阅读说明：本技术 一种三维纤维骨架多孔材料及其制备方法 (Three-dimensional fiber framework porous material and preparation method thereof ) 是由 焦秀玲 邱烽 陈代荣 夏玉国 于 2021-07-07 设计创作，主要内容包括：本发明涉及一种三维纤维骨架多孔材料,所述的多孔材料是以纳米级或微米级纤维为骨架,纤维之间以无序或部分有序的方式排列,纤维之间形成纳米级、微米级或毫米级的孔道,纤维直径为50nm-1微米,三维纤维骨架多孔材料的平均孔径为50nm～10毫米；本发明的制备过程包括二维多孔材料表面液膜的形成,通过化学或物理方式使二维多孔材料内部液相生成气体,二维材料在气体压力作用下的膨胀,液体从体系中的去除步骤。本发明制备的三维纤维骨架多孔材料密度小且可调,孔隙率高,有良好的力学性能,导热系数小,吸声性能好,制备过程简单,绿色环保,适于大量制备。(The invention relates to a three-dimensional fiber framework porous material, wherein the porous material takes nano-scale or micron-scale fibers as a framework, the fibers are arranged in a disordered or partially ordered mode, nano-scale, micron-scale or millimeter-scale pore channels are formed among the fibers, the diameter of the fibers is 50nm-1 micron, and the average pore diameter of the three-dimensional fiber framework porous material is 50 nm-10 mm; the preparation process of the invention comprises the steps of forming a liquid film on the surface of the two-dimensional porous material, generating gas from the liquid phase in the two-dimensional porous material through a chemical or physical mode, expanding the two-dimensional material under the action of gas pressure, and removing the liquid from the system. The three-dimensional fiber framework porous material prepared by the invention has the advantages of small and adjustable density, high porosity, good mechanical property, small heat conductivity coefficient, good sound absorption performance, simple preparation process, environmental protection and suitability for mass preparation.)

1. A three-dimensional fiber framework porous material takes nano-scale or micron-scale fibers as a framework, the fibers are arranged in a disordered or partially ordered mode, nano-scale, micron-scale or millimeter-scale pore channels are formed among the fibers, the diameter of the fibers is 50nm-1 micron, the average pore diameter of the three-dimensional fiber framework porous material is 50 nm-10 mm, and the fibers serving as the framework are selected from one of organic polymer fibers, inorganic/organic polymer composite fibers, inorganic fibers, organic/organic polymer composite fibers and inorganic/inorganic composite fibers.

2. The three-dimensional fiber skeleton porous material according to claim 1, wherein the fiber as the skeleton is selected from organic polymer fiber or inorganic/organic polymer composite fiber, and the porosity of the three-dimensional fiber skeleton porous material is 90-99%.

3. The method for preparing the three-dimensional fiber framework porous material according to claim 1, comprising the following steps:

a. after the two-dimensional porous material is immersed in the solution, taking out the two-dimensional porous material or dropwise adding the solution on the surface of the two-dimensional porous material to enable the two-dimensional porous material to be completely immersed in the liquid and form a liquid film on the surface of the fiber film;

b. enabling the two-dimensional porous material to fill the liquid to generate gas in a physical or chemical mode;

c. the two-dimensional porous material gradually expands under the action of gas pressure to form a three-dimensional fiber skeleton porous material;

d. drying the three-dimensional fibrous skeleton porous material.

4. The preparation method according to claim 3, wherein in the step a, the two-dimensional porous material is formed by wet spinning, dry spinning, blowing, centrifugal spinning or electrostatic spinning, and the two-dimensional porous material is directly formed on a collecting substrate to form a two-dimensional fiber membrane, a fiber blanket or a fiber felt, or is formed into a two-dimensional porous material constructed by fibers by post-processing the fibers;

preferably, in the step a, the two-dimensional porous material is formed by electrospinning, and the electrospinning is a solution electrospinning method or a melt electrospinning method.

5. The preparation method according to claim 3, wherein in the step a, the sol precursor before the two-dimensional porous material is formed is a polymer solution or a melt, a polymer and inorganic compound mixed solution or a sol, an inorganic compound solution or a sol.

