Negative pressure electrostatic spinning device and method

Abstract

The invention belongs to the technical field of electrostatic spinning, and particularly relates to a negative pressure electrostatic spinning device and method.The device comprises a negative pressure roller mechanism, and the negative pressure roller mechanism is placed in an electrostatic spinning box; the liquid outlet end of the spray head mechanism faces the negative pressure roller mechanism, and the negative pressure roller mechanism is used for collecting fibers; the spray head mechanism comprises an extrusion adjusting piece, a flexible piece and a furling nozzle, the flexible piece is located between the extrusion adjusting piece and the furling nozzle, the flexible piece can be extruded by adjusting the overlapping distance between the extrusion adjusting piece and the furling nozzle, and then the hole diameter of a liquid outlet of the flexible piece is controlled; the nozzle mechanism is connected with the positive electrode of the high-voltage power supply, and the negative-pressure roller mechanism is connected with the negative electrode of the high-voltage power supply. A combined structure of a flexible part, an extrusion adjusting part and a folding nozzle is adopted, the aperture of a liquid outlet is adjusted in real time through mechanical extrusion, the flow and jet flow form of a spinning solution are dynamically controlled, and a basis is provided for preparation of fibers arranged in a specific orientation.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrospinning, and particularly relates to a negative-pressure electrospinning device and method. Background Art

[0002] Electrospinning is a technology for preparing ultrafine nanofibers using a high-voltage electrostatic field. Its core principle is to overcome the surface tension of a polymer solution or melt through the electric field force, causing the liquid droplet to form a Taylor cone at the spinneret and eject a charged jet. During the flight, the solvent evaporates or the melt solidifies, and finally fibers are formed on the receiving device. This technology does not require high temperature or chemical coagulation reactions and can directly produce solid fibers from solutions. It is applicable to organic polymers, inorganic materials, and composite materials, and can precisely control the fiber diameter, porous structure, or core-shell morphology by adjusting parameters such as solution properties, electric field strength, and collection distance. Due to its simple operation, low cost, and wide material applicability, electrospinning has broad application prospects in the fields of biomedicine, filtration materials, energy, and intelligent textiles.

[0003] The prior art CN109371477A discloses an electrospinning nozzle. The electrospinning nozzle is composed of a liquid inlet, a cavity, and a nozzle. The cavity is composed of an upper cavity and a lower cavity. The inner wall surface of the upper cavity is cylindrical, and the inner wall surface of the lower cavity is arc-shaped. The nozzle is located at the lower end of the lower cavity. The upper cavity and the lower cavity are threadedly connected. The liquid inlet is located on the upper end surface of the upper cavity. The central axes of the liquid inlet, the upper cavity, the lower cavity, and the nozzle are the same. Although this prior art can overcome the difficulty that one-dimensional solid nanomaterials fail to be arranged in the same direction as the fibers during the electrospinning process and achieve the aligned arrangement of one-dimensional solid nanomaterials in electrospun nanofibers, there are still the following technical problems: The nozzle of this prior art cannot control the ejection amount of the spinning solution according to different fiber materials. During the negative-pressure electrospinning process, if the aperture of the nozzle cannot be adjusted, it will directly affect the flow rate stability of the spinning solution and the uniformity of the electric field distribution, resulting in the failure of the specific orientation arrangement of the fibers. Specifically, a nozzle with a fixed aperture is difficult to adapt to spinning solutions with different viscosities or concentrations: When the viscosity of the spinning solution is high, a fixed small aperture is likely to cause too fast ejection flow rate, and the fibers are not fully stretched by the electric field, resulting in uneven diameters (such as an uneven distribution of 50 - 500 nm), weakening the guiding effect of the electrostatic field on the fiber orientation; while for a low-viscosity solution, the flow rate is too slow in a fixed large aperture, which is likely to cause solution dripping or uneven solvent evaporation, forming randomly aggregated fiber clusters. In addition, the fixed aperture limits the ability to regulate the electric field gradient - for example, to produce highly oriented PLA fibers, a 0.2 mm micropore needs to be matched to enhance the electric field focusing. However, if the existing nozzle has a fixed aperture of 0.5 mm, the electric field strength is insufficient, and the fibers are randomly stacked on the collection surface (orientation CV value > 30%). This process rigidity directly leads to fluctuations in product performance and requires frequent replacement of the nozzle to deal with different materials, significantly increasing the production cost and the difficulty of technical adaptation.

