Reverse-phase dual-electrode coupling type rifle aerodynamic electrostatic spinning technology

Abstract

The invention discloses a reversed-phase dual-electrode coupling type rifle aerodynamic electrostatic spinning technology, relates to the technical field of electrostatic spinning, and aims to solve the technical problem of non-uniform deposition of fibers, the reversed-phase dual-electrode coupling type rifle aerodynamic electrostatic spinning technology comprises two spinning nozzles capable of rotating, and a spinning solution is arranged below the spinning nozzles; the spinning nozzles can be immersed in a spinning solution and load the spinning solution in the rotating process, high-voltage generators are arranged on the outer sides of the two spinning nozzles, the two high-voltage generators provide positive static electricity and negative static electricity for the two spinning nozzles respectively, high-speed air flow is arranged between the peripheries of the two spinning nozzles, and the high-speed air flow is arranged between the peripheries of the two spinning nozzles. A collector made of metal materials is arranged on one side of the high-speed airflow, a center shaft is arranged in the center of the spinning nozzle, and a driving device is arranged at the end of the center shaft. The method has the advantages that the yield is improved, meanwhile, the potential rise of the collector caused by fiber deposition is inhibited, and various negative effects caused by retention of fibers in a spinning area are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of electrostatic spinning, and more specifically to an anti-phase dual-electrode coupled rifled aerodynamic electrostatic spinning technology. Background Art

[0002] Needle-free electrospinning is an advanced process that uses an open spinneret structure to convert polymer fluid into nanofibers under the action of a high electric field. In existing needle-free electrospinning devices, the jet and the fiber usually come from a single or high-voltage electrode with the same polarity. During the jet stretching and swinging process, the mutual repulsion and interference between the fibers are particularly obvious, especially when the output is high. The charge carried by the fiber is difficult to be neutralized in time on the collector, resulting in an increase in the collector potential. This will reduce the effective electric field and hinder the subsequent deposition of fibers, thereby reducing the spinning efficiency. In addition, the suspension of the fiber in the spinning area will also lead to uneven deposition of the fiber, affecting the uniformity of the fiber membrane. In view of this, we propose an anti-phase dual-electrode coupled riveted aerodynamic electrospinning technology. Summary of the invention

[0003] The purpose of the present invention is to provide a reverse dual-electrode coupled rifling aerodynamic electrospinning technology to solve the current technical problem of uneven fiber deposition.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: an inverse dual-electrode coupled riveted aerodynamic electrospinning technology, comprising two rotatable spinnerets, a spinning liquid is provided under the spinneret, the spinneret can be immersed in the spinning liquid and load the spinning liquid during the rotation process, a high-voltage generator is provided on the outside of the two spinnerets, the two high-voltage generators respectively provide positive static electricity and negative static electricity to the two spinnerets, a high-speed airflow is provided between the peripheries of the two spinnerets, and a collector made of metal material is provided on one side of the high-speed airflow.

[0005] Preferably, a central axis is provided at the center of the spinneret, and a driving device is provided at the end of the central axis.

[0006] Preferably, the high voltage electrode of the high voltage generator is connected to the spinneret at a relative position, and the ground terminal of the high voltage generator is connected to the collector.

[0007] Preferably, the high-speed airflow is arranged in a central area between two spinnerets, the high-speed airflow is directed toward a collector, and a container for holding spinning solution is arranged at the lower half of the spinneret.

[0008] Preferably, an air supply device is provided at the outlet of the high-speed airflow, and the air supply device is a hollow tube body, a plurality of airflow cavities are provided on the tube body, and a high-pressure air inlet is provided on one side of the tube body.

[0009] Preferably, the spinneret is a rifled needleless spinneret, which comprises a plurality of continuous or discontinuous rifled metal wires, and an extension rod is connected between the interior of the rifled needleless spinneret and the central axis.

[0010] Preferably, the collector is a rotating drum.

