CN115536842B - A kind of preparation method of microtube - Google Patents

Abstract

The application relates to a method for preparing a micron tube in the technical field of micro-nano equipment, comprising the following steps: selecting a nuclear pore membrane; performing sensitization and activation treatment on the inner wall of the membrane hole of the nuclear pore membrane; The reducing solution of the metal ion of the microtube or the alloy microtube flows through the membrane hole of the nuclear pore membrane, and forms a coating on the inner wall of the membrane hole of the nuclear pore membrane; the nuclear pore membrane is dissolved to obtain the microtube. The method for preparing microtubes of the present application has simple operation, controllable conditions, high efficiency and energy saving, can realize simultaneous reaction of multi-level materials, and can prepare magnetic microtubes with uniform texture and difficult polymerization, which has important application value.

Description

A kind of preparation method of microtube

technical field

The present application relates to the technical field of micro-nano devices, in particular to a method for preparing microtubes.

Background technique

In recent years, microtubes have attracted widespread attention due to their superior specific surface area and strong surface activity. For example, metal microtubes are popular because of their good electrical conductivity, mechanical properties and magnetism. There are mainly two methods of preparation: growth (including prosthetic group catalyzed synthesis, self-assembly) and etching (including etching the axis, etching the mold), but the metal microtubes produced by growth or etching are prone to length, pore diameter, etc. The phenomenon of uneven wall thickness, tubular bending, uneven dispersion, etc., and complicated and difficult to control preparation conditions are common, which greatly affects the use of micron tubes.

Contents of the invention

The purpose of the present invention is to provide a method for preparing microtubes. The method for preparing microtubes provided by the present invention has the advantages of simple operation, controllable conditions, high efficiency and energy saving, and simultaneous reaction of multi-stage materials. High uniformity in size, smooth tube surface, and resistance to aggregation.

According to one aspect of the present invention, a method for preparing a micron tube is provided, comprising the following steps: selecting a nuclear pore membrane; performing sensitization and activation treatment on the inner wall of the membrane hole of the nuclear pore membrane; The reducing solution of the metal ion of the tube or the alloy microtube flows through the membrane hole of the nuclear pore membrane to form a coating on the inner wall of the membrane hole of the nuclear pore membrane; the nuclear pore membrane is dissolved to obtain the microtube.

By using the preparation method of microtubes in the technical solution, the inner wall of the membrane hole of the nuclear pore membrane is sensitized using a polymer solvent, and the inner wall of the membrane hole of the nuclear pore membrane is activated by a solvent having a micronucleus effect, Micronuclei are formed on the inner wall of the membrane pores of the nuclear pore membrane, which facilitates the in-situ reduction of the reducing solution of metal ions in the membrane pores, reduces the agglomeration of nano-metal particles during the reduction process in the membrane pores, and finally produces uniform texture and uniform pore size. and smooth-surfaced microtubes.

The present invention uses dopamine as a polymer to uniformly deposit in the membrane pores, which can not only allow more complete adsorption of silver ions, but also make the surface of the prepared microtubes smooth without collapse; silver nitrate will form Ag microtubes on the surface of dopamine after being adsorbed by dopamine. The nucleus can not only facilitate the in-situ reduction of nickel-cobalt reducing solution in the membrane pores, but also reduce the agglomeration of nickel-cobalt nano-metal particles in the reduction process in the membrane pores; finally prepare micron tubes with uniform texture, uniform pore size and smooth surface .

In addition, the method for preparing microtubes according to the present application may also have the following additional technical features:

In some embodiments of the present invention, the pore diameter of the membrane pores of the nuclear pore membrane is 0.01-30 μm;

Preferably, the membrane pores of the nuclear pore membrane have a pore diameter of 0.05-10 μm.

In some embodiments of the present invention, the sensitization treatment of the membrane pores of the nuclear pore membrane includes the following steps: adding a dopamine polymer into a Tris-HCl buffer solution to prepare a dopamine solution; ultrasonically stirring the dopamine solution to obtain Mix the dopamine solution uniformly; flow the dopamine solution through the membrane pores of the nuclear pore membrane; complete the sensitization treatment of the inner wall of the membrane pores of the nuclear pore membrane.

In some embodiments of the present invention, the concentration of the dopamine solution is 1.8-2.2 g/L.

