Spray head, spinning device and spinning method for preparing concentric sheath-embedded nanofibers

Abstract

The invention provides a storage tank type multi-fluid parallel combined control nozzle for preparing a same-core sheath-embedded structure nanofiber, which comprises a capillary tube combined eccentric sleeve, a first gathering inlet pipe, a second gathering inlet pipe and a storage tank, and is characterized in that the capillary tube combined eccentric sleeve comprises a first capillary tube and a second capillary tube; the upper end of any second capillary tube extends into the second gathering inlet pipe, and the lower end of any second capillary tube penetrates into the first capillary tube from the side wall of the upper portion of the first capillary tube and then extends to the lower end of the first capillary tube. The invention further provides a multi-jet-flow electrostatic spinning device and a method for preparing the same-core sheath-embedded structure nanofiber through the multi-jet-flow electrostatic spinning device. The method is simple in application, simple and convenient in process, convenient to operate and easy to control, can effectively expand the scale of preparing the same-core sheath-embedded structure nanofibers under a high-voltage electric field, and provides powerful support for development, production and commercial application of nano products based on the same-core sheath-embedded structure.

Description

Technical Field

[0001] The present invention belongs to the field of nanomaterial preparation, and in particular relates to a tank-type multi-fluid parallel combination control nozzle for batch preparation of a core-in-sheath structure, a multi-fluid high-pressure electrostatic spinning device with the nozzle, and a method for single-step large-scale electrostatic spinning preparation of nanofibers with the core-in-sheath structure characteristics using the device. Background Art

[0002] The material world is structure-driven (Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology 2019, DOI:10.1002 / wnan.1601). Nanostructures imply new nanotechnology, and the methods for preparing nanomaterials should be classified according to their final structure (the original text is “In nanoscience, the ability to make new structures enables new science and technology. The ways nanomaterials are made can be classified according to what determines the final structure of the material” in Isaacoff BP, KA Brown. Progress in top-down control of bottom-up assembly. Nano Letters 2017, 17, 6508-6510). The importance of artificial nanostructures and their preparation methods in the field of nanotechnology is self-evident.

[0003] In nature, whether macroscopically or microscopically, in cells or molecules, composite multi-compartment structures with both parallel and core-shell structures are ubiquitous. These interconnected structures together give objects unique properties and functions. The principle of "following nature," using composite multi-compartment structures with both parallel and core-shell structures as a supporting platform, can provide effective inspiration and ideas for the design and development of a wide range of advanced functional nanomaterials. However, compared to nature, humans are still very immature in the preparation and application of complex artificial nanostructures. The two most common structural features are core-shell / core-sheath and side-by-side structures (side-by-side, or Janus structure, Janus is the name of the two-faced god in Roman mythology, so objects with side-by-side structural relationships are often named after Janus, such as Janus nanoparticles, Janus sheets, and Janus rods) (Walther A, Müller AH. Janus particles: Synthesis, self-assembly, physical properties, and applications. ChemicalReviews 2013,113(7), 5194-5261). These are also the two most common basic structures in nature. The former reflects the internal and external spatial relationship, while the latter reflects the left-right or up-down spatial relationship. These two most basic two-compartment structural features have provided extensive support for the construction of the structure-property-functional utility relationship of nanomaterials in the nearly three decades since the rise of nanotechnology (LiM, Wang H, Zhu W, Li W, Wang C, Lu X. RuNi nanoparticles embedded in N-dopedcarbon nanofibers as a robust bifunctional catalyst for efficient overall water splitting. Advanced Science 2020, 7, 1901833).