6. The method according to claim 3, wherein the gas is chemically generated in step b by catalytic decomposition of hydrogen peroxide, catalytic decomposition of sodium borohydride or decomposition of ammonium bicarbonate.

7. The method according to claim 3, wherein the gas generated by the chemical reaction in the step b is non-toxic oxygen, hydrogen or carbon dioxide.

8. The preparation method according to claim 3, wherein in the step b, a catalyst for catalyzing a chemical reaction and generating a gas may be previously added to the sol for preparing the two-dimensional porous material and remain in the fibers of the two-dimensional porous material by spinning, or be introduced by adding to the solution for forming the liquid film.

9. The method according to claim 6, wherein when the gas is generated by catalytically decomposing hydrogen peroxide to generate oxygen, the catalyst is a zirconium-containing compound, ferric chloride, or ferrous chloride; the zirconium-containing compound is zirconium hydroxide or zirconium oxychloride;

when the gas is generated by decomposing hydrogen peroxide to generate oxygen, the generation of the gas and the expansion of the fiber membrane are accelerated under the condition of alkaline gas;

the gas generation mode is that when sodium borohydride is catalytically decomposed to generate hydrogen, the generation of the gas and the expansion of the fiber membrane are catalyzed and accelerated under the condition of acid gas;

the gas is generated by decomposing ammonium bicarbonate to generate ammonia gas, water and carbon dioxide, and the gas is generated and the fiber membrane is expanded by heating.

10. The method according to claim 3, wherein the drying in step d is performed by atmospheric drying, freeze drying or supercritical drying.

Technical Field

The invention relates to a three-dimensional fiber framework porous material and a preparation method thereof, belonging to the field of new materials.

Background

The three-dimensional porous material is in a three-dimensional aggregation state formed by solid particles or fibers, wherein the interior of the three-dimensional porous material contains a large amount of gas as a dispersion medium, and the three-dimensional porous material has good heat insulation performance and noise absorption performance and simultaneously has smaller density. Therefore, the three-dimensional porous material has wide application in the fields of energy catalysis, biological medical treatment, petrochemical industry, aerospace, building materials and national defense and military industry. In the existing three-dimensional porous material, the framework material mainly comprises two types: solid particles and micro-nano fibers. The main preparation method of the three-dimensional porous material composed of one-dimensional nano fibers or nano wires is as follows (Y.Si, J.Yu, X.Tang, J.Ge and B.Ding, Ultralight nanofiber-allocated cellular aerogels with super elasticity and multifunctionality. Nat. Commun.5,5802 (2014); Z.Yu, B.Qin, Z.Ma, J.Huang, S.Li, H.ZHao, H.Li, Y.Zhu, H.Wu, and S.Yu, Superelastic hard carbon nanofiber aerogels. Adv.Mat.1900651 (2019)): firstly, dispersing the prepared fibers or nanowires in a liquid phase to form a suspension, then solidifying the suspension by gelling or freezing, and finally removing the solvent by freeze drying or supercritical extraction to obtain the three-dimensional porous material. The method has the main problems that the obtained three-dimensional material has short fibers, poor continuity and small acting force between the fibers, so that the mechanical property is poor, the preparation process is complicated and the cost is high. Furthermore, there are also reports (m.k.joshi, h.r.pant, a.p.tiwari, h.j.kim, c.h.park, c.s.kim, Multi-layered macroporous solid-membrane-diffusion via a non-polar gas bubbling detection. chem.eng.j.275, 79-88 (2015)), j.jiang, z.li, h.wang, y.wang, m.a.carlson, m.j.terminal, m.r.macewan, l.gu, j.xie, Expanded 3D nanofiber filters: cell dilution, neolysis, host reaction, heald.v.addend 3, t.r.t.c.t.t.r.t.m.t.m.t.t.t.m.t.t.m.t.t.t.m.t.t.t.t.t.t.t.t.t.t.t.t.t.t.c, and the problem of rapid drying of the fibers by vacuum drying of the porous membranes, drying of the resulting fibers, drying process, or drying of the fiber by vacuum (m.k.h.t.h.r.t.t.c.t.t.p. pat, 3, k. h.t.t.t.t.t.t.t.t.t.t.t.f. fiber, fiber production, drying, fiber production by a, drying process, and drying process, high costs are still present problems.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a three-dimensional fiber framework porous material and a preparation method thereof.

