阅读说明：本技术 一种柔性三维磁性纳米纤维材料及其制备方法和应用 (Flexible three-dimensional magnetic nanofiber material and preparation method and application thereof ) 是由 程志强 蔡川 李士军 赵春莉 刘文丛 于晓斌 姜秋实 于 2020-12-16 设计创作，主要内容包括：本发明公开了一种柔性三维磁性纤维材料及其制备方法和应用,该三维磁性纳米纤维材料采用静电纺丝结合后期热处理方法制备得。该三维磁性纳米纤维材料的纤维相互交织呈蓬松棉花状,热处理后得到的四氧化三铁均匀的分布在纤维的内部或表面。本发明优点主要体现在：(1)提供了一种简单、经济、高效制备柔性三维磁性纳米纤维材料的方法。(2)对溶液配制和纺丝过程具有良好的可调节行,适合制备具有不同纤维粗细和不同密度的柔性三维磁性纳米纤维材料。(3)本发明用于生物工程、药物传输、传感器、磁性标记方面。(The invention discloses a flexible three-dimensional magnetic fiber material, a preparation method and application thereof. The fibers of the three-dimensional magnetic nanofiber material are mutually interwoven into a fluffy cotton shape, and ferroferric oxide obtained after heat treatment is uniformly distributed in the fibers or on the surfaces of the fibers. The advantages of the invention are mainly reflected in that: (1) provides a simple, economical and efficient method for preparing the flexible three-dimensional magnetic nanofiber material. (2) The method has good adjustable line for the solution preparation and spinning process, and is suitable for preparing flexible three-dimensional magnetic nanofiber materials with different fiber thicknesses and different densities. (3) The invention is used in bioengineering, drug delivery, sensors, and magnetic labeling.)

1. A preparation method of a flexible three-dimensional magnetic nanofiber material is characterized by comprising the following specific steps:

the first step is as follows: preparing a spinning solution, adding polyacrylonitrile powder into dimethylformamide, and stirring until the polyacrylonitrile powder is completely dissolved to obtain a PAN solution; then adding iron salt and continuously stirring until the iron salt is fully dissolved to obtain uniform and stable spinning solution;

the second step is that: carrying out electrostatic spinning on the spinning solution at the temperature of 15-30 ℃ and the relative humidity of 20-50% to obtain a precursor fiber film with a three-dimensional structure, and drying the precursor fiber film at the temperature of 40-90 ℃ for 5-12 h;

the third step: and under the inert gas atmosphere, pre-oxidizing the precursor fiber film with the three-dimensional structure obtained in the second step, and carbonizing to obtain the flexible three-dimensional magnetic nanofiber material, wherein the fiber diameter is 600-800 nm.

2. The method for preparing the flexible three-dimensional magnetic nanofiber material as claimed in claim 1, wherein the method comprises the following steps: in the first step, the mass fraction of polyacrylonitrile in the spinning solution is 10-18%, and the polymerization degree is 80000-250000; the mass fraction of the ferric salt is 1-6%.

3. The method for preparing the flexible three-dimensional magnetic nanofiber material as claimed in claim 1, wherein the method comprises the following steps: in the first step, the heating and stirring temperature is 50 ℃, the stirring speed is 240rpm, the stirring time before the iron salt is added is 4-7 hours, and the stirring time after the iron salt is added is 10-24 hours.

4. The method for preparing the flexible three-dimensional magnetic nanofiber material as claimed in claim 1, wherein the method comprises the following steps: in the first step, the ferric salt is one of ferric chloride, ferric sulfate or ferric nitrate.

5. The method for preparing the flexible three-dimensional magnetic nanofiber material as claimed in claim 1, wherein the method comprises the following steps: the electrostatic spinning process parameters in the second step are as follows: the voltage is 15-25 kV, the feeding speed is 0.4-1.5 mL/h, and the distance between the receiving device and the spray head is 10-30 cm.

6. The method for preparing the flexible three-dimensional magnetic nanofiber material as claimed in claim 1, wherein the method comprises the following steps: the third step is that the concrete parameters of pre-oxidation are as follows: the temperature is 180-260 ℃, the heat preservation time is 1-2 h, and the heating rate is 1-15 ℃/min.

7. The method for preparing the flexible three-dimensional magnetic nanofiber material as claimed in claim 1, wherein the method comprises the following steps: the third step is that the carbonization treatment specifically comprises the following parameters that the temperature is 800-1150 ℃, and the inert gas is: nitrogen or argon, the heat preservation time is 0.5-2 h, and the heating rate is 1-10 ℃/min.

