Electrospinning fiber deposition area control device, control method and application

Abstract

The present invention belongs to the technical field of electrospinning fiber preparation, and discloses an electrospinning fiber deposition area control device, control method and application. The device comprises: an electrospinning nozzle is coaxially arranged through the central circular hole of the upper electrode support, the bottom of the electrospinning nozzle extends out of the bottom surface of the upper electrode support, and multiple jets are sprayed from the bottom of the electrospinning nozzle; the jet receives the lower electrode plate placed under the electrospinning nozzle; a plurality of long strip grooves are evenly distributed in an annular manner on the upper electrode support, and a reciprocating motor is fixedly installed on the upper part of each long strip groove, and electrodes of different shapes installed on the upper electrode support are connected to the reciprocating motor through the long strip groove through a connecting rod; electrodes of different shapes are connected to a first high-voltage electrostatic generator; and the lower electrode plate is connected to a second high-voltage electrostatic generator. Experiments show that from a single electrospinning nozzle, the jet expands and shrinks in the left and right directions and circulates back and forth. Macroscopically, it is manifested as uniform distribution of ultrafine fiber felt fibers, and product quality is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrostatic spinning fiber preparation, and in particular relates to an electrostatic spinning fiber deposition area control device, a control method and an application. Background Art

[0002] Electrospinning is an advanced manufacturing technology for polymer materials, in which polymer melt or solution forms a tiny jet under the action of a high-voltage electrostatic field and finally solidifies to form fibers. The electrospinning method is simple in principle and produces fibers with small diameters, making it one of the ideal methods for mass production of micro-nano fibers.

[0003] During the electrospinning process, droplets of polymer melt or solution fall rapidly under the stretching action of the high-voltage electrostatic field and sway or whip during the fall. The solidified fibers fall disorderly on the collection plate to form a fiber mat. The area and uniformity of the fiber mat on the final collection plate are affected by many factors such as nozzle diameter, spinning distance, polymer material and voltage. The deposition area is generally circular but the area is random and uncontrollable. This characteristic caused by the principle of electrospinning affects the application of electrospinning in certain fields. For example, in the process of electrospinning industrialization, in order to expand the fiber production capacity, an array multi-nozzle design is adopted. Since each nozzle produces fibers and falls to form a circular distribution of fiber mat deposition areas, there is a certain distance between the nozzles. Therefore, the fiber distribution of the final fiber mat is very uneven. The fiber distribution in the area between the nozzles is significantly less than the corresponding area at the bottom of the nozzle, which seriously affects the use of the fiber mat. In order to improve this defect, researchers used the method of swinging the spinning nozzle integrated plate left and right to improve the uniformity of the web laying. However, the swinging of the spinning nozzle integrated plate greatly increased the complexity of the equipment. In addition, due to the heavy weight and large inertia of the spinning nozzle integrated plate, the acceleration and deceleration rate is slow when changing direction, and the swinging process speed is uneven, resulting in large unevenness in the fiber mat, which cannot meet the use requirements. In addition, in high-end fields such as tissue engineering, biomedicine and sensors, it is also necessary to regulate the deposition area and deposition shape of electrospun fiber membranes to meet special use requirements.

[0004] Through the above analysis, the problems and defects of the prior art are as follows:

[0005] (1) During the industrialization of electrospinning, when ultrafine fibers are mass-produced, since the nozzles need to be spaced a certain distance apart, the fiber mat deposition area is mainly below each nozzle and is circular, resulting in uneven fiber distribution throughout the fiber mat, which seriously affects product quality.

[0006] (2) In special precision fields such as tissue engineering, biomedicine and sensors, existing equipment and technologies cannot meet the requirements of precisely controlling the shape of the fiber deposition area. Summary of the invention

[0007] In order to overcome the problems existing in the related art, the embodiments disclosed in the present invention provide an electrostatic spinning fiber deposition area control device, a control method and an application.

