Stretchable elastic carbon nanofiber membrane material and preparation method thereof
By constructing a micro-wrinkled structure of multilayer carbon nanofiber membranes and removing polystyrene through electrospinning and pre-shrinking treatment, the brittle fracture problem of traditional carbon nanofiber membranes was solved, and a stretchable elastic carbon nanofiber membrane was prepared, expanding its application in flexible electronics and aerospace.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANJING TECH UNIV
- Filing Date
- 2026-03-24
- Publication Date
- 2026-05-12
AI Technical Summary
Traditional carbon nanofiber membranes suffer from brittle fracture due to tensile deformation, limiting their application in strain sensors, safety protective equipment, and wearable devices that need to withstand dynamic large strains.
By electrospinning a carbon precursor polymer with a polystyrene solution, combined with pre-shrinking and carbonization treatment, a micro-folded structure of a multilayer carbon nanofiber membrane was constructed. The polystyrene was then removed by dissolving it with ethyl acetate, thus preparing a stretchable and elastic carbon nanofiber membrane.
The stretchable elastic properties of carbon nanofiber membranes have been achieved, enhancing their application potential in wearable devices, strain sensors, and air purification.
Smart Images
Figure CN122013441A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of carbon nanofiber membrane technology, specifically a stretchable elastic carbon nanofiber membrane material and its preparation method. Background Technology
[0002] With the rapid development of flexible wearable electronic devices, intelligent strain sensors, and novel flexible energy storage devices, there is an urgent need for flexible matrix materials that combine excellent mechanical flexibility, high conductivity, and high electrochemical activity. Among numerous candidate materials, carbon nanofiber membranes, due to their three-dimensional interconnected porous network structure, high specific surface area, excellent electronic conductivity, and outstanding physicochemical stability, show broad application prospects in these cutting-edge fields.
[0003] Traditional carbon nanofiber membranes are typically prepared from polymer precursor solutions via electrospinning and high-temperature carbonization. For example, patent CN114318664B discloses a flexible carbon nanofiber membrane with an oriented structure and its preparation method. This method involves continuous electrospinning using a high-speed rotating metal receiving roller with multiple nozzles, followed by high-temperature carbonization in a high-purity nitrogen atmosphere. During carbonization, the polymer chains undergo intense dehydrogenation, cyclization, and cross-linking reactions, forming a highly dense, disordered graphite or graphite-like microcrystalline structure, which endows the carbon nanofiber membrane with a certain degree of bending flexibility. However, the maximum tensile strain that conventional pure carbon nanofiber membranes can withstand is typically only about 5%, exhibiting extremely poor tensile deformation capacity macroscopically, and is prone to brittle fracture under large tensile or compressive dynamic external forces. This inherent defect severely restricts its practical application in strain sensors, safety protective equipment, and wearable devices that need to withstand large dynamic strains.
[0004] To improve the stretchability of carbon nanofiber membranes, patent CN119877184A discloses an ultrathin transparent carbon nanofiber membrane flexible strain sensor and its preparation method. The core strategy involves compositeding the carbon nanofiber membrane with organic elastomers such as polyurethane. While introducing an organic polymer matrix solves the stretchability problem of carbon nanofiber membranes to some extent, it also severely sacrifices the intrinsic physicochemical advantages of pure carbon materials, such as high-temperature resistance and corrosion resistance, greatly limiting the application scenarios of this type of composite material in harsh environments such as extreme temperatures and highly corrosive media. Therefore, how to break through the inherent limitations of traditional pure carbon materials being "hard and brittle" through the rational design of carbon nanofiber precursor components and the precise control of microstructure and morphology (such as fiber curl, flexibility of cross-linking nodes, and multidimensional topological design of membrane materials), and develop a pure carbon nanofiber membrane that combines high conductivity, high porosity, and intrinsic stretchability, has become a key technical challenge urgently needing to be solved in the fields of materials science and flexible electronics. Summary of the Invention
[0005] In view of this, the present invention provides a stretchable elastic carbon nanofiber membrane material and its preparation method, realizing the preparation of carbon nanofiber membrane material with stretchable elastic recovery performance, high conductivity and high air permeability, breaking the inherent perception of traditional carbon materials as "hard and brittle", and greatly improving the application prospects of carbon nanofiber membrane materials in wearable devices, strain sensor devices and air purification.
