Basket type multi-fluid parallel combined control nozzle, spinning device and application method of spinning device

Abstract

The invention discloses a basket type multi-fluid parallel combined control nozzle, a spinning device and an application method of the basket type multi-fluid parallel combined control nozzle. The nozzle comprises a capillary tube gathering inlet pipe, a series of stainless steel capillary tubes and a basket body. The basket body is a closed basket body; the capillary tube gathering inlet tube is positioned on the outer side of the basket body, and one end of the capillary tube gathering inlet tube is connected with one ends of all series of stainless steel capillary tubes; the other ends of all the series stainless steel capillary tubes are unfolded with the capillary tube gathering inlet tube as the center, the series stainless steel capillary tubes penetrate into the basket body from one end of the basket body and penetrate out of the basket body from the other end of the basket body, and the basket body is provided with small holes beside the series stainless steel capillary tubes penetrating out of the basket body. The small holes and the serial stainless steel capillary outlets form serial parallel outlets; and the basket body is also provided with an inlet. The nozzle is reasonable in structural design, multiple parallel nozzle outlets serve as macroscopic templates, multiple strands of parallel spinning fluid are stretched into parallel nanofibers with clear structures through the interaction of a high-voltage electrostatic field and the fluid, and the application prospect is good.

Description

Technical Field

[0001] The present invention relates to the technical field of nanomaterial preparation, and relates to a basket-type multi-fluid parallel combination control nozzle, a spinning device and an application method thereof, and specifically relates to a basket-type multi-fluid parallel combination control nozzle, a multi-fluid high-pressure electrospinning device using the basket-type multi-fluid parallel combination control nozzle, and a method for single-step batch electrospinning preparation of nanofibers with parallel structural characteristics using the above-mentioned device. Background Art

[0002] High-voltage electrospinning (electrospinning) is a top-down nanofabrication technology that uses an external electric field to overcome the surface tension and viscoelastic forces of the droplet at the nozzle tip, forming a jet. Under the combined effects of electrostatic repulsion, Coulomb force, and surface tension, the atomized liquid jet is bent, stretched, and split at high frequencies, stretching tens of millions of times within tens of milliseconds. After solvent evaporation or melt cooling, nanofibers are obtained at the receiving end. This technology has a simple process, easy operation, a wide range of materials, and strong controllability. Furthermore, it can produce nanofibers with microstructural characteristics through nozzle design. It is considered the most promising method for the industrial production of continuous nanofibers, and its application in the preparation of functional nanofibers has excellent prospects.

[0003] The greatest advantage of electrospinning is that, through the design and modification of the spinneret structure, polymer micro- and nanofibers with specific structural characteristics can be efficiently prepared in a single step. This is difficult to achieve using other "bottom-up" chemical synthesis methods. The most common methods are the use of a coaxial capillary metal sleeve as the spinneret to produce core-sheath nanofibers (Polym. Rev. 2008, 48, 353-377) and the use of a left-right spinneret to produce parallel nanofibers (Chem. Rev. 2013, 113, 5194-5261). With the development of nanotechnology today, the concept of simply reducing the micro- and nanoscale dimensions of products to achieve corresponding nano-functionality has gradually become less mainstream. Currently, more attention is focused on nanodevices, complex micro- and nanostructures, and the structure-activity relationship at the nanoscale. How to efficiently prepare micro- and nanofibers with complete structural integrity and complex features, and how to tailor their functions based on their structural characteristics, is a research hotspot in nanotechnology and a key challenge in micromanufacturing and the production of novel micro- and nano-products.

[0004] Functional micro- and nanomaterials can provide high-tech support for the national economic restructuring and the reform of traditional industries. Their industrialized manufacturing is a strategic emerging industry receiving key national support and development. In today's nanotechnology era, functional micro- and nanomaterials are rapidly penetrating every application field. "This invisible substance is revolutionizing every field." Globally, in developed and developing countries alike, research on functional nanomaterials has yielded remarkable results. Against this backdrop, those who pioneer the industrialized manufacturing of various functional micro- and nanomaterials will enjoy preferential access to the vast body of research findings, reaping greater economic and social benefits.