[0008] The technical scheme is as follows: an electrospinning fiber deposition area control device, comprising: an electrospinning nozzle, an upper electrode support, and a lower electrode plate, wherein the electrospinning nozzle passes through the upper electrode support and is coaxially arranged with its central circular hole, the bottom of the electrospinning nozzle extends out of the bottom surface of the upper electrode support, and multiple jets are sprayed from the bottom of the electrospinning nozzle; the jets are sprayed onto the lower electrode plate placed under the electrospinning nozzle; a plurality of long strip through grooves are evenly distributed in an annular pattern on the upper electrode support, a reciprocating motor is fixedly installed on the upper part of each long strip through groove, and electrodes of different shapes installed on the upper electrode support are connected to the reciprocating motor through connecting rods passing through the long strip through grooves;

[0009] The electrodes of different shapes are connected to a first high-voltage electrostatic generator; and the lower electrode plate is connected to a second high-voltage electrostatic generator.

[0010] In one embodiment, the electrodes of different shapes are arc electrodes with equal width arc segments, and the radius of the arc electrode is equal to the radius of the electrospinning nozzle or is 2-5 mm larger than the radius of the electrospinning nozzle.

[0011] In one embodiment, the corners of the arc electrode are rounded, and there are multiple arc electrodes, which are evenly arranged at certain intervals around the upper electrode support.

[0012] In one embodiment, the electrodes of different shapes are spherical electrodes, and there are multiple spherical electrodes that are evenly arranged at certain intervals around the upper electrode support.

[0013] In one embodiment, the upper electrode support is a disk structure with a hole in the center, and the diameter is 5-20 mm larger than the diameter of the area where the fiber deposition needs to be controlled.

[0014] Another object of the present invention is to provide a method for controlling the deposition area of ​​electrospinning fibers, comprising:

[0015] Turn on the second high-voltage electrostatic generator, the lower electrode plate is directly charged, so that the electrospinning nozzle is induced to be charged to form a jet, adjust the voltage until the jet is uniform, turn on the first high-voltage electrostatic generator, and charge the arc electrode connected thereto. The first high-voltage electrostatic generator and the second high-voltage electrostatic generator are powered with the same charge, so the arc electrode directly connected thereto and the lower electrode plate carry the same charge. Due to the induced charging, the electrospinning nozzle carries a charge with a polarity opposite to that of the lower electrode plate, and the jet generated from the electrospinning nozzle also carries a charge with a polarity opposite to that of the lower electrode plate. According to the principle that like charges repel and opposite charges attract, the jet and the lower electrode plate carry different charges, and the jet is attracted to move downward. At the same time, the jet and the arc electrode carry different charges, and the jet is attracted by the arc electrode and tends to expand outward;

[0016] When the fiber deposition shape is precisely controlled, the arc electrode is replaced with a spherical electrode, and the voltage of the corresponding spherical electrode is controlled to control the lateral deposition shape of the fiber at the corresponding position. The shape of the fiber deposition area is controlled by controlling the voltage of multiple spherical electrodes.

[0017] In one embodiment, the jet is attracted by the arc electrode and tends to expand outward. The jet is affected by the downward attraction F2 of the lower electrode plate and the lateral attraction F1 of the arc electrode. The resultant force is F, and the direction is obliquely downward. Under the premise that F2 remains unchanged, the lateral displacement of the jet is controlled by controlling the size of F1; under the premise that F1 remains unchanged, the lateral displacement of the jet is controlled by adjusting the distance between the lower electrode plate and the electrospinning nozzle.

[0018] Another object of the present invention is to provide an application of the electrospinning fiber deposition area control device in the preparation of tissue engineering ultrafine fiber felt.

[0019] Another object of the present invention is to provide an application of the electrospinning fiber deposition area control device in the preparation of biomedical ultrafine fiber felt.

[0020] Another object of the present invention is to provide an application of the electrospinning fiber deposition area control device in the preparation of a sensor ultrafine fiber felt substrate.

