Preparation method of elastic conductive fiber

Abstract

The invention discloses an elastic conductive fiber preparation method, which comprises: dissolving any one of polyurethane, a styrene-butadiene-styrene block copolymer, nylon 6, cellulose acetate, polyvinyl alcohol or polyacrylonitrile in a solvent, placing in a magnetic stirrer at a room temperature, and stirring until complete dissolution, obtaining a polymer solution; carrying out electrostatic spinning on the polymer solution, and receiving by using a plane tinfoil or a roller to obtain a fiber membrane; soaking the fiber membrane in the silk fibroin solution, and drying to obtain a composite fiber membrane; uniformly coating two side surfaces of the composite fiber membrane with a conductive material to obtain a double-layer composite membrane; ethyl alcohol is evenly sprayed on the surfaces of the two sides of the double-layer composite film, and then the double-layer composite film is twisted to obtain the elastic conductive fiber. The interface bonding between the conductive material and the substrate is enhanced by a fibroin soaking method, and the prepared elastic conductive fiber has high elasticity and high conductivity.

Description

Technical Field

[0001] The technical field of fiber preparation specifically relates to a preparation method and application of a highly conductive and highly elastic spiral fiber. Background Art

[0002] Flexible stretchable electronic devices overcome the shortcomings of traditional rigid devices. They are lightweight, flexible and stretchable, and have attracted widespread attention in the field of wearable technology. There are currently two main methods for preparing large-strain stretchable conductors. One is to combine a substrate with good elasticity with an active material with good conductivity, and the other is to improve the extensibility of the substrate by changing the structure. However, due to the relatively tight interface between the substrate and the active material, most current stretchable electronic devices often face problems of unstable performance and functional failure, especially under large strain conditions. Therefore, it is necessary to propose a new preparation method and application of high-conductivity and high-elasticity fibers to solve the above-mentioned technical problems. Summary of the invention

[0003] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0004] The purpose of the present invention is to provide a fiber with simple operation method, adjustable material and size, high elasticity and high conductivity, which can be used in the field of stretchable electronic devices.

[0005] In order to achieve these purposes and other advantages according to the present invention, a method for preparing an elastic conductive fiber is provided, comprising the following steps:

[0006] Step 1, dissolving any one of polyurethane, styrene-butadiene-styrene block copolymer, nylon 6, cellulose acetate, polyvinyl alcohol or polyacrylonitrile in a solvent, and stirring in a magnetic stirrer at room temperature until completely dissolved to obtain a polymer solution;

[0007] Step 2, electrospinning the polymer solution prepared in step 1, wherein the polymer solution is stretched into filaments under the action of a high-voltage electrostatic field, and received by a flat tin foil or a roller to obtain a fiber membrane;

[0008] Step 3, sequentially degumming, dissolving, dialysis and centrifuging the silk to obtain silk fibroin and dissolving it in water to obtain a silk fibroin solution;

[0009] Step 4, soaking the fiber membrane prepared in step 2 in the silk fibroin solution prepared in step 3, and obtaining a composite fiber membrane after drying;

[0010] Step 5, uniformly coating the conductive material on both sides of the composite fiber membrane prepared in step 4 to obtain a double-layer composite membrane;

[0011] Step six, spraying ethanol evenly on both sides of the double-layer composite film prepared in step five to obtain a treated double-layer composite film;

[0012] Step seven, fixing one end of the treated double-layer composite film prepared in step six on a stepping twisting machine, and fixing the other end on a customized iron block, and twisting to obtain elastic conductive fibers.

[0013] Preferably, the solvent in step 1 is any one or two of N,N-dimethylformamide, butyl acetate, acetone, N,N-dimethylacetamide, and formic acid.

[0014] Preferably, the high-voltage electrostatic field voltage of the electrospinning in step 2 is 10-25 kV, the diameter of the metal nozzle of the electrospinning is 0.4-2 mm, the spinning distance of the electrospinning is 10-20 cm, and the rotation speed of the flat tin foil or drum is 100-300 rpm.

[0015] Preferably, the concentration of the silk fibroin solution prepared in step three is 2-50%.

[0016] Preferably, step four comprises the following steps: peeling off the fiber membrane from the flat tin foil or roller and fixing it on a stainless steel frame; soaking the stainless steel frame with the membrane in the silk fibroin solution, and then taking out the stainless steel frame with the membrane and drying it in a fume hood to obtain the composite fiber membrane; the stainless steel frame has a length of 4-20 cm and a width of 2-10 cm, and the soaking time is 5-150 minutes.

[0017] Preferably, the conductive material in step five is any one or two of metal nanowires or nanoparticles, graphene, carbon nanotubes, Mxene, PEDOT / PSS aqueous dispersion, and liquid metal.

[0018] Preferably, the number of times of spraying ethanol in step six is ​​1-10 times.