[0011] The technology uses a spinning head with positive and negative electrodes to form a high-voltage electric field. The fibers produced by the positive spinning head are positively charged, while the fibers produced by the negative spinning head are negatively charged. In the process of the fibers approaching each other and moving, they are affected by the high-speed airflow in the vertical direction, prompting the fibers to move to the same collector. On the collector, the opposite charges carried by the fibers are neutralized, effectively preventing the accumulation of charges on the collector, thereby promoting the continuous deposition of the fibers. Through this co-deposition of fibers with opposite charges, as well as the guidance and acceleration of the airflow, precise control of fiber deposition is achieved. The rifling structure, due to its large curvature, helps to form a local high electric field, which is crucial for the formation of fibers. High-speed airflow is a key factor in achieving fiber deposition. Without it, the fibers can only collide with each other between the two generators and cannot be effectively deposited on the collector. The design of opposite electrodes ensures the mutual neutralization of fiber charges, which plays a vital role in achieving uniform fiber collection.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. Efficient charge neutralization and fiber collection: By co-spinning fibers with opposite charges and achieving their co-deposition, this technology effectively eliminates the problem of charge accumulation on the collector and the resulting repulsive effect on subsequent fiber deposition, thereby achieving efficient fiber collection.

[0014] 2. Voltage regulation and output improvement: By using two high-voltage generators, the present invention significantly expands the voltage regulation range, thereby directly improving the fiber output and meeting the needs of large-scale production.

[0015] 3. Airflow guidance and fiber quality optimization: The vertical high-speed airflow guides and propels the fibers, generating shear force, which not only stretches the nanofibers to a certain extent and accelerates the volatilization of the solvent, but also effectively overcomes the obstacles formed by the reverse airflow during needle-free electrospinning, thereby improving the uniformity of fiber collection and enhancing the ability to adjust the fiber diameter.

[0016] In summary, the present invention achieves a dual improvement in fiber collection efficiency and quality through an ingenious charge neutralization mechanism, a voltage regulation strategy, and an airflow guiding technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1It is a structural schematic diagram of the present invention;

[0018] Figure 2 It is a working principle diagram of the present invention.

[0019] Explanation of the numbers in the figure: 1. spinneret; 101. rifled needleless spinneret; 2. high voltage generator; 3. collector; 4. central axis; 5. air supply device. DETAILED DESCRIPTION

[0020] Traditional electrospinning technology usually uses needle nozzles, which are limited by low production efficiency and are mainly suitable for laboratory environments. It is difficult to meet the needs of industrial-scale nanofiber production. In order to break through this limitation, the current electrospinning technology for mass production of nanofibers tends to use needle-free nozzles. This design allows the spinning solution to form a jet directly on the fluid surface, effectively avoiding the problem of easy clogging of needle nozzles. Similar to needle electrospinning, the electric field in the needle-free electrospinning process is also formed between the nozzle and the fiber collector. The fiber yield is affected by the structure of the spinning device, the distance between the nozzle and the collector, and other factors. The unidirectional migration of the jet will cause mutual interference between them, causing the fiber to suspend in the spinning area and fail to deposit on the collector in time, resulting in fiber loss or uneven deposition, affecting the yield and quality of nanofibers.

[0021] The main factor causing the loss or uneven deposition of fibers is the technical limitations in the single-electrode spinning process. Since the generated fibers carry the same type of charge, the fibers that have been deposited on the collector will electrostatically repel the newly formed fibers, further affecting the uniform deposition of the fibers. Finally, the suspension of the unsuccessfully deposited fibers in the spinning area will hinder the deposition of new fibers, causing the fibers to escape from the collector and the non-uniform aggregation of the fibers. These factors not only reduce the collection efficiency of the fibers, but also destroy the overall uniformity of the fiber membrane, thus limiting the widespread adoption of needle-free electrospinning technology in practical applications.

[0022] In addition, it should be noted that increasing the voltage to increase the fiber yield is not feasible because the increase in voltage is limited by air breakdown. Secondly, shortening the distance between the collector and the spinneret to increase the yield is also not feasible because this will result in insufficient drying of the fibers, which will cause adhesion between the fibers and affect the quality of the final product.

