Method for preparing micro-nano fibers by using ion blower gun to assist needleless electrostatic spinning equipment

Abstract

The invention discloses a method for preparing micro-nano fibers through needle-free electrostatic spinning equipment assisted by an ion blower gun, and belongs to the technical field of spinning. The method specifically comprises the following steps: S1, dissolving a high-molecular polymer in a proper solvent to prepare a spinning precursor solution; and S2, preparing the micro-nano fiber from the spinning solution on a suitable collection surface by using an ion blower gun assisted needleless electrostatic spinning device. Through the synergistic effect of directional airflow generated by the ion blower gun and a controllable electric field, fiber surface charges are effectively neutralized, the jet instability is inhibited, and the controllability of a fiber flight path is improved. Meanwhile, the ionic wind assists in enhancing interface attachment between the fiber and the collector, uniform deposition is promoted, and the compactness and adhesive force of the fiber membrane are remarkably improved. According to the method, chemical modification does not need to be carried out on a material system, the intrinsic performance of the fiber is kept, universality and expandability are achieved, and a new path is provided for continuous preparation of the high-performance micro-nano fiber.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of textiles, and particularly relates to a method for preparing micro-nano fibers by using an ion air gun assisted needleless electrospinning device. BACKGROUND

[0002] At present, electrospinning is one of the most direct and effective technologies for preparing micro-nano fibers, and the core is to use a high-voltage electric field to stretch a charged polymer solution or melt into a micro-nano fiber. The key links include Taylor cone formation, jet stretching and solidification, and fiber collection. However, the accumulation of electric charges generated in the electrospinning process will affect the deposition efficiency of the fibers. Therefore, in actual operation, affected by environmental factors and material compatibility, the fibers often face problems such as poor adhesion and poor uniformity between the fibers and the collection surface.

[0003] In addition to optimizing the spinning parameters and controlling the environment, the traditional methods for enhancing the adhesion of electrospun fibers include: 1) multi-component blending electrospinning, that is, adding inorganic nanoparticles or mixing two or more polymers in the polymer solution to improve the stability and adhesion of the fibers through intermolecular interaction; 2) designing a composite structure, including a multi-layer composite structure and coaxial electrospinning; and 3) post-treatment, including heating treatment and crosslinking agent modification. However, these methods are often complex, high in cost, and strongly dependent on the material system, making it difficult to achieve universal application.

[0004] Traditional methods rely on physical or chemical modification methods, which can improve the adhesion performance of the fibers to a certain extent, but often involve the risk of introducing additional impurities or changing the intrinsic properties of the fibers, and it is difficult to fundamentally improve the directional deposition and interfacial bonding ability of the fibers during the collection process. SUMMARY

[0005] [TECHNICAL PROBLEM] The accumulation of electric charges in the electrospinning process causes the fiber flight trajectory to deviate and deposit unevenly, making it difficult to control the orientation of the fibers and insufficient adhesion, which seriously affects the structural uniformity and interfacial bonding performance of the fiber membrane, and further restricts its application in the fields of flexible electronics, filtration and separation, and biomedical applications; For the problem of poor fiber adhesion, traditional methods are difficult to fundamentally improve the directional deposition and interfacial bonding ability of the fibers during the collection process, and in actual operation, fine adjustment of the spinning parameters and stable control of the environmental conditions are often required, which reduces the range of performance adjustment of the fibers themselves.

[0006] [TECHNICAL SCHEME] To solve the above problems, the application provides a technology for preparing micro-nano fibers by using an ion wind gun assisted needleless electrospinning device. A strip-shaped nozzle is added to the side of the electrode wire, the nozzle is connected to the ion wind gun, the ionizing head inside the ion wind gun is connected to a high-voltage power supply, and the ionizing head continuously ionizes air to generate positive and negative ions, the positive and negative ions are blown to the spinning area along with the airflow, neutralize the surface charge of the fiber bundle, and effectively suppress the repulsion effect caused by the accumulation of electric charge. By adjusting the wind speed and ion density of the ion wind gun, and cooperating with the controllable electric field, the jet path is stabilized, and the directional deposition capability of the fibers on the collection device is improved. At the same time, the ion wind assists in enhancing the interface adhesion between the fibers and the collector, significantly improving the compactness and adhesion of the fiber membrane. This method does not require chemical modification of the material system, maintains the intrinsic properties of the fibers, is universal and scalable, and provides a new path for the continuous preparation of high-performance micro-nano fibers.

