阅读说明：本技术 一种变电场纳米纤维纺丝装置 (Variable electric field nanofiber spinning device ) 是由 覃小红 熊健 王黎明 俞建勇 于 2021-09-09 设计创作，主要内容包括：本发明涉及一种变电场纳米纤维纺丝装置,包括电场梯度调控装置、高压发生器、高聚物纺丝液供液装置和纳米纤维收集装置。本发明采用的电场梯度调控装置改变了传统静电纺丝技术的电场力空间分布,可以为初始射流拉伸段提供单调递增的电场拉伸力,因而可获得直径显著小于100纳米的超细纳米纤维,同时有效提升纤维内部大分子链取向度,这对提高纳米纤维的尺寸效应和应用能力具有重要意义。(The invention relates to a variable electric field nanofiber spinning device which comprises an electric field gradient regulating and controlling device, a high-voltage generator, a high polymer spinning solution supply device and a nanofiber collecting device. The electric field gradient regulating and controlling device adopted by the invention changes the spatial distribution of the electric field force of the traditional electrostatic spinning technology, and can provide monotonically increasing electric field stretching force for the initial jet flow stretching section, so that the superfine nano fiber with the diameter obviously smaller than 100 nanometers can be obtained, and meanwhile, the orientation degree of macromolecular chains in the fiber is effectively improved, which has important significance for improving the size effect and the application capability of the nano fiber.)

1. The spinning device is characterized by comprising a spinning solution supply device, a nanofiber collecting device, a high-pressure generator, a spinning nozzle and a metal ring; the spinning solution supply device is connected with the spinning nozzle, and the nanofiber collecting device is arranged above the spinning nozzle; wherein a metal ring is arranged outside the spinning nozzle, and the center of the metal ring is concentric with the spinning nozzle.

2. The apparatus of claim 1, wherein the spinning solution supplying means comprises a propeller pump, a syringe and a liquid guide tube, wherein one end of the liquid guide tube is connected to the syringe, and the other end is connected to the bottom of the spinning nozzle.

3. The apparatus of claim 1, wherein the nanofiber collection apparatus is a metal plate, a metal roller, or a conductive conveyor belt.

4. The device of claim 1, wherein the nanofiber collection device is grounded.

5. The device of claim 1, wherein the distance between the nanofiber collecting device and the spinning nozzle is 5-30 cm.

6. The apparatus of claim 1, wherein the spinning nozzle is a metal hollow needle; the radius R of the metal ring ranges from 1cm to 30 cm.

7. The apparatus of claim 1, wherein the spinning nozzle tip is spaced from the metal ring by a distance LL is determined by the physical relationship of the gradient of the variable electric field, the physical relationship isWherein R is the radius of the metal ring.

8. The device of claim 1, wherein the metal ring is connected to the positive electrode of the high voltage generator through a wire; the voltage regulating range of the high-voltage generator is 0-60 KV.

9. The apparatus of claim 1, wherein the spinneret is supported by an insulating support, and the distance L between the top of the spinneret and the metal ring is adjustable by the support.

10. An ultrafine nanofiber, wherein the ultrafine nanofiber is obtained by spinning using the apparatus of claim 1.

Technical Field

The invention belongs to the field of spinning devices, and particularly relates to a variable electric field nanofiber spinning device.

Background

In the development of fiber aggregate materials and engineering, the realization of the ultra-fining of fibers is always an important research direction. The diameter of human hair is about 70 mu m, the diameter of cotton fibers commonly used in textile materials is about 12 mu m, silk is typically thin in natural fibers of traditional textiles, the diameter is about 4 mu m, and the diameter of the fibers produced by an ultrafine chemical fiber technology can reach 0.4-4 mu m. The preparation of 0.1-1 μm submicron fiber and finer 1-100 nm nanofiber by technical innovation is an important subject focused by textile industry and related industries.

With the intensive research of nanotechnology, the electrospinning technology for rapidly obtaining fibers with diameter distribution ranging from hundreds of nanometers to several micrometers has been rapidly developed in recent 20 years. The prepared nano-scale fiber has larger specific surface area, abundant pore channel structures, flexible surface functionalization characteristics and superior interface and surface effects. The electrostatic spinning technology is widely applied to the fields of energy, environment, bioscience, medical engineering, military, national security and the like.

