Core-sheath / parallel structure hybrid nanofiber membrane, preparation method, spinning head and high-voltage electrostatic spinning device

Abstract

The invention discloses a core-sheath / parallel structure hybrid nanofiber membrane, a preparation method, a spinning head and a high-voltage electrostatic spinning device. The spinning head comprises a transversely-arranged cylindrical spinning solution storage device with spinneret orifices in the bottom end and a plurality of stainless steel capillary tubes penetrating through the cylindrical spinning solution storage device. And the capillary tubes are gathered above the spinning solution storage device to form two common fluid inlets. Part of the capillary tubes and spinneret orifices in the bottom of the cylindrical spinning solution storage device are arranged in parallel to form parallel outlets of two fluids; the other part of the stainless steel capillary tube directly passes through the center of the spinneret orifice of the cylindrical spinning solution storage device to form a coaxial outlet of the two fluids; and the parallel outlets and the coaxial outlets are uniformly distributed in a staggered manner at the bottom of the transverse storage device. According to the spinning device, an outlet jointly formed by a spinneret hole in the bottom of a spinning head and a metal capillary tube serves as a template, different multi-strand microfluid combinations are guided into a high-voltage electrostatic field, and the core-sheath / parallel structure hybrid nanofiber membrane is directly prepared in batches in a single step.

Description

Technical Field

[0001] This invention relates to nanomaterials and their preparation methods and apparatus, and particularly to a single-step direct batch preparation method for core-sheath / parallel hybrid nanofiber membranes, namely, a single-step direct batch preparation method for core-sheath / parallel hybrid nanofiber membranes, a special spinning head capable of simultaneously guiding different dual-fluid combinations in coaxial and parallel modes, and a multi-fluid high-voltage electrospinning apparatus with the spinning head as the core device. Background Technology

[0002] High-voltage electrospinning (HPE) is a top-down nanofiber manufacturing technology. It utilizes an external electric field to overcome the surface tension and viscoelasticity of the liquid droplets at the spinning head tip, forming a jet. Under the combined action of electrostatic repulsion, Coulomb force, and surface tension, the atomized liquid jet is subjected to high-frequency bending, stretching, and splitting, being stretched millions of times within tens of milliseconds. Nanofibers are then obtained at the receiving end through solvent evaporation or melt cooling. This technology is simple to process, easy to operate, allows for a wide range of material selection, and offers strong controllability. Furthermore, it allows for the design and fabrication of nanofibers with microstructural characteristics through coaxial or parallel spinning head structures. It is considered one of the most promising methods for achieving continuous industrial production of nanofibers, and its application in the fabrication of functional nanofibers shows great promise.

[0003] The greatest advantage of electrospinning is its ability to efficiently prepare polymer micro / nanofibers with corresponding structural features in a single step through the design and modification of the spinneret structure, a feat difficult to achieve with other "bottom-up" chemical synthesis methods. The most common methods are using coaxial capillary metal sleeves as spinnerets to prepare core-sheath structured nanofibers (Polym. Rev. 2008, 48, 353-377) and using spinnerets with left-right relationships to prepare parallel nanofibers (Chem. Rev. 2013, 113, 5194-5261). With the development of nanotechnology, the concept of simply reducing the micro / nano size of products to obtain corresponding nano-functionality has gradually become less mainstream. Currently, more attention is focused on nanodevices, complex micro / nano structures, and the structure-property relationships at the corresponding nanoscale levels. How to effectively prepare structurally complete micro / nanofibers with complex structural features, and how to design their functions based on these structural features, is both a research hotspot in nanotechnology and a key issue that needs to be addressed in the field of microfabrication and the production of novel micro / nanofiber products. Among them, the most basic two-chamber core-sheath nanostructure is favored by many advanced functional nanomaterials research and development due to the isolation and protection provided by the outer sheath. The electrospinning preparation of core-sheath nanostructures was once considered one of the most significant breakthroughs in this field (Dzenis, Yuris. Spinning continuous fibers for nanotechnology. Science 2004, 304, 1917-1919). Side-by-side nanostructures, due to their bilateral contact with the surrounding environment, can provide effective support for the research and development of multifunctional composite materials. However, their preparation has always been a challenge in the field of electrospinning due to electrostatic repulsion. Yu Dengguang et al. successfully solved this problem by using a special spinning head with an eccentric sleeve (Yu Dengguang, Wang Xia, Li Xiaoyan, Xu Ying, Yang Chen. An eccentric sleeve side-by-side spinning head and its application. Chinese Invention Patent ZL201510024991.1). It is evident that if nanostructures can combine core-sheath and parallel structures, they will provide stronger support for the development of advanced functional nanomaterials. Based on this, Yu Dengguang et al. reported the preparation and application of various three-fluid core-sheath / parallel three-chamber composite nanostructures (Yu Dengguang, Li Haolin, Zheng Zhaobin, Zhang Man. A microfluidic control nozzle with one sheath and two cores, spinning device and spinning method. Chinese Invention Patent ZL201611017806.7; Yu Dengguang, Li Haolin, Li Jiaojiao, Li Haipeng. A microfluidic control nozzle with the same core and parallel different sheaths, spinning device and spinning method. Chinese Invention Patent ZL201611122996.9; Yu Dengguang, Yang Junhe, Zhang Lingling, Zhang Yaoyao. A microfluidic control nozzle with one side containing coaxiality in a parallel configuration, spinning device and spinning method. Chinese Invention Patent ZL201611004513.5).However, these three-chamber structures face two unavoidable challenges in preparation and industrialization: 1) it is difficult to mass-produce single needles; 3) the compatibility and functional component loading of the three fluids greatly limit the selection of raw materials for preparation.