[0005] The molecule is an interface. Below the molecule lies pure chemical synthesis based on covalent and ionic bonds (corresponding to the chemical industry). Above the molecule, visible to the human eye (approximately 0.1 mm), lies the micro- and nanoscale realm. This is a rich source of information for humanity's current understanding of the world and a focal point for its transformation of the material world (corresponding to micro- and nanofabrication of functional materials, and the new chemical molecular synthesis mentioned above also serves this purpose). In July 1990, the first International Conference on Nanoscience and Nanotechnology was held in Baltimore, USA, marking the official birth of nanoscience and technology. By 1999, nanotechnology had begun to gradually enter the market. Over the past 20 years, many countries and regions have actively formulated relevant strategies and plans, invested heavily in seizing strategic advantages in nanotechnology, established nanomaterials research centers, and included nanotechnology in their basic science and technology plans. A search using the keyword "nano" in Web of Science yields over 1.5 million references and over 300,000 patents. However, the number of nano-products currently on the market that benefit the public is still very limited. Globally, the proportion of nanoscience research output is very low, and the industrialization of nanotechnology falls far short of expectations!

[0006] Therefore, it is of great practical significance to develop a functional nanomaterial with complex structural characteristics that can be produced on an industrial scale. Summary of the Invention

[0007] Due to the above-mentioned defects in the prior art, the present invention provides a functional nanomaterial with complex structural characteristics that can be produced on an industrial scale, specifically a basket-type multi-fluid parallel combination control nozzle, a multi-fluid high-pressure electrospinning device using the basket-type multi-fluid parallel combination control nozzle, and a method for single-step batch electrospinning preparation of nanofibers with parallel structural characteristics using the above-mentioned device. It provides possibilities for the design, preparation and commercialization of new nanofunctional materials based on parallel structures, and overcomes the problem that functional nanomaterials with complete structures and complex structural characteristics are difficult to prepare and difficult to achieve industrial scale.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A basket-type multi-fluid parallel combination control nozzle, comprising a capillary tube inlet pipe, a series of stainless steel capillaries and a basket body;

[0010] The basket is a closed basket, that is, a spinning solution storage tank;

[0011] The capillary summary inlet pipe is located outside the basket body. One end of the capillary summary inlet pipe is connected to one end of all the series of stainless steel capillaries. The other ends of all the series of stainless steel capillaries are extended with the capillary summary inlet pipe as the center. The series of stainless steel capillaries penetrate into the basket body from one end and exit from the other end. The basket body is provided with a small hole next to where the series of stainless steel capillaries pass through the basket body. The small hole and the series of stainless steel capillary outlets constitute a series of parallel outlets (the series of parallel outlets constitute a parallel guide outlet for two fluids to flow out in parallel, and one of the parallel outlets is a metal needle-shaped tube opening and the other is a polymer hole opening). The side of the basket body corresponding to where the series of stainless steel capillaries pass through the basket body is provided with an inlet connected to the interior space of the basket body.

[0012] The basket-type multi-fluid parallel combination control nozzle of the present invention has a reasonable structural design. The nozzle is provided with multiple series of parallel outlets, which synchronously guide two different fluids into the high-voltage electrostatic field. The multiple parallel nozzle outlets are used as macro templates. Under the high-voltage electrostatic field, the multiple parallel spinning fluids are stretched into solid nanofibers with clear parallel structures within a few milliseconds through the interaction between the high-voltage electrostatic field and the fluid. The numerous nozzles of the nozzle are needle-type metal tips plus polymer small hole structures of the basket body, which is conducive to the guiding effect of the "needle" and the "wall attachment" effect of the liquid flowing out of the polymer small hole, ensuring the accurate "replication" of the macro parallel outlet template to the micro two-chamber parallel structure characteristic nanofiber under the high-voltage electrostatic field. It overcomes the limitations of traditional needle-type electrospinning technology in preparing parallel structure nanofibers on a laboratory scale, and has the ability to prepare structurally complete parallel structure nanofibers in a single step, effectively and on a large scale, and has good application prospects.

[0013] As the preferred technical solution:

[0014] A basket-type multi-fluid parallel combination control nozzle as described above, wherein the basket body is a cylindrical structure;

[0015] The basket body and the capillary collection inlet pipe are both made of polypropylene.