The porosity of the three-dimensional fiber framework porous material is adjustable, can reach more than 99 percent, and has anisotropic mechanical property, high compression resilience, low heat conductivity coefficient, good noise absorption performance and waterproof and breathable performance.

The preparation method is simple, low in cost and easy to popularize and utilize.

The invention is realized by the following technical scheme:

a three-dimensional fiber framework porous material takes nano-scale or micron-scale fibers as a framework, the fibers are arranged in a disordered or partially ordered mode, nano-scale, micron-scale or millimeter-scale pore channels are formed among the fibers, the diameter of the fibers is 50nm-1 micron, the average pore diameter of the three-dimensional fiber framework porous material is 50 nm-10 mm, and the fibers serving as the framework are selected from one of organic polymer fibers, inorganic/organic polymer composite fibers, inorganic fibers, organic/organic polymer composite fibers and inorganic/inorganic composite fibers.

Preferably, according to the present invention, the fibers as a skeleton are selected from organic polymer fibers or inorganic/organic polymer composite fibers.

Organic polymer fibers, inorganic/organic polymer composite fibers, inorganic fibers, organic/organic polymer composite fibers, inorganic/inorganic composite fibers are prepared according to the prior art in the field.

According to the invention, the porosity of the three-dimensional fiber skeleton porous material is preferably 90-99%.

According to the invention, the three-dimensional fiber skeleton porous material has anisotropic tensile strength and elongation at break.

Preferably, according to the invention, the three-dimensional fibrous skeleton cellular material has a high resilience to compression.

According to the invention, the three-dimensional fiber framework porous material has good sound absorption performance and waterproof and air permeability.

The three-dimensional fiber framework porous material forms a liquid film on the surface in liquid, forms a closed space inside the liquid, can float on the surface of the liquid for a long time without sinking, and the liquid is selected according to the type of the three-dimensional fiber framework porous material.

The three-dimensional fiber framework porous material of the invention can extrude liquid by applying external force under the condition that the pore channel is filled with liquid, thereby forming a two-dimensional porous fiber membrane.

The three-dimensional fiber framework porous material is calcined in inert atmosphere to be converted into a three-dimensional porous carbon material or a three-dimensional porous carbon/inorganic substance composite material.

Calcination and carbonization under an inert atmosphere are carried out according to conventional techniques in the art.

The preparation method of the three-dimensional fiber skeleton porous material comprises the following steps:

a. after the two-dimensional porous material is immersed in the solution, taking out the two-dimensional porous material or dropwise adding the solution on the surface of the two-dimensional porous material to enable the two-dimensional porous material to be completely immersed in the liquid and form a liquid film on the surface of the fiber film;

b. generating gas inside the liquid filled with the two-dimensional porous material through a physical or chemical mode;

c. the two-dimensional porous material gradually expands under the action of gas pressure to form a three-dimensional fiber skeleton porous material;

d. drying the three-dimensional fibrous skeleton porous material.

The conversion process of the 2D porous material to the 3D porous material comprises the steps of forming a liquid film on the surface of the two-dimensional porous material, enabling the two-dimensional porous material to be filled with liquid to generate gas through a chemical or physical mode, expanding the two-dimensional material under the action of gas pressure, removing (drying) the liquid from a system and the like.

According to the present invention, in the step a, the two-dimensional porous material is formed by wet spinning, dry spinning, blowing, centrifugal spinning or electrostatic spinning, and the two-dimensional porous material is directly formed on the collecting substrate to form a two-dimensional fiber membrane, a fiber blanket or a fiber felt, or is formed into a two-dimensional porous material constructed by fibers by post-processing the fibers.

According to the present invention, in the step a, the two-dimensional porous material is preferably formed by electrospinning, and the electrospinning is a solution electrospinning method or a melt electrospinning method.

According to the present invention, in step a, the sol precursor before the two-dimensional porous material is formed is a polymer solution or melt, a mixed solution or sol of polymer and inorganic compound, or an inorganic compound solution or sol.