[0004] Hundreds of thousands of research articles on the Web of Science explore the themes of "core-shell or core-sheath" and "Janus or side-by-side." Building on the comprehensive research and coverage of these two-compartment structures, various multi-compartment complex nanostructures are attracting widespread attention worldwide. These structures include three-level or higher core-shell structures, three-level or higher parallel structures, and island-in-the-sea structures with multiple cores and one sheath. Among various multi-compartment nanostructures (e.g., multiple-compartment nanostructure, hierarchical structure, multi-chamber nanostructure, composite / complicated / complex nanostructure), multi-compartment structures composed of parallel and core-shell structures possess the advantages and characteristics of both core-sheath and parallel structures. Therefore, compared with single multi-level core-shell structures or single multi-level parallel structures, multi-chamber structures offer greater advantages in the design of nanomaterial functions. Because the material-environment interface plays a crucial role in the function of nanomaterials, compared with multi-level composite multi-chamber structures in which parallel structures are contained within core-shell structures, composite multi-chamber structures in which core-sheath structures are contained within parallel structures will be more flexible and effective in regulating the function of nanomaterials (Lauhon LJ, Gudiksen MS, Wang D, Lieber CM. Epitaxialcore–shell and core-multishell nanowire heterostructures. Nature 2002, 420, 57-61).

[0005] The preparation of complex nanostructures is similar to that of ordinary nanomaterials, with two main approaches: top-down and bottom-up. A variety of different preparation techniques have emerged for each of these approaches. Among the many top-down technologies, electrohydrodynamic atomization (EHDA), based on the interaction between fluid and high-voltage electrostatics, includes high-voltage static electrospinning, high-voltage electrostatic spraying, and jet printing (Liu H, Zhang S, Liu L, Yu J, Ding B. High-performance PM0.3 airfilters using self-polarized electret nanofiber / nets. Advanced Functional Materials 2020, 1909554). This approach effectively overcomes the shortcomings of bottom-up technology, such as its cumbersome, time-consuming process and difficulty or even impossibility in scalable production, and has therefore gained popularity in recent years. Among various EHDA technologies, high-voltage static electrospinning (electrospinning) has seen rapid growth due to its robust nanofiber production capabilities, simple and efficient preparation process, and flexible and versatile strategies for regulating nanofiber functionality. On the other hand, the single-step, batch preparation of complex nanostructures remains a difficult problem currently facing nanotechnology. Addressing this challenge will open new avenues for the commercial application of numerous advanced functional materials based on complex nanostructures. Multi-fluid electrospinning technology offers a potential solution to this problem.

[0006] Existing nanofibers with a core-in-sheath structure hold broad commercial application prospects. However, the manufacturing process is complex, preventing the efficient, single-step, and large-scale production of structurally complete nanofibers. This hinders the design and preparation of novel nanomaterials based on this structure. Summary of the Invention

[0007] The purpose of the present invention is to provide a nozzle, a spinning device and a spinning method for preparing concentric sheathed nanofibers, so as to solve the technical problem in the prior art that structurally complete concentric sheathed nanofibers cannot be prepared in a single step effectively and on a large scale.

[0008] The present invention provides a tank-type multi-fluid parallel combination control nozzle for preparing co-core sheathed structure nanofibers, comprising a capillary combination eccentric sleeve, a first summary inlet pipe, a second summary inlet pipe and a tank, wherein the capillary combination eccentric sleeve comprises at least two first capillaries and a second capillary tube, the number of the second capillaries is equal to the number of the first capillaries, the first summary inlet pipe and the second summary inlet pipe are located above the tank, the upper end of any first capillary tank extends to the first summary inlet pipe, and the lower end of any first capillary tube passes through the upper side wall, the inner cavity, and the lower side wall of the tank in sequence and protrudes downward from the lower side of the tank. The first capillary tubes in the storage tank are arranged in parallel and spaced apart along the length direction of the storage tank, the upper end of any second capillary tube extends into the second collective inlet pipe, the lower end of any second capillary tube penetrates into the first capillary tube from the upper side wall of the first capillary tube and then extends to the lower end of the first capillary tube, the axis of the second capillary tube is eccentrically arranged with respect to the axis of the first capillary tube, one end or both ends of the storage tank are provided with a fluid inlet, and a fluid outlet is provided in the lower side wall of the storage tank adjacent to any first capillary tube, and the lower end outlet of the first capillary tube, the lower end outlet of the second capillary tube and the fluid outlet of the storage tank constitute a three-fluid combination outlet.