[0004] Therefore, there is an urgent need for a negative pressure electrospinning device and method to solve the above technical problems. Summary of the Invention

[0005] The object of the present invention is to provide a negative pressure electrospinning device and method, which adopts a combined structure of a flexible member, an extrusion adjustment member and a converging nozzle. By mechanically extruding to adjust the aperture of the liquid outlet, the limitation of the fixed aperture of the traditional nozzle is broken through. According to the characteristic requirements of different fiber materials (such as organic polymers, composite materials), the flow rate of the spinning solution can be controlled, thereby regulating the fiber diameter, providing a basis for the preparation of fibers arranged in a specific orientation.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A negative pressure electrospinning device includes

[0008] A negative pressure roller mechanism, the negative pressure roller mechanism is placed inside the electrospinning box, and the negative pressure roller mechanism is used to collect fibers;

[0009] A nozzle mechanism, the liquid outlet end of the nozzle mechanism faces the negative pressure roller mechanism, the nozzle mechanism includes an extrusion adjustment member, a flexible member and a converging nozzle, the flexible member is located between the extrusion adjustment member and the converging nozzle, and by adjusting the overlapping distance between the extrusion adjustment member and the converging nozzle, the flexible member can be extruded, thereby controlling the aperture of the liquid outlet of the flexible member;

[0010] A high-voltage power supply, the nozzle mechanism is connected to the positive electrode of the high-voltage power supply, and the negative pressure roller mechanism is connected to the negative electrode of the high-voltage power supply.

[0011] Preferably, the negative pressure roller mechanism includes two symmetrically arranged supports provided on the inner bottom surface of the electrospinning box. A negative pressure roller body is rotatably connected between the two supports. The inside of the negative pressure roller body is a hollow structure. At least one row of through holes are circumferentially and equally spaced on the surface of the negative pressure roller body, and the through holes communicate with the hollow space inside the negative pressure roller body;

[0012] The negative pressure roller body is connected to a negative pressure generating device through a pipeline, and by starting the negative pressure generating device, a negative pressure environment is formed inside the negative pressure roller body.

[0013] As a specific implementation method, one end of the first connecting rod is in contact with the inner wall of the negative pressure roller body, and the other end of the first connecting rod extends out of the negative pressure roller body. A plurality of second connecting rods are fixedly connected to the first connecting rod, and the other end of the second connecting rod is rotatably connected to a ventilation tube. A countersunk hole is also provided on the negative pressure roller body, and the ventilation tube is placed inside the through hole and movably connected to the through hole. The countersunk hole is used to prevent the ventilation tube from falling into the inside of the negative pressure roller body.

[0014] As a specific implementation method, the diameter of the through hole is 2-3 mm.

[0015] As a specific implementation method, the inclination angle of the ventilator can be adjusted within a range of 25°-45°.

[0016] As a specific implementation method, annular baffles are detachably sleeved on the outer sides of both ends of the negative pressure roller body.

[0017] Preferably, the nozzle mechanism is transmission-connected with a position adjustment mechanism, the position adjustment mechanism comprises an X-axis adjustment mechanism and a Y-axis adjustment mechanism, and the X-axis adjustment mechanism is transmission-connected with the Y-axis adjustment mechanism;

[0018] The Y-axis adjustment mechanism includes a mounting plate fixedly connected to the top wall inside the electrospinning box, and the bottom surface of the mounting plate is provided with two groups of fixed frames along its length direction, and the two groups of fixed frames are symmetrically arranged, wherein a first worm is rotatably connected between the fixed frames of one group, and a second worm is rotatably connected between the fixed frames of the other group;

[0019] The first worm and the second worm are meshedly connected with a worm wheel, the bottom of each set of the fixed frames is fixedly connected with a first slide rail, the two first slide rails are slidably connected with a slider, and the worm wheel is rotationally connected to the slider.