[0006] This invention is achieved through the following technical solution: S1. Dissolve the carbon precursor polymer in a solvent and stir it evenly with magnetic force to obtain carbon precursor solution A. S2. Dissolve polystyrene in a solvent and stir it evenly with magnetic force to obtain spinning solution B; S3. Electrospinning is performed on solutions A and B in a certain combination order. After a certain time, the solutions are peeled off from the substrate and then placed in an oven to dry for a certain time to obtain a multilayer carbon precursor nanofiber membrane C. S4. The obtained multilayer carbon precursor nanofiber membrane C is heated to a certain temperature in air atmosphere for pre-shrinkage, kept at the temperature for a period of time and then cooled down. Then it is placed in a certain solvent and slowly stirred for a certain time to dissolve and remove polystyrene, so as to obtain a single-layer pure carbon precursor nanofiber membrane D. S5. The single-layer pure carbon precursor nanofiber membrane D is pre-oxidized by heating to a certain temperature in an air atmosphere, and then carbonized by heating to a certain temperature at a certain heating rate in an inert atmosphere. After holding at the temperature for a period of time, it is cooled down to prepare a stretchable elastic carbon nanofiber membrane material.
[0007] Preferably, in S1, the carbon precursor polymer is at least one of polyacrylonitrile, polyimide, polyvinylpyrrolidone, and polyvinyl alcohol; the solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, acetone, dichloromethane, acetylacetone, and toluene; and the concentration of the carbon precursor polymer in the carbon precursor solution A is 8-20 wt%.
[0008] Preferably, in S2, the solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, acetone, dichloromethane, and toluene; and the polystyrene concentration in spinning solution B is 10-18 wt%.
[0009] Preferably, in step S3, the combination sequence can be one of the following: polystyrene / carbon precursor nanofiber bilayer membrane, polystyrene / carbon precursor-polystyrene / carbon precursor nanofiber sandwich membrane, polystyrene / carbon precursor / polystyrene nanofiber sandwich membrane, polystyrene / carbon precursor-polystyrene / polystyrene nanofiber sandwich membrane, or carbon precursor / polystyrene / carbon precursor nanofiber sandwich membrane; the process parameters of the electrospinning process are: ambient temperature 20-30℃, humidity 20%-60%, injection speed 1-2mL / h, positive voltage 12-24kV, negative voltage -1.0-2.0kV, receiving distance 15-20cm, and receiving speed 50-100r / min; the receiving substrate includes one of the following: silicone paper, release paper, nonwoven fabric, tin foil, and copper mesh; the drying temperature is 50-70℃, and the drying time is 6-24h.
[0010] Preferably, in step S4, the pre-shrinking temperature is raised from room temperature to 120–150°C at a rate of 5–10°C / min, and the holding time is 0.5–1 h; the solvent is ethyl acetate, the stirring speed is 100–200 rpm, and the stirring time is 8–24 h.
[0011] Preferably, in step S5, the pre-oxidation temperature is increased from room temperature to 240–290°C at a rate of 1–5°C / min, and the holding time is 1–4 h. Preferably, in step S5, the inert atmosphere is at least one of nitrogen and argon; the carbonization temperature is increased from room temperature to 600-900°C at a rate of 1-5°C / min, and the holding time is 1-5h.
[0012] Beneficial effects: The stretchable elastic carbon nanofiber membrane material and its preparation method described in this invention utilize the thermal shrinkage effect of the polystyrene layer to induce the construction of micro-folds and buckling structures in the carbon precursor nanofiber membrane. The polystyrene is removed by dissolving it with ethyl acetate, leaving only the pure carbon precursor nanofiber membrane. This solves the problem of the influence of polystyrene on the carbon precursor nanofibers during the pre-oxidation and carbonization process, thereby endowing the carbon nanofiber membrane with a stretchable and elastic performance transformation, further promoting the application of carbon materials in energy conservation, environmental protection, flexible electronics, aerospace and other fields. Attached Figure Description
[0013] Figure 1 Electron microscopy image of the surface morphology of the stretchable elastic carbon nanofiber membrane prepared in Example 1.
[0014] Figure 2 Electron micrograph of the bent fibers of the stretchable elastic carbon nanofiber membrane prepared in Example 1.
[0015] Figure 3This is a cross-sectional electron microscope image of the pre-shrinked pure carbon precursor nanofiber membrane in Example 1.