[0019] Preferably, the twisting speed of the stepping twisting machine in step seven is 50-300 rpm, and the advancing speed is 0.5-30 mm / s.

[0020] Preferably, the elastic conductive fiber prepared in step seven is composed of three components, namely, the fiber membrane, the silk fibroin and the conductive material, which are wrapped layer by layer, and the volume ratio is 9:1:1-3:1:1.

[0021] Preferably, the elastic conductive fiber prepared in step seven has an initial length of 0.4-20 cm, a diameter of 0.1-5 mm, and a length of 2-40 cm after stretching.

[0022] The present invention at least has the following beneficial effects: the present invention combines the electrostatic spinning method, the soaking method, the coating method and the twisting method, and the preparation method is simple and convenient for practical operation. The soaking method of silk fibroin strengthens the interface bonding between the conductive material and the substrate, and the prepared elastic conductive fiber has high elasticity and high conductivity.

[0023] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a flow chart of a method for preparing elastic conductive fibers. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0026] It should be understood that terms such as “having”, “including” and “comprising” used herein do not specify the existence or addition of one or more other elements or combinations thereof.

[0027] Example 1

[0028] Step 1, dissolving the hydrophobic polyurethane in a mixed solvent of analytically pure N,N-dimethylformamide and butyl acetate (mass ratio of 2:3) to prepare a polyurethane solution with a mass fraction of 18wt%, and placing it in a magnetic stirrer at room temperature and stirring until it is completely dissolved to obtain a polymer solution;

[0029] Step 2: Electrospin the polymer solution prepared in step 1. Under the action of a high-voltage electrostatic field, the polymer solution is stretched into filaments, which are received by a flat tin foil or a roller to obtain a fiber membrane. In the syringe of the electrospinning device, the diameter of the electrospinning metal nozzle is 1.3 mm, the spinning distance is 15 cm, and the high-voltage electrostatic field voltage is 12 kV.

[0030] Step 3, sequentially degumming, dissolving, dialysis and centrifuging the silk to obtain silk fibroin and dissolving it in water to obtain a silk fibroin solution;

[0031] Step 4, peeling off the fiber membrane from the flat tin foil or roller and fixing it on a stainless steel frame; the stainless steel frame is 7 cm long and 4 cm wide; soaking the stainless steel frame with the membrane in a 5 wt% silk fibroin solution for 60 minutes, then taking out the stainless steel frame with the membrane and drying it in a fume hood to obtain the composite fiber membrane;

[0032] Step 5, evenly coating the liquid metal on both sides of the composite fiber membrane prepared in step 4 to obtain a double-layer composite membrane;

[0033] Step six, spraying ethanol evenly on both sides of the double-layer composite film prepared in step five to obtain a treated double-layer composite film;

[0034] Step 7: Fix one end of the treated double-layer composite film prepared in step 6 on a stepping twisting machine and the other end on a custom iron block, and twist it to obtain elastic conductive fiber. The twisting speed of the twisting machine is 100 rpm. The initial length of the prepared elastic conductive fiber is 0.5 cm, and the length after stretching is 8 cm.

[0035] Example 2

[0036] Step 1, dissolving cellulose acetate in a mixed solvent of analytical grade acetone and N,N-dimethylacetamide (volume ratio of 3:2) to prepare a cellulose acetate solution with a mass fraction of 12.5wt%, and stirring the solution in a magnetic stirrer at room temperature until the solution is completely dissolved to obtain a polymer solution;

[0037] Step 2: Electrospin the polymer solution prepared in step 1. Under the action of a high-voltage electrostatic field, the polymer solution is stretched into filaments, which are received by a flat tin foil or a roller to obtain a fiber membrane. In the syringe of the electrospinning device, the diameter of the electrospinning metal nozzle is 0.8 mm, the spinning distance is 20 cm, and the high-voltage electrostatic field voltage is 13 kV.

[0038] Step 3, sequentially degumming, dissolving, dialysis and centrifuging the silk to obtain silk fibroin and dissolving it in water to obtain a silk fibroin solution;

[0039] Step 4, peeling off the fiber membrane from the flat tin foil or roller and fixing it on a stainless steel frame; the stainless steel frame is 8 cm long and 3 cm wide; soaking the stainless steel frame with the membrane in a silk fibroin solution with a mass fraction of 7 wt% for 30 minutes, then taking out the stainless steel frame with the membrane and drying it in a fume hood to obtain the composite fiber membrane;

[0040] Step 5, uniformly coating the silver nanowires on both sides of the composite fiber membrane prepared in step 4 to obtain a double-layer composite membrane;

[0041] Step six, spraying ethanol evenly on both sides of the double-layer composite film prepared in step five to obtain a treated double-layer composite film;

[0042] Step 7: Fix one end of the treated double-layer composite film prepared in step 6 on a stepping twisting machine and the other end on a custom iron block, and twist it to obtain elastic conductive fiber. The twisting speed of the twisting machine is 120 rpm. The initial length of the prepared elastic conductive fiber is 0.5 cm, and the length after stretching is 5 cm.