[0020] As a specific implementation method, the X-axis adjustment mechanism includes two second slide rails symmetrically fixedly connected to the bottom surface of the slider, and a same slide frame is slidably connected between the two second slide rails, and the sliding direction of the slide frame is perpendicular to the sliding direction of the slider;

[0021] The bottom surface of the worm wheel is coaxially fixedly connected with a transmission shaft, and the transmission shaft is coaxially fixedly connected with a gear after passing through the slider. The transmission shaft is fixedly connected to the slider, and a rack is fixedly connected to the inner wall of the sliding frame along its sliding direction, and the gear is meshingly connected with the rack.

[0022] As a specific implementable manner, an adjustable distance and angle transformation mechanism is provided between the nozzle mechanism and the position adjustment mechanism, and the adjustable distance and angle transformation mechanism is used to adjust the distance and angle between the nozzle mechanism and the negative pressure roller mechanism;

[0023] The adjustable distance and angle transformation mechanism includes a connecting plate fixedly connected to the sliding frame. The bottom surface of the connecting plate is fixedly connected with a fixing plate. The bottom surface of the fixing plate is rotatably connected with four telescopic members. The four telescopic members are distributed in a rectangle. The bottom ends of the telescopic members are rotatably connected to the same movable plate, and the extrusion adjustment member is fixedly connected to the movable plate.

[0024] A use method of a negative pressure electrospinning device includes the following steps:

[0025] S1. Dissolve or melt the spinning material to prepare a spinning solution. According to the characteristics and structural requirements of the required fibers, by adjusting the overlapping distance between the extrusion adjustment member 501 and the converging nozzle 503, the flexible member 502 can be extruded, and further the aperture of the liquid outlet of the flexible member 502 can be controlled;

[0026] S2. Start the negative pressure roller mechanism to rotate it, turn on the high-voltage power supply, form an electric field force between the nozzle mechanism and the negative pressure roller mechanism and the suction force on the surface of the negative pressure roller mechanism. During the jet movement process, the solvent volatilizes or the melt solidifies to form nanofibers and uniformly adsorb on the surface of the negative pressure roller mechanism;

[0027] S3. When the fibers are collected on the surface of the negative pressure roller mechanism, stop the spinning process and peel the fibers from the surface of the negative pressure roller mechanism.

[0028] Compared with the prior art, the present invention has the following advantages and technical effects:

[0029] The present invention adopts a combined structure of a flexible member, an extrusion adjustment member and a converging nozzle, and adjusts the aperture of the liquid outlet by mechanical extrusion, breaking through the limitation of the fixed aperture of the traditional nozzle. According to the characteristic requirements of different fiber materials (such as organic polymers, composite materials), the flow rate and jet shape of the spinning solution can be controlled, so as to regulate the fiber diameter, providing a basis for the preparation of fibers with specific orientation arrangements. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings:

[0031] Figure 1Schematic diagram of the overall structure of the present invention;

[0032] Figure 2 Schematic diagram of the structure when the box door of the present invention is opened;

[0033] Figure 3 Schematic diagram of the structure after removing the housing around the perimeter and at the top;

[0034] Figure 4 Schematic diagram of the structure of the nozzle mechanism;

[0035] Figure 5 Exploded view of the nozzle mechanism;

[0036] Figure 6 Schematic diagram of the structure of the negative pressure roller mechanism;

[0037] Figure 7 Schematic diagram of the structure of the position adjustment mechanism and the adjustable distance and angle transformation mechanism;

[0038] Figure 8 Exploded view of the position adjustment mechanism;

[0039] Figure 9 Schematic diagram of the structure of the adjustable distance and angle transformation mechanism;

[0040] Figure 10 Schematic diagram of the internal structure of the negative pressure roller body;

[0041] Among them, 1, electrospinning box; 2, negative pressure roller mechanism; 3, position adjustment mechanism; 4, adjustable distance and angle transformation mechanism; 5, nozzle mechanism; 6, liquid storage box; 7, peristaltic pump; 8, high-precision flow pump; 201, support; 202, baffle; 203, negative pressure roller body; 204, through hole; 205, first connecting rod; 206, second connecting rod; 207, ventilation tube; 301, mounting plate; 302, first worm; 303, second worm; 304, worm gear; 305, first slide rail; 306, second slide rail; 307, slider; 308, sliding frame; 309, gear; 310, rack; 311, first chute; 312, second chute; 401, fixing plate; 402, telescopic member; 403, movable plate; 404, connecting plate; 501, extrusion adjustment member; 502, flexible member; 503, converging nozzle. Detailed implementation manners