The existing electrostatic spinning device mainly comprises a traditional single-needle electrostatic spinning device and a novel needle-free electrostatic spinning device. The traditional single-needle electrostatic spinning device mainly comprises a high-voltage power supply system, a capillary liquid supply system and a fiber collecting polar plate. The positive electrode and the negative electrode of the high-voltage power supply are respectively applied to the capillary nozzle and the collecting device end to form a high-voltage electric field. The capillary liquid supply system is generally a metal hollow needle, and the spinning solution is pushed and extruded at the tip of the needle through a syringe pump. And drawing the spinning solution into a Taylor cone by a high-voltage electric field. With the further accumulation of charges, jet flow is ejected from the top of the Taylor cone, and the nanofiber is finally generated through electric field force drafting and thinning and solvent volatilization. This process allows the production of submicron fibers with diameters ranging from 100nm to 3 μm.

Fiber refinement, especially when fiber fineness is reduced from submicron (100-1000 nm) to true nanoscale (<100nm), fiber characteristics such as specific surface area, pore structure, bending stiffness, strength, shear modulus, surface adhesion, wetting behavior will change significantly. With the continuous and deep research and application of one-dimensional nano materials, the traditional single-needle electrostatic spinning can not meet the preparation requirement of superfine nano fiber materials (<100 nm).

The development of a nanofiber production device which breaks through the refining limit of the existing electrostatic spinning fibers is very important in both the academic research field and the production application field.

Disclosure of Invention

The invention aims to provide a variable electric field nanofiber spinning device to solve the problem that superfine nanofibers with true nanometer sizes (<100nm) cannot be produced by the existing electrostatic spinning technology.

The electric field gradient regulating and controlling device adopted by the invention changes the spatial distribution of the electric field force of the traditional electrostatic spinning technology, and can provide monotonically increasing electric field stretching force for the initial jet flow stretching section, so that the superfine nano fiber with the diameter obviously smaller than 100 nanometers can be obtained, and meanwhile, the orientation degree of macromolecular chains in the fiber is effectively improved, which has important significance for improving the size effect and the application capability of the nano fiber.

The spinning device comprises a spinning solution supply device, a nanofiber collecting device, a high-pressure generator, a spinning spray head and a metal ring, wherein the nanofiber collecting device is arranged on the spinning solution supply device; the spinning solution supply device is connected with the spinning nozzle, and the nanofiber collecting device is arranged right above the spinning nozzle; wherein a metal ring is arranged outside the spinning nozzle, and the center of the metal ring is concentric with the spinning nozzle.

The spinning nozzle and the metal ring form an electric field gradient regulating device.

The spinning solution supply device comprises a propulsion pump, an injector and a liquid guide pipe, wherein one end of the liquid guide pipe is connected with the injector, and the other end of the liquid guide pipe is connected with the bottom of the spinning nozzle.

The liquid supply speed of the high polymer spinning solution supply device is 0-15 mL/h.

The top of the spinning nozzle is positioned between the metal ring and the nanofiber collecting device.

The nanofiber collecting device is a metal flat plate, a metal roller or a conductive conveying belt, wherein the metal roller is driven to rotate by a motor.

The nanofiber collecting device is grounded.

The distance between the nanofiber collecting device and the spinning nozzle is 5-30 cm.

The spinning nozzle is a metal hollow needle head; furthermore, the spinning nozzle is a metal hollow needle head with the specification of 15-25G.

The radius R of the metal ring ranges from 1cm to 30 cm.

The distance between the top of the spinning nozzle and the metal ring is L, L is determined by the physical relationship of variable electric field gradient, and the physical relationship isWherein R is the radius of the metal ring.

The metal ring is connected with the anode of the high-voltage generator through a lead; the voltage regulating range of the high-voltage generator is 0-60 KV.

Furthermore, the metal ring is connected with the positive electrode of the high-voltage spinning power supply through a lead wire which is reliably insulated from the outside.

The spinning nozzle is supported by the insulating support, and the distance L between the top of the spinning nozzle and the metal ring can be adjusted by the support.

The superfine nanofiber is obtained by spinning through the device.

The superfine nano fiber is not more than 100 nm.

Further, the spinning carried out by the device is as follows:

(1) adjusting the distance between the nanofiber collecting device and the spinning nozzle;

(2) selecting a metal ring with a radius R;

(3) adjusting the distance L between the top of the spinning nozzle and the metal ring;

(4) opening the high polymer spinning solution supply device and setting the liquid supply speed;

(5) turning on a power supply of the high-voltage generator, and adjusting spinning voltage;

(6) an ultrafine jet is excited from the top of a spinning nozzle and is subjected to stretching refinement and solvent volatilization solidification to form ultrafine nano fibers;

(7) the nanofiber collecting device receives the formed ultrafine nanofibers.