[0021] Combining all the above technical solutions, the advantages and positive effects of the present invention are as follows:

[0022] First, in view of the technical problems existing in the above-mentioned prior art and the difficulty of solving the problems, this paper closely combines the technical scheme to be protected by the present invention and the results and data in the research and development process, and analyzes in detail and deeply how the technical scheme of the present invention solves the technical problems, and some creative technical effects brought about after solving the problems, which are specifically described as follows: In order to change the size of the fiber deposition area and control the shape of the fiber deposition area in the existing electrospinning technology, most of them adopt the method of controlling the movement path of the nozzle, but most of the nozzles integrate complex systems such as temperature control and airflow assistance. The movement of the nozzle will bring a series of technical difficulties, and then bring new problems such as complex equipment and low control accuracy. The present invention takes a different approach and adopts a method of using multiple groups of electrodes and changing the voltage of some electrodes to achieve precise control of the fiber deposition area, simplifying the equipment and realizing precise control of the area and shape of the fiber deposition area.

[0023] Second, as auxiliary evidence of the inventiveness of the claims of the present invention, it is also reflected in the following important aspects:

[0024] (1) In the process of electrospinning industrialization, the present invention simplifies the existing equipment and improves the uniformity of fiber distribution of the fiber mat, thereby improving product quality and value.

[0025] (2) The present invention breaks the application bottleneck of this technology at home and abroad, and the technical solution of the present invention will be quickly and widely used in the electrospinning fiber preparation industry;

[0026] (3) The technical solution of the present invention overcomes two major problems of the prior art: first, it overcomes the problem of uneven distribution of fiber felt in the prior art; second, it achieves precise control of the deposition area of ​​the electrospinning fiber felt, expanding the application prospects of electrospinning.

[0027] (4) In the existing electrospinning technology applications, in order to improve the uniformity of fiber felt and control the fiber deposition area, the technicians first think of changing the movement path of the nozzle to achieve this. The present invention overcomes this technical prejudice and uses a multi-electrode superposition force method to achieve the above purpose, thereby expanding the technical application of electrospinning. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings herein are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the description, serve to explain the principles of the present disclosure;

[0029] Figure 1 Schematic diagram of an electrospinning fiber deposition control device with arc electrodes provided in an embodiment of the present invention;

[0030] Figure 2 Schematic diagram of an electrospinning fiber deposition control device with a ball electrode provided in an embodiment of the present invention;

[0031] Figure 3 It is a synthetic schematic diagram of the force exerted on the jet during the electrospinning fiber deposition regulation provided by an embodiment of the present invention;

[0032] Figure 4 It is a schematic diagram of a method for controlling uniform fiber distribution of a fiber mat in an experiment in which a fiber deposition area is gradually enlarged by gradually increasing the voltage applied by the arc electrode provided by an embodiment of the present invention;

[0033] In the figure: 1. electrospinning nozzle; 2. upper electrode holder; 3. reciprocating motor; 4. arc electrode; 5. jet; 6. lower electrode plate; 7. first high-voltage electrostatic generator; 8. second high-voltage electrostatic generator; 9. spherical electrode. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

[0035] 1. Explanation of the embodiment:

[0036] like Figure 1-Figure 2 As shown, an embodiment of the present invention provides an electrospinning fiber deposition area control device, including: an electrospinning nozzle 1, an upper electrode support 2, and a lower electrode plate 6, wherein the electrospinning nozzle 1 passes through the central circular hole of the upper electrode support 2 and is coaxially arranged, the bottom of the electrospinning nozzle 1 extends out of the bottom surface of the upper electrode support 2, and multiple jets 5 are sprayed from the bottom of the electrospinning nozzle 1; the jets 5 are sprayed onto the lower electrode plate 6 placed under the electrospinning nozzle 1; a plurality of long strip through grooves are evenly distributed in an annular pattern on the upper electrode support 2, and a reciprocating motor 3 is fixedly installed on the upper part of each long strip through groove, and electrodes of different shapes installed on the upper electrode support 2 are connected to the reciprocating motor 3 through the long strip through grooves via connecting rods;

[0037] The electrodes of different shapes are connected to a first high-voltage electrostatic generator 7 , and the lower electrode plate 6 is connected to a second high-voltage electrostatic generator 8 .

