrane is obtained; the propulsion speed ratio of the PVP solution and the PDMS diluent containing silicone pressure-sensitive adhesive is (7~9):3; the weight-volume ratio of PVP in the PVP solution is 15 w / v%~20 w / v%; the PDMS diluent containing silicone pressure-sensitive adhesive includes PDMS, silicone pressure-sensitive adhesive and diluent in a weight ratio of (1.5~2.5):3:

3. In steps S1) and S3), the receiving end of the coaxial electrospinning is located directly below the exit end of the coaxial electrospinning, the exit end is loaded with a positive high voltage of 15 kV to 28 kV, and the receiving end is loaded with a negative high voltage of 6 kV to 10 kV.

2. The preparation method according to claim 1, characterized in that, In steps S1) and S3), the temperature of the receiving end of the coaxial electrospinning is 100℃~140℃.

3. The preparation method according to claim 1, characterized in that, In step S1), before performing the coaxial electrospinning, the PDMS dilution solution is heat-treated at 60℃~80℃ for 20 min~50 min. In step S3), before coaxial electrospinning, the PDMS dilution containing silicone pressure-sensitive adhesive is heat-treated at 60℃~80℃ for 20 min~50 min.

4. The preparation method according to claim 1, characterized in that, In step S2), the curing temperature is 80~120℃ and the curing time is 3 h~4 h.

5. The self-adhesive unidirectional hydrophilic silicone fiber membrane obtained by the preparation method according to any one of claims 1 to 4.

6. The application of the self-adhesive unidirectional hydrophilic silicone fiber membrane according to claim 5 in the preparation of wearable electronic devices.

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