[0004] The molecule represents an interface; below the molecule level lies purely in chemical synthesis based on covalent and ionic bonds (corresponding to the chemical industry). Above the molecule level, below the visible scale (approximately 0.1 mm), lies the micro- and nanoscale realm. This is the richest source of knowledge about the world and the focal point for humanity's transformation of the material world (corresponding to the micro- and nano-fabrication of functional materials, and the aforementioned new chemical molecule synthesis also serves this purpose). In July 1990, the first International Conference on Nanoscience and Technology was held in Baltimore, USA, marking the formal birth of nanoscience and technology. By 1999, nanotechnology began to gradually enter the market. Over the past 20 years, numerous countries and regions have formulated relevant strategies or plans, investing heavily to seize the strategic high ground in nanotechnology, establishing nanomaterials research centers, and listing nanotechnology as a key research and development priority in their basic science and technology plans. A search of Web of Science using "nano" as a keyword yields over 1.5 million articles and over 300,000 patents, yet the number of nano-products benefiting the public on the market remains very limited. Essentially, globally, the proportion of nanotechnology research output is very low, and the industrialization of nanotechnology is far from expected! Compared to other technologies, the "valley of death" between nanoscience and industrialization is larger, which further highlights the importance and urgency of accelerating the industrial manufacturing of various functional micro and nanomaterials. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a core-sheath / parallel structure hybrid nanofiber membrane and its preparation method, spinning head and high voltage electrospinning device.

[0006] Technical solution: The first aspect of the present invention is to provide the coaxial / parallel coexisting spinning head, which includes a horizontally placed cylindrical spinning solution reservoir with a spinneret at the bottom and multiple through stainless steel capillaries. All the stainless steel capillaries converge above the spinning solution reservoir, forming two common fluid inlets from separate to unified, for the synchronous delivery of two other different spinning solutions.

[0007] Furthermore, all capillaries on the coaxial / parallel spinning heads protrude 1 mm from the bottom edge of the spinning solution container.

[0008] Furthermore, a portion of the capillaries are arranged side-by-side with the spinnerets at the bottom of the spinning solution reservoir, forming parallel outlets for the two fluids; another portion of the stainless steel capillaries pass directly through the center of the spinnerets in the spinning solution reservoir, forming coaxial outlets for the two fluids; the parallel outlets and coaxial outlets are evenly and alternately arranged at the bottom of the horizontally placed reservoir.