[0042] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0043] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] The present invention discloses a negative-pressure electrospinning device, which specifically includes the following embodiments:

[0045] Embodiment 1:

[0046] Referring to Figures 1 to 4 , this embodiment discloses a negative-pressure electrospinning device, including

[0047] a negative-pressure roller mechanism 2, which is placed inside the electrospinning box 1;

[0048] a nozzle mechanism 5, the liquid outlet end of the nozzle mechanism 5 faces the negative-pressure roller mechanism 2, and the negative-pressure roller mechanism 2 is used to collect fibers; the nozzle mechanism 5 includes an extrusion adjustment member 501, a flexible member 502, and a converging nozzle 503. The flexible member 502 is located between the extrusion adjustment member 501 and the converging nozzle 503. By adjusting the overlapping distance between the extrusion adjustment member 501 and the converging nozzle 503, the flexible member 502 can be extruded, and thus the aperture of the liquid outlet of the flexible member 502 can be controlled; as Figure 3 shown, the nozzle mechanism 5 of this embodiment is provided with two rows, symmetrically distributed on both sides of the negative-pressure roller mechanism 2. Such a setting only exists as an implementable embodiment of the present invention. The number of the nozzle mechanisms 5 of the present invention is not limited, and the number, rows, or distribution positions of the nozzle mechanisms 5 can be adjusted according to actual needs.

[0049] As Figure 5 shown, the converging nozzle 503 of this embodiment has a cavity inside, and a hole for liquid to flow out is provided at the front end, and a thread is provided on the inner wall at the rear end. The flexible member 502 is located inside the cavity. A thread is provided on the outer side of one end of the extrusion adjustment member 501 close to the converging nozzle 503. The extrusion adjustment member 501 and the converging nozzle 503 are threadedly connected. By rotating the extrusion adjustment member 501, the flexible member 502 can be extruded or relaxed, thereby changing the aperture size of the nozzle. By replacing the converging nozzle 503, the shape of the nozzle opening (such as circular, oval, slit-shaped, etc.) can be changed to precisely control the ejection volume and jet form of the spinning solution. Among them, the outer diameter of the thick end of the flexible member 502 is 5 mm, the tip is 1 mm, and the adjustment range is 0.1-1 mm. The extrusion adjustment member 501 of this embodiment is a setscrew, and the material of the flexible member 502 is silicone material. The above is only one implementation means that can realize the present invention, and the present invention is not limited thereto.

[0050] Inside the electrospinning box 1, there is also a liquid storage box 6. The liquid storage box 6 is sequentially connected to a peristaltic pump 7 and a high-precision flow pump 8 through a connecting pipe along the liquid flow direction. The high-precision flow pump 8 is connected to the nozzle mechanism 5 through a connecting pipe. By setting two pumps, the ejection amount and jet form of the spinning solution can be accurately controlled. The high-precision flow pump 8 can stably and accurately transport the spinning solution to the spinning nozzle, ensuring the continuity and stability of the spinning solution supply during the spinning process.

[0051] High-voltage power supply, the nozzle mechanism 5 is connected to the positive electrode of the high-voltage power supply, and the negative pressure roller mechanism 2 is connected to the negative electrode of the high-voltage power supply. The high-voltage power supply can provide a stable high voltage between the nozzle mechanism 5 and the negative pressure roller mechanism 2. The voltage output range is 0 - 50 kV, and it can be accurately adjusted according to the spinning material and process requirements.

[0052] Example 2:

[0053] The difference between this embodiment and Embodiment 1 is only that: the negative pressure roller mechanism 2 of this embodiment includes two symmetrically arranged supports 201 provided on the inner bottom surface of the electrospinning box 1. A negative pressure roller body 203 is rotatably connected between the two supports 201. The inside of the negative pressure roller body 203 is a hollow structure. The negative pressure roller body 203 is connected to a negative pressure generating device through a pipeline. By starting the negative pressure generating device, a negative pressure environment is formed on the surface of the negative pressure roller body 203; at least one row of through holes 204 evenly distributed circumferentially are formed on the surface of the negative pressure roller body 203. The aperture of the through holes 204 is 2 - 3 mm, and the through holes 204 communicate with the hollow space inside the negative pressure roller body 203.