[0007] The application provides a method for preparing micro-nano fibers by using an ion wind gun assisted needleless electrospinning device, which comprises the following steps: S1. Dissolving a high molecular polymer in a suitable solvent to prepare a spinning precursor solution; S2. Preparing micro-nano fibers on a suitable collection surface by using the ion wind gun assisted needleless electrospinning device.

[0008] In an embodiment of the application, in step S1, the high molecular polymer is selected from one or more of polyethylene oxide, polycaprolactone, thermoplastic polyurethane elastomer, polyurethane, polyacrylonitrile, polystyrene, polyvinylidene fluoride, polylactic acid, and polymethyl methacrylate.

[0009] In an embodiment of the application, in step S1, the solvent is selected from one or more of water, acetone, N,N-dimethylformamide, dimethylacetamide, tetrahydrofuran, and ethanol.

[0010] In an embodiment of the application, in step S1, the content of the high molecular polymer in the spinning precursor solution is 3-20 wt%.

[0011] In an embodiment of the application, in step S2, the ion wind gun assisted needleless electrospinning device comprises the following components: an electrode wire 1, a liquid brushing tank 2, a direct current high-voltage power supply 3, a winding roller 4, a metal plate 5, an ion wind gun 6, a nozzle 7, an ionizing head 8, and a compressed air interface 9; the electrode wire 1 is connected in series with the liquid brushing tank 2, the electrode wire 1 is connected to the positive electrode of the direct current high-voltage power supply 3, the metal plate 5 is arranged above the electrode wire 1, the metal plate 5 is connected to the negative electrode of the direct current high-voltage power supply 3 or is grounded, the ionizing head 8 inside the ion wind gun 6 is connected to the direct current high-voltage power supply 3, the nozzle 7 is connected to the compressed air interface 9, and the ion wind gun assisted needleless electrospinning device is as shown in Figure 1 .

[0012] In one embodiment of the present invention, in step S2, the electrode wire 1 is a smooth metal wire and serves as the emitter of the spinning solution. The needleless electrospinning device has multiple electrode wires 1 arranged in parallel, with a spacing of 300-500 mm between two adjacent electrode wires. The length of each electrode wire is set according to the required fiber membrane size.

[0013] In one embodiment of the present invention, in step S2, the spinning precursor solution is placed into the brushing tank 2, which can reciprocate on the electrode wire 1. The distance between the electrode wire 1 and the metal plate 5 is 10-40 cm, the spinning voltage is 20-60 kV, the reciprocating speed of the brushing tank 2 is 100-300 mm / s, the rotation speed of the winding roller 4 is 1.0-20.0 m / min, and the airflow rate of the nozzle 7 is 20-100 mL / s.

[0014] In one embodiment of the present invention, in step S2, the ion density of the ion gun is typically 10. 5 -10 7 / cm 3 The ion wind speed is between 0.3 and 0.6 m / s.

[0015] This invention provides micro / nanofibers prepared by the method described above.

[0016] Beneficial effects: The directional airflow generated by the ion gun, combined with a controllable electric field, effectively neutralizes the surface charge of the fibers, suppresses jet instability, and improves the controllability of the fiber flight trajectory. Simultaneously, the ion wind assists in enhancing the interfacial adhesion between the fibers and the collector, promoting uniform deposition and significantly improving the density and adhesion of the fiber membrane. This method requires no chemical modification of the material system, maintains the intrinsic properties of the fibers, and possesses both universality and scalability, providing a new pathway for the continuous fabrication of high-performance micro / nanofibers.

[0017] In needle-free electrospinning, the stable airflow generated by the ion gun effectively guides the jet extension direction, reducing fiber skewing and agglomeration. By adjusting the ionization head voltage and compressed air pressure, precise control of the fiber deposition area is achieved, further improving membrane uniformity. This equipment is easy to operate, adaptable to various polymer systems, and shows broad application prospects in tissue engineering scaffolds, air filtration, and sensor devices. Attached Figure Description

[0018] Figure 1 Structural diagram of a needleless electrospinning device assisted by an ion air gun; In the diagram: 1. Electrode wire; 2. Brush liquid tank; 3. DC high voltage power supply; 4. Rewinding roller; 5. Metal plate; 6. Ionizing air gun; 7. Nozzle; 8. Ionizing head; 9. Compressed air interface.

