CN103088443A - Umbrella-shaped electrostatic spinning sprayer and electrostatic spinning method - Google Patents

Abstract

The invention relates to an umbrella-shaped electrostatic spinning nozzle and an electrostatic spinning method. The nozzle includes an umbrella-shaped spinning nozzle, a numerically controlled infusion device and a solution collection tank. The numerically controlled infusion device mainly includes a solution propeller and a solution collection tank. Controller; there is a cylindrical hollow in the middle of the umbrella-shaped spinneret, and the output end of the solution propeller is placed in the cylindrical hollow of the umbrella-shaped spinneret; the controller controls the spinning The flow rate and flow rate of the silk solution; the bottom of the umbrella-shaped spinneret is placed with the solution collection tank; the electrospinning method includes: connecting the terminal on the umbrella-shaped spinneret to the high-voltage positive electrode, through the numerical control type infusion The device continuously adds conductive polymer solution to the umbrella-shaped spinneret placed horizontally, starts electrospinning, and is collected by the collection device to form nanofibers. The nozzle of the invention avoids clogging, is easy to clean, and has good stability; the electrostatic spinning method of the invention improves production efficiency and increases the output of electrostatic spinning.

Description

An umbrella-shaped electrostatic spinning nozzle and electrostatic spinning method

technical field

The invention belongs to the field of electrostatic spinning devices and methods thereof, in particular to an umbrella-shaped electrostatic spinning nozzle and an electrostatic spinning method.

Background technique

Electrospinning is a relatively popular simple method for manufacturing nanofibers. It has become a hot spot in the current research on nanofiber manufacturing due to its excellent characteristics such as simple equipment, easy operation, wide source of materials, and no damage to the material body during the process. The nanofibers produced by electrospinning have the characteristics of small diameter, large specific surface area, and high porosity, and have great application potential in the fields of biomedicine, air filtration, and protective clothing.

Electrospinning is to bring the polymer solution to thousands or even tens of thousands of volts of high-voltage static electricity. The charged droplets form a Taylor cone under the action of the electric field force. When the electric field force is large enough, the electric field force can overcome the surface tension of the solution at the tip of the Taylor cone. A fine jet is formed. The charged polymer jet is stretched and thinned under the action of electric field force, viscous resistance, surface tension, etc. At the same time, the charged jet bends due to the existence of surface charges in the electric field. The thin stream evaporates the solvent during the injection process and eventually falls on the receiving device, forming a nanofibrous mat similar to a non-woven fabric.

The low output of electrospinning is the biggest technical obstacle for this technology to move from the laboratory to industrial production and application. In order to improve the production efficiency of electrospinning, researchers have conducted more research on the spinning nozzle device, but most of them use a single needle as a spinning nozzle or assemble it to solve this technical obstacle, so single or multiple needles are used It is very common for a cylinder-type spinning device to push out the solution by mechanical force and form a Taylor cone in an electrostatic field, thereby drawing out one or more jet-spun nanofibers. However, there is serious mutual interference in the electric field between needle spinneret holes, and it is difficult to obtain large-scale promotion. Moreover, in the traditional electrospinning process, the propulsion speed of the infusion is slow, and the flow rate of the spinning solution is small. The method of increasing the delivery speed cannot guarantee the stability of spinning and cannot carry out normal production. In addition, affected by the viscosity and spinnability of the spinning solution, the diameter of the spinneret hole is mostly in the micron level, which is prone to clogging due to too fast volatilization of the solvent, resulting in production interruption, which affects production efficiency, and is difficult to maintain and difficult to clean. defect. At present, the open-up spinneret studied by some scholars has improved the needle spinneret to a certain extent, but there are still many shortcomings, such as the surface viscosity of the polymer solution caused by solvent volatilization, and it is difficult to form a stable jet under the same parameter conditions. , or the instability of the jet, which affects the smooth progress of the spinning process, or the number of jets is limited, and the output of nanofibers is not significantly improved.

Contents of the invention

The technical problem to be solved by the present invention is to provide an umbrella-shaped electrostatic spinning nozzle and an electrostatic spinning method. The nozzle avoids clogging, is easy to clean, and has good stability; the electrostatic spinning method improves production efficiency.

An umbrella-shaped electrospinning nozzle of the present invention includes three parts: an umbrella-shaped spinneret, a numerically controlled infusion device, and a solution collection tank. The numerically controlled infusion device mainly includes a solution propeller and a controller; the umbrella There is a hollow in the middle of the umbrella-shaped spinneret, and the output end of the solution propeller is placed in the hollow of the umbrella-shaped spinneret; the controller controls the flow rate and flow of the spinning solution, The top layer of the umbrella-shaped spinneret is continuously injected with spinning solution; the bottom of the umbrella-shaped spinneret is placed with the solution collection tank; the spinneret is provided with a terminal connected to a high-voltage positive electrode.