[0009] Furthermore, the number of the first capillaries and the number of the second capillaries are both six.

[0010] Furthermore, the lower end of the first capillary tube protrudes from the lower side wall of the storage tank by 1 mm.

[0011] Furthermore, the first capillary tube, the second capillary tube, the first collecting inlet pipe, the second collecting inlet pipe, and the storage tank are all glued, fixed, and sealed with epoxy resin.

[0012] The present invention also provides a multi-jet electrospinning device, comprising a high-voltage generator, a first injection pump, a second injection pump, a third injection pump, the tank-type multi-fluid parallel combination control nozzle according to claim 1, a first syringe, a second syringe, a third syringe, a first silicone hose, a second silicone hose, a third silicone hose and a fiber receiving plate; the first syringe is installed in the first injection pump, and the outlet of the first syringe is connected to the fluid inlet of the tank through the first silicone hose, the second syringe is installed in the second injection pump, and the outlet of the second syringe is connected to the upper end of the first capillary through the second silicone hose, the third syringe is installed in the third injection pump, and the outlet of the third syringe is connected to the upper end of the second capillary through the third silicone hose, one end of the current output end of the high-voltage generator is electrically connected to the first capillary and the second capillary, the other end of the current output end of the high-voltage generator is grounded, and the fiber receiving plate is located below the tank-type multi-fluid parallel combination control nozzle, and the fiber receiving plate is grounded.

[0013] Furthermore, the tank-type multi-fluid parallel combination control nozzle is connected to a fixed suspension bracket.

[0014] Furthermore, the fiber receiving board is a cardboard wrapped with aluminum foil.

[0015] The present invention also provides a method for preparing concentric sheath structure nanofibers using the multi-jet electrospinning device, which is characterized in that it includes the following steps: adding a first spinning solution into a first syringe, adding a second spinning solution into a second syringe, adding a third spinning solution into a third syringe, turning on the high-voltage generator, the first injection pump, the second injection pump, and the third injection pump, the first spinning solution is transported from the first syringe to the storage tank through the first elastic silicone tube and then flows out from the fluid outlet of the storage tank, the second spinning solution is transported from the second syringe to the first capillary through the second silicone hose and then flows out from the lower end of the first capillary, the third spinning solution is transported from the third syringe to the second capillary through the third silicone hose and then flows out from the lower end of the second capillary, and the concentric sheath structure nanofibers are prepared through the action of a high-voltage electrostatic field and received by a fiber receiving plate.

[0016] Furthermore, the first spinning solution is an ethanol and N,N-dimethylacetamide solution containing 20% ​​by mass concentration of ethyl cellulose and 5% by mass concentration of Panax notoginseng powder, and the volume ratio of ethanol to N,N-dimethylacetamide is 9:1; the second spinning solution is an ethanol and glacial acetic acid solution containing 8% by mass concentration of polyvinyl pyrrolidone and 2% by mass concentration of tranexamic acid, and the volume ratio of ethanol to glacial acetic acid is 9:1; the third spinning solution is an ethanol solution containing 25% by mass concentration of ethyl cellulose and 5% by mass concentration of curcumin; the sheath liquid flow rate of the first syringe is 10 mL / h, the flow rate of the second syringe is 10 mL / h, the flow rate of the third syringe is 10 mL / h, the receiving distance of the fiber receiving plate is 15 cm, and the voltage of the high-voltage generator is 38 kV.

[0017] The principle of this invention is that a multi-fluid, parallel, combined, controlled nozzle with a reservoir tank simultaneously directs three different fluid streams into a high-voltage electrostatic field. Using multiple, complex, combined nozzle outlets as a macroscopic template, the interaction between the high-voltage electrostatic field and the fluids stretches the multiple spinning fluids into solid nanofibers with a distinct concentric sheath structure within milliseconds. Furthermore, the nozzles, each composed of a needle-like metal tip (i.e., a capillary tube) and a small polymer hole (i.e., a fluid outlet), facilitate the guiding action of the "needle" and the "wall-attaching" effect of the liquid flowing out of the small polymer hole. This ensures accurate "replication" of the macroscopic combined outlet template to the microscopic three-chamber concentric sheath structure of the nanofiber under the high-voltage electrostatic field.

