Broom type double-fluid parallel combined control nozzle, spinning device and spinning method

Abstract

The invention provides a broom type double-fluid parallel combined control spray head. The broom type double-fluid parallel combined control spray head comprises a flow guide wedge, at least two capillary tubes and a gathering inlet tube, an inner cavity is formed in the flow guide wedge, a fluid inlet is formed in the top of the flow guide wedge, a fluid outlet gap is formed in the bottom of the flow guide wedge in the length direction in an extending mode, the capillary tubes are attached to the outer side face of the flow guide wedge at intervals in the length direction of the flow guide wedge, and the gathering inlet tube is located above the flow guide wedge. The upper ends of the capillary tubes extend into the gathering inlet pipe, and the lower ends of the capillary tubes protrude out of the lower edge of the flow guide wedge. The invention further provides a multi-jet-flow electrostatic spinning device and a method for preparing the parallel-structure nanofibers 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, the scale of preparing the parallel structure nanofibers can be effectively expanded under a high-voltage electric field, and powerful support is provided for development, production and commercial application of parallel structure-based nanoproducts.

Description

Technical Field

[0001] The present invention relates to the field of nanomaterial preparation, and in particular to a broom-shaped dual-fluid parallel combination control nozzle, a broom-shaped dual-fluid high-voltage electrospinning device, and a method for preparing nanofibers with parallel structural characteristics by electrospinning in a single step in batches using the device. Background Art

[0002] High-voltage electrospinning (electrospinning) is a top-down nanofabrication technique that uses an external electric field to overcome the surface tension and viscoelastic forces of a 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 formed at the receiving end. This technology offers a simple process, easy control, a wide range of materials, strong controllability, and the ability to produce nanofibers with unique microstructures 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 holds great promise.

[0003] The greatest advantage of electrospinning is that, through the design and modification of the spinning head structure, polymer micro- and nanofibers with specific structural characteristics can be produced, which 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 spinning head 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 effectively produce micro- and nanofibers with complete structural integrity and complex features, and how to tailor their functions based on the structural characteristics of the fibers, is a research hotspot in nanotechnology and a key challenge in the field of micromanufacturing and the production of new micro- and nano-products.

[0004] The molecule is an interface. Below the molecule, chemical synthesis is purely based on covalent and ionic bonds (corresponding to the chemical industry). Above the molecule, below the 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 nano-fabrication 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 Technology 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 formulated relevant strategies and plans, invested heavily in seizing strategic nanotechnology positions, established nanomaterials research centers, and included nanotechnology as a research and development priority in 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 current application of nano-products remains very limited, and the industrialized manufacturing of various functional micro- and nanomaterials is extremely important and urgent.

[0005] In the existing technology, parallel structured nanofibers have broad application prospects. However, their manufacturing process is relatively complicated and not suitable for industrial manufacturing. It is impossible to prepare structurally complete parallel structured nanofibers in a single step effectively and on a large scale. Summary of the Invention

[0006] The purpose of the present invention is to provide a broom-type dual-fluid parallel combination control nozzle, a spinning device and a spinning method, which are used to solve the technical problem in the prior art that it is impossible to effectively and batch-scale prepare structurally complete parallel structure nanofibers in a single step.

[0007] The present invention provides a broom-type dual-fluid parallel combination control nozzle, which includes a guide wedge, at least two capillaries, and a collection inlet pipe; an inner cavity is provided in the guide wedge, a fluid inlet is provided at the top of the guide wedge, and a fluid outlet gap is provided at the bottom of the guide wedge extending along the length direction; the capillaries are attached to the outer surface of the guide wedge at intervals along the length direction of the guide wedge; the collection inlet pipe is located above the guide wedge, the upper ends of the capillaries extend into the collection inlet pipe, and the lower ends of the capillaries protrude from the lower edge of the guide wedge.

[0008] Furthermore, the guide wedge is formed by bending a copper plate.

[0009] Furthermore, a spring is provided in the fluid outlet gap, and both ends of the spring are respectively connected to the inner side surfaces of both sides of the guide wedge.

[0010] Furthermore, the number of the capillaries is eight.

[0011] Furthermore, the lower end of the capillary tube protrudes 1 mm from the lower edge of the guide wedge, and the gap between any two adjacent capillaries is 3 cm.

[0012] Furthermore, the capillary tube, the collecting inlet pipe and the outer side surface of the guide wedge are all bonded and sealed with epoxy resin adhesive.

[0013] Furthermore, a strip-shaped flat steel rod is adhered to the side surface of the guide wedge through epoxy resin adhesive, and the outer surface of the guide wedge is evenly coated with insulating silicone.