The umbrella-shaped spinneret is disc-shaped and has a four-layer structure. The diameter from the top layer to the bottom layer gradually increases, and the height of each layer is 6mm, and the height of each layer is the same; each layer of the umbrella-shaped spinneret A copper hollow cylindrical sleeve with a height of 1mm is added to the edge, and the outer diameter is the same as the diameter of each layer (from the top layer to the bottom layer: 25mm, 35mm, 45mm, 55mm).

The umbrella-shaped spinneret is made of copper material, which has good electrical conductivity and reduces energy loss.

The hollow part is cylindrical, and its axis coincides with the central axis of the umbrella-shaped spinneret.

The solution collection tank is made of plexiglass and placed at the bottom of the umbrella-shaped spinneret.

The electrospinning nozzle also includes a shield; the umbrella-shaped spinneret and the solution collection tank are arranged on the upper part of the shield; the solution propeller is arranged inside the shield , the electric field interference is shielded by the shielding cover.

A kind of electrospinning method of the present invention, this method adopts umbrella-shaped electrospinning nozzle, and concrete steps comprise:

Connect the terminal post on the umbrella-shaped spinneret to the high-voltage positive electrode to introduce high-voltage static electricity; continuously add conductive polymer solution to the horizontally placed umbrella-shaped spinneret through the numerical control infusion device, start electrospinning, and collect through the collection device , forming nanofibers.

In the present invention, the conductive polymer solution is continuously added to the umbrella-shaped spinneret placed horizontally through the numerical control infusion device, and the spinning solution will emerge from the top layer of the umbrella-shaped spinneret and flow freely along the edge of each layer of copper plate. Finally, each layer of copper plate forms a spinning solution layer with a uniform thickness and a certain curvature in all directions; most of the charges are gathered at the edge arc of each layer of spinning solution on the umbrella-shaped spinneret, so the electric field here The force is the easiest to overcome the surface tension of the spinning solution itself to form Taylor cones, and hundreds or even thousands of jets are drawn upwards. After the solvent evaporates, they are collected by the collection device to form nanofibers.

Due to the adoption of the above-mentioned technical scheme, the present invention has the following advantages and positive effects compared with the prior art: the spinneret used in the present invention is an open upward needle-free copper nozzle, which avoids the blockage of the needle structure device phenomenon, there is no need to frequently replace and clean the spinneret hole, which greatly improves the production efficiency, and is easy to clean after use; the solution is in a dynamic flow state, and the electric field intensity at the edge of each layer of the copper umbrella-shaped spinneret is the largest, Under the action of the same voltage, it can overcome the surface tension of the spinning solution to form multiple jets, increase the output of electrospinning, improve the stability of nozzle spinning, and realize continuous and large-scale production of nanofibers. The invention can effectively solve the disadvantages of easy blockage, low efficiency and difficult cleaning of the needle type nozzle, and overcome the disadvantage that the open type nozzle is difficult to form a jet.

The invention improves the traditional electrospinning nozzle, adopts the nozzle device to produce nanofibers, realizes spraying more jets in a smaller area, and improves production efficiency and polymer solution utilization to a certain extent rate and increase the yield of electrospinning.

Beneficial effect

(1) The nozzle of the present invention avoids clogging, is easy to clean, and has good stability;

(2) The electrospinning method of the present invention improves production efficiency and increases the yield of electrospinning.

Description of drawings

Fig. 1 is the schematic diagram of the electrospinning nozzle of the embodiment of the present invention;

Fig. 2 is the spinneret side view of the embodiment of the present invention;

Fig. 3 is a structural schematic diagram of an electrospinning nozzle device according to an embodiment of the present invention;

Fig. 4 is a schematic diagram of the electrospinning nozzle and the spinning solution on it according to the embodiment of the present invention;

Fig. 5 is a scanning electron micrograph of nanofibers made of PVA solution spun by the electrospinning nozzle of the embodiment.

Explanation of the numbers in the accompanying drawings:

1. Umbrella spinneret; 2. Solution thruster; 3. Controller; 4. Solution collection tank; 5. Terminal post; 6. High voltage positive electrode; 7. Shielding cover; 8. Hollow part.

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

The new umbrella-shaped electrospinning nozzle shown in Figure 1 is used for spinning. The solution is polyvinyl alcohol (PVA) aqueous solution with a mass concentration of 10%. In the cylindrical hollow 8 in the middle of the head 1, the spinning solution will emerge from the top layer of the umbrella-shaped spinneret 1, forming a spinning solution layer with a uniform thickness and a certain curvature in all directions of each layer of copper plate. The distance between the receiving base fabric and the upper end of the umbrella-shaped spinneret 1 is kept at 20cm, the controller 3 is turned on, the voltage of the high-voltage generator is adjusted to 50kV, the base fabric moves at a speed of 0.01m/min, and the trolley carrying the spinneret does reciprocating motion. The diameters of the manufactured nanofibers are mostly distributed between 200~300nm, and the dispersion is small, as shown in the scanning electron microscope image 5 (the scanning electron microscope image of the nanofiber mat, the magnification is 5000 times, and the average diameter is about 260nm). The amount of solution consumed by the umbrella spinneret is 3ml/min, that is, the output of the spun nanofiber is about 180g/h.