[0018] The present invention is simple to apply, has a simple process, is easy to operate and easy to control. It can effectively expand the scale of preparing core-sheath structured nanofibers under a high-voltage electric field, and provide strong support for the development, production and commercial application of nano-products based on the core-sheath structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of a multi-fluid parallel combination control nozzle with a tank structure for preparing co-core sheathed nanostructures. Reference numerals: 1 - first aggregate inlet pipe, 2 - second aggregate inlet pipe, 3 - fluid inlet, 4 - three-fluid combination outlet, 5 - capillary combination eccentric sleeve, 51 - first capillary tube, 52 - second capillary tube, 6 - tank.

[0020] Figure 2 This is a schematic diagram of the structure of a multi-jet electrospinning device according to the present invention. Reference numerals: 7 - high-voltage generator, 8 - first syringe pump, 9 - second syringe pump, 10 - third syringe pump, 11 - tank-type multi-fluid parallel combination control nozzle, 12 - first syringe, 13 - second syringe, 14 - third syringe, 15 - first silicone hose, 16 - second silicone hose, 17 - third silicone hose, 18 - fiber receiving plate, 19 - fixed suspension bracket.

[0021] Figure 3 This is a series of parallel Taylor cone diagrams of synchronous multi-fluid electrospinning during the batch preparation of core-sheath structure nanofibers in the present invention.

[0022] Figure 4 This is a representative composite Taylor cone image of the single-step batch preparation of core-sheath structured nanofibers according to the present invention.

[0023] Figure 5 This is a scanning electron microscope observation image of the core-sheath structure nanofiber prepared in the present invention.

[0024] Figure 6 Transmission electron microscope observation image of the core-sheath structure nanofiber prepared by the present invention. DETAILED DESCRIPTION

[0025] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application. Example

[0026] like Figure 1As shown, the present invention provides a tank-type multi-fluid parallel combination control nozzle for preparing co-core sheathed structure nanofibers, comprising a capillary combination eccentric sleeve 5, a first summary inlet pipe 1, a second summary inlet pipe 2 and a storage tank 6, wherein the capillary combination eccentric sleeve 5 comprises at least two first capillaries 51 and second capillaries 52, the number of the second capillaries 52 is equal to the number of the first capillaries 51, the first summary inlet pipe 1 and the second summary inlet pipe 2 are located above the storage tank 6, the upper end of any first capillary 51 extends to the first summary inlet pipe 1, and the lower end of any first capillary 51 passes through the upper side wall, the inner cavity, and the lower side wall of the storage tank 6 in sequence and protrudes downward from the lower side wall of the storage tank 6, The first capillary tubes 51 in the tank 6 are arranged in parallel and spaced apart along the length direction of the tank 6. The upper end of any second capillary tube 52 extends into the second collective inlet pipe 2, and the lower end of any second capillary tube 52 penetrates into the first capillary tube 51 from the upper side wall of the first capillary tube 51 and then extends to the lower end of the first capillary tube 51. The axis of the second capillary tube 52 is eccentric to the axis of the first capillary tube 51. A fluid inlet 3 is provided at one or both ends of the tank 6, and a fluid outlet is provided in the lower side wall of the tank adjacent to any first capillary tube 51. The lower end outlet of the first capillary tube 51, the lower end outlet of the second capillary tube 52 and the fluid outlet of the tank 6 constitute a three-fluid combination outlet 4.

[0027] Furthermore, the number of the first capillary tubes 51 and the number of the second capillary tubes 52 are both six.