[0014] The present invention also provides a multi-jet electrospinning device, comprising a high-voltage generator, a first injection pump, a second injection pump, the broom-type dual-fluid parallel combination control nozzle according to claim 1, a fiber receiving plate, a first syringe, a second syringe, a first silicone hose and a second silicone hose; the first syringe is installed in the first injection pump, the second syringe is installed in the second injection pump, the outlet of the first syringe is connected to the fluid inlet of the guide wedge through the first silicone hose, the outlet of the second syringe is connected to the upper end of the capillary through the second silicone hose, one end of the current output end of the high-voltage generator is electrically connected to one of the capillaries, the other end of the current output end of the high-voltage generator is grounded, the fiber receiving plate is located below the broom-type dual-fluid parallel combination control nozzle, and the fiber receiving plate is grounded.

[0015] The present invention also provides a method for preparing parallel structure nanofibers using the multi-jet electrospinning device, comprising the following steps: adding a first spinning solution into a first syringe, adding a second spinning solution into a second syringe, turning on the first injection pump, the second injection pump, and the high-voltage generator, the first syringe transporting the first spinning solution through a silicone tube and a fluid inlet into a guide wedge 1 and then flowing out from the fluid outlet gap at the bottom of the guide wedge, the second syringe introducing the second spinning solution through a silicone hose into a capillary and then flowing out from the lower end of the capillary, preparing parallel structure nanofibers through the action of a high-voltage electrostatic field, and receiving them through a fiber receiving plate.

[0016] Furthermore, the first spinning solution is an ethyl cellulose ethanol solution with a mass percentage concentration of 25%, the second spinning solution is a shellac ethanol solution with a mass percentage concentration of 60%, the sheath liquid flow rate of the first syringe is controlled by the first injection pump to be 10 mL / h, the flow rate of the second syringe is controlled by the second injection pump to be 10 mL / h, the receiving distance of the fiber receiving plate is 20 cm, and the voltage of the high-voltage generator is 28 kV.

[0017] The principle of the present invention is that multiple parallel nozzle outlets consisting of a capillary lower end outlet and a fluid outlet slit can be simultaneously set in a broom-type dual-fluid parallel combination control nozzle, which synchronously guides two different fluids into a high-voltage electrostatic field. Using the multiple parallel nozzle outlets 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. On the other hand, the parallel nozzle outlets are all composed of a needle-like metal tip (i.e., a capillary) plus a confined free liquid surface (i.e., a fluid outlet slit) with a guide wedge, which is conducive to the guiding effect of the "needle" and the easy-to-scale preparation feature of confined free liquid surface electrospinning, ensuring that the two different fluids can be quickly stretched and dried under the high-voltage electrostatic field to form solid nanofibers with a parallel structure.

[0018] The present invention has simple application, simple process, convenient operation and easy control. It can effectively expand the scale of preparing parallel structure nanofibers under high voltage electric field, and provide strong support for the development, production and commercial application of nano products based on parallel structure.

[0019] Based on repeated experiments, the present invention follows the behavioral characteristics of fluids under high-voltage electric fields and basic natural laws to develop a broom-type dual-fluid combination control nozzle. By using this nozzle to assemble an electrospinning device and implement the electrospinning process, it is possible to effectively and batch-scale prepare structurally complete parallel-structured nanofibers in a single step, providing possibilities for the design and preparation of new nano-functional materials based on parallel structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of a broom-type dual-fluid parallel combination control nozzle of the present invention. Reference numerals: 1-flow guide wedge, 2-fluid inlet, 3-spring, 4-capillary tube, 5-collecting inlet pipe, 6-fixing flat steel rod.

[0021] Figure 2 This is a front-view image of a broom-shaped dual-fluid parallel combination control nozzle of the present invention.

[0022] Figure 3 This is a top-down view of the capillary / guide wedge parallel guide outlet in a broom-type dual-fluid parallel combination control nozzle of the present invention.

[0023] Figure 4 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 - broom-type dual-fluid parallel combination control nozzle, 11 - fiber receiving plate, 12 - first syringe, 13 - second syringe, 14 - first silicone hose, 15 - second silicone hose, 16 - alligator clip.

[0024] Figure 5 This is a representative picture of the fluid stretching process for the single-step batch preparation of parallel-structured nanofibers of the present invention.

[0025] Figure 6 This is a representative composite Taylor cone image of the single-step batch preparation of parallel structured nanofibers of the present invention.

[0026] Figure 7 This is a scanning electron microscope observation image of the parallel structured nanofibers prepared in a single step batch according to the present invention.