[0023] In response to the above-mentioned difficulties, the present invention proposes an innovative inverse dual-electrode coupled needle-free electrospinning technology. Two spiral structure nozzles with rifling are used, and opposite high voltages are given to them. Under the action of high voltage, the jets generated by the spinning solution each carry opposite charges, attract each other, and migrate toward each other. Under the action of vertical airflow, these jets change their spinning paths and are finally deposited on the collector. This technology effectively reduces the electrostatic interference between jets in the traditional needle-free electrospinning process, making it easier for fibers with opposite charges to aggregate and deposit. At the same time, the action of airflow helps to produce finer fibers. Therefore, this technology not only improves the yield and fineness of nanofibers, but also significantly improves the collection efficiency of nanofibers, realizing the industrial production and wide application of nanofibers. The specific structure is as follows.

[0024] like Figure 1 to Figure 2 As shown, the present invention relates to an inverse dual-electrode coupled rifling aerodynamic electrospinning technology, comprising two rotatable spinnerets 1, a spinning solution is provided below the spinnerets 1, the spinnerets 1 can be immersed in the spinning solution and loaded with the spinning solution during the rotation process, high-voltage generators 2 are provided on the outside of the two spinnerets 1, the two high-voltage generators 2 respectively provide positive static electricity and negative static electricity to the two spinnerets 1, a high-speed airflow is provided between the peripheries of the two spinnerets 1, a collector 3 made of metal material is provided on one side of the high-speed airflow, a central axis 4 is provided at the center of the spinneret 1, a driving device is provided at the end of the central axis 4, the driving device can be a driving motor or other driving equipment, the high-voltage electrode of the high-voltage generator 2 is connected to the spinneret 1 at a relative position, the ground end of the high-voltage generator 2 is connected to the collector 3, the high-speed airflow is arranged in the central area between the two spinnerets 1, the high-speed airflow is the wind direction toward the collector 3, the high-speed airflow can also be arranged at any position of the periphery according to the guide structure, the lower half of the spinneret 1 is provided with a container for holding the spinning solution, the shape of the container is not limited, and both a trough body and a round shell body are possible.

[0025] Specifically, an air supply device 5 is provided at the outlet of the high-speed airflow. The air supply device 5 can be of various structures. The air supply device 5 of the present design is a hollow tube body, on which a plurality of airflow cavities are provided, and a high-pressure air inlet is provided on one side of the tube body. If it is a tube body, the diameter of the airflow cavity is not limited to 1 mm, and the interval can be 4-100 mm. In addition to using the pipeline type, a plate body of the airflow cavity can also be designed under the spinning device to cover the spinning space.

[0026] Specifically, the spinneret 1 is a rifling needleless spinneret 101, which includes a plurality of continuous or discontinuous rifling metal wires. An extension rod is connected between the inside of the rifling needleless spinneret 101 and the central axis 4. When the rifling wire is a discontinuous structure, the rifling wire on each unit is similar to a horizontal wing structure, and the angle of the horizontal wing of the outer layer can be rotated between 0°-180°. The horizontal wings are evenly arranged along the ring, with a spacing greater than 2mm. In addition to adopting a reciprocating spinneret structure, the present invention also includes other needleless electrospinning head designs, such as a spiral blade spinneret structure or a spiral spinneret structure to replace the rifling wire;

[0027] Since the rifled needleless spinneret 101 comprises a plurality of continuous or discontinuous rifled metal wires, each wire has a diameter of 1-5 mm, and the spacing between adjacent rifled wires is greater than 1-50 mm, the rifled needleless spinneret 101 has a central axis 4 and an external rotation drive device, and the rifled wire structure is partially immersed in the spinning solution, and can be rotated as needed during spinning to load the spinning solution.

[0028] Specifically, the collector 3 can be a chain plate type, a patterned type, a stationary or rotating drum, etc., and is connected to the grounding ends of the two high-voltage generators 2 through the collector 3. When the fibers on both sides are in contact with the collector 3, charge neutralization can be achieved.

[0029] It should be noted that the device is suitable for mass preparation of fiber non-woven fabrics, composite films of non-woven fabrics and particulate matter, and particulate stacking structures. The spinning technology is suitable for polymer solutions, polymer melts, sol-gels and protoplasmic particle suspensions with a viscosity between 1 mPa·s-100000 mPa·s. During the spinning process, the potential difference generated between the two opposite high-voltage generators 2 is not less than 40 kV. The two high-voltage generators 2 can spin one spinning solution at the same time, or they can spin two different spinning solutions.