[0009] Another aspect of the present invention is to provide a coaxial / parallel coexisting spinning head and a high-voltage electrospinning device, characterized in that: it includes a first injection pump, a first syringe, a second injection pump, a second syringe, a third injection pump, a third syringe, a fiber receiving plate, a high-voltage generator, and the coaxial / parallel coexisting spinning head. The first syringe is installed in the first injection pump, and the first syringe directly injects fluid into the spinning solution container of the coaxial / parallel coexisting spinning head through a hose, serving both as the outer sheath fluid in the coaxial structure and as the core-sheath / parallel structure hybrid nanofiber membrane. The first syringe is installed in the second injection pump, and injects fluid into multiple stainless steel capillaries simultaneously through a hose to provide the core spinning fluid in the coaxial structure; the second syringe is installed in the third injection pump, and injects fluid into multiple stainless steel capillaries simultaneously through a hose to provide the other side of the core-sheath / parallel hybrid nanofiber membrane; the high-voltage generator and the coaxial / parallel coexisting spinning head are connected by alligator clips, and a fiber receiving plate is provided at the lower end of the coaxial / parallel coexisting spinning head.

[0010] Another aspect of the present invention is to provide a method for batch preparation of core-sheath / parallel structure hybrid nanofiber membranes using the aforementioned electrospinning apparatus. A first spinning liquid is added to a first syringe, a second spinning liquid is added to a second syringe, and a third spinning liquid is added to a third syringe. An injection pump and a high-voltage generator are started. Using the outlet formed by the bottom spinneret of the coaxial / parallel coexisting spinning head and the metal capillary as a template, different combinations of multi-strand microfluidics are introduced into a high-voltage electrostatic field. This allows for the direct and batch preparation of highly uniformly hybrid core-sheath / parallel structure nanofiber membranes in a single step.

[0011] Furthermore, the first spinning solution is an ethanol solution of 25% ethyl cellulose by mass percentage; the second spinning solution is an ethanol solution of 8% polyvinylpyrrolidone; and the third spinning solution is an aqueous ethanol solution of 75% by volume of 20% zein by mass percentage.

[0012] Another aspect of the present invention is to provide a core-sheath / side-by-side hybrid nanofiber membrane.

[0013] The present invention provides a spinning head comprising a horizontally positioned cylindrical spinning solution reservoir with a spinneret at the bottom and multiple through-through stainless steel capillaries. All stainless steel capillaries converge above the spinning solution reservoir, forming two common fluid inlets in a "from individual to unified" manner for the synchronous delivery of two different spinning solutions. Simultaneously, all capillaries protrude slightly about 1 mm from the bottom edge of the spinning solution reservoir. Further, some capillaries are arranged parallel to the spinneret at the bottom of the cylindrical spinning solution reservoir, forming parallel outlets for the two fluid streams; other stainless steel capillaries pass directly through the center of the spinneret in the cylindrical spinning solution reservoir, forming coaxial outlets for the two fluid streams; the parallel and coaxial outlets are evenly and alternately arranged at the bottom of the horizontally positioned reservoir. The present invention also provides a high-voltage electrospinning apparatus containing the above-described coaxial / parallel structure of a spinning head. Using the bottom orifice of the coaxial / parallel structured spinning head and the outlet formed by the metal capillary as a template, different combinations of multi-strand microfluidics are introduced into a high-voltage electrostatic field, enabling the direct batch production of core-sheath / parallel structured hybrid nanofiber membranes in a single step, and these membranes can be highly uniformly mixed.

[0014] The principle of this invention is as follows: Multiple coaxial and parallel nozzle outlets can be simultaneously arranged within a coaxial / parallel structured spinning head, and these outlets are evenly distributed in an alternating pattern. This synchronously guides two fluid streams with different combinations into a high-voltage electrostatic field. Using the multiple coaxial and parallel nozzle outlets as a macroscopic template, under the high-voltage electrostatic field, through the interaction between the high-voltage electrostatic field and the fluid, multiple core-sheath and parallel spinning fluids are stretched into a core-sheath / parallel structured hybrid nanofiber membrane within milliseconds. Furthermore, the numerous nozzles in the coaxial / core-sheath / parallel structured spinning head are needle-like metal tips combined with a polymer (polypropylene PP) spinneret structure containing a spinning fluid reservoir. This facilitates the guiding effect of the "needle" and the "wall adhesion" effect of the liquid flowing out of the polymer spinneret, ensuring accurate "replication" from the macroscopic parallel outlet template to the microscopic two-chamber core-sheath or parallel structure under the high-voltage electrostatic field.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] Based on the aforementioned important issues, namely "composite or hybrid nanostructures", "controllable preparation of nanostructures", and "large-scale production of functional nanomaterials", this invention, through repeated experiments, follows the behavioral characteristics of fluids under high-voltage electric fields and basic natural laws, and explores a coaxial / parallel structured spinning head based on a combination of spinning solution storage and needle. By assembling an electrospinning device and implementing the electrospinning process using this coaxial / parallel structured spinning head, it is possible to prepare structurally complete core-sheath / parallel structured hybrid nanofiber membranes in a single step, effectively and on a large scale. This provides possibilities for the design, preparation, and commercialization of novel nanofunctional materials based on core-sheath and parallel structures.