[0016] In the basket-type multi-fluid parallel combination control nozzle as described above, all series of stainless steel capillaries are evenly distributed around the circumference of the symmetry axis of the basket body.

[0017] A basket-type multi-fluid parallel combination control nozzle as described above, wherein the series of stainless steel capillaries are tightly attached to the inner wall of the basket body;

[0018] All series of stainless steel capillaries and basket bodies are formed into a basket shape.

[0019] In the basket-type multi-fluid parallel combination control nozzle described above, the connection between the series of stainless steel capillaries and the basket body is fixed with epoxy resin.

[0020] The present invention also provides a spinning device, comprising a first injection pump, a first syringe, a second injection pump, a second syringe, a fiber receiving plate, a high-voltage generator, and the basket-type multi-fluid parallel combination control nozzle as described above;

[0021] The first syringe is mounted on a first syringe pump, and the outlet of the first syringe is connected to an inlet on a basket body of a basket-type multi-fluid parallel combination control nozzle through a silicone tube. The second syringe is mounted on a second syringe pump, and the outlet of the second syringe is connected to an end of a capillary tube inlet pipe away from a series of stainless steel capillaries through a silicone tube.

[0022] The fiber receiving plate is positioned directly below the series of parallel outlets of a basket-type multi-fluid parallel combination control nozzle. The high-voltage generator is electrically connected to the basket-type multi-fluid parallel combination control nozzle. By combining the first syringe pump, the first syringe, the second syringe pump, the second syringe, the fiber receiving plate, the high-voltage generator, and the basket-type multi-fluid parallel combination control nozzle, a high-voltage electrostatic field is generated to coordinate with the series of parallel outlets of the basket-type multi-fluid parallel combination control nozzle to achieve large-scale production of parallel-structured nanofibers.

[0023] As the preferred technical solution:

[0024] In the spinning device as described above, the high-voltage generator and the basket-type multi-fluid parallel combination control nozzle are connected via an alligator clip;

[0025] The fiber receiving plate is a cardboard wrapped in aluminum foil;

[0026] The fiber receiving plate and the high voltage generator are both grounded.

[0027] In addition, the present invention also provides a method for using the spinning device described above, wherein a first spinning solution and a second spinning solution are added to a first syringe and a second syringe, respectively, and the first and second syringe pumps and a high-voltage generator are activated. Nanofibers having parallel structural characteristics can be produced in batches in a single step through the action of a high-voltage electrostatic field. The above-mentioned batch production method of nanofibers having parallel structural characteristics has a simple step sequence, is convenient to operate, and is easy to control. Under a high-voltage electric field, it can effectively expand the scale of preparing nanofibers having parallel structures, provide strong support for the development, production, and commercial application of nano-products based on parallel structures, and realize the industrial-scale production of functional nanomaterials with complex structural characteristics.

[0028] As the preferred technical solution:

[0029] In the method described above, the first spinning solution is an ethanol or methanol solution of a pH-sensitive polyacrylic acid resin with a mass percentage concentration of 11-15%;

[0030] The second spinning solution is an equal volume ratio solution of ethanol or methanol acetone with a mass percentage concentration of 50-80% shellac;

[0031] The sheath fluid flow rate of the first syringe is 8-20 mL / h, and the flow rate of the second syringe is 8-20 mL / h;

[0032] The fiberboard receiving distance is 10-30 cm, and the output voltage of the high-voltage generator is 30-40 kV.

[0033] According to the method described above, the first spinning solution is an ethanol solution with a mass percentage concentration of 13% Eudragit E100;

[0034] The second spinning solution is an ethanol solution with a mass percentage concentration of 60% shellac;

[0035] The sheath fluid flow rate of the first syringe is 10 mL / h, and the flow rate of the second syringe is 10 mL / h;

[0036] The fiberboard receiving distance is 20 cm, and the output voltage of the high-voltage generator is 34 kV.

[0037] The above technical solution is only a feasible technical solution of the present invention. The protection scope of the present invention is not limited thereto. Those skilled in the art can reasonably adjust the specific design according to actual needs.