In some embodiments of the present invention, the dopamine solution is ultrasonically stirred for 12-36 hours.

In some embodiments of the present invention, the sensitization treatment of the membrane pores of the nuclear pore membrane can also use polymer solvents such as polypyrrole that can achieve homogeneous deposition and have adhesion.

In some embodiments of the present invention, the activation treatment of the membrane pores of the nuclear pore membrane includes the following steps: adding silver nitrate to deionized water to prepare a silver nitrate solution; flowing the silver nitrate solution through the membrane pores of the nuclear pore membrane ; Complete the activation treatment of the inner wall of the membrane hole of the nuclear pore membrane.

In some embodiments of the present invention, the concentration of the silver nitrate solution is 1.2-1.8 g/L.

In some embodiments of the present invention, the silver nitrate is added into deionized water and stirred ultrasonically for 2-7 minutes.

In some embodiments of the present invention, the activation treatment of the membrane pores of the nuclear pore membrane can also use a solvent with a micronucleus effect.

In some embodiments of the present invention, the reducing solution containing metal ions used to form single metal microtubes or alloy microtubes includes nickel sulfate, cobalt sulfate, sodium pyrophosphate, concentrated ammonia and dimethylaminoformaldehyde borane and deionized water.

In some embodiments of the present invention, after the nuclear pore membrane is dissolved, the silver metal and/or black residue in the solution is recovered by magnetism, and the microtubes are obtained after washing with deionized water for several times.

In some embodiments of the present invention, the nuclear pore membrane is at least one of polycarbonate, polyester and polyimide, and the solvent used for dissolving the nuclear pore membrane is N,N-dimethyl Acetamide;

Preferably, the nuclear pore membrane is made of polycarbonate material.

In some embodiments of the present invention, the nuclear pore membrane is installed in the filter head, and the dopamine solution, the silver nitrate solution and the reducing solution all flow through the membrane pores of the nuclear pore membrane using a peristaltic pump filtration method.

Preferably, when the suction filtration solution is dopamine solution, the peristaltic pump speed is 200-600L/min, the suction filtration time is 20-60min, and then continue to pump air for 0.5-2min; when the suction filtration solution is silver nitrate solution or reducing solution At this time, the peristaltic pump speed is 400-600L/min, the suction time is 10-30min, and then continue to pump air for 0.5-2min; the purpose of continuing to pump air is to dredge the membrane pores.

Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

1. The present invention adopts the peristaltic pump suction filtration method and cooperates with the filter head to reduce the deposition of metal on the membrane surface, thereby depositing in the membrane pores as much as possible. In addition, the thickness of the micron tube wall increases with the prolongation of the suction filtration time and the increase of the suction filtration speed. increase, so that it is convenient to adjust the wall thickness of the microtube.

2. In the present invention, dopamine is wrapped on the outer layer of Ni/Co@PDA microtubes through successive suction filtration, which has adsorption properties; the magnetic metal is coated on the inner layer of Ni/Co@PDA microtubes, which has certain antifouling properties, so that Ni /Co@PDA microtubes can be used as special carriers for adsorbing and transporting proteins and other polymers.

3. The nuclear pore membrane made of polycarbonate has better effects in the sensitivity of membrane etching, the difficulty of forming holes and the control of pore size, and it is easier to prepare high-specification micron tubes.

Description of drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiment. The drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the application. Also throughout the drawings, the same reference numerals are used to designate the same components. In the attached picture:

Figure 1 is a schematic diagram of the experimental operation process for the multi-stage preparation of magnetic Ni/Co@PDA microtubes based on the membrane separation technology modification method of the present application;

Figure 2 is a scanning electron microscope (SEM) image of the surface of the nuclear pore membrane of the present application and magnetic Ni/Co@PDA microtubes, Figure 2a is a scanning electron microscope image of the surface of the nuclear pore membrane, Figure 2b, Figure 2c and Figure 2d are respectively Ni/Co SEM images of @PDA microtubes at different magnifications.

Detailed ways

It should be clear that the described embodiments are only some of the embodiments of the present application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.

When the following description refers to the accompanying drawings, the same numerals in different drawings refer to the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with aspects of the present application as recited in the appended claims.