According to the present invention, in step a, the sol precursor before the two-dimensional porous material is formed is a polymer solution or a melt, or a mixed solution or a sol of a polymer and an inorganic compound.

In step a, the solution contains a compound capable of generating gas.

Preferably, in step a, the liquid film formed on the surface of the fiber film is a water-based solution film, and the water-based solution includes an aqueous solution or a water/organic solvent mixed solution.

Preferably, in step b, the gas is generated chemically by catalytic decomposition of hydrogen peroxide, by catalytic decomposition of sodium borohydride or by decomposition of ammonium bicarbonate.

Preferably, in step b, the gas generated by the chemical reaction is non-toxic oxygen, hydrogen or carbon dioxide.

Preferably, in step b, the catalyst for catalyzing the chemical reaction and generating gas may be previously added to the sol for preparing the two-dimensional porous material and remain in the fibers of the two-dimensional porous material by spinning, or be introduced by adding to the solution for forming the liquid film.

Preferably, in step b, when the gas is generated by catalytic decomposition of hydrogen peroxide to generate oxygen, the catalyst is a zirconium-containing compound, ferric chloride or ferrous chloride.

Further preferably, the zirconium-containing compound is zirconium hydroxide or zirconium oxychloride.

According to the present invention, in step b, when the gas is generated by decomposing hydrogen peroxide to generate oxygen, the generation of the gas and the expansion of the fiber membrane are catalyzed and accelerated under the condition of alkaline gas.

According to the invention, in the step b, when the gas is generated by the catalytic decomposition of sodium borohydride to generate hydrogen, the generation of the gas and the expansion of the fiber membrane are accelerated under the condition of acid gas.

According to the present invention, in step b, the gas is generated by decomposing ammonium bicarbonate to generate ammonia gas, water and carbon dioxide, and the generation of gas and the expansion of the fiber membrane are accelerated by heating.

According to the present invention, in step d, the drying mode is preferably atmospheric drying, freeze drying or supercritical drying.

The expansion of the two-dimensional material and the formation mechanism of the internal pore channels are as follows: because the two-dimensional material is formed by crosslinking a plurality of layers of fibers, when the two-dimensional material is contacted with a relative liquid, the liquid infiltrates on the surfaces of the fibers and forms liquid films among the fibers, when substances in the liquid phase generate chemical reaction to generate gas due to the change of the surrounding environment, the gas cannot escape due to the existence of the liquid films, gas pressure is generated inside, the fibers are stretched and gradually filled with the gas under the pressure, the inside of the three-dimensional material formed at the end of the reaction is mainly filled with the gas, and the surface liquid films still exist.

The invention has the technical characteristics and advantages that:

1. the three-dimensional fiber framework porous material provided by the invention has a novel microstructure, small material density and high porosity, the porosity of the material can be controlled by adjusting the concentration of decomposable substances in a liquid phase, and the porosity is 90-99%.

2. The three-dimensional fiber skeleton porous material provided by the invention has anisotropic tensile strength and elongation at break.

3. The three-dimensional fiber framework porous material provided by the invention has high compression resilience and low thermal conductivity.

4. The three-dimensional fiber framework porous material provided by the invention has good sound absorption performance, water resistance and air permeability and excellent comprehensive performance.

5. The preparation process is simple to operate, green and environment-friendly, and is suitable for mass preparation.

Drawings

FIG. 1 is a diagram of a zirconium hydroxide @ polyacrylonitrile nanofiber-based three-dimensional porous material of example 1;

FIG. 2 is a schematic view of the compression rebound process of the zirconium hydroxide @ polyacrylonitrile nanofiber-based three-dimensional porous material of example 1;

FIG. 3 is a stress-strain graph of the zirconium hydroxide @ polyacrylonitrile nanofiber-based three-dimensional porous material of example 1;

FIG. 4 is a graph of the zirconium hydroxide @ polyacrylonitrile nanofiber-based three-dimensional porous material of example 1 as a function of temperature;

FIG. 5 is a graph of the absorption performance of the zirconium hydroxide @ polyacrylonitrile nanofiber-based three-dimensional porous material of example 1 for different frequencies of noise;

fig. 6 is a scanning electron microscope picture of zirconium hydroxide @ polyacrylonitrile nanofiber-based three-dimensional porous material of example 1 at different magnifications.