[0054] The negative pressure roller body 203 is connected to a negative pressure generator through a negative pressure pipeline. The function of the negative pressure generator is to form a negative pressure environment on the surface of the negative pressure roller body 203. These through holes 204 communicate with the hollow space of the negative pressure roller body 203. Under the action of negative pressure, the fibers ejected from the nozzle mechanism 5 are quickly and evenly adsorbed on the surface of the negative pressure roller body 203 under the combined action of the electric field force and the negative pressure suction force. At the same time, the negative pressure roller body 203 is driven to rotate by a driving motor, and the rotation speed can be adjusted within the range of 1 - 100 r / min. By controlling the rotation speed of the negative pressure roller body 203, the winding angle and collection density of the fibers on the roller surface can be accurately controlled, and further the effective control of the fiber orientation and arrangement mode can be realized.

[0055] Refer to Figure 10One end of the first connecting rod 205 is in contact with the inner wall of the negative pressure roller body 203, and the other end of the first connecting rod 205 extends out of the negative pressure roller body 203. The extended end is convenient for the operator to rotate the first connecting rod 205. A plurality of second connecting rods 206 are fixedly connected to the first connecting rod 205. The number of the second connecting rods 206 is the same as the number of through holes 204 distributed along the axial direction of the negative pressure roller body 203. The other end of the second connecting rod 206 is rotatably connected to a ventilation tube 207. Countersunk holes are also provided on the negative pressure roller body 203. The number of the countersunk holes is the same as the number of the second connecting rod 206. The ventilation tube 207 is placed inside the through hole 204 and movably connected to the through hole 204. The countersunk holes are used to prevent the ventilation tube 207 from falling into the negative pressure roller body 203.

[0056] By pulling the first connecting rod 205, the operator can drive the second connecting rod 206 to slide left and right, and then drive the ventilation tube 207 to swing left and right, so as to adjust the inclination angle of the ventilation tube 207 in the left and right directions. By rotating the first connecting rod 205, the operator can drive the second connecting rod 206 to rotate circumferentially, and then drive the ventilation tube 207 to rotate circumferentially, so as to adjust the circumferential inclination angle of the ventilation tube 207. The inclination angle adjustment range of the ventilation tube 207 is 25°-45°.

[0057] The angle of the ventilating tube 207 is adjustable, and combined with the negative pressure area on the surface of the negative pressure roller body 203, it is equivalent to providing invisible pulling force for the fibers, so that the fibers are distributed more evenly.

[0058] A circular ring-shaped baffle 202 is detachably mounted on the outer sides of both ends of the negative pressure roller body 203. In the present embodiment, the baffle 202 is mounted on the outer side of the negative pressure roller body 203. A friction strip is arranged inside the baffle 202, which is kept stationary by friction. The baffle 202 can prevent the fibers from scattering to the two ends of the negative pressure roller body 203 during the collection process, thereby ensuring that the fibers are evenly distributed in the effective collection area on the surface of the negative pressure roller body 203.

[0059] Embodiment 3:

[0060] like Figure 8 As shown, the difference between this embodiment and embodiment 2 is that: the nozzle mechanism 5 is transmission-connected with the position adjustment mechanism 3, the position adjustment mechanism 3 includes an X-axis adjustment mechanism and a Y-axis adjustment mechanism, and the X-axis adjustment mechanism and the Y-axis adjustment mechanism are transmission-connected;

[0061] The Y-axis adjustment mechanism includes a mounting plate 301 fixedly connected to the inner top wall of the electrospinning box 1. Along the length direction of the bottom surface of the mounting plate 301, there are two groups of fixed frames symmetrically arranged. A first worm 302 is rotatably connected between one group of fixed frames. The first worm 302 is connected to a first motor, and the first motor is fixedly installed on the bottom surface of the mounting plate 301. A second worm 303 is rotatably connected between the other group of fixed frames. The second worm 303 is connected to a second motor, and the second motor is fixedly installed on the bottom surface of the mounting plate 301. A same worm gear 304 is meshingly connected between the first worm 302 and the second worm 303. The worm gear 304 is rotatably connected to the top wall of the mounting plate 301. The bottom of each group of fixed frames is fixedly connected with a first slide rail 305. A same slider 307 is slidably connected between the two first slide rails 305. The worm gear 304 is rotatably connected to the slider 307.