[0027] Figure 8 This is a transmission electron microscope observation image of the parallel structured nanofibers prepared in a single step batch according to the present invention. DETAILED DESCRIPTION

[0028] 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.

[0029] Example 1

[0030] like Figure 1 As shown, the present invention provides a broom-type dual-fluid parallel combination control nozzle, including a guide wedge 1, at least two capillaries 4, and a summary inlet pipe 5; an inner cavity is provided in the guide wedge 1, a fluid inlet 2 is provided at the top of the guide wedge 1, and a fluid outlet gap is provided at the bottom of the guide wedge 1 extending along the length direction. The capillaries 4 are attached to the outer surface of the guide wedge 1 at intervals along the length direction of the guide wedge 1, and the summary inlet pipe 5 is located above the guide wedge 1, the upper end of the capillary 4 extends into the summary inlet pipe 5, and the lower end of the capillary 4 protrudes from the lower edge of the guide wedge 1.

[0031] Furthermore, the guide wedge 1 is formed by bending a copper plate.

[0032] Furthermore, a spring 3 is provided in the fluid outlet gap, and both ends of the spring 3 are respectively connected to the inner side surfaces of the guide wedge 1. During the manufacturing process, the width of the fluid outlet gap is changed by changing the size of the spring 3.

[0033] Furthermore, the number of the capillaries 4 is eight.

[0034] Furthermore, the lower end of the capillary tube 4 protrudes 1 mm from the lower edge of the guide wedge 1, and the gap between any two adjacent capillaries 4 is 3 cm.

[0035] Furthermore, the capillary tube 4, the collecting inlet pipe 5 and the outer side surface of the guide wedge 1 are all bonded and sealed with epoxy resin adhesive.

[0036] Furthermore, a strip-shaped flat steel rod 6 is attached to the side of the guide wedge 1 through epoxy resin adhesive. The strip-shaped flat steel rod 6 is used to install and fix the broom-type dual-fluid parallel combination control nozzle. The outer side of the guide wedge 1 is evenly coated with insulating silicone to prevent the escape of high-voltage static electricity and save energy. The entire broom-type dual-fluid parallel combination control nozzle is shown in the following figure. Figure 2 As shown, the capillary / guiding wedge has a confined free liquid surface parallel guiding outlet 5 as shown in FIG. Figure 3 shown.

[0037] Specifically, the collecting inlet pipe 5 is a polypropylene plastic tube. The capillary tube 4 is made of conductive metal.

[0038] Example 2

[0039] The present invention also provides a multi-jet electrospinning device, the composition diagram of which is shown in FIG. Figure 4 As shown, its basic structure includes: a high-voltage generator 7, a first injection pump 8, a second injection pump 9, a broom-type dual-fluid parallel combination control nozzle 10, a fiber receiving plate 11, a first syringe 12, a second syringe 13, a first silicone hose 14 and a second silicone hose 15; the first syringe 12 is installed in the first injection pump 8, and the second syringe 12 is installed in the second injection pump 13. The outlet of the first syringe 12 is connected to the fluid inlet 2 of the guide wedge 1 through the first silicone hose 14, and the outlet of the second syringe 13 is connected to the upper end of the capillary 4 through the second silicone hose 15. One end of the current output end of the high-voltage generator 7 is electrically connected to one of the capillaries 4, and the other end of the current output end of the high-voltage generator 7 is grounded. The fiber receiving plate 11 is located below the broom-type dual-fluid parallel combination control nozzle 10, and the fiber receiving plate 11 is grounded.

[0040] Specifically, the current output end of the high voltage generator 7 is connected to the capillary 4 via an alligator clip 16. The receiving plate 11 is a cardboard wrapped with aluminum foil. The present invention also provides a method for preparing parallel 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, turning on the first injection pump 8, the second injection pump 9, and the high-voltage generator 7, the first syringe 12 transports the first spinning solution into the guide wedge 1 through the silicone tube 14 and the fluid inlet 2, and then flows out from the fluid outlet gap at the bottom of the guide wedge 1, the second syringe 13 introduces the second spinning solution into the capillary 4 through the silicone hose 15 and then flows out from the lower end of the capillary 4, and through the action of the high-voltage electrostatic field, parallel structure nanofibers are prepared and received by the fiber receiving plate 11.