FIG. 7 is an optical photograph of the polyamide-6 (nylon-6) nanofiber-based three-dimensional porous material of example 5 using a mixed solution of ammonium bicarbonate and hydrogen peroxide as a catalyst.

Fig. 8 is an optical photograph of the polyacrylonitrile nanofiber-based three-dimensional porous material using the mixed solution of ammonium bicarbonate and hydrogen peroxide as the catalyst of example 6.

Fig. 9 is an optical photograph of the silica nanofiber-based three-dimensional porous material of example 8.

Detailed Description

In order to make the invention more comprehensible, the invention is further described in the following with reference to specific examples, but the scope of the invention is not limited thereto.

Example 1

Preparation of zirconium hydroxide @ Polyacrylonitrile (PAN) composite nanofiber membrane

Dissolving 1g of Polyacrylonitrile (PAN) in 10mL of N, N-Dimethylformamide (DMF), mechanically stirring to completely dissolve the PAN, dissolving 1.5g of zirconium tetrachloride in the system, and stirring until the zirconium tetrachloride is completely dissolved to form a yellowish sol precursor;

performing electrostatic spinning on the sol precursor, wherein the positive pressure is 18kV, the negative pressure is-1.5 kV, the temperature is 25 ℃, the humidity is less than 25%, and the distance between the positive electrode and the negative electrode is 20 cm; ZrOCl obtained by electrostatic spinning₂@ PAN nanofiber membrane was placed in a beaker and treated under an ammonia atmosphere to obtain Zr (OH)₄/NH₄Cl @ PAN nanofiber membrane, and then soaking in deionized water for 15min to remove NH₄Cl, air drying under natural conditions to obtain Zr (OH)₄@ PAN nanofiber membranes;

zirconium hydroxide @Polyacrylonitrile (Zr (OH)₄@ PAN) preparation of nanofiber-based three-dimensional porous material

Zr (OH)₄@ PAN nanofiber membrane surface was uniformly coated with 2mL of a 30% hydrogen peroxide solution by mass concentration, and placed in an ammonia atmosphere to obtain Zr (OH)₄@ PAN nanofiber-based three-dimensional porous material, and drying under the air atmosphere condition of normal temperature and normal pressure.

Experimental example 1:

1. zirconium hydroxide @ Polyacrylonitrile (Zr (OH) obtained in example 1₄@ PAN) optical photographs of nanofiber-based three-dimensional porous materials are shown in fig. 1.

2. The compression rebound process of the three-dimensional porous material is schematically shown in fig. 2, and as can be seen from fig. 2, the three-dimensional porous material has high compression rebound resilience.

3. The stress-strain curve of the three-dimensional porous material is shown in fig. 3, and it can be seen from fig. 3 that the three-dimensional porous material has anisotropic mechanical properties, and the strength in the horizontal direction and the strength in the vertical direction are 8935Pa and 886Pa respectively.

4. The thermal conductivity coefficients of the three-dimensional porous material at different temperatures are shown in table 1 below,

TABLE 1

The curve of the three-dimensional porous material changing with the temperature is shown in fig. 4, and it can be seen from table 1 and fig. 4 that the thermal conductivity of the three-dimensional porous material is 0.042-0.046W/(mK), the thermal conductivity is small, and the thermal insulation performance is good.

5. The graph of the absorption performance of the three-dimensional porous material to noise of different frequencies is shown in fig. 5, which shows that the three-dimensional porous material has good noise absorption performance.

Example 2

Preparation of zirconium hydroxide @ Polyacrylonitrile (PAN) composite nanofiber membrane

The procedure of example 1 was followed.

Zirconium hydroxide @ polyacrylonitrile (Zr (OH)₄@ PAN) preparation of nanofiber-based three-dimensional porous material

Dissolving 1g of sodium borohydride powder in 50mL of deionized water, uniformly wetting the zirconium hydroxide @ polyacrylonitrile fiber membrane with a sodium borohydride solution, converting the fiber membrane into a three-dimensional porous material in an acetic acid atmosphere, and drying at normal temperature and normal pressure to obtain the zirconium hydroxide @ polyacrylonitrile nanofiber-based three-dimensional porous material.