[0016] Figure 4 This is a surface electron microscope image of the pure carbon precursor nanofiber membrane after cleaning with ethyl acetate in Example 1.
[0017] Figure 5 The stretchable elastic recovery properties of the stretchable elastic carbon nanofiber membrane prepared in Example 1. Detailed Implementation
[0018] The present invention will be further explained below with reference to the embodiments. The following embodiments are only used to illustrate the present invention, but are not intended to limit the scope of the present invention. Example 1
[0019] S1. Polyacrylonitrile was dissolved in N,N-dimethylformamide and stirred at 500 r / min for 6 h at 80 °C. After stirring evenly with magnetic force, a carbon precursor solution A with a polymer concentration of 10 wt% was obtained. S2. Polystyrene was dissolved in N,N-dimethylformamide solvent and magnetically stirred for 6 hours at room temperature to obtain spinning solution B with a polymer concentration of 15wt%. S3. Solutions A and B were spun in a polystyrene / carbon precursor-polystyrene / carbon precursor combination sequence. Under the conditions of humidity 40±10% and temperature 25±2℃, silicone paper was used as the receiving substrate. The injection speed was set to 1mL / h, the receiving distance was set to 17cm, and the receiving speed was 60r / min. The spinning voltage of the first layer was +20kV / -1.0kV, the spinning voltage of the second layer was +20kV / -1.0kV, and the spinning voltage of the third layer was +17kV / -1.0kV. The spinning time of each layer was 30min. Then, the solution was peeled off from the silicone paper and dried in an oven at 60℃ for 6h to obtain a multilayer carbon precursor nanofiber membrane C. S4. The obtained multilayer carbon precursor nanofiber membrane C was pre-shrinked by heating it to 140°C at a rate of 5°C / min in air atmosphere, holding it at the temperature for 30 min, and then cooling it down. It was then placed in ethyl acetate and slowly stirred at 100 r / min for 24 h to dissolve and remove polystyrene, thus obtaining a single-layer pure carbon precursor nanofiber membrane D. S5. The monolayer pure carbon precursor nanofiber membrane D is pre-oxidized in air at a rate of 1℃ / min to 280℃, held for 2 hours and then cooled. Then, it is carbonized in nitrogen at a rate of 5℃ / min to 800℃, held for 3 hours and then cooled to obtain a stretchable elastic carbon nanofiber membrane material.
[0020] Figure 1 and Figure 2The images show electron microscope (EM) images of the prepared stretchable elastic carbon nanofiber membrane material at 1.0 K and 20.0 K. The images show that the membrane material surface has a significant multi-level wrinkled structure and a unique buckled fiber configuration. The coupling of this wrinkled and buckled structure is the main reason why the carbon nanofiber membrane has stretchable elastic properties. Figure 3 The image shows a cross-sectional electron microscope image of the pure carbon nanofiber membrane after S4 pre-shrinkage. It can be seen that molten PS adheres to the carbon precursor nanofibers, and these adhered PS directly affect the pre-oxidation process of the carbon precursor nanofibers. Figure 4 The image shows a surface electron microscope (SEM) image of a pure carbon precursor nanofiber membrane after PS removal with ethyl acetate. It can be seen that large-area blocky molten PS was dissolved and removed after slow stirring. Figure 5 The elastic recovery properties of the prepared stretchable elastic carbon nanofiber membrane under tensile strains of 30%, 40%, 50%, 60%, 70%, and 80% are shown. It can be seen that the carbon nanofiber membrane exhibits excellent recovery properties after loading and unloading. Example 2
[0021] S1. Polyacrylonitrile and polyvinylpyrrolidone (mass ratio 1:1) are dissolved in N,N-dimethylformamide and stirred at 500 r / min for 8 h at 80 °C. After stirring evenly with magnetic force, a carbon precursor solution A with a polymer concentration of 12 wt% is obtained. S2. Polystyrene was dissolved in N,N-dimethylformamide solvent and magnetically stirred for 6 hours at room temperature to obtain spinning solution B with a polymer concentration of 10wt%. S3. Solutions A and B were spun in a polystyrene / carbon precursor / polystyrene combination sequence. Under the conditions of humidity 60±5% and temperature 25±2℃, nonwoven fabric was used as the receiving substrate. The injection speed was set to 2mL / h, the receiving distance was set to 15cm, and the receiving speed was 60r / min. The spinning voltage of the first layer was +20kV / -1.0kV, the spinning voltage of the second layer was +17kV / -1.0kV, and the spinning voltage of