Advantageous effects

The invention provides a new gradient electric field distribution, which changes the monotonous decreasing electric field intensity distribution along the direction of a collecting device inherent in the electrostatic spinning technology. The new gradient electric field distribution has the characteristic that the electric field intensity is increased monotonously and then decreased monotonously. This facilitates the sufficient drawing and thinning of the jet flow at the starting point of the jet flow movement, thereby realizing the preparation of the superfine nano fiber with the fiber diameter being significantly lower than 100nm and further lower than 50 nm. Meanwhile, the orientation degree of macromolecular chains in the fibers is effectively improved, and the strength and the electrical property of the nano fibers are obviously enhanced.

Drawings

FIG. 1 is a schematic view of a variable electric field gradient superfine nanofiber manufacturing apparatus for spinning;

FIG. 2 is a schematic perspective view of an electric field gradient control device;

FIG. 3 is a front view of the electric field gradient adjustment device;

FIG. 4 is a top view of the electric field gradient controlling device.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

Example 1

The variable electric field gradient nanofiber spinning device comprises a spinning solution supply device, a nanofiber collecting device, a high-voltage generator 4, a spinning spray head 6 and a metal ring 12; the spinning solution supply device is connected with the spinning nozzle 6, and the nanofiber collecting device is arranged above the spinning nozzle 6; wherein a metal circular ring 12 is arranged outside the spinning nozzle 6, and the center of the metal circular ring 12 is concentric with the spinning nozzle 6. The spinning nozzle 6 and the metal ring 12 form an electric field gradient regulation and control device, wherein the spinning nozzle is a metal hollow needle, and the metal ring is connected with the anode of the high-voltage generator through a conducting wire which is reliably insulated from the outside.

The spinning solution supply device comprises a propulsion pump 1, an injector 2 and a liquid guide pipe 3, wherein one end of the liquid guide pipe 3 is connected with the injector 2, and the other end of the liquid guide pipe is connected with the bottom of a spinning spray head 6. The top of the spinning nozzle 6 is positioned between the metal ring 12 and the nanofiber collecting device.

The top of the spinning nozzle and the metalThe distance of the circular ring is L, L is determined by the physical relation of the variable electric field gradient, and the physical relation isWherein R is the radius of the metal ring. The spinning nozzle is supported by the insulating support, and the distance L between the top of the spinning nozzle and the metal ring can be adjusted by the support.

Example 2

The polyacrylonitrile superfine nanofiber is produced by using a variable electric field gradient superfine nanofiber preparation device, and polyacrylonitrile powder with the molecular weight of 86000 is dissolved in N, N-dimethylformamide to prepare spinning solution with the mass fraction of 8%. Adjusting the distance between the nanofiber collecting device and the spinning nozzle 6 to be 15 cm; selecting a metal ring 12 with the radius of 5 cm; the distance between the top of the spinning nozzle 6 and the metal ring 12 is adjusted to be 0.5 cm; opening the high polymer spinning solution supply device and setting the liquid supply speed to be 1 mL/min; turning on a power supply of the high-voltage generator 4, and adjusting the spinning voltage to 12 kV; an ultrafine jet 7 is excited from the top of a spinning nozzle 6 and is subjected to drawing refinement and solvent volatilization solidification to form an ultrafine nanofiber 10; the nanofiber collecting device receives the formed ultrafine nanofibers 10. Thus, uniform superfine nano-fibers with the average fiber diameter of 58nm are prepared. The average diameter of the nanofiber obtained by electrospinning the same spinning solution under the same spinning distance and spinning voltage conditions by using a traditional single-needle electrostatic spinning device is 135 nm.

Example 3

The polyvinyl alcohol superfine nanofiber is produced by using a variable electric field gradient superfine nanofiber preparation device, and polyvinyl alcohol powder with the model of 1799 is dissolved in water at 80 ℃ to prepare a spinning solution with the mass fraction of 7%. Adjusting the distance between the nanofiber collecting device and the spinning nozzle 6 to be 18 cm; selecting a metal ring 12 with the radius of 6 cm; the distance between the top of the spinning nozzle 6 and the metal ring 12 is adjusted to be 1 cm; opening the high polymer spinning solution supply device and setting the liquid supply speed to be 0.8 mL/min; turning on a power supply of the high-voltage generator 4, and adjusting the spinning voltage to 10 kV; an ultrafine jet 7 is excited from the top of a spinning nozzle 6 and is subjected to drawing refinement and solvent volatilization solidification to form an ultrafine nanofiber 10; the nanofiber collecting device receives the formed ultrafine nanofibers 10. Thus, uniform ultrafine nanofibers having an average fiber diameter of 46nm were obtained. The average diameter of the nanofiber obtained by electrospinning the same spinning solution under the conditions of the same spinning distance and the same spinning voltage by using a traditional single-needle electrostatic spinning device is 111 nm.