[0038] The above invention has the following advantages or beneficial effects:

[0039] (1) The basket-type multi-fluid parallel combination control nozzle of the present invention has a reasonable structural design. The nozzle is provided with multiple series of parallel outlets, which synchronously guide two different fluids into the high-voltage electrostatic field. The multiple parallel nozzle outlets are used as a macro template. Under the high-voltage electrostatic field, through the interaction between the high-voltage electrostatic field and the fluid, the multiple parallel spinning fluids are stretched into solid nanofibers with clear parallel structures within a few milliseconds;

[0040] (2) The basket-type multi-fluid parallel combination control nozzle of the present invention has a plurality of nozzles with needle-type metal tips and a polymer hole structure in the basket body, which is conducive to the guiding effect of the "needle" and the "wall attachment" effect of the liquid flowing out of the polymer hole, ensuring the accurate "replication" of the nanofibers from the macroscopic parallel outlet template to the microscopic two-chamber parallel structure under high-voltage electrostatic field;

[0041] (3) The basket-type multi-fluid parallel combination control nozzle of the present invention overcomes the limitations of conventional needle-type electrospinning technology in preparing parallel structure nanofibers on a laboratory scale, and enables the efficient and large-scale preparation of structurally complete parallel structure nanofibers in a single step.

[0042] (4) The method for preparing nanofibers with parallel structural characteristics of the present invention has simple steps, convenient operation, and easy control. It can effectively expand the scale of preparing parallel-structured nanofibers under a high-voltage electric field, provide strong support for the development, production and commercial application of nano-products based on parallel structures, and realize the industrial-scale production of functional nanomaterials with complex structural characteristics, with good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention and its features, configurations, and advantages will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings. Like reference numerals indicate like parts throughout the drawings. The drawings are not necessarily drawn to scale, emphasis being placed on illustrating the subject matter of the present invention.

[0044] Figure 1 This is a schematic structural diagram of a basket-type multi-fluid parallel combination control nozzle according to the present invention;

[0045] Figure 2 This is a schematic structural diagram of a multi-fluid high-pressure electrospinning device using the basket-type multi-fluid parallel combination control nozzle of the present invention;

[0046] Figure 3 This is a scanning electron microscope observation image of the nanofiber with parallel structural characteristics prepared by the present invention;

[0047] Figure 4 This is a transmission electron microscope observation image of the nanofiber with parallel structural characteristics prepared by the present invention;

[0048] Among them, 1-capillary aggregate inlet tube, 2-series of stainless steel capillaries, 3-basket body, 4-inlet, 5-series of parallel outlets, 6-epoxy resin, 7-high-voltage generator, 8-first injection pump, 9-second injection pump, 10-basket-type multi-fluid parallel combination control nozzle, 11-fiber receiving plate, 12-first syringe, 13-second syringe, 14-first high-elastic silicone hose, 15-second high-elastic silicone hose, 16-crocodile clip. DETAILED DESCRIPTION

[0049] Below in conjunction with accompanying drawing and specific embodiment, the present invention is further described.Should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.In addition, should be understood that after reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

[0050] Example 1

[0051] A basket-type multi-fluid parallel combination control nozzle, such as Figure 1 As shown, it includes a capillary aggregate inlet pipe 1, a series of stainless steel capillaries 2 and a basket 3;

[0052] The basket 3 is a closed basket, which has a cylindrical structure and is made of polypropylene;

[0053] The capillary summary inlet tube 1 (made of polypropylene) is located on the outside of the basket body 3. One end of the capillary summary inlet tube 1 is connected to one end of all the series stainless steel capillaries 2 (there are 5 series stainless steel capillaries in total). The other ends of all the series stainless steel capillaries 2 are spread out with the capillary summary inlet tube 1 as the center and all the series stainless steel capillaries 2 are evenly distributed around the symmetry axis of the basket body 3 (adjacent series stainless steel capillaries 2 maintain a uniform interval of 72 degrees). The series stainless steel capillaries 2 penetrate into the basket body 3 from one end and exit from the other end of the basket body 3. The joints between the series stainless steel capillaries 2 and the basket body 3 are fixed with epoxy resin 6. The series stainless steel capillaries 2 are tightly attached to the inner wall of the basket body 3 inside the basket body 3. The basket body 3 has a small hole next to the series stainless steel capillary 2 passing through the basket body 3. The small hole is connected to the series stainless steel capillary outlet (the series stainless steel capillary outlet protrudes from the bottom of the basket body by about 1.0 mm) constitutes a series of parallel outlets 5, and the basket 3 corresponds to a series of stainless steel capillaries 2 that penetrate into the basket 3 and have an inlet 4 that communicates with the inner space of the basket 3;

[0054] The whole formed by all series of stainless steel capillaries 2 and the basket body 3 is in the shape of a basket.