[0030] The actual data used are as follows;

[0031] Using the described electrospinning apparatus ( Figure 1 ) PVA nanofibers were prepared under the conditions of 14% spinning solution concentration, 18 cm collection distance, -25 kV cathode voltage, 65 kV cathode voltage, 17 cm shortest distance between opposite electrodes, and 2 m / s airflow. PVA (polyvinyl alcohol, average molecular weight 70,000-80,000) obtained from Chongqing Chuanwei Chemical Co., Ltd. of Sinopec Group was used. PVA nanofibers were prepared by conventional single needle electrospinning with an outer diameter of 0.9 mm and an inner diameter of 0.62 mm, and compared with an inverted dual electrode coupled rifling aerodynamic needleless electrospinning device. The average diameter of the nanofibers photographed by SEM was calculated under the image analysis software Image.

[0032] Experimental results:

[0033] In the electrospinning device, the PVA solution is evenly covered on the surface of the slowly rotating spinneret 1, and under the action of the electric field, jets with opposite charges are formed on the left and right, converging above the pores, and converging to the collector 3 under the action of the airflow. Compared with the nanofibers prepared by the conventional single-needle electrospinning device, the nanofibers are finer, and it is found that the nanofiber productivity of the inverse double-electrode coupled rifling aerodynamic needleless electrospinning device is as high as 10g / h, while the conventional single-needle electrospinning productivity is less than 0.3g / h.

[0034] The embodiments of the present invention disclose preferred embodiments, but are not limited thereto. A person skilled in the art can easily understand the spirit of the present invention based on the above embodiments and make different extensions and changes. However, as long as they do not deviate from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. An inverse dual-electrode coupled rifling aerodynamic electrospinning technology, characterized in that: The invention comprises two rotatable spinnerets (1), wherein a spinning liquid is provided below the spinnerets (1), wherein the spinnerets (1) can be immersed in the spinning liquid and loaded with the spinning liquid during the rotation process, wherein high voltage generators (2) are provided outside the two spinnerets (1), wherein the two high voltage generators (2) respectively provide positive static electricity and negative static electricity to the two spinnerets (1), wherein a high-speed airflow is provided between the outer peripheries of the two spinnerets (1), and a collector (3) made of a metal material is provided on one side of the high-speed airflow.

2. The inverse dual-electrode coupled rifling aerodynamic electrospinning technology according to claim 1 is characterized in that: A central shaft (4) is provided at the center of the spinneret (1), and a driving device is provided at the end of the central shaft (4).

3. The inverse dual-electrode coupled rifling aerodynamic electrospinning technology according to claim 2 is characterized in that: The high voltage electrode of the high voltage generator (2) is connected to the spinneret (1) at a relative position, and the grounding end of the high voltage generator (2) is connected to the collector (3).

4. The inverse dual-electrode coupled rifled aerodynamic electrospinning technology according to claim 3, characterized in that: The high-speed airflow is arranged in the central area between the two spinnerets (1), the high-speed airflow is directed toward the collector (3), and a container for holding the spinning solution is arranged at the lower half of the spinneret (1).

5. The inverse dual-electrode coupled rifling aerodynamic electrospinning technology according to claim 4, characterized in that: An air supply device (5) is provided at the outlet of the high-speed air flow. The air supply device (5) is a hollow tube body, a plurality of air flow cavities are provided on the tube body, and a high-pressure air inlet is provided on one side of the tube body.

6. The inverse dual-electrode coupled rifled aerodynamic electrospinning technology according to claim 4, characterized in that: The spinneret (1) is a rifled needleless spinneret (101), which comprises a plurality of continuous or discontinuous rifled metal wires, and an extension rod is connected between the inside of the rifled needleless spinneret (101) and the central axis (4).

7. The inverse dual-electrode coupled rifled aerodynamic electrospinning technology according to claim 4, characterized in that: The collector (3) is a rotating drum.

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