Example 3

Preparation of zirconium hydroxide @ Polyacrylonitrile (PAN) composite nanofiber membrane

The procedure of example 1 was followed.

Zirconium hydroxide @ polyacrylonitrile (Zr (OH)₄@ PAN) preparation of nanofiber-based three-dimensional porous material

Dissolving 1g of ammonium bicarbonate in 50mL of deionized water, uniformly coating the zirconium hydroxide @ polyacrylonitrile fiber membrane with an ammonium bicarbonate solution, and heating the zirconium hydroxide @ polyacrylonitrile fiber membrane on a heating plate to obtain the zirconium hydroxide @ polyacrylonitrile nanofiber-based three-dimensional porous material.

Example 4

Preparation of polyamide-6 (nylon-6) nanofiber fiber membrane

Dissolving 4g of polyamide-6 (nylon-6) in 22.6mL of 88 mass percent formic acid solution, and mechanically stirring until the mixture is completely dissolved; preparing a polyamide-6 nanofiber fibrous membrane by taking the solution as a precursor through electrostatic spinning, wherein the electrostatic spinning parameters are as follows: positive pressure of 20kV, negative pressure of-1.5 kV, temperature of 25 ℃, humidity of less than 25 percent and distance between the positive electrode and the negative electrode of 20 cm.

Preparation of polyamide-6 (nylon-6) nanofiber-based three-dimensional porous material

Dissolving 1g of ferric trichloride powder in 50mL of deionized water, and immersing the fiber membrane in FeCl₃And taking out the solution, uniformly coating 2mL of 30% hydrogen peroxide solution on the fiber membrane, placing the fiber membrane in an ammonia atmosphere to convert the fiber membrane into a three-dimensional porous material, and naturally drying the three-dimensional porous material at normal temperature and normal pressure to obtain the nylon-6 nanofiber-based three-dimensional porous material.

The prepared nylon-6 three-dimensional porous material has the porosity of about 97 percent, the pore diameter of nano-scale to millimeter-scale, and excellent compression resilience and mechanical strength.

Example 5

Preparation of polyamide-6 (nylon-6) nanofiber fiber membrane

The procedure of example 4 was followed.

Preparation of polyamide-6 (nylon-6) nanofiber-based three-dimensional porous material

2.2g of ammonium bicarbonate was dissolved in 10mL of deionized water, and 10mL of 30% hydrogen peroxide solution was added to the solution to form a mixed system. Placing the polyamide-6 (nylon-6) fibrous membrane on a heating plate at 120 ℃, reversely buckling a culture dish above the fibrous membrane to form a relatively sealed space, decomposing the fibrous membrane with the hydrogen peroxide and the ammonium bicarbonate by heating, taking out the fibrous membrane, and drying the fibrous membrane at normal temperature and normal pressure to form the polyamide-6 (nylon-6) nanofiber-based three-dimensional porous material.

An optical photograph of the polyamide-6 (nylon-6) nanofiber based three-dimensional porous material is shown in fig. 7.

The prepared polyamide-6 (nylon-6) nanofiber-based three-dimensional porous material has the porosity of about 97 percent, the pore diameter of nano-meter to millimeter level and excellent compression resilience and mechanical strength.

Example 6

Preparation of polyacrylonitrile nanofiber-based three-dimensional porous material

Dissolving 1g of polyacrylonitrile in 10mL of N, N-dimethylformamide, and completely dissolving under magnetic stirring to form a spinning solution; forming a polyacrylonitrile nanofiber membrane through electrostatic spinning, wherein the spinning conditions are as follows: positive pressure 15kV, negative pressure-1.5 kV, temperature 25 ℃, humidity less than 25 percent and distance between the positive electrode and the negative electrode of 20 cm;

2.2g of ammonium bicarbonate was dissolved in 10mL of deionized water, and 10mL of 30% hydrogen peroxide solution was added to the solution to form a mixed system. Placing the polyacrylonitrile fiber membrane on a heating plate at 120 ℃, reversely buckling a culture dish above the fiber membrane to form a relatively sealed space, and taking out the polyacrylonitrile fiber membrane and the ammonium bicarbonate to dry at normal temperature and normal pressure along with the thermal decomposition of the hydrogen peroxide and the ammonium bicarbonate to form the polyacrylonitrile nanofiber-based three-dimensional porous material.