8. The method for preparing the flexible three-dimensional magnetic nanofiber material as claimed in claim 1, wherein the method comprises the following steps: the magnetic nanofiber material obtained by carbonization in the third step is ferroferric oxide/carbon nanofiber material.

9. The method for preparing the flexible three-dimensional magnetic nanofiber material as claimed in claim 1, wherein the method comprises the following steps: the density of the magnetic nanofiber material obtained by carbonization treatment in the third step is 5-15mg/cm³The specific surface area is 400-700m²(ii)/g, the average pore diameter is 0.5-3 um.

10. A flexible three-dimensional magnetic nanofiber material prepared by the method as claimed in any one of claims 1 to 9.

Technical Field

The invention relates to a flexible three-dimensional magnetic ferroferric oxide/carbon nanofiber material as well as a preparation method and application thereof.

Background

The electrospinning technique, also referred to as electrospinning technique for short, is a technique in which polymer fibers with diameters distributed between micrometers and nanometers are obtained by introducing electrostatic forces and drawing the polymer. The electrospinning technology was explored as early as the thirties of the twentieth century, and in the last decade after 1933, Formhals invented three experimental facilities for electrospinning fiber manufacture, and patents corresponding to these facilities are the very beginning of more detailed patents relating to spinning equipment, and many design ideas in these patents play an important guiding role in the design of today. But until the last practical 90 s the electrospinning technology was really not of interest. Particularly, after 2000 years, scientific research institutions and industries in various countries around the world have shown great interest in electrostatic spinning, so that research on electrostatic spinning is accelerated.

Nanomaterials are known as "21 actual most promising materials", and according to the IUPAC definition, nanomaterials mainly refer to materials with at least one dimension in space being on the order of nanometers. When the size of the nano material is less than 100nm, especially 10nm, the nano effect such as surface effect, quantum size effect and macroscopic quantum tunneling effect, etc., exhibited by the nano material, will cause the nano material to exhibit many characteristics different from other materials. One of the emerging areas of research in current composite materials is nanocomposites. Organic/inorganic composite spinning, i.e., dispersing inorganic materials in organic materials to form a composite spun material, wherein the inorganic materials function as a dispersed phase and the polymer material is a continuous phase. The organic/inorganic composite spinning has the characteristics of inorganic and organic nano materials. Among them, composite spinning, which is obtained by dispersing an inorganic material or a precursor solution thereof in a polymer solution through electrospinning, is a common and simplest method for preparing inorganic/organic composite electrospinning.

Disclosure of Invention

The invention aims to provide a flexible three-dimensional magnetic ferroferric oxide/carbon nanofiber material as well as a preparation method and application thereof.

The above purpose is realized by the following technical scheme:

a flexible three-dimensional magnetic nanofiber material and a preparation method and application thereof are characterized by comprising the following specific steps:

the first step is as follows: preparing a spinning solution, adding Polyacrylonitrile (PAN) powder into Dimethylformamide (DMF), and stirring until the PAN powder is completely dissolved to obtain a PAN solution; then adding iron salt and continuously stirring until the iron salt is fully dissolved to obtain uniform and stable spinning solution.

The second step is that: and (2) carrying out electrostatic spinning on the spinning solution at the temperature of 15-30 ℃ and the relative humidity of 20-50% to obtain a precursor fiber film with a three-dimensional structure, and drying the precursor fiber film at the temperature of 40-90 ℃ for 5-12 h.

The third step: and under the inert gas atmosphere, pre-oxidizing the precursor fiber film with the three-dimensional structure obtained in the second step, and carbonizing to obtain the flexible three-dimensional magnetic nanofiber material, wherein the fiber diameter is 600-800 nm.

In the first step, the mass fraction of polyacrylonitrile in the spinning solution is 10-18%, and the polymerization degree is 80000-250000; the mass fraction of the ferric salt is 1-6%.

In the first step, the heating and stirring temperature is 50 ℃, the stirring speed is 240rpm, the stirring time before the iron salt is added is 4-7h, and the stirring time after the iron salt is added is 10-24 h.

The first ferric salt is one of ferric chloride, ferric sulfate or ferric nitrate.

The electrostatic spinning process parameters in the second step are as follows: the voltage is 15-25V, the feeding speed is 0.4-1.5 mL/h, and the distance between the receiving device and the spray head is 10-30 cm.