[0028] Furthermore, the lower end of the first capillary tube 51 protrudes from the lower side wall of the storage tank 6 by 1 mm.

[0029] Furthermore, the first capillary tube 51 , the second capillary tube 52 , the first collecting inlet pipe 1 , the second collecting inlet pipe 2 , and the storage tank 6 are all glued, fixed, and sealed with epoxy resin.

[0030] Specifically, the first and second aggregate inlet pipes 1 and 2, and the storage tank 6 are made of polypropylene. The first and second capillary tubes 51 and 52 are made of conductive metal. The fluid inlet 3 of the storage tank 6 can be used as a cleaning port. Example

[0031] like Figure 2As shown, the present invention also provides a multi-jet electrospinning device, including a high-voltage generator 7, a first injection pump 8, a second injection pump 9, a third injection pump 10, a tank-type multi-fluid parallel combination control nozzle 11, a first syringe 12, a second syringe 13, a third syringe 14, a first silicone hose 15, a second silicone hose 16, a third silicone hose 17 and a fiber receiving plate 18; the first syringe 12 is installed in the first injection pump 8, the outlet of the first syringe 12 is connected to the fluid inlet 3 of the tank 6 through the first silicone hose 15, and the second syringe 13 is installed In the second injection pump 9, the outlet of the second syringe 13 is connected to the upper end of the first capillary 51 through the second silicone hose 16, the third syringe 14 is installed in the third injection pump 10, and the outlet of the third syringe 14 is connected to the upper end of the second capillary 52 through the third silicone hose 17. One end of the current output end of the high-voltage generator 7 is electrically connected to the first capillary 51 and the second capillary 52, and the other end of the current output end of the high-voltage generator 7 is grounded. The fiber receiving plate 18 is located below the tank-type multi-fluid parallel combination control nozzle 11, and the fiber receiving plate 18 is grounded.

[0032] Furthermore, the storage tank type multi-fluid parallel combination control nozzle 11 is connected to a fixed suspension bracket 19. The entire storage tank type multi-fluid parallel combination control nozzle 11 can be suspended and fixed on the operating table through a fixed suspension bracket 19.

[0033] Furthermore, the fiber receiving plate 18 is a cardboard wrapped with aluminum foil.

[0034] The present invention also provides a method for preparing concentric sheath structure nanofibers using the multi-jet electrospinning device, comprising the following steps: adding a first spinning solution into a first syringe 12, adding a second spinning solution into a second syringe 13, adding a third spinning solution into a third syringe 14, turning on a high-voltage generator 7, a first injection pump 8, a second injection pump 9, and a third injection pump 10; the first spinning solution is transported from the first syringe 12 to the storage tank 6 through a first elastic silicone tube 15 and then flows out from the fluid outlet of the storage tank 6; the second spinning solution is transported from the second syringe 13 to the first capillary 51 through a second silicone hose 16 and then flows out from the lower end of the first capillary 51; the third spinning solution is transported from the third syringe 14 to the second capillary 52 through a third silicone hose 17 and then flows out from the lower end of the second capillary 52; and through the action of a high-voltage electrostatic field, concentric sheath structure nanofibers are prepared and received by a fiber receiving plate 18.

[0035] The high voltage generator 7 is directly electrically connected to the first capillary 51 and the second capillary 52 to facilitate the transmission of high voltage electrostatic energy.

[0036] Electrospinning was performed using the multi-jet electrospinning apparatus described in Example 2 to directly prepare nanofibers with a core-in-sheath structure in a batch in a single step. The steps are as follows: (1) Preparation of spinning solution The first spinning solution is an ethanol and N,N-dimethylacetamide solution containing 20% ​​by weight ethyl cellulose and 5% by weight Panax notoginseng powder, with the volume ratio of ethanol to N,N-dimethylacetamide being 9:1. The solution is prepared by dispersing 200g of ethyl cellulose and 50g of Panax notoginseng powder in 750g of a mixed solvent. The mixed solvent is a mixture of ethanol and N,N-dimethylacetamide in a volume ratio of 9:1.