Example 2

An umbrella-shaped electrospinning nozzle, including an umbrella-shaped spinneret 1, a numerically controlled infusion device and a solution collection tank 4, characterized in that the numerically controlled infusion device mainly includes a solution propeller 2 and a controller 3 There is a cylindrical hollow place 8 in the middle part of the umbrella spinneret 1, and the output end of the solution propeller 2 is inserted into the cylindrical hollow place 8 of the umbrella spinneret 1; the control Device 3 controls the flow rate and the flow rate of spinning solution, and continuously injects spinning solution into the top layer of the umbrella-shaped spinneret 1; the bottom of the umbrella-shaped spinneret 1 is placed with the solution collection tank 4; The spinneret 1 is provided with a terminal 6 connected with the high voltage positive electrode 5 . The axis of the cylindrical hollow 8 coincides with the central axis of the umbrella-shaped spinneret 1 , as shown in FIGS. 1 and 2 .

Example 3

An umbrella-shaped electrospinning nozzle, including an umbrella-shaped spinneret 1, a numerically controlled infusion device and a solution collection tank 4, characterized in that the numerically controlled infusion device mainly includes a solution propeller 2 and a controller 3 There is a cylindrical hollow place 8 in the middle part of the umbrella spinneret 1, and the output end of the solution propeller 2 is inserted into the cylindrical hollow place 8 of the umbrella spinneret 1; the control Device 3 controls the flow rate and the flow rate of spinning solution, and continuously injects spinning solution into the top layer of the umbrella-shaped spinneret 1; the bottom of the umbrella-shaped spinneret 1 is placed with the solution collection tank 4; The spinneret 1 is provided with a terminal 6 connected with the high voltage positive electrode 5 . The axis of the cylindrical hollow 8 coincides with the central axis of the umbrella spinneret 1 .

The electrospinning nozzle also includes a shield 7; the umbrella-shaped spinneret 1 and the solution collection tank 4 are arranged on the top of the shield 7; the solution propeller 2 is arranged on the The inside of the shielding case 7 is shielded from electric field interference by the shielding case 7, as shown in FIG. 3 .

Claims (6)

1. a umbrella electrostatic spinning nozzle, comprise umbrella spinning head (1), digital control type infusion set and solution feeder (4) three parts, it is characterized in that, described digital control type infusion set mainly comprises solution propeller (2) and controller (3); Described umbrella spinning head (1) middle part has a hollow position (8), described solution propeller (2) output to insert in the hollow position (8) of described umbrella spinning head (1); Described controller (3) is controlled flow velocity and the flow of spinning solution, continues to inject spinning solution to described umbrella spinning head (1) top layer; Described solution feeder (4) is placed in described umbrella spinning head (1) bottom; Described spinning head (1) is provided with the binding post (6) that is connected with high pressure positive electrode (5).

2. a kind of umbrella electrostatic spinning nozzle according to claim 1 is characterized in that: described umbrella spinning head (1) has four-layer structure for discoid, and the diameter from top layer to bottom increases gradually, and the height of every layer is 6mm, and every layer height is identical; Every layer of edge of described umbrella spinning head (1) is added with and highly is the copper open circles column sleeve of 1mm, and the external diameter size is identical with the diameter of every layer.

3. a kind of umbrella electrostatic spinning nozzle according to claim 1 is characterized in that: described hollow position (8) is for cylindrical, and its axis overlaps with the axis of described umbrella spinning head (1).

4. a kind of umbrella electrostatic spinning nozzle according to claim 1 is characterized in that: described solution feeder (4) adopts lucite to make, and is positioned over described umbrella spinning head (1) bottom.

5. a kind of umbrella electrostatic spinning nozzle according to claim 1, it is characterized in that: described electrostatic spinning nozzle also comprises radome (7); Described umbrella spinning head (1) and described solution feeder (4) are arranged on the top of described radome (7); Described solution propeller (2) is arranged on described radome (7) inside, is disturbed by described radome (7) electric field shielding.

6. electrospinning process, the method adopts umbrella electrostatic spinning nozzle as described in claim 1-7, comprising:

Binding post (6) on umbrella spinning head (1) is connected the high pressure positive electrode, introduce high-pressure electrostatic; Continue to add conductive polymer solution by the digital control type infusion set in the umbrella spinning head (1) of the level of placement, the beginning electrostatic spinning is collected by gathering-device, forms nanofiber.

Images