In the description of the present application, it should be understood that the terms "first", "second" and so on are used for descriptive purposes only, and should not be understood as indicating or implying relative importance. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application in specific situations. In addition, in the description of the present application, unless otherwise specified, "plurality" means two or more. "And/or" describes the association relationship of associated objects, indicating that there may be three types of relationships, for example, A and/or B may indicate: A exists alone, A and B exist simultaneously, and B exists independently. The character "/" generally indicates that the contextual objects are an "or" relationship.

In order to facilitate the understanding of the preparation method of the microtube provided in the embodiment of the present application, firstly, its application scenario is explained. The preparation method of the microtube provided in the embodiment of the present application is used to prepare the microtube; Among them, metal microtubes are popular because of their good electrical conductivity, mechanical properties and magnetism; at present, there are two main methods for the preparation of metal microtubes: growth and etching. However, the length, pore diameter and wall thickness of the prepared metal microtubes are not uniform, the tubular shape is bent, the dispersion is uneven, and the preparation conditions are complicated and difficult to control, which greatly limits the development of metal microtubes.

Among them, nickel and cobalt metals play an important role in the fields of hydrogen storage materials, catalytic degradation, supercapacitors and other fields because of their good hydrogen evolution and storage properties and catalytic activity; nickel and cobalt metal tubular materials have a larger ratio than traditional materials. The surface area can better reflect the excellent performance; in recent years, there are many methods of developing nickel and cobalt metals into metal microtubes, but the microtubes still have the problems of different tube pore sizes, rough tube surfaces, and easy polymerization.

Therefore, the present application provides a method for preparing microtubes, which is simple in operation, controllable in conditions, highly efficient and energy-saving, can realize simultaneous reaction of multi-level materials, and can prepare magnetic microtubes with uniform texture and difficult polymerization. Important application value. In addition, the preparation method of microtubes provided by this application, based on the modification method of membrane separation technology, can not only prepare magnetic Ni/Co@PDA microtubes in multiple stages, but also realize the production of various single metal and alloy microtubes. Preparation, such as copper, cadmium, zinc, chromium, etc.

The nuclear pore membrane involved in the application has universality, and the membrane hole can be used as a template for the straight hole morphology, commonly used polycarbonate membrane (PC), polyester membrane (PET) and polyimide membrane ( PI) and other nuclear pore membranes can be used as preparation templates. Considering the advantages of membrane etching sensitivity, cheap pore formation, and controllable pore size, the nuclear pore membrane made of polycarbonate has the best effect. The pore size range of the nuclear pore membrane is It can be 0.01-30 μm, and the pore diameter of further membrane pores can be 0.05-10 μm. The examples of this application are described with a nuclear pore membrane with a pore diameter of 0.2 μm.

In this application, when the single metal or alloy microtubes are prepared, the microtubes can be recovered magnetically and then cleaned. Separate and wash.

The preparation method of the microtube provided by the embodiment of the present application will be described below in conjunction with the accompanying drawings, taking the magnetic Ni/Co@PDA microtube as an example; Figure 1 is the multi-stage preparation of magnetic Ni/Co@PDA based on the membrane separation technology modification method of the present application Schematic diagram of the experimental operation process of the microtube; Fig. 2 is a scanning electron microscope image of the surface of the nuclear pore membrane and magnetic Ni/Co@PDA microtubes of the present application, wherein Fig. 2a is a scanning electron microscope image of the surface of the nuclear pore membrane, Fig. 2b, Fig. 2c and Figure 2d is the SEM images of Ni/Co@PDA microtubes at different magnifications, respectively.

Example 1

S1, preparation of dopamine solution; add 2.422g Tirs in a clean beaker, then add 200mL deionized water, adjust the pH to 8.5 with 0.1M HCl solution after stirring evenly, then add 0.4g PDA, i.e. dopamine, to the solution, ultrasonically and After stirring for 24 hours, a dopamine solution with a uniform concentration of 2 g/L was obtained, which was ready for use.

S2. Nuclear pore membrane installation: fix the polycarbonate nuclear pore membrane with a clean pore size of 0.2 μm in a detachable filter head with a diameter of 25 mm, tighten the filter head to ensure airtightness, and connect multiple filter heads back and forth. Two hoses are connected to the beginning and end of the two outermost filter heads, and one of the hoses is passed through the peristaltic pump for use.