[0038] Example 1

[0039] like Figure 1 As shown, the electrospinning fiber deposition control device with arc electrode provided in an embodiment of the present invention includes: an electrospinning nozzle 1, an upper electrode bracket 2, a reciprocating motor 3, an arc electrode 4, a jet 5, a lower electrode plate 6, a first high-voltage electrostatic generator 7, and a second high-voltage electrostatic generator 8.

[0040] The upper electrode support 2 is a disc structure with a hole in the center, the disc structure has a thickness of 10-20 mm, a diameter 5-20 mm larger than the diameter of the area where the fiber deposition needs to be controlled, and is made of insulating materials such as polytetrafluoroethylene;

[0041] The electrospinning nozzle 1 is coaxially arranged through the central circular hole of the upper electrode support 2, the bottom of the electrospinning nozzle 1 extends 10-30 mm from the bottom surface of the upper electrode support 2, and a plurality of long strip through grooves are evenly distributed in an annular manner on the upper electrode support 2, the number of the long strip through grooves is 2-8, and a reciprocating motor 3 is fixedly installed on the upper part of each long strip through groove, and the arc electrode 4 is connected to the reciprocating motor 3 through the long strip through groove by a connecting rod, the arc electrode 4 is an arc segment of equal width, and the material is a conductive material such as iron, and the radius of the arc electrode 4 is equal to or 2-5 mm larger than the radius of the electrospinning nozzle 1;

[0042] The arc electrodes 4 have a width of 3-10 mm, with rounded corners, and a length such that the arc electrodes 4 do not touch each other and the distance between them is 10-20 mm;

[0043] A plurality of jets 5 are ejected from under the electrospinning nozzle 1; the jets 5 are connected to a lower electrode plate 6 placed under the electrospinning nozzle 1, the lower electrode plate 6 is 80-200 mm away from the lower end surface of the electrospinning nozzle 1, the electrospinning nozzle 1 is grounded, the arc electrode 4 is connected to a first high-voltage electrostatic generator 7, and the arc electrodes 4 connected to the first high-voltage electrostatic generator 7 may be one, several or all of them, and the lower electrode plate 6 is connected to a second high-voltage electrostatic generator 8.

[0044] Example 2

[0045] like Figure 2 As shown, the electrospinning fiber deposition control device with a spherical electrode 9 provided in the embodiment of the present invention includes: replacing the arc electrode 4 with a spherical electrode 9. Other structures and connection relationships are the same as those of the electrospinning fiber deposition control device with an arc electrode.

[0046] Example 3

[0047] The working process and working principle of the electrospinning fiber deposition control device with arc electrodes provided in Example 1 of the present invention, or the electrospinning fiber deposition control device with ball electrodes 9 provided in Example 2, include:

[0048] First, turn on the second high-voltage electrostatic generator 8, and the lower electrode plate 6 is directly charged, so that the electrospinning nozzle 1 is induced to be charged to form a jet 5, and the voltage is adjusted until the jet 5 is stable and uniform, and then turn on the first high-voltage electrostatic generator 7, and the arc electrode 4 connected thereto is charged. The first high-voltage electrostatic generator 7 and the second high-voltage electrostatic generator 8 are powered with the same charge, so the arc electrode 4 and the lower electrode plate 6 directly connected thereto carry the same charge. Due to the induced charging, the electrospinning nozzle 1 carries a charge with a polarity opposite to that of the lower electrode plate 6, and the jet 5 generated from the electrospinning nozzle 1 also carries a charge with a polarity opposite to that of the lower electrode plate 6. According to the principle that like charges repel and opposite charges attract, the jet 5 and the lower electrode plate 6 carry different charges, and the jet 5 is attracted to move downward. At the same time, the jet 5 and the arc electrode 4 carry different charges, and the jet 5 is attracted by the arc electrode 4 and has a tendency to expand outward. The stronger the voltage applied to the arc electrode 4, the stronger the attraction to the jet 5, and the greater the tendency of the jet 5 to expand outward. Figure 3As shown, the jet 5 is acted upon by the downward attraction F2 of the lower electrode plate 6 and the lateral attraction F1 of the arc electrode 4, the resultant force of which is F, and the direction is obliquely downward. Under the premise that F2 remains unchanged, the lateral displacement of the jet 5 can be controlled by controlling the size of F1; under the premise that F1 remains unchanged, the lateral displacement of the jet 5 can also be controlled by adjusting the distance between the lower electrode plate 6 and the electrospinning nozzle 1. The greater the distance, the greater the lateral displacement of the jet 5. However, since the distance becomes longer, the induced field strength of the electrospinning nozzle 1 will become smaller, resulting in the decrease of the jet 5 and other disadvantages. Therefore, when increasing the distance between the lower electrode plate 6 and the electrospinning nozzle 1, it is necessary to simultaneously increase the voltage applied to the lower electrode plate 6 to ensure that the induced field strength at the electrospinning nozzle 1 is strong enough to maintain the number and stability of the jet 5.