[0019] Figure 2 Adhesion testing of PEO micro / nanofibers prepared using an ion gun-assisted needleless electrospinning device.

[0020] Figure 3 SEM images of PEO micro / nanofiber membranes prepared using an ion gun-assisted needleless electrospinning device. Detailed Implementation

[0021] The needleless electrospinning equipment assisted by an ion gun includes the following components: electrode wire 1, brushing liquid tank 2, DC high voltage power supply 3, winding roller 4, metal plate 5, ion gun 6, nozzle 7, ionization head 8, and compressed air interface 9. The electrode wire 1 is a smooth metal wire, and two electrode wires 1 are arranged in parallel with a length set according to the required fiber membrane width, generally 40cm. The electrode wire 1 is connected in series with the brushing liquid tank 2, which can reciprocate on the needleless electrode 1. The electrode wire 1 is connected to the positive terminal of the DC high voltage power supply 3, and the metal plate 5 is placed directly above the electrode wire 1. The metal plate 5 is connected to the negative terminal of the DC high voltage power supply 3 or grounded. The ionization head 8 inside the ion gun 6 is connected to the DC high voltage power supply 3, the nozzle 7 is connected to the compressed air interface 9, and the winding roller 4 drives the collector to move between the electrode wire 1 and the metal plate 5.

[0022] Example 1 A method for preparing polyethylene oxide (PEO) micro / nanofibers using an ion gun-assisted needleless electrospinning device includes the following steps: S1. Dissolve 3 g of PEO in 97 g of water and stir until completely dissolved to obtain a uniform spinning precursor solution; S2. Place the precursor solution into the brushing tank 2. The distance between the electrode wire 1 and the metal plate 5 is 25-30 cm. The spinning voltage is 25-30 kV. The reciprocating speed of the brushing tank 2 is 200-300 mm / s. The rotation speed of the winding roller 4 is 1.0-1.5 m / min.

[0023] S3. Gas enters nozzle 7 through compressed air interface 9, with an airflow rate of 20-25 mL / s at nozzle 7. The ion density of the ion gun is 10. 5 / cm 3 The ion wind speed is 0.3 m / s.

[0024] Comparative Example 1 A method for preparing polyethylene oxide (PEO) micro / nanofibers using a conventional needleless electrospinning apparatus, comprising the following steps: S1. Dissolve 3 g of PEO in 97 g of water and stir until completely dissolved to obtain a uniform spinning precursor solution; S2. Place the precursor solution into the brushing tank 2. The distance between the electrode wire 1 and the metal plate 5 is 25-30 cm. The spinning voltage is 25-30 kV. The reciprocating speed of the brushing tank 2 is 200-300 mm / s. The rotation speed of the winding roller 4 is 1.0-1.5 m / min.

[0025] Figure 2 This image shows the adhesion test results of the PEO micro / nanofiber membrane prepared in Example 1 using an ion gun-assisted needleless electrospinning device. PEO micro / nanofiber membranes prepared using ordinary electrospinning equipment cannot be tested for adhesion using a spring balance because their poor adhesion means they cannot be peeled off simply by causing a change in the spring balance reading. However, the PEO micro / nanofiber membrane prepared using the ion gun-assisted needleless electrospinning method requires a force of 0.4 N to peel off and exhibits superior mechanical properties. Therefore, the PEO micro / nanofiber membrane prepared using the ion gun-assisted needleless electrospinning device has superior adhesion, more uniform fiber distribution, and significantly improved interfacial bonding performance.

[0026] Figure 3 The image shows a SEM image of a PEO micro / nanofiber membrane prepared using an ion gun-assisted needleless electrospinning device. The SEM image shows that the fiber network is tightly connected at the junctions, indicating that the problem of poor inter-fiber adhesion caused by charge deposition has been solved.