S3. Place the remaining two ends of the two hoses in step S2 in the dopamine solution in step S1, turn on the peristaltic pump to adjust the rotating speed to 400L/min, and remove it after circulating suction filtration for 30min at room temperature, so that dopamine The membrane pores can be uniformly deposited, and then continue to pump air for 1 minute to discharge the remaining dopamine solution in the hose and dredge the membrane pores.

S4, 0.3194g silver nitrate is added to the deionized water of 200mL, ultrasonic stirring 5min, preparation concentration is the silver nitrate solution of 1.597g/L, repeats the peristaltic pump suction filtration process of step S3, wherein the peristaltic pump speed is 500L/min, The circulating suction filtration time is 20 min, and the air pumping time is continued for 1 min. The silver nitrate solution is pumped, and the dopamine deposited in the membrane pores in step S3 absorbs silver ions to perform in-situ reduction to form Ag micronuclei.

S5, 12.5g of nickel sulfate, 12.5g of cobalt sulfate, 50g of sodium pyrophosphate, 28% concentrated ammonia water of 45ml and 1.5g of dimethylaminoborane were added to 1L of deionized water successively, and ultrasonically stirred for 15min to prepare a mixture containing nickel sulfate and sulfuric acid. For the reducing solution of cobalt, repeat the peristaltic pump suction filtration process of step S3, wherein the peristaltic pump speed is 500L/min, the circulation suction filtration time is 20min, and the time for continuing to pump air is 1min, and the nickel-cobalt reducing solution is pumped, step S4 The Ag micronucleus in the film promotes the in-situ reduction of nickel-cobalt reducing solution in the membrane pores, and reduces the agglomeration of nickel-cobalt nano-metal particles during the reduction process in the membrane pores, so that the nuclear pore membrane is coated with nickel and cobalt metals to form metal layer.

S6. After the reaction, remove the filter head, wash the surface of the membrane with deionized water for 3 times, absorb excess water, and place the membrane in a clean beaker for use.

S7. Add a certain amount of N,N-dimethylacetamide into the beaker. After the membrane structure is melted, obtain microtubes and disperse the microtubes. Ultrasound for 20 minutes to further improve the effect. When the reaction is incomplete or just happens to be complete The inner wall of the Ni/Co@PDA microtube will be deposited with nano-metal particles and turn black. When the over-reaction is complete, the nano-metal particles deposited on the inner wall of the Ni/Co@PDA microtube will agglomerate and reveal a metallic luster; then the silver metal in the solution is recovered by magnetic and/or black residue, Ni/Co@PDA microtubes were obtained after washing 3 times with deionized water.

Example 2

S1. Preparation of dopamine solution; add 2.422g Tirs to a clean beaker, then add 200mL deionized water, stir evenly, adjust pH to 8.5 with 0.1M HCl solution, then add 0.36g dopamine polymer to the solution, ultrasonicate and stir After 12 hours, a dopamine solution with a uniform concentration of 1.8 g/L was obtained and was ready for use.

S2. Nuclear pore membrane installation: fix the polycarbonate nuclear pore membrane with a clean pore size of 0.2 μm in a detachable filter head with a diameter of 25 mm, tighten the filter head to ensure airtightness, and connect multiple filter heads back and forth. Two hoses are connected to the beginning and end of the two outermost filter heads, and one of the hoses is passed through the peristaltic pump for use.

S3. Place the remaining two ends of the two hoses in step S2 in the dopamine solution in step S1, turn on the peristaltic pump to adjust the rotating speed to 200L/min, and remove it after circulatory filtration at room temperature for 20min, so that dopamine The membrane pores can be uniformly deposited, and then continue to pump air for 1 minute to discharge the remaining dopamine solution in the hose and dredge the membrane pores.

S4, 0.24g silver nitrate is added to the deionized water of 200mL, ultrasonic stirring 2min, preparation concentration is the silver nitrate solution of 1.2g/L, repeats the peristaltic pump suction filtration process of step S3, wherein the peristaltic pump speed is 400L/min, The circulating suction filtration time is 10 min, and the air pumping time is continued for 1 min. The silver nitrate solution is pumped, and the dopamine deposited in the membrane pores in step S3 absorbs silver ions to perform in-situ reduction to form Ag micronuclei.