[0049] When it is necessary to precisely control the shape of fiber deposition, the arc electrode 4 can be replaced with a spherical electrode 9, and the voltage of the corresponding spherical electrode 9 can be controlled to control the lateral deposition shape of the fiber at the corresponding position. The larger the voltage, the farther the fiber deposition at the corresponding position extends laterally. The shape of the fiber deposition area can be controlled by controlling the voltage of multiple spherical electrodes 9.

[0050] In the embodiment of the present invention, the dynamic continuous change of the fiber deposition area and shape can be achieved by continuously changing the voltage applied to the arc electrode 4 or the spherical electrode 9 or by using the reciprocating motor 3 to make the arc electrode 4 or the spherical electrode 9 reciprocate.

[0051] Example 4

[0052] A circular tip needleless electrospinning nozzle 1 with a nozzle diameter of 30 mm is used. In order to increase the fiber yield, the target product is an ultrafine fiber felt. A multi-row array nozzle is used for simultaneous spinning. If only a lower electrode plate 6 is provided, the voltage applied to the lower electrode plate 6 is 80 kV, and the spinning distance is 200 mm, each electrospinning nozzle 1 can generate 65 jets 5 under the action of a high-voltage electrostatic field, that is, 65 fibers are formed. The fiber yield is increased, but the fiber distribution is uneven. There are fewer fibers distributed on the fiber felt corresponding to the electrospinning nozzles 1, and the product cannot be used.

[0053] After adopting the method described in the present invention, when working, first turn on the second high-voltage electrostatic generator 8, adjust the voltage to 80kV, the spinning distance to 200mm, each nozzle generates 65 jets 5, connect the two arc electrodes 4 perpendicular to the winding direction of the fiber felt to the first high-voltage electrostatic generator 7, turn on the first high-voltage electrostatic generator 7, adjust the voltage to 20kV, control the reciprocating motor 3 to reciprocate in the form of a sinusoidal function curve, and the movement of the same row is consistent, and the movement directions of adjacent rows are opposite.

[0054] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0055] 2. Application examples:

[0056] Application Examples

[0057] When using a multi-row array nozzle, first turn on the second high-voltage electrostatic generator 8, adjust the voltage to 80kV, the spinning distance is 200mm, each nozzle generates 65 jets 5, connect the two arc electrodes 4 perpendicular to the fiber mat winding direction to the first high-voltage electrostatic generator 7, turn on the first high-voltage electrostatic generator 7, adjust the voltage to 20kV, control the reciprocating motor 3 to reciprocate in the form of a sine function curve, and the movement of the same row is consistent, and the movement direction of adjacent rows is opposite. The fiber yield can be increased and the fiber distribution is more uniform, which greatly improves the quality of the product, so that the product meets the use requirements in high-end fields such as tissue engineering, biomedicine and sensors.

[0058] III. Evidence of the relevant effects of the embodiments:

[0059] like Figure 4 As shown, the experiment shows that when viewed from a single electrospinning nozzle 1, the jet 5 expands and contracts in the left and right directions and circulates back and forth. Macroscopically, the ultrafine fiber felt fibers are evenly distributed and the product quality is improved.