[0037] The second spinning solution is an ethanol and glacial acetic acid solution containing 8% polyvinylpyrrolidone and 2% tranexamic acid by mass, and the volume ratio of ethanol to glacial acetic acid is 9:1. The preparation method is as follows: 80g of polyvinylpyrrolidone and 20g of tranexamic acid are dissolved in 900g of a mixed solvent, which is a mixture of ethanol and glacial acetic acid solution in a volume ratio of 8:2.

[0038] The third spinning solution is an ethanol solution containing 25% by mass of ethyl cellulose and 5% by mass of curcumin. The preparation method is as follows: 250g of ethyl cellulose and 50g of curcumin are dissolved in 750g of ethanol solution, and the mixture is stirred to dissolve to form a yellow co-solvent solution.

[0039] (2) adding the first spinning solution, the second spinning solution and the third spinning solution obtained in step (1) into the corresponding first syringe 12, the second syringe 13 and the third syringe 14 respectively, and then starting the first syringe pump 8, the second syringe pump 9 and the third syringe pump 10; (3) The sheath liquid flow rate of the first syringe 12 is controlled to be 10 mL / h by the first syringe pump 8, the flow rate of the second syringe 13 is controlled to be 10 mL / h by the second syringe pump 9, and the flow rate of the third syringe 14 is controlled to be 10 mL / h by the third syringe pump 10. The high-voltage generator 7 is turned on, and the receiving distance of the fiber receiving plate 18 (i.e., the vertical distance from the lower end outlet of the first capillary 51 to the fiber receiving plate 18) is adjusted to 15 cm. The voltage is increased to 38 kV for electrospinning, and the same core embedded sheath structure nanofibers can be prepared in a single step. The electrospinning start Taylor cone shooting results of the nozzle based on the multi-fluid combination control of the same core embedded sheath structure are shown in the figure. Figure 3 As shown, the single composite Taylor cone shooting result of the multi-fluid combination control nozzle based on the same core embedded sheath structure is as follows Figure 4 As shown, the chimeric double sheath is clearly discernible.

[0040] The surface of the core-sheathed nanofiber prepared in Example 1 was observed by field scanning electron microscopy. Figure 5 The prepared parallel structure nanofibers were collected evenly and showed a good linear state, with a diameter of 690±150nm. The prepared parallel structure nanofibers were observed using a high-resolution transmission electron microscope, and the results were as follows: Figure 6 As shown, the nanofiber consists of four grayscale parts, reflecting the internal structural characteristics of the core-sheath structure.

[0041] The above description is merely an example of the implementation of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the technical principles of the present invention. These improvements should also be regarded as within the scope of protection of the present invention.

Claims

1. A tank-type multi-fluid parallel combination control nozzle for preparing core-sheathed nanofibers, characterized in that: The eccentric sleeve comprises a capillary tube combination, a first summary inlet pipe, a second summary inlet pipe and a storage tank. The capillary tube combination eccentric sleeve comprises at least two first capillaries and a second capillary tube. The number of the second capillaries is equal to the number of the first capillaries. The first summary inlet pipe and the second summary inlet pipe are located above the storage tank. The upper end of any first capillary storage tank extends to the first summary inlet pipe. The lower end of any first capillary tube sequentially passes through the upper side wall, the inner cavity and the lower side wall of the storage tank and protrudes downward from the lower side wall of the storage tank. The first capillary tube in the storage tank extends along the length direction of the storage tank. The tanks are arranged in parallel and at intervals, the upper end of any second capillary tube extends into the second collective inlet tube, the lower end of any second capillary tube penetrates into the first capillary tube from the upper side wall of the first capillary tube and then extends to the lower end of the first capillary tube, the axis of the second capillary tube is eccentrically arranged with respect to the axis of the first capillary tube, one end or both ends of the storage tank are provided with a fluid inlet, and a fluid outlet is provided in the lower side wall of the storage tank adjacent to any first capillary tube, the lower end outlet of the first capillary tube, the lower end outlet of the second capillary tube and the fluid outlet of the storage tank constitute a three-fluid combination outlet.