S5, 12.5g of nickel sulfate, 12.5g of cobalt sulfate, 50g of sodium pyrophosphate, 28% concentrated ammonia water of 45ml and 1.5g of dimethylaminoborane were added to 1L of deionized water successively, and ultrasonically stirred for 10min to prepare a mixture containing nickel sulfate and sulfuric acid. For the reductive solution of cobalt, repeat the peristaltic pump suction filtration process of step S3, wherein the peristaltic pump speed is 400L/min, the circulation suction filtration time is 10min, and the continuous air pumping time is 1min, and the nickel-cobalt reductive solution is pumped, step S4 The Ag micronucleus in the film promotes the in-situ reduction of nickel-cobalt reducing solution in the membrane pores, and reduces the agglomeration of nickel-cobalt nano-metal particles during the reduction process in the membrane pores, so that the nuclear pore membrane is coated with nickel and cobalt metals to form metal layer.

S6. After the reaction, remove the filter head, wash the surface of the membrane with deionized water for 3 times, absorb excess water, and place the membrane in a clean beaker for use.

S7. Add a certain amount of N,N-dimethylacetamide into the beaker. After the membrane structure is melted, obtain microtubes and disperse the microtubes. Ultrasound for 20 minutes to further improve the effect. When the reaction is incomplete or just happens to be complete The inner wall of the Ni/Co@PDA microtube will be deposited with nano-metal particles and turn black. When the over-reaction is complete, the nano-metal particles deposited on the inner wall of the Ni/Co@PDA microtube will agglomerate and reveal a metallic luster; then the silver metal in the solution is recovered by magnetic and/or black residue, Ni/Co@PDA microtubes were obtained after washing 3 times with deionized water.

Example 3

S1. Preparation of dopamine solution; add 2.422g Tirs to a clean beaker, then add 200mL deionized water, stir evenly and adjust the pH to 8.5 with 0.1M HCl solution, then add 0.44g dopamine polymer to the solution, ultrasonicate and stir After 36 hours, a dopamine solution with a uniform concentration of 2.2 g/L was obtained and was ready for use.

S2. Nuclear pore membrane installation: fix the polycarbonate nuclear pore membrane with a clean pore size of 0.2 μm in a detachable filter head with a diameter of 25 mm, tighten the filter head to ensure airtightness, and connect multiple filter heads back and forth. Two hoses connect the beginning and end of the two outermost filter heads, and one of the hoses is passed through the peristaltic pump for use.

S3. Place the remaining two ends of the two hoses in step S2 in the dopamine solution in step S1, turn on the peristaltic pump to adjust the rotating speed to 600L/min, and remove it after 60min of circulating suction at room temperature, so that dopamine The membrane pores can be uniformly deposited, and then continue to pump air for 1 minute to discharge the remaining dopamine solution in the hose and dredge the membrane pores.

S4, 0.36g silver nitrate is added to the deionized water of 200mL, ultrasonic stirring 7min, preparation concentration is the silver nitrate solution of 1.8g/L, repeats the peristaltic pump suction filtration process of step S3, wherein the peristaltic pump speed is 600L/min, The circulating suction filtration time is 30 min, and the air pumping time is continued for 1 min. The silver nitrate solution is pumped, and the dopamine deposited in the membrane pores in step S3 absorbs silver ions for in-situ reduction to form Ag micronuclei.

S5, 12.5g of nickel sulfate, 12.5g of cobalt sulfate, 50g of sodium pyrophosphate, 28% concentrated ammonia water of 45ml and 1.5g of dimethylaminoborane were added to 1L of deionized water successively, and ultrasonically stirred for 20min to prepare a mixture containing nickel sulfate and sulfuric acid. For the reductive solution of cobalt, repeat the peristaltic pump suction filtration process of step S3, wherein the peristaltic pump speed is 600L/min, the circulation suction filtration time is 30min, and the time for continuing to pump air is 1min, and the nickel-cobalt reductive solution is pumped, step S4 The Ag micronucleus in the film promotes the in-situ reduction of nickel-cobalt reducing solution in the membrane pores, and reduces the agglomeration of nickel-cobalt nano-metal particles during the reduction process in the membrane pores, so that the nuclear pore membrane is coated with nickel and cobalt metals to form metal layer.

S6. After the reaction, remove the filter head, wash the surface of the membrane with deionized water for 3 times, absorb excess water, and place the membrane in a clean beaker for use.