The third step is that the concrete parameters of pre-oxidation are as follows: the temperature is 180-260 ℃, the heat preservation time is 1-2 h, and the heating rate is 1-15 ℃/min.

The third step is that the carbonization treatment specifically comprises the following parameters that the temperature is 800-1150 ℃, and the inert gas is: nitrogen or argon, the heat preservation time is 0.5-2 h, and the heating rate is 1-10 ℃/min.

The magnetic nanofiber material obtained by carbonization in the third step is ferroferric oxide/carbon nanofiber material.

The density of the magnetic nanofiber material obtained by carbonization treatment in the third step is 5-15mg/cm³The specific surface area is 400-700m²(ii)/g, the average pore diameter is 0.5-3 um.

A flexible three-dimensional magnetic nanofiber material is used in the aspects of bioengineering, drug delivery, sensors and magnetic labels.

This technical scheme has following beneficial effect:

1. the preparation method of the flexible three-dimensional magnetic nanofiber material provided by the invention combines the electrostatic spinning technology and the post-heat treatment method, and has the characteristics of simple operation, low cost and easy industrialization. Meanwhile, the ferric chloride and the polyacrylonitrile are fully and uniformly mixed in the spinning solution, so that the phenomenon of ferroferric oxide agglomeration after heat treatment can be effectively avoided, and the flexible three-dimensional magnetic nanofiber material with the novel structure has potential application values in the aspects of bioengineering, drug delivery, sensors and magnetic labels.

2. The flexible three-dimensional magnetic nanofiber material is prepared by adopting an electrostatic spinning technology and combining a later-stage heat treatment method, the average diameter of the flexible three-dimensional magnetic nanofiber material is 600-800 nm, ferric chloride is added, the flexible three-dimensional magnetic nanofiber material is converted into ferroferric oxide after heat treatment, meanwhile, polyacrylonitrile fiber is also converted into carbon fiber, the conductivity of a conductive polymer is obviously increased due to the combination of the ferroferric oxide and the carbon fiber, the internal resistance of the material is reduced, and higher sensitivity can be obtained when the flexible three-dimensional magnetic nanofiber material is used as a strain sensor.

Drawings

FIG. 1 is an example of a three-dimensional structure nanofiber material of the present invention taken with a camera;

FIG. 2 is an example of a three-dimensional structured nanofiber material of the present invention taken under a camera in a bent state;

fig. 3 and 4 show an example of the structure of the three-dimensional nanofiber material of the present invention under a scanning electron microscope.

Detailed Description

In order to better understand the present invention, the following examples are further provided to illustrate the content of the present invention, but the content of the present invention is not limited to the following examples, and should not be construed as limiting the scope of the present invention.

Example 1:

the first step is as follows: preparing a spinning solution, adding Polyacrylonitrile (PAN) powder into Dimethylformamide (DMF), and stirring until the PAN powder is completely dissolved to obtain a PAN solution; then adding iron salt and continuously stirring until the iron salt is fully dissolved to obtain uniform and stable spinning solution.

The second step is that: and (2) carrying out electrostatic spinning on the spinning solution at the temperature of 20 ℃ and the relative humidity of 30% to obtain a precursor fiber film with a three-dimensional structure, and drying the precursor fiber film at the temperature of 50 ℃ for 6 h.

The third step: and under the inert gas atmosphere, pre-oxidizing the precursor fiber film with the three-dimensional structure obtained in the second step, and carbonizing to obtain the flexible three-dimensional magnetic nanofiber material, wherein the fiber diameter is 600-800 nm.

In the first step, the mass fraction of polyacrylonitrile in the spinning solution is 10%, and the polymerization degree is 150000; the mass fraction of the iron salt is 4%.

In the first step, the heating and stirring temperature is 50 ℃, the stirring speed is 240rpm, the stirring time before the iron salt is added is 4 hours, and the stirring time after the iron salt is added is 18 hours.

The first ferric salt is ferric chloride.

The electrostatic spinning process parameters in the second step are as follows: the voltage was 15V, the feeding rate was 0.5mL/h, and the distance between the receiving device and the spray head was 15 cm.

The third step is that the concrete parameters of pre-oxidation are as follows: the temperature is 210 ℃, the heat preservation time is 1h, and the heating rate is 5 ℃/min.

The third step is that the carbonization treatment has the specific parameters that the temperature is 1000 ℃, and the inert gas is as follows: nitrogen, the heat preservation time is 2h, and the heating rate is 5 ℃/min.

The magnetic nanofiber material obtained by carbonization in the third step is ferroferric oxide/carbon nanofiber material.