[0027] Example 2 A method for preparing polyurethane (PU) micro / nanofibers using an ion gun needleless electrospinning device includes the following steps: S1. Dissolve 15 g PU in 85 g DMF and stir until completely dissolved to obtain a uniform spinning precursor solution; S2. Gas enters nozzle 6 through compressed air interface 9, with a gas flow rate of 20-25 mL / s at nozzle 6. The ion density of the ion gun is 10. 6 / cm 3 The ion wind speed is 0.3 m / s.

[0028] S3. Place the precursor solution into the brushing tank 2, the distance between the electrode wire 1 and the metal plate 5 is 20-25 cm, the spinning voltage is 20-25 kV, the reciprocating speed of the brushing tank 2 is 150-250 mm / s, and the rotation speed of the winding roller 4 is 0.8-1.2 m / min.

[0029] PU micro / nanofiber membranes prepared using an ion gun-assisted needleless electrospinning device exhibit uniform fiber diameter distribution, excellent mechanical properties, and superior structural stability in terms of flexibility and fatigue resistance. The continuity of the fiber network and interfacial bonding are significantly enhanced, effectively improving the material's durability under dynamic loads. The ion gun-assisted needleless electrospinning process, through the synergistic effect of controlled electric field distribution and airflow assistance, provides a new approach for the large-scale preparation of high-performance nanofiber membranes.

[0030] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A method for preparing micro-nano fibers by an ion wind gun assisted needleless electrospinning device, characterized in that, The method comprises the following steps: S1. dissolving the high molecular polymer in a solvent to obtain a spinning precursor solution; S2. preparing micro-nano fibers on a suitable collecting surface by ion wind gun assisted needleless electrospinning equipment.

2. The method of claim 1, wherein, In step S1, the high molecular polymer is selected from one or more of polyethylene oxide, polycaprolactone, thermoplastic polyurethane elastomer, polyurethane, polyacrylonitrile, polystyrene, polyvinylidene fluoride, polylactic acid, and polymethyl methacrylate.

3. The method of claim 1, wherein, In step S1, the solvent is selected from one or more of water, acetone, N,N-dimethylformamide, dimethylacetamide, tetrahydrofuran, and ethanol.

4. The method of claim 1, wherein, In step S1, the content of the high molecular polymer in the spinning precursor solution is 3-20 wt%.

5. The method of claim 1, wherein, In step S2, the ion wind gun assisted needleless electrospinning equipment comprises the following components: an electrode wire (1), a brush liquid tank (2), a direct current high voltage power supply (3), a winding roller (4), a metal plate (5), an ion wind gun (6), a nozzle (7), an ionization head (8), and a compressed air interface (9).

6. The method of claim 5, wherein, The electrode wire (1) is connected in series with the brush liquid tank (2), the electrode wire (1) is connected to the positive electrode of the direct current high voltage power supply (3), the metal plate (5) is arranged directly above the electrode wire (1), the metal plate (5) is connected to the negative electrode of the direct current high voltage power supply (3) or grounded, the ionization head (8) inside the ion wind gun (6) is connected to the direct current high voltage power supply (3), and the nozzle (7) is connected to the compressed air interface (9).

7. The method of claim 5, wherein, The electrode wire (1) is a smooth metal wire and is the emitter of the spinning solution. The needleless electrospinning device has a plurality of parallel electrode wires (1), the distance between two adjacent electrode wires is 300-500 mm, and the length of each electrode wire is set according to the size of the fiber membrane required.

8. The method of claim 5, wherein, The spinning precursor solution is placed in the brush liquid tank (2), the brush liquid tank (2) can reciprocate on the electrode wire (1), the distance between the electrode wire (1) and the metal plate (5) is 10-40 cm, the spinning voltage is 20-60 kV, the reciprocating speed of the brush liquid tank (2) is 100-300 mm / s, the rotating speed of the winding roller (4) is 1.0-20.0 m / min, and the airflow flow rate of the nozzle (7) is 20-100 mL / s.

9. The method of claim 5, wherein, The ion density of the ion wind gun (6) is typically between 10 5 / cm 7 / cm 3 and the ion wind speed is between 0.3-0.6 m / s.

10. The micro-nano fiber prepared by the method of any one of claims 1-9.

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