the third layer was +20kV / -1.0kV. The spinning time of each layer was 30min. Then, the solution was peeled off from the nonwoven fabric and dried in an oven at 70℃ for 12h to obtain a multilayer carbon precursor nanofiber membrane C. S4. The obtained multilayer carbon precursor nanofiber membrane C was pre-shrinked by heating it to 120°C at a rate of 10°C / min in air atmosphere, and then cooled down after holding it at that temperature for 1 hour. It was then placed in ethyl acetate and slowly stirred at 100 r / min for 24 hours to dissolve and remove polystyrene, thus obtaining a single-layer pure carbon precursor nanofiber membrane D. S5. The monolayer pure carbon precursor nanofiber membrane D is pre-oxidized in air at a rate of 5℃ / min to 290℃, held for 1 hour and then cooled. Then, it is carbonized in argon at a rate of 5℃ / min to 600℃, held for 5 hours and then cooled to obtain a stretchable elastic carbon nanofiber membrane material. Example 3
[0022] S1. Polyacrylonitrile and polyvinylpyrrolidone (mass ratio 1:1) are dissolved in N,N-dimethylformamide and stirred at 500 r / min for 8 h at 80 °C. After stirring evenly with magnetic force, a carbon precursor solution A with a polymer concentration of 8 wt% is obtained. S2. Polystyrene was dissolved in tetrahydrofuran solvent and magnetically stirred for 6 hours at room temperature to obtain spinning solution B with a polymer concentration of 16wt%. S3. Solutions A and B were spun in sequence with polystyrene / carbon precursors. Under the conditions of humidity 35±5% and temperature 20±2℃, release paper was used as the receiving substrate. The injection speed was set to 1.5mL / h, the receiving distance was set to 20cm, the receiving speed was 60r / min, the spinning voltage of the first layer was +20kV / -1.3kV, the spinning voltage of the second layer was +12kV / -2.0kV, and the spinning time of each layer was 30min. Then, the solution was peeled off from the release paper and dried in an oven at 50℃ for 24h to obtain a multilayer carbon precursor nanofiber membrane C. S4. The obtained multilayer carbon precursor nanofiber membrane C was pre-shrinked by heating it to 130°C at a rate of 5°C / min in air atmosphere, and then cooled down after holding it at that temperature for 1 hour. It was then placed in ethyl acetate and slowly stirred at 150 r / min for 8 hours to dissolve and remove polystyrene, thus obtaining a single-layer pure carbon precursor nanofiber membrane D. S5. The monolayer pure carbon precursor nanofiber membrane D is pre-oxidized in air at a rate of 1℃ / min to 240℃, held for 4 hours and then cooled. Then, it is carbonized in nitrogen at a rate of 5℃ / min to 900℃, held for 1 hour and then cooled to obtain a stretchable elastic carbon nanofiber membrane material. Example 4
[0023] S1. Polyacrylonitrile was dissolved in N,N-dimethylformamide and stirred at 500 r / min for 12 h at 80 °C. After stirring evenly with magnetic force, a carbon precursor solution A with a polymer concentration of 20 wt% was obtained. S2. Polystyrene was dissolved in N,N-dimethylformamide and tetrahydrofuran solvent, and the mixture was magnetically stirred at room temperature for 12 hours to obtain spinning solution B with a polymer concentration of 18wt%. S3. Solutions A and B were spun in the order of carbon precursor / polystyrene / carbon precursor under the conditions of humidity 30±5% and temperature 25±2℃, with a copper mesh as the receiving substrate, a push rate of 1mL / h, a receiving distance of 18cm, and a receiving speed of 60r / min. The spinning voltage of the first layer solution B was +17.5kV / -1.3kV, the spinning voltage of the second layer solution A was +24kV / -1.3kV, and the spinning voltage of the third layer solution B was +17.5kV / -1.3kV. The spinning time of each layer was 30min. Then, the solution was peeled off from the silicone paper and dried in an oven at 60℃ for 24h to obtain a multilayer carbon precursor nanofiber membrane C. S4. The obtained multilayer carbon precursor nanofiber membrane C was pre-shrinked by heating it to 150°C at a rate of 5°C / min in air atmosphere, and then cooled down after holding it at that temperature for 1 hour. It was then placed in ethyl acetate and slowly stirred at 200 r / min for 12 hours to dissolve and remove polystyrene, thus obtaining a single-layer pure carbon precursor nanofiber membrane D. S5. The monolayer pure carbon precursor nanofiber membrane D is pre-oxidized in air at a rate of 2℃ / min to 280℃, held for 3 hours and then cooled. Then, it is carbonized in argon at a rate of 1℃ / min to 800℃, held for 3 hours and then cooled to obtain a stretchable elastic carbon nanofiber membrane material.