An optical photograph of the polyacrylonitrile nanofiber-based three-dimensional porous material is shown in fig. 8.

The prepared polyacrylonitrile nano-fiber-based three-dimensional porous material has the porosity of about 97 percent, the pore diameter of nano-meter to millimeter level and excellent compression resilience and mechanical strength.

Example 7

Preparation of polymethyl methacrylate nanofiber-based three-dimensional porous material

Dissolving 1g of polymethyl methacrylate in 12mL of N, N-dimethylformamide, and completely dissolving under magnetic stirring to form a spinning solution; forming a polymethyl methacrylate nanofiber membrane through electrostatic spinning, wherein the spinning conditions are as follows: positive pressure of 20kV, negative pressure of-1.5 kV, temperature of 25 ℃, humidity of less than 25 percent and distance between positive and negative electrodes of 20 cm;

dissolving 1g of ferric trichloride powder in 50mL of mixed solution of deionized water and ethanol (volume ratio is 1:1), and immersing the polymethyl methacrylate fiber membrane in FeCl₃And taking out the solution, uniformly coating 2mL of 30% hydrogen peroxide solution on the fiber, converting the fiber membrane into a three-dimensional porous material in ammonia atmosphere, and naturally drying under the conditions of normal temperature and normal pressure to obtain the polymethyl methacrylate nanofiber-based three-dimensional porous material.

Example 8

Preparation of silicon dioxide nanofiber-based three-dimensional porous material

22.3mL of tetraethyl orthosilicate was added to 19.8mL of deionized water, 58.2. mu.L of phosphoric acid was added to the above mixed solution under mechanical stirring, and after 12 hours of stirring, a 10% polyvinyl alcohol solution of equal mass was added, and stirring was continued for 2 hours to obtain a spinnable sol.

Preparation of SiO by electrostatic spinning₂The positive pressure of the PVA nano-fiber membrane is 18kV, and the distance between the syringe needle and the aluminum foil is 19 cm. Placing the nano-fiber membrane prepared by electrospinning in a muffle furnace for calcining, heating to 800 ℃ at the heating rate of 10 ℃/min to obtain flexible SiO₂A nanofiber membrane.

Taking 1g FeCl₃Dissolving the soft SiO in 50mL of deionized water₂Soaking the nanofiber membrane in FeCl₃In the solution, after natural drying, 2mL of 30% hydrogen peroxide solution is uniformly coated on the fiber membrane, the fiber membrane is converted into a three-dimensional porous material in an ammonia atmosphere, and the three-dimensional porous material is dried at normal temperature and normal pressureAnd drying to obtain the silica nanofiber-based three-dimensional porous material.

An optical photograph of the silica nanofiber-based three-dimensional porous material is shown in fig. 9.

Example 9

Preparation of zirconium hydroxide @ polyamide-6 (nylon-6) composite micron fiber-based three-dimensional porous material

7.6g of polyamide-6 (nylon-6) was dissolved in 20.5g of formic acid and 35g of acetic acid to form a uniform and stable sol, and 19.93g of zirconium acetate solution was added to the sol system, and after mixing uniformly, spinning was carried out.

And (2) trimming and shearing micron-sized zirconium acetate @ polyamide-6 (nylon-6) micron fibers obtained by spinning into a square fiber membrane, uniformly coating 2mL of 30% hydrogen peroxide solution on the fiber membrane, fumigating the fiber membrane in an ammonia atmosphere, and drying the fiber membrane at normal temperature and normal pressure to obtain the zirconium hydroxide @ polyamide-6 (nylon-6) composite micron fiber-based three-dimensional porous material.

The above description is only an example of the present invention and is not intended to limit the present invention. Various modifications and alterations to this invention will become apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.