[0062] The X-axis adjustment mechanism includes two second slide rails 306 symmetrically and fixedly connected to the bottom surface of the slider 307. A same sliding frame 308 is slidably connected between the two second slide rails 306. The sliding direction of the sliding frame 308 is perpendicular to the sliding direction of the slider 307. A transmission shaft is coaxially and fixedly connected to the bottom surface of the worm gear 304. After passing through the slider 307, the transmission shaft is coaxially and fixedly connected with a gear 309. The transmission shaft is fixedly connected to the slider 307. A rack 310 is fixedly connected to the inner wall of the sliding frame 308 along its sliding direction. The gear 309 is meshingly connected with the rack 310.

[0063] Driven by the first motor and the second motor, there will be two motion modes:

[0064] Motion in the Y-axis direction: The first is when the rotation directions of the first worm 302 and the second worm 303 are the same. At this time, the worm gear 304 does not rotate. Under the meshing connection of the first worm 302 and the second worm 303 (that is, the teeth of the worm gear 304 are engaged with the worms, and at this time, the worm gear 304 is relatively fixed with the two worms), the slider 307 will be driven to slide in the first slide rail 305 due to the rotation of the first worm 302 and the second worm 303 (a first chute 311 is provided on the first slide rail 305, and first convex blocks are fixedly connected to both ends of the slider 307. The first convex platform is slidably fitted inside the first chute 311), thereby driving the nozzle mechanism 5 to move along the Y-axis direction.

[0065] Movement in the X-axis direction: Second, when the rotation directions of the first worm 302 and the second worm 303 are opposite, the worm wheel 304 will rotate at this time, and then synchronously drive the gear 309 to rotate. The gear 309 is meshed and connected with the rack 310. When the gear 309 is used as the driving end, the sliding frame 308, as the moving end, will slide along the X-axis due to the meshing connection between the gear 309 and the rack 310 (a second chute 312 is provided on the second slide rail 306, and second bumps are fixedly connected to both ends of the sliding frame 308, and the second bumps are slidably fitted inside the second chute 312), thereby driving the nozzle mechanism 5 to move along the X-axis direction.

[0066] By controlling the helix directions of the first worm 302 and the second worm 303, the position of the nozzle mechanism 5 can be accurately controlled, and further the effective control of the fiber orientation and arrangement mode can be realized.

[0067] Embodiment 4:

[0068] As Figure 9 shown, the difference between this embodiment and Embodiment 3 is only that: an adjustable-distance angle conversion mechanism 4 is provided between the nozzle mechanism 5 and the position adjustment mechanism 3 in this embodiment, and the adjustable-distance angle conversion mechanism 4 is used to adjust the distance and angle between the nozzle mechanism 5 and the negative pressure roller mechanism 2;

[0069] The adjustable-distance angle conversion mechanism 4 includes a connecting plate 404 fixedly connected to the sliding frame 308. A fixing plate 401 is fixedly connected to the bottom surface of the connecting plate 404. Four telescopic members 402 are rotatably connected to the bottom surface of the fixing plate 401. The four telescopic members 402 are distributed in a rectangle. The bottom ends of the telescopic members 402 are rotatably connected to the same movable plate 403. The extrusion adjustment member 501 is fixedly connected to the movable plate 403.

[0070] The telescopic member 402 in this embodiment can be a cylinder, a hydraulic cylinder or other structures with a telescopic function. When in use, by controlling the telescopic length of the telescopic member 402, the distance and inclination angle between the nozzle mechanism 5 and the negative pressure roller body 203 can be adjusted ( Figure 9 the situation where the nozzle mechanism 5 and the negative pressure roller body 203 are horizontally arranged is shown in

[0071] The present invention also discloses a use method of the negative pressure electrospinning device, which specifically includes:

[0072] S1. Equipment assembly and debugging: Assemble each component such as the nozzle mechanism 5, high-voltage power supply, negative-pressure roller mechanism 2, etc. according to the design requirements. After assembly, conduct a comprehensive debugging of the equipment to check whether the connections of all components are firm, whether the electrical system is normal, and whether the liquid supply system (including the liquid storage box 6, peristaltic pump 7, high-precision flow pump 8) is well-sealed and has a stable flow rate. Debug the negative-pressure roller mechanism 2 to ensure that the negative-pressure roller body 203 can rotate normally, the negative-pressure generating device can generate a stable negative pressure, and there is no blockage in the suction holes. At the same time, according to actual requirements, preliminarily set and optimize parameters such as the voltage of the high-voltage power supply, the rotation speed of the roller, and the negative-pressure value. Dissolve or melt the spinning material to prepare a spinning solution. According to the characteristics and structural requirements of the desired fibers, by adjusting the overlapping distance between the extrusion adjustment part 501 and the converging nozzle 503, the flexible part 502 can be extruded, and then the aperture of the liquid outlet of the flexible part 502 can be controlled;

[0073] S2. Taking the preparation of polylactic acid (PLA) nanofibers as an example, dissolve PLA in a mixed solvent of dichloromethane and N,N-dimethylformamide (DMF) to prepare a spinning solution with a mass concentration of 9%. Select a spinning nozzle with a circular aperture of 0.5 mm and add the spinning solution to the liquid storage box 6 of the liquid supply system. Set the voltage of the high-voltage power supply to 12 kV, the negative-pressure value of the negative-pressure roller body 203 to 4 kPa, and the rotation speed of the negative-pressure roller body 203 to 20 r / min. Start the negative-pressure roller mechanism 2 to make it rotate, turn on the high-voltage power supply, form an electric field force between the nozzle mechanism 5 and the negative-pressure roller mechanism 2 and the suction force on the surface of the negative-pressure roller mechanism 2. During the jet movement process, the solvent volatilizes or the melt solidifies to form nanofibers and uniformly adsorb on the surface of the negative-pressure roller mechanism 2. During the spinning process, observe the jet state and collection situation of the fibers and make fine adjustments to the parameters according to the actual situation.

[0074] S3. After the fibers are completely collected on the surface of the negative-pressure roller mechanism 2, stop the spinning process, peel the fibers from the surface of the negative-pressure roller mechanism 2, and collect a uniform and continuous PLA nanofiber membrane from the surface of the negative-pressure roller body 203. Observed by scanning electron microscope (SEM), the fiber diameters are uniform, and the average diameter is about 200 nm, and the fiber orientation is well-arranged.

[0075] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0076] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A negative pressure electrospinning device, characterized in that: include A negative pressure roller mechanism (2), the negative pressure roller mechanism (2) is placed inside the electrospinning box (1), and the negative pressure roller mechanism (2) is used to collect fibers; A nozzle mechanism (5), wherein the liquid outlet end of the nozzle mechanism (5) faces the negative pressure roller mechanism (2), and the nozzle mechanism (5) comprises an extrusion adjustment member (501), a flexible member (502) and a gathering nozzle (503), wherein the flexible member (502) is located between the extrusion adjustment member (501) and the gathering nozzle (503), and the flexible member (502) can be squeezed by adjusting the overlapping distance between the extrusion adjustment member (501) and the gathering nozzle (503), thereby controlling the aperture of the liquid outlet of the flexible member (502); A high-voltage power supply, the nozzle mechanism (5) is connected to the positive electrode of the high-voltage power supply, and the negative-pressure roller mechanism (2) is connected to the negative electrode of the high-voltage power supply.

2. The negative pressure electrospinning device according to claim 1, wherein: The negative pressure roller mechanism (2) comprises two symmetrically arranged supports (201) arranged on the inner bottom surface of the electrospinning box (1), a negative pressure roller body (203) is rotatably connected between the two supports (201), the interior of the negative pressure roller body (203) is a hollow structure, and the surface of the negative pressure roller body (203) is provided with at least one row of through holes (204) distributed at equal intervals in the circumferential direction, and the through holes (204) are communicated with the hollow space inside the negative pressure roller body (203); The negative pressure roller body (203) is connected to a negative pressure generating device via a pipeline, and a negative pressure environment is formed inside the negative pressure roller body (203) by starting the negative pressure generating device.

3. The negative pressure electrospinning device according to claim 2, wherein: One end of a first connecting rod (205) is in contact with the inner wall of the negative pressure roller body (203), and the other end of the first connecting rod (205) extends out of the negative pressure roller body (203). A plurality of second connecting rods (206) are fixedly connected to the first connecting rod (205), and the other end of the second connecting rod (206) is rotatably connected to a ventilation tube (207). A countersunk hole is also provided on the negative pressure roller body (203), and the ventilation tube (207) is placed inside the through hole (204) and movably connected to the through hole (204). The countersunk hole is used to prevent the ventilation tube (207) from falling into the negative pressure roller body (203).