[0017] The method for batch preparation of core-sheath / parallel structure hybrid nanofiber membranes of the present invention is simple to apply, convenient to operate, and easy to control. Under a high voltage electric field, it can effectively expand the preparation scale of core-sheath / parallel structure hybrid nanofiber membranes and nanofibers, providing strong support for the development, production, and commercial application of multifunctional nanoproducts based on core-sheath / parallel structure hybrid nanofiber membranes. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a coaxial / parallel structure spinning head according to the present invention: wherein: 1-capillary collection inlet pipe I, 2-stainless steel capillary collection inlet pipe II, 3-polypropylene (PP) spinning solution storage inlet or cleaning port, 4-outlet formed by the stainless steel capillary and the bottom spinneret hole of the spinning solution storage (where 41-coaxial outlet; 42-parallel outlet), 5-series stainless steel capillary, 6-PP spinning solution storage.

[0019] Figure 2 This is an overall photograph of a coaxial / parallel structure coexisting spinning head according to the present invention;

[0020] Figure 3 This is a bottom view of the spinning solution storage device of the coaxial / parallel structure of the spinning head of the present invention;

[0021] Figure 4 It is a coaxial outlet formed by the stainless steel capillary tube and the bottom spinneret of the spinning solution storage device;

[0022] Figure 5 It is a parallel outlet formed by the stainless steel capillary tube and the bottom spinneret of the spinning solution storage device;

[0023] Figure 6 This is a schematic diagram of an electrospinning device incorporating a coaxial / parallel structure of spinning heads according to the present invention:

[0024] 7-High pressure generator, 8-First injection pump, 9-Second injection pump, 10-Third injection pump, 11-Plastic beverage bottle assembled spinning head, 12-First syringe, 13-Second syringe, 14-Third syringe, 15-First high-elasticity silicone hose, 16-Second high-elasticity silicone hose, 17-Third high-elasticity silicone hose, 18-Fiber receiving plate, 19-Spinning head fixing and suspension support;

[0025] Figure 7 Scanning electron microscope image of the core-sheath / side-by-side hybrid nanofiber membrane prepared in this invention;

[0026] Figure 8 Transmission electron microscopy image of the core-sheath structure in the core-sheath / parallel structure hybrid nanofiber membrane prepared in this invention;

[0027] Figure 9 Transmission electron microscopy image of the core-sheath structure in the core-sheath / parallel hybrid nanofiber membrane prepared in this invention. Detailed Implementation

[0028] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0029] Example 1

[0030] like Figure 1 As shown, the coaxial / parallel structure coexisting spinning head of this embodiment includes a capillary concentrator inlet tube I, a stainless steel capillary concentrator inlet tube II, a polypropylene (PP) spinning solution storage inlet or cleaning port 3, a coaxial outlet 41 formed by the stainless steel capillary and the bottom spinneret of the spinning solution storage; a parallel outlet 42 formed by the stainless steel capillary and the bottom spinneret of the spinning solution storage; a series of stainless steel capillary tubes 5, and a spinning solution storage 6.

[0031] The capillary inlet pipes I and II are made of polypropylene plastic, each containing three stainless steel capillary tubes 5. These stainless steel capillary tubes are evenly staggered and pass through the spinning solution container downwards to the bottom of the spinning solution storage tank. The openings of the stainless steel capillary tubes protrude approximately 1 mm from the bottom of the spinning solution container. The capillary tubes are spaced 3 cm apart. The spinning solution storage tank itself contains a fluid inlet 3 (which can also serve as a post-use cleaning port). The stainless steel capillary tubes are fixed to the spinning solution storage tank and other parts using epoxy resin adhesive. A spinneret is formed next to the portion of the capillary tubes that exits the bottom of the spinning solution storage tank, creating parallel outlets for the two fluid streams. Another portion of the stainless steel capillary tubes passes directly through the center of the spinneret, creating a coaxial outlet for the two fluid streams. The parallel outlets and the coaxial outlets are staggered and evenly distributed at the bottom of the container.