[0043] The number of devices and processing scales described here are used to simplify the description of the present invention. Applications, modifications and variations of the present invention will be obvious to those skilled in the art.

[0044] As described above, the present invention combines electrospinning, soaking, coating and twisting, and the preparation method is simple and convenient for practical operation. The method of soaking silk strengthens the interface bonding between the conductive material and the substrate, and the prepared elastic conductive fiber has high elasticity and high conductivity. The elastic conductive fiber prepared according to the present invention can be applied to a variety of stretchable electronic devices such as health monitoring, rehabilitation medicine, smart industry and aerospace. For example, the monitoring and alarm of a safe, when the strain of the elastic conductive fiber is small, the alarm device does not react, and when the strain is large, the alarm sounds an alarm, indicating that the safe is opened.

[0045] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A method for preparing an elastic conductive fiber, characterized in that: The following steps are involved: Step 1, dissolving any one of polyurethane, styrene-butadiene-styrene block copolymer, nylon 6, cellulose acetate, polyvinyl alcohol or polyacrylonitrile in a solvent, and stirring in a magnetic stirrer at room temperature until completely dissolved to obtain a polymer solution; Step 2, electrospinning the polymer solution prepared in step 1, wherein the polymer solution is stretched into filaments under the action of a high-voltage electrostatic field, and received by a flat tin foil or a roller to obtain a fiber membrane; Step 3, sequentially degumming, dissolving, dialysis and centrifuging the silk to obtain silk fibroin and dissolving it in water to obtain a silk fibroin solution; Step 4, soaking the fiber membrane prepared in step 2 in the silk fibroin solution prepared in step 3, and obtaining a composite fiber membrane after drying; Step 5, uniformly coating the conductive material on both sides of the composite fiber membrane prepared in step 4 to obtain a double-layer composite membrane; Step six, spraying ethanol evenly on both sides of the double-layer composite film prepared in step five to obtain a treated double-layer composite film; Step seven, fixing one end of the treated double-layer composite film prepared in step six on a stepping twisting machine, and fixing the other end on a customized iron block, and twisting to obtain elastic conductive fibers.

2. The method for preparing the elastic conductive fiber according to claim 1, characterized in that: The solvent in step 1 is any one or two of N,N-dimethylformamide, butyl acetate, acetone, N,N-dimethylacetamide, and formic acid.

3. The method for preparing the elastic conductive fiber according to claim 1, characterized in that: The high-voltage electrostatic field voltage of the electrospinning in the step 2 is 10-25 kV, the diameter of the metal nozzle of the electrospinning is 0.4-2 mm, the spinning distance of the electrospinning is 10-20 cm, and the rotation speed of the flat tin foil or the drum is 100-300 rpm.

4. The method for preparing the elastic conductive fiber according to claim 1, characterized in that: The concentration of the silk fibroin solution prepared in step three is 2-50%.

5. The method for preparing the elastic conductive fiber according to claim 1, characterized in that: The step 4 comprises the following steps: peeling off the fiber membrane from the flat tin foil or roller and fixing it on a stainless steel frame; soaking the stainless steel frame with the membrane in the silk fibroin solution, and then taking out the stainless steel frame with the membrane and drying it in a fume hood to obtain the composite fiber membrane; The stainless steel frame has a length of 4-20 cm, a width of 2-10 cm, and a soaking time of 5-150 minutes.

6. The method for preparing the elastic conductive fiber according to claim 1, characterized in that: The conductive material described in step five is any one or two of metal nanowires or nanoparticles, graphene, carbon nanotubes, Mxene, PEDOT / PSS aqueous dispersion, and liquid metal.

7. The method for preparing the elastic conductive fiber according to claim 1, characterized in that: The number of times of spraying ethanol in step six is ​​1-10 times.

8. The method for preparing the elastic conductive fiber according to claim 1, characterized in that: The twisting speed of the stepping twisting machine in step seven is 50-300 rpm, and the advancing speed is 0.5-30 mm / s.

9. The method for preparing the elastic conductive fiber according to claim 1, characterized in that: The elastic conductive fiber prepared in the step seven is composed of three components, the fiber film, the silk fibroin and the conductive material, which are wrapped layer by layer, and the volume ratio is 9:1:1-3:1:

1.

10. The method for preparing the elastic conductive fiber according to claim 1, characterized in that: The elastic conductive fiber prepared in step seven has an initial length of 0.4-20 cm, a diameter of 0.1-5 mm, and a length of 2-40 cm after stretching.

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