Claims
1. A stretchable elastic carbon nanofiber membrane material and its preparation method, characterized in that, The preparation of the membrane material includes the following steps: S1. Dissolve the carbon precursor polymer in a solvent and stir it evenly with magnetic force to obtain carbon precursor solution A. S2. Dissolve polystyrene in a solvent and stir it evenly with magnetic force to obtain spinning solution B; S3. Electrospinning is performed on solutions A and B in a certain combination order. After a certain time, the solutions are peeled off from the substrate and then placed in an oven to dry for a certain time to obtain a multilayer carbon precursor nanofiber membrane C. S4. The obtained multilayer carbon precursor nanofiber membrane C is heated to a certain temperature in air atmosphere for pre-shrinkage, kept at the temperature for a period of time and then cooled down. Then it is placed in a certain solvent and slowly stirred for a certain time to dissolve and remove polystyrene, so as to obtain a single-layer pure carbon precursor nanofiber membrane D. S5. The single-layer pure carbon precursor nanofiber membrane D is pre-oxidized by heating to a certain temperature in an air atmosphere, and then carbonized by heating to a certain temperature at a certain heating rate in an inert atmosphere. After holding at the temperature for a period of time, it is cooled down to prepare a stretchable elastic carbon nanofiber membrane material.
2. The stretchable elastic carbon nanofiber membrane material and its preparation method according to claim 1, characterized in that, In S1, the carbon precursor polymer is at least one of polyacrylonitrile, polyimide, polyvinylpyrrolidone, and polyvinyl alcohol; the solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, acetone, dichloromethane, acetylacetone, and toluene; and the concentration of the carbon precursor polymer in the carbon precursor solution A is 8-20 wt%.
3. The stretchable elastic carbon nanofiber membrane material and its preparation method according to claim 1, characterized in that, In S2, the solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, acetone, dichloromethane, and toluene; the polystyrene concentration in spinning solution B is 10-18 wt%.
4. The stretchable elastic carbon nanofiber membrane material and its preparation method according to claim 1, characterized in that, In S3, the combination sequence can be one of the following: polystyrene / carbon precursor nanofiber bilayer membrane, polystyrene / carbon precursor-polystyrene / carbon precursor nanofiber sandwich membrane, polystyrene / carbon precursor / polystyrene nanofiber sandwich membrane, polystyrene / carbon precursor-polystyrene / polystyrene nanofiber sandwich membrane, or carbon precursor / polystyrene / carbon precursor nanofiber sandwich membrane; the process parameters of the electrospinning process are: ambient temperature 20-30℃, humidity 20%-60%, injection speed 1-2mL / h, positive voltage 12-24kV, negative voltage -1.0-2.0kV, receiving distance 15-20cm, and receiving speed 50-100r / min; the receiving substrate includes one of the following: silicone paper, release paper, nonwoven fabric, tin foil, and copper mesh; the drying temperature is 50-70℃, and the drying time is 6-24h.
5. The stretchable elastic carbon nanofiber membrane material and its preparation method according to claim 1, characterized in that, In step S4, the pre-shrinking temperature is raised from room temperature to 120–150°C at a rate of 5–10°C / min, and the holding time is 0.5–1 h; the solvent is ethyl acetate, the stirring speed is 100–200 rpm, and the stirring time is 8–24 h.
6. The stretchable elastic carbon nanofiber membrane material and its preparation method according to claim 1, characterized in that, In S5, the pre-oxidation temperature is increased from room temperature to 240-290℃, the heating rate is 1-5℃ / min, and the holding time is 1-5h.
7. The stretchable elastic carbon nanofiber membrane material and its preparation method according to claim 1, characterized in that, In S5, the inert atmosphere is at least one of nitrogen and argon; the carbonization temperature is increased from room temperature to 600-900℃, the heating rate is 1-5℃ / min, and the holding time is 1-5h.