[0032] Furthermore, the coaxial / parallel structure coexisting spinning head can be suspended and fixed by a metal rod wrapped in insulating polytetrafluoroethylene. A photograph of the entire coaxial / parallel structure coexisting spinning head is shown below. Figure 2 As shown in the image, the bottom view of the coaxial / parallel structure of the spinning head is as follows. Figure 3 As shown, the coaxial fluid outlet formed by the stainless steel capillary tube and the small hole at the bottom of the spinning solution container is as follows: Figure 4 As shown, the parallel fluid outlets formed by the stainless steel capillary tube and the small hole at the bottom of the spinning solution container are as follows: Figure 5 As shown.

[0033] Example 2

[0034] The electrospinning apparatus for preparing core-sheath / parallel structure hybrid nanofiber membranes in this embodiment has the following components: Figure 6 As shown, it specifically includes: 7-high pressure generator, 8-first injection pump, 9-second injection pump, 10-third injection pump, 11-coaxial / parallel structure coexisting spinning head, 12-first syringe, 13-second syringe, 14-third syringe, 15-first high-elasticity silicone hose, 16-second high-elasticity silicone hose, 17-third high-elasticity silicone hose, 18-fiber receiving plate, 19-spinning head fixing and suspension support.

[0035] An electrospinning apparatus using coaxial / parallel structured spinning heads is used to directly prepare core-sheath / parallel structured hybrid nanofiber membranes in a single step. The specific steps are as follows: A first syringe 12 is installed inside a first injection pump 8. A first spinning liquid is added to the syringe 12, and the syringe 12 directly delivers the spinning liquid to a spinning liquid container through a high-elasticity silicone tube 15. A second syringe 13 is installed inside a second injection pump 9. A second spinning liquid is added to the syringe 9, and the spinning liquid is introduced into the stainless steel capillary manifold I of the spinning head 11 through a high-elasticity silicone tube 16. A third syringe 14 is installed inside a third injection pump 10. A third spinning liquid is added to the syringe 10, and the spinning liquid is introduced into another stainless steel capillary manifold II of the spinning head 11 through a high-elasticity silicone tube 17.

[0036] The high-voltage generator 7 and the spinning head 11 can be directly connected via a stainless steel capillary tube to facilitate the transmission of high-voltage electrostatic energy. A fiber receiving plate 18 is provided at the lower end of the spinning head 11. The receiving plate 18 is a cardboard wrapped with aluminum foil and is grounded. The entire spinning head 11 for preparing the core-sheath / parallel structure hybrid nanofiber membrane can be suspended and fixed on the operating table by a fixing bracket 19.

[0037] Application Example 1

[0038] Using the electrospinning apparatus with coaxial / parallel coexisting spinning heads described in Example 2, a high-voltage electrospinning process is carried out to directly prepare core-sheath / parallel structure hybrid nanofiber membranes in a single step in batches. The steps are as follows:

[0039] (1) Preparation of spinning solution

[0040] (1) Preparation of spinning solution

[0041] The first spinning solution is an ethanol solution of 25% ethyl cellulose by mass percentage, and its preparation method is as follows:

[0042] 250g of ethyl cellulose powder is placed in 750g of ethanol and stirred to dissolve, thus obtaining the spinning solution.

[0043] The second spinning solution is a polyvinylpyrrolidone solution with a mass percentage concentration of 8%, which is prepared as follows: 80g of polyvinylpyrrolidone is dissolved in 920g of ethanol.

[0044] The third spinning solution is a 75% (volume ratio) aqueous solution of 20% zein in ethanol. The preparation method is as follows: Dissolve 200g of zein in 800g of ethanol solution and stir to dissolve.

[0045] (2) Add the first, second and third spinning solutions obtained in step (1) into the corresponding syringes, and then turn on the first injection pump, the second injection pump and the third injection pump.