The density of the magnetic nanofiber material obtained by carbonization treatment in the third step is 13mg/cm³Specific surface area of 600m²(iv)/g, average pore diameter of 0.5 um.

Example 2:

the first step is as follows: preparing a spinning solution, adding Polyacrylonitrile (PAN) powder into Dimethylformamide (DMF), and stirring until the PAN powder is completely dissolved to obtain a PAN solution; then adding iron salt and continuously stirring until the iron salt is fully dissolved to obtain uniform and stable spinning solution.

The second step is that: and (2) carrying out electrostatic spinning on the spinning solution at the temperature of 25 ℃ and the relative humidity of 40% to obtain a precursor fiber film with a three-dimensional structure, and drying the precursor fiber film at the temperature of 60 ℃ for 12 h.

The third step: and under the inert gas atmosphere, pre-oxidizing the precursor fiber film with the three-dimensional structure obtained in the second step, and carbonizing to obtain the flexible three-dimensional magnetic nanofiber material, wherein the fiber diameter is 600-700 nm.

In the first step, the mass fraction of polyacrylonitrile in the spinning solution is 12%, and the polymerization degree is 250000; the mass fraction of the iron salt is 3%.

In the first step, the heating and stirring temperature is 50 ℃, the stirring speed is 240rpm, the stirring time before the iron salt is added is 4 hours, and the stirring time after the iron salt is added is 18 hours.

The first ferric salt is ferric nitrate.

The electrostatic spinning process parameters in the second step are as follows: the voltage was 18V, the feed rate was 0.5mL/h, and the distance between the receiving device and the spray head was 20 cm.

The third step is that the concrete parameters of pre-oxidation are as follows: the temperature is 260 ℃, the heat preservation time is 1h, and the heating rate is 5 ℃/min.

The third step, the carbonization treatment has the specific parameters that the temperature is 1150 ℃, the inert gas is as follows: nitrogen, the heat preservation time is 2h, and the heating rate is 5 ℃/min.

The magnetic nanofiber material obtained by carbonization in the third step is ferroferric oxide/carbon nanofiber material.

The density of the magnetic nanofiber material obtained by carbonization treatment in the third step is 11mg/cm³Specific surface area of 550m²(iv)/g, average pore diameter of 0.9 um.

Example 3:

the first step is as follows: preparing a spinning solution, adding Polyacrylonitrile (PAN) powder into Dimethylformamide (DMF), and stirring until the PAN powder is completely dissolved to obtain a PAN solution; then adding iron salt and continuously stirring until the iron salt is fully dissolved to obtain uniform and stable spinning solution.

The second step is that: and (2) carrying out electrostatic spinning on the spinning solution at the temperature of 30 ℃ and the relative humidity of 30% to obtain a precursor fiber film with a three-dimensional structure, and drying the precursor fiber film at the temperature of 80 ℃ for 6 h.

The third step: and under the inert gas atmosphere, pre-oxidizing the precursor fiber film with the three-dimensional structure obtained in the second step, and carbonizing to obtain the flexible three-dimensional magnetic nanofiber material, wherein the fiber diameter is 600-800 nm.

In the first step, the mass fraction of polyacrylonitrile in the spinning solution is 14%, and the polymerization degree is 80000; the mass fraction of the iron salt is 5%.

In the first step, the heating and stirring temperature is 50 ℃, the stirring speed is 240rpm, the stirring time before the iron salt is added is 4 hours, and the stirring time after the iron salt is added is 18 hours.

The first ferric salt is ferric sulfate.

The electrostatic spinning process parameters in the second step are as follows: the voltage was 20V, the feeding rate was 1mL/h, and the distance between the receiving device and the spray head was 20 cm.

The third step is that the concrete parameters of pre-oxidation are as follows: the temperature is 240 ℃, the heat preservation time is 2h, and the heating rate is 5 ℃/min.

The third step is that the carbonization treatment has the specific parameters that the temperature is 900 ℃, the inert gas is as follows: nitrogen, the heat preservation time is 1h, and the heating rate is 5 ℃/min.

The magnetic nanofiber material obtained by carbonization in the third step is ferroferric oxide/carbon nanofiber material.

The density of the magnetic nanofiber material obtained by carbonization treatment in the third step is 11mg/cm³Specific surface area of 500m²(ii)/g, average pore diameter of 1 um.

Example 4:

a flexible three-dimensional magnetic nanofiber material is used in the aspects of bioengineering, drug delivery, sensors and magnetic labels.