2. The tank-type multi-fluid parallel combination control nozzle for preparing core-sheathed nanofibers according to claim 1, characterized in that: The number of the first capillaries and the number of the second capillaries are both six.

3. The tank-type multi-fluid parallel combination control nozzle for preparing nanofibers with a core-sheath structure according to claim 1, characterized in that: The lower end of the first capillary tube protrudes from the lower side wall of the storage tank by 1 mm.

4. The tank-type multi-fluid parallel combination control nozzle for preparing core-sheathed nanofibers according to claim 1, characterized in that: The first capillary tube, the second capillary tube, the first collecting inlet tube, the second collecting inlet tube and the storage tank are all glued, fixed and sealed by epoxy resin.

5. A multi-jet electrospinning device, characterized in that: It includes a high-voltage generator, a first injection pump, a second injection pump, a third injection pump, the tank-type multi-fluid parallel combination control nozzle according to claim 1, a first syringe, a second syringe, a third syringe, a first silicone hose, a second silicone hose, a third silicone hose and a fiber receiving plate; The first syringe is installed in the first syringe pump, and the outlet of the first syringe is connected to the fluid inlet of the storage tank through the first silicone hose. The second syringe is installed in the second syringe pump, and the outlet of the second syringe is connected to the upper end of the first capillary through the second silicone hose. The third syringe is installed in the third syringe pump, and the outlet of the third syringe is connected to the upper end of the second capillary through the third silicone hose. One end of the current output end of the high-voltage generator is electrically connected to the first capillary and the second capillary, and the other end of the current output end of the high-voltage generator is grounded. The fiber receiving plate is located below the tank-type multi-fluid parallel combination control nozzle, and the fiber receiving plate is grounded.

6. The multi-jet electrospinning device according to claim 5, characterized in that: The tank-type multi-fluid parallel combination control nozzle is connected to a fixed suspension bracket.

7. The multi-jet electrospinning device according to claim 5, characterized in that: The fiber receiving plate is a cardboard wrapped with aluminum foil.

8. A method for preparing nanofibers with a core-in-sheath structure using the multi-jet electrospinning device according to claim 5, characterized in that: The method comprises the following steps: adding a first spinning solution into a first syringe, adding a second spinning solution into a second syringe, adding a third spinning solution into a third syringe, turning on a high-voltage generator, a first injection pump, a second injection pump and a third injection pump; delivering the first spinning solution from the first syringe to a storage tank through a first elastic silicone tube and then flowing out from the fluid outlet of the storage tank; delivering the second spinning solution from the second syringe to a first capillary through a second silicone hose and then flowing out from the lower end of the first capillary; delivering the third spinning solution from the third syringe to a second capillary through a third silicone hose and then flowing out from the lower end of the second capillary; and preparing concentric-sheathed structured nanofibers through the action of a high-voltage electrostatic field and receiving them through a fiber receiving plate.

9. The method for preparing the nanofiber with a core-sheath structure according to claim 8, wherein: The first spinning solution is an ethanol and N,N-dimethylacetamide solution containing 20% ​​by mass of ethyl cellulose and 5% by mass of Panax notoginseng powder, and the volume ratio of ethanol to N,N-dimethylacetamide is 9:1; the second spinning solution is an ethanol and glacial acetic acid solution containing 8% by mass of polyvinyl pyrrolidone and 2% by mass of tranexamic acid, and the volume ratio of ethanol to glacial acetic acid is 9:1; the third spinning solution is an ethanol solution containing 25% by mass of ethyl cellulose and 5% by mass of curcumin; the sheath liquid flow rate of the first syringe is 10 mL / h, the flow rate of the second syringe is 10 mL / h, and the flow rate of the third syringe is 10 mL / h. The receiving distance of the fiber receiving plate is 15 cm, and the voltage of the high-voltage generator is 38 kV.

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