[0055] Example 2

[0056] A multi-fluid high-pressure electrospinning device using a basket-type multi-fluid parallel combination control nozzle, such as Figure 2 As shown, it includes a high-voltage generator 7, a first injection pump 8, a second injection pump 9, a basket-type multi-fluid parallel combination control nozzle 10, a fiber receiving plate 11, a first syringe 12, a second syringe 13, a first high-elastic silicone hose 14, a second high-elastic silicone hose 15 and an alligator clip 16;

[0057] The first syringe 12 is mounted on the first syringe pump 8, and the outlet of the first syringe 12 is connected to the inlet of the basket body of the basket-type multi-fluid parallel combination control nozzle 10 through a first high-elastic silicone hose 14. The second syringe 13 is mounted on the second syringe pump 9, and the outlet of the second syringe 13 is connected to the end of the capillary tube inlet pipe 1 away from the end of the series stainless steel capillary 2 through a second high-elastic silicone hose 15;

[0058] The fiber receiving board 11 is a cardboard wrapped with aluminum foil. The fiber receiving board 11 is arranged directly below the series of parallel outlets of the basket-type multi-fluid parallel combination control nozzle 10. The high-voltage generator 7 is electrically connected to the basket-type multi-fluid parallel combination control nozzle 10 through an alligator clip 16. The fiber receiving board 11 and the high-voltage generator 7 are both grounded.

[0059] The installation and use of the multi-fluid high-voltage electrospinning device are as follows:

[0060] The first spinning solution and the second spinning solution are added to the first syringe and the second syringe respectively, and the first injection pump and the second injection pump are started to transport the first spinning solution in the first syringe and the second spinning solution in the second syringe to the basket and the capillary inlet pipe. The high-voltage generator is turned on, and the nanofibers with parallel structural characteristics can be prepared in a single step batch through the action of the high-voltage electrostatic field.

[0061] Application Example 1

[0062] The method of using the spinning device as described in Example 2 comprises the following steps:

[0063] (1) Preparation of spinning solution;

[0064] The first spinning solution is an ethanol solution with a mass percentage concentration of 13% Eudragit E100, and the preparation method is as follows: 130 g of Eudragit E100 is added to 770 g of ethanol, and stirred to obtain a Eudragit E100 ethanol solution with a mass percentage concentration of 13%;

[0065] The second spinning solution is an ethanol solution with a mass percentage concentration of 60% shellac, which is prepared as follows: 600 g of shellac is added to 400 g of ethanol and stirred to obtain a 60% shellac ethanol solution;

[0066] (2) adding the first and second spinning solutions obtained in step (1) into corresponding syringes respectively, and then starting the first injection pump and the second injection pump;

[0067] (3) Control the sheath liquid flow rate of the first syringe to 10 mL / h, control the flow rate of the second syringe to 10 mL / h, turn on the high-voltage generator, adjust the fiberboard receiving distance to 20 cm, increase the voltage to 34 kV for electrospinning, and parallel structured nanofibers can be prepared in a single step.

[0068] The surface of the parallel structure nanofibers prepared in Example 1 was sprayed with gold using a field scanning electron microscope and the results were as follows: Figure 3 As shown in Figure 2, the prepared parallel structure nanofibers are collected evenly and show a good linear state, with a diameter of 640±130 nm. The prepared parallel structure nanofibers were observed using high-resolution transmission electron microscopy, and the results are shown in Figure 2. Figure 4 As shown, the left and right sides of the nanofiber consist of two grayscale parts, reflecting the parallel structural characteristics.

[0069] Those skilled in the art should understand that they can implement variations by combining the prior art with the above embodiments, which will not be described in detail here. Such variations do not affect the essence of the present invention and will not be described in detail here.