[0060] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for regulating the deposition area of ​​electrospinning fibers, characterized in that: The electrospinning fiber deposition area control method comprises: The second high-voltage electrostatic generator (8) is turned on to make the electrostatic spinning nozzle (1) inductively charged to form a jet (5), the first high-voltage electrostatic generator (7) is turned on, the arc electrode (4) connected to the first high-voltage electrostatic generator (7) is charged, the first high-voltage electrostatic generator (7) and the second high-voltage electrostatic generator (8) are powered with the same charge, the arc electrode (4) and the lower electrode plate (6) have the same charge, the electrostatic spinning nozzle (1) carries a charge with a polarity opposite to that of the lower electrode plate (6), the jet (5) and the lower electrode plate (6) have different charges, the jet (5) is attracted to move downward, and at the same time, the jet (5) and the arc electrode (4) have different charges, and the jet (5) is attracted by the arc electrode (4) and has a tendency to expand outward; When controlling the fiber deposition shape, the arc electrode (4) is replaced with a spherical electrode (9), and the voltage of the spherical electrode (9) is controlled to control the lateral deposition shape of the fiber at the corresponding position, and the shape of the fiber deposition area is controlled by controlling the voltage of multiple spherical electrodes (9); The jet (5) is attracted by the arc electrode (4) and has a tendency to expand outward. The jet (5) is acted upon by the downward attraction force F2 of the lower electrode plate (6) and the lateral attraction force F1 of the arc electrode (4). The resultant force is F and the direction is obliquely downward. Under the premise that F2 remains unchanged, the lateral displacement of the jet (5) is controlled by controlling the size of F1. Under the premise that F1 remains unchanged, the lateral displacement of the jet (5) is controlled by adjusting the distance between the lower electrode plate (6) and the electrospinning nozzle (1). An electrospinning fiber deposition area control device using the electrospinning fiber deposition area control method comprises: an electrospinning nozzle (1), the electrospinning nozzle (1) passes through the central circular hole of an upper electrode support (2) and is coaxially arranged on the electrode support (2), the bottom of the electrospinning nozzle (1) extends out of the bottom surface of the upper electrode support (2), and multiple jets (5) are sprayed from the bottom of the electrospinning nozzle (1); the jets (5) are sprayed onto a lower electrode plate (6) disposed below the electrospinning nozzle (1); a plurality of long strip through grooves are evenly distributed in an annular pattern on the upper electrode support (2), a reciprocating motor (3) is fixedly mounted on the upper part of each long strip through groove, and an electrode mounted on the upper electrode support (2) is connected to the reciprocating motor (3) through a connecting rod passing through the long strip through groove; the electrode mounted on the upper electrode support (2) is connected to a first high-voltage electrostatic generator (7); and the lower electrode plate (6) is connected to a second high-voltage electrostatic generator (8).

2. The electrospinning fiber deposition area control method according to claim 1, characterized in that: The electrode is an arc electrode (4) with arc segments of equal width, and the radius of the arc electrode (4) is equal to the radius of the electrospinning nozzle (1) or is 2-5 mm larger than the radius of the electrospinning nozzle (1).

3. The electrospinning fiber deposition area control method according to claim 2, characterized in that: The corners of the circular arc electrode (4) are rounded, and there are a plurality of circular arc electrodes (4) which are arranged at equal intervals around the upper electrode support (2).

4. The electrospinning fiber deposition area control method according to claim 1, characterized in that: The electrode is a spherical electrode (9), and there are a plurality of spherical electrodes (9) which are arranged at equal intervals around the upper electrode support (2).

5. The electrospinning fiber deposition area control method according to claim 1, characterized in that: The upper electrode support (2) is a disc structure with a hole in the center, and its diameter is 5-20 mm larger than the diameter of the area for controlling fiber deposition.

6. Application of an electrospinning fiber deposition area control device using the control method described in any one of claims 1 to 5 in the preparation of tissue engineering ultrafine fiber felt.

7. Application of an electrospinning fiber deposition area control device using the control method described in any one of claims 1 to 5 in the preparation of biomedical ultrafine fiber felt.

8. Application of an electrospinning fiber deposition area control device using the control method described in any one of claims 1 to 5 in the preparation of a sensor ultrafine fiber felt substrate.

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