4. The negative pressure electrospinning device according to claim 2, wherein: The through hole (204) has a diameter of 2-3 mm.

5. The negative-pressure electrospinning device according to claim 3, wherein: The inclination angle of the ventilator (207) can be adjusted in the range of 25°-45°.

6. The negative pressure electrospinning device according to claim 2, wherein: Circular ring-shaped baffles (202) are detachably sleeved on the outer sides of both ends of the negative pressure roller body (203).

7. The negative-pressure electrospinning device according to claim 1, wherein: The nozzle mechanism (5) is transmission-connected to a position adjustment mechanism (3), the position adjustment mechanism (3) comprises an X-axis adjustment mechanism and a Y-axis adjustment mechanism, and the X-axis adjustment mechanism and the Y-axis adjustment mechanism are transmission-connected; The Y-axis adjustment mechanism includes a mounting plate (301) fixedly connected to the inner top wall of the electrospinning box (1). Two groups of fixed frames are arranged along the length direction of the bottom surface of the mounting plate (301). The two groups of fixed frames are symmetrically arranged. A first worm (302) is rotatably connected between one group of fixed frames, and a second worm (303) is rotatably connected between the other group of fixed frames; A same worm wheel (304) is meshed and connected between the first worm (302) and the second worm (303). A first slide rail (305) is fixedly connected to the bottom of each group of fixed frames. The same slider (307) is slidably connected between the two first slide rails (305). The worm wheel (304) is rotatably connected to the slider (307).

8. The negative pressure electrospinning device according to claim 7, characterized in that: The X-axis adjustment mechanism includes two second slide rails (306) symmetrically and fixedly connected to the bottom surface of the slider (307). The same sliding frame (308) is slidably connected between the two second slide rails (306). The sliding direction of the sliding frame (308) is perpendicular to the sliding direction of the slider (307); A transmission shaft is coaxially and fixedly connected to the bottom surface of the worm wheel (304). The transmission shaft passes through the slider (307) and is coaxially and fixedly connected to a gear (309). The transmission shaft is fixedly connected to the slider (307). A rack (310) is fixedly connected to the inner wall of the sliding frame (308) along its sliding direction. The gear (309) is meshed and connected to the rack (310).

9. The negative-pressure electrospinning device according to claim 8, characterized in that: An adjustable-distance angle transformation mechanism (4) is provided between the nozzle mechanism (5) and the position adjustment mechanism (3). The adjustable-distance angle transformation mechanism (4) is used to adjust the distance and angle between the nozzle mechanism (5) and the negative pressure roller mechanism (2); The adjustable-distance angle transformation mechanism (4) includes a connecting plate (404) fixedly connected to the sliding frame (308). A fixing plate (401) is fixedly connected to the bottom surface of the connecting plate (404). Four telescopic members (402) are rotatably connected to the bottom surface of the fixing plate (401). The four telescopic members (402) are distributed in a rectangle. The bottom ends of the telescopic members (402) are rotatably connected to the same movable plate (403). The extrusion adjustment member (501) is fixedly connected to the movable plate (403).

10. The use method of a negative pressure electrospinning device according to any one of claims 1-9, characterized in that: It includes the following steps: S1. Dissolve or melt the spinning material to prepare a spinning solution. According to the characteristics and structural requirements of the required fibers, by adjusting the overlapping distance between the extrusion adjustment member (501) and the converging nozzle (503), the flexible member (502) can be extruded, and further the aperture of the liquid outlet of the flexible member (502) can be controlled; S2. Start the rotation of the negative pressure roller mechanism (2), turn on the high-voltage power supply, form an electric field force between the nozzle mechanism (5) and the negative pressure roller mechanism (2) and the suction force on the surface of the negative pressure roller mechanism (2). During the jet movement process, the solvent volatilizes or the melt solidifies to form nanofibers and uniformly adsorb on the surface of the negative pressure roller mechanism (2); S3. When the fibers are completely collected on the surface of the negative pressure roller mechanism (2), stop the spinning process and peel the fibers from the surface of the negative pressure roller mechanism (2).

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