[0070] The above describes the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-mentioned disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes, which does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention that do not depart from the content of the technical solutions of the present invention are still within the scope of protection of the technical solutions of the present invention.

Claims

1. A basket-type multi-fluid parallel combination control nozzle, characterized by: Including capillary inlet pipe, series of stainless steel capillaries and basket; The basket body is a closed basket body; The capillary tube aggregation inlet pipe is located on the outside of the basket body. One end of the capillary tube aggregation inlet pipe is connected to one end of all the series of stainless steel capillaries. The other ends of all the series of stainless steel capillaries are extended with the capillary tube aggregation inlet pipe as the center. The series of stainless steel capillaries penetrate into the basket body from one end of the basket body and exit from the other end of the basket body. The basket body is provided with a small hole next to the series of stainless steel capillaries passing through the basket body. The small hole and the series of stainless steel capillary outlets constitute a series of parallel outlets. The side of the basket body corresponding to the series of stainless steel capillaries passing through the basket body is provided with an inlet connected to the internal space of the basket body.

2. A basket-type multi-fluid parallel combination control nozzle according to claim 1, characterized in that: The basket body is a cylindrical structure; The basket body and the capillary collection inlet pipe are both made of polypropylene.

3. The basket-type multi-fluid parallel combination control nozzle according to claim 2, characterized in that: All series of stainless steel capillaries are evenly distributed around the circumference of the symmetry axis of the basket.

4. The basket-type multi-fluid parallel combination control nozzle according to claim 3, characterized in that: The series of stainless steel capillaries are in close contact with the inner wall of the basket; All series of stainless steel capillaries and basket bodies are formed into a basket shape.

5. The basket-type multi-fluid parallel combination control nozzle according to claim 1, characterized in that: The connection between the series of stainless steel capillaries and the basket body is fixed with epoxy resin.

6. A spinning device, characterized in that The device comprises a first injection pump, a first syringe, a second injection pump, a second syringe, a fiber receiving plate, a high-voltage generator, and a basket-type multi-fluid parallel combination control nozzle according to any one of claims 1 to 5; The first syringe is mounted on a first syringe pump, and the outlet of the first syringe is connected to an inlet on a basket body of a basket-type multi-fluid parallel combination control nozzle through a silicone tube. The second syringe is mounted on a second syringe pump, and the outlet of the second syringe is connected to an end of a capillary tube inlet pipe away from a series of stainless steel capillaries through a silicone tube. The fiber receiving plate is arranged directly below the series of parallel outlets of the basket-type multi-fluid parallel combination control nozzle, and the high-voltage generator is electrically connected to the basket-type multi-fluid parallel combination control nozzle.

7. A spinning device according to claim 6, characterized in that: The high-pressure generator is connected to the basket-type multi-fluid parallel combination control nozzle via an alligator clip; The fiber receiving plate is a cardboard wrapped in aluminum foil; The fiber receiving plate and the high voltage generator are both grounded.

8. A method using the spinning device according to any one of claims 6 to 7, characterized in that: The first spinning solution and the second spinning solution are added to the first syringe and the second syringe respectively, and the first injection pump, the second injection pump and the high-voltage generator are started. Nanofibers with parallel structural characteristics can be prepared in batches in a single step through the action of a high-voltage electrostatic field.

9. The method according to claim 8, characterized in that The first spinning solution is an ethanol or methanol solution of a pH-sensitive polyacrylic acid resin with a mass percentage concentration of 11-15%; The second spinning solution is an equal volume ratio solution of ethanol or methanol acetone with a mass percentage concentration of 50-80% shellac; The sheath fluid flow rate of the first syringe is 8-20 mL / h, and the flow rate of the second syringe is 8-20 mL / h; The fiberboard receiving distance is 10-30 cm, and the output voltage of the high-voltage generator is 30-40 kV.

10. The method according to claim 9, characterized in that The first spinning solution is an ethanol solution with a mass percentage concentration of 13% Eudragit E100; The second spinning solution is an ethanol solution with a mass percentage concentration of 60% shellac; The sheath fluid flow rate of the first syringe is 10 mL / h, and the flow rate of the second syringe is 10 mL / h; The fiberboard receiving distance is 20 cm, and the output voltage of the high-voltage generator is 34 kV.

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