[0041] Application Example 1 Electrospinning was performed using a multi-jet electrospinning device containing a broom-type dual-fluid parallel combination control nozzle as described in Example 2 to directly prepare parallel structured nanofibers in batches in a single step. The steps are as follows: (1) Preparation of spinning solution The first spinning solution is an ethyl cellulose ethanol solution with a mass percentage concentration of 25%, and the preparation method is as follows: 25 g of ethyl cellulose is added to 75 g of ethanol, and stirred to obtain an ethyl cellulose ethanol solution with a mass percentage concentration of 25%; The second spinning solution is a 60% by weight shellac ethanol solution, which is prepared as follows: 60 g of shellac is added to 40 g of ethanol and stirred to obtain a 60% by weight shellac ethanol solution; (2) Add the first spinning solution and the second spinning solution obtained in step (1) into the first syringe 12 and the second syringe 13 respectively, and then start the first injection pump 8 and the second injection pump 9; (3) The sheath liquid flow rate of the first syringe is controlled to 10 mL / h by the first syringe pump 8, and the flow rate of the second syringe 13 is controlled to 10 mL / h by the second syringe pump 9. The high-voltage generator 7 is turned on, and the receiving distance of the fiber receiving plate 11 is adjusted to 20 cm. The voltage is increased to 28 kV for electrospinning, and parallel structured nanofibers can be prepared in a single step.

[0042] The representative fluid stretching process of single-step batch preparation of parallel structure nanofibers is shown in the figure. Figure 5 As shown, the representative composite Taylor cone images of the single-step batch preparation of parallel structure nanofibers are shown in Figure 6 shown.

[0043] Application Example 2 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 7 The prepared parallel structure nanofibers were collected evenly and showed 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 were shown in Figure 2. Figure 8 As shown, the left and right sides of the nanofiber consist of two grayscale parts, reflecting the parallel structural characteristics.

[0044] 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 broom-type dual-fluid parallel combination control nozzle, characterized by: The invention comprises a guide wedge, at least two capillaries and a collecting inlet pipe; an inner cavity is provided in the guide wedge, a fluid inlet is provided at the top of the guide wedge, a fluid outlet slit is provided at the bottom of the guide wedge extending along the length direction, the capillaries are attached to the outer surface of the guide wedge at intervals along the length direction of the guide wedge, the collecting inlet pipe is located above the guide wedge, the upper end of the capillary extends into the collecting inlet pipe, and the lower end of the capillary protrudes from the lower edge of the guide wedge.

2. The broom-type dual-fluid parallel combination control nozzle according to claim 1, characterized in that: The guide wedge is formed by bending a copper plate.

3. The broom-type dual-fluid parallel combination control nozzle according to claim 1, characterized in that: A spring is provided in the fluid outlet gap, and both ends of the spring are respectively connected to the inner side surfaces of both sides of the guide wedge.

4. The broom-type dual-fluid parallel combination control nozzle according to claim 1, characterized in that: The number of the capillaries is eight.

5. The broom-type dual-fluid parallel combination control nozzle according to claim 1, characterized in that: The lower end of the capillary tube protrudes 1 mm from the lower edge of the guide wedge, and the gap between any two adjacent capillaries is 3 cm.

6. The broom-type dual-fluid parallel combination control nozzle according to claim 1, characterized in that: The capillary tube, the collecting inlet pipe and the outer side surface of the guide wedge are all bonded and sealed with epoxy resin adhesive.

7. The broom-type dual-fluid parallel combination control nozzle according to claim 1, characterized in that: A strip-shaped flat steel rod is adhered to the side surface of the guide wedge through epoxy resin adhesive, and the outer side surface of the guide wedge is evenly coated with insulating silica gel.

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

9. A method for preparing parallel structured nanofibers using the multi-jet electrospinning device according to claim 8, 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, turning on the first injection pump, the second injection pump and the high-voltage generator, the first syringe conveying the first spinning solution into the guide wedge 1 through the silicone tube and the fluid inlet, and then flowing out from the fluid outlet gap at the bottom of the guide wedge, the second syringe conveying the second spinning solution into the capillary through the silicone hose and then flowing out from the lower end of the capillary, preparing parallel structure nanofibers through the action of a high-voltage electrostatic field, and receiving them through a fiber receiving plate.

10. The method for preparing parallel structured nanofibers according to claim 9, wherein: The first spinning solution was an ethyl cellulose ethanol solution with a mass percentage concentration of 25%, the second spinning solution was a shellac ethanol solution with a mass percentage concentration of 60%, the sheath liquid flow rate of the first syringe was controlled by the first injection pump to be 10 mL / h, and the flow rate of the second syringe was controlled by the second injection pump to be 10 mL / h, the receiving distance of the fiber receiving plate was 20 cm, and the voltage of the high-voltage generator was 28 kV.

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