[0046] (3) Control the flow rate of the sheath fluid of the first syringe to 10 mL / h, control the flow rate of the second syringe to 10 mL / h, control the flow rate of the third syringe to 10 mL / h, turn on the high voltage generator, adjust the receiving distance of the fiberboard to 15 cm, and raise the voltage to 32 kV for electrospinning. This will allow for the single-step batch preparation of three-chamber interlocking and parallel structured nanofibers.

[0047] Application Example 2

[0048] The surface of the core-sheath / parallel hybrid nanofiber membrane prepared in Application Example 1 was observed using field scanning electron microscopy after surface sputtering with gold. The results are as follows: Figure 7 As shown. The prepared core-sheath / parallel structure hybrid nanofiber membrane exhibits uniform nanofiber collection and good linearity, with a diameter of 690±170 nm. High-resolution transmission electron microscopy was used to observe the nanofibers in the prepared core-sheath / parallel structure hybrid nanofiber membrane. The results show that some nanofibers are core-sheath structures (e.g., ...). Figure 8 As shown), some are parallel structures (such as...). Figure 9 As shown in the figure, this reflects the coexistence of two nanostructures in the core-sheath / parallel structure hybrid nanofiber membrane.

[0049] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A coaxial / parallel coexisting spinning head, characterized in that: The coaxial / parallel spinning head includes a horizontally placed cylindrical spinning solution reservoir with a spinneret at the bottom and multiple through-through stainless steel capillaries. All the stainless steel capillaries converge above the spinning solution container, forming two common fluid inlets from separate to unified, for the synchronous delivery of two other different spinning solutions.

2. The coaxial / parallel coexisting spinning head according to claim 1, characterized in that: All capillaries on the coaxial / parallel spinning heads protrude 1 mm from the bottom edge of the spinning solution container.

3. The coaxial / parallel coexisting spinning head according to claim 1, characterized in that: A portion of the capillary tubes are arranged side-by-side with the spinneret holes at the bottom of the spinning solution reservoir, forming parallel outlets for the two fluids; another portion of the stainless steel capillary tubes pass directly through the center of the spinneret holes in the spinning solution reservoir, forming coaxial outlets for the two fluids; the parallel outlets and coaxial outlets are evenly and alternately arranged at the bottom of the horizontally placed reservoir.

4. A high-voltage electrospinning device, characterized in that: The device includes a first injection pump, a first syringe, a second injection pump, a second syringe, a third injection pump, a third syringe, a fiber receiving plate, a high-pressure generator, and the coaxial / parallel coexisting spinning head according to any one of claims 1-3. The first syringe is installed in the first injection pump and directly injects fluid into the spinning solution container of the coaxial / parallel coexisting spinning head through a hose, serving as both the outer sheath fluid in the coaxial structure and the fluid on one side of the core-sheath / parallel hybrid nanofiber membrane. The second syringe is installed in the second injection pump and simultaneously injects fluid into multiple stainless steel capillaries through a hose, providing the core spinning fluid in the coaxial structure. The third injector is installed in the third injection pump. The third injector injects fluid into multiple stainless steel capillaries simultaneously through a hose, providing the spinning fluid to the other side of the core-sheath / parallel structure hybrid nanofiber membrane. The high-pressure generator and the coaxial / parallel coexisting spinning head are connected by alligator clips. The lower end of the coaxial / parallel coexisting spinning head is provided with a fiber receiving plate.

5. A method for batch preparation of core-sheath / parallel structure hybrid nanofiber membranes using the electrospinning apparatus of claim 4, characterized in that: A first spinning liquid is added to the first syringe, a second spinning liquid is added to the second syringe, and a third spinning liquid is added to the third syringe. The injection pump and high-pressure generator are started. Using the outlet formed by the bottom spinneret of the coaxial / parallel coexisting spinning head and the metal capillary as a template, different combinations of multi-strand microfluidics are introduced into a high-voltage electrostatic field. This allows for the direct and batch production of nanofiber membranes with highly uniform core-sheath / parallel structures in a single step.

6. The method according to claim 5, characterized in that, The first spinning solution is an ethanol solution of 25% ethyl cellulose by mass; the second spinning solution is an ethanol solution of 8% polyvinylpyrrolidone; and the third spinning solution is an aqueous solution of 75% ethanol by volume of 20% zein by mass.

7. A core-sheath / side-by-side hybrid nanofiber membrane prepared by the method of claim 5 or 6.

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