S7. Add a certain amount of N,N-dimethylacetamide into the beaker. After the membrane structure is melted, obtain microtubes and disperse the microtubes. Ultrasound for 20 minutes to further improve the effect. When the reaction is incomplete or just happens to be complete The inner wall of the Ni/Co@PDA microtube will be deposited with nano-metal particles and turn black. When the over-reaction is complete, the nano-metal particles deposited on the inner wall of the Ni/Co@PDA microtube will agglomerate and reveal a metallic luster; then the silver metal in the solution is recovered by magnetic and/or black residue, Ni/Co@PDA microtubes were obtained after washing 3 times with deionized water.

SEM tests were carried out on the nuclear pore membrane of Example 1 and the obtained Ni/Co@PDA microtubes; Figure 2 is a scanning electron microscope image of the nuclear pore membrane surface and magnetic Ni/Co@PDA microtubes, and Figure 2a is a nuclear pore membrane Surface SEM images, Figure 2b, Figure 2c and Figure 2d are the SEM images of Ni/Co@PDA microtubes at different magnifications, respectively.

As shown in Figure 2a and Figure 2b, according to the results, the prepared tubular material has the same pore size and length as the nuclear pore membrane, as shown in Figure 2c and Figure 2d, the granular structure of the prepared tubular material surface proves to be Ni /Co metal was successfully coated on the support. The present invention uses dopamine as a polymer to uniformly deposit in the membrane pores, which can not only allow more complete adsorption of silver ions, but also make the surface of the prepared microtubes smooth without collapse; silver nitrate will form Ag microtubes on the surface of dopamine after being adsorbed by dopamine. The nucleus can not only facilitate the in-situ reduction of nickel-cobalt reducing solution in the membrane pores, but also reduce the agglomeration of nickel-cobalt nano-metal particles in the reduction process in the membrane pores; finally prepare micron tubes with uniform texture, uniform pore size and smooth surface .

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (7)

1. A preparation method of micron tube, is characterized in that, comprises the following steps: Select the nuclear pore membrane; Carrying out sensitization treatment and activation treatment to the inner wall of the membrane hole of the nuclear pore membrane; The sensitization treatment of the inner wall of the membrane hole of the nuclear pore membrane includes the following steps: adding the dopamine polymer to the Tris-HCl buffer solution to prepare a dopamine solution; ultrasonically stirring the dopamine solution to obtain a uniformly mixed dopamine solution; The dopamine solution flows through the membrane pores of the nuclear pore membrane; the sensitization treatment of the inner wall of the membrane pores of the nuclear pore membrane is completed; The described activation treatment of the inner wall of the membrane hole of the nuclear pore membrane includes the following steps: adding silver nitrate to deionized water to prepare a silver nitrate solution; flowing the silver nitrate solution through the membrane pores of the nuclear pore membrane; completing the membrane of the nuclear pore membrane Activation treatment of the inner wall of the hole; wherein, the concentration of the silver nitrate solution is 1.2-1.8 g/L; The reducing solution containing the metal ions used to form single metal microtubes or alloy microtubes flows through the membrane holes of the nuclear pore membrane to form a coating on the inner wall of the membrane pores of the nuclear pore membrane; The reducing solution of metal ions of metal microtubes or alloy microtubes includes nickel sulfate, cobalt sulfate, sodium pyrophosphate, concentrated ammonia water, dimethylaminoborane and deionized water; The nuclear pore membrane is dissolved to obtain microtubes. 2 . The method for preparing microtubes according to claim 1 , wherein the pore diameter of the membrane pores of the nuclear pore membrane is 0.05-10 μm. 3. the preparation method of microtube according to claim 1, is characterized in that, the concentration of described dopamine solution is 1.8-2.2 g/L. 4. the preparation method of microtube according to claim 1, is characterized in that, the time of ultrasonic stirring of described dopamine solution is 12-36 h. 5. the preparation method of microtube according to claim 1, is characterized in that, after described nuclear pore membrane dissolves, utilizes the silvery metal and/or black residue in the magnetic reclaim solution solution, washes repeatedly with deionized water Microtubes are obtained. 6. the preparation method of microtube according to claim 1, is characterized in that, described nuclear pore membrane is at least a kind of material in polycarbonate, polyester and polyimide, and described nuclear pore membrane dissolves and uses The solvent is N,N-dimethylacetamide. 7. The method for preparing microtubes according to claim 6, wherein the nuclear pore membrane is made of polycarbonate.