Low-density SiC nanofibers and preparation method thereof

Abstract

The invention discloses low-density SiC nanofibers and a preparation method thereof. The density of the SiC nanofibers is about 0.3-0.6g / cubic centimeter (the density of commercialized SiC is about 1.1-1.3g / cubic centimeter), the diameters of the fibers are 100-500 nanometers and the length-diameter is greater than 100. The SiC nanofibers are prepared by adopting an electrospinning technique combined with a high-temperature carbon thermal reduction method, and the obtained SiC nano fibers are uniformly distributed. The SiC nanofibers provided by the invention are simple and feasible in preparation method and low in raw material price, and the structure and the morphology of the fibers are easy to control, so that the preparation method is a synthetic technology which is relatively strong in comprehensiveness and suitable for industrial popularization.

Description

technical field

[0001] The invention belongs to the field of preparation of high-performance inorganic functional materials, and in particular relates to a low-density SiC nanofiber and a preparation method thereof. Background technique

[0002] One-dimensional nanomaterials have unique properties and broad application prospects, and have developed into an important branch of functional materials in recent years. At present, there are many methods for synthesizing one-dimensional nanomaterials, and the prepared shapes are too numerous to enumerate, such as nanofibers, nanowires, nanoribbons, nanotubes, etc. Among the wide variety of synthetic methods, electrospinning technology (a process based on electrostatic interaction) stands out as one of the focuses of people's research. One-dimensional nanofibers prepared by electrospinning are based on uniaxial stretching of a polymer solution or a viscoelastic jet of melt. This method is similar to the mechanical stretching techn...

Examples

Embodiment 1

[0029] Add 2.8 grams of polyacrylonitrile (PAN, molecular weight 22600) into 16 ml of N,N-dimethylformamide (DMF), stir well to form solution A; take another 1.5 ml of tetraethyl orthosilicate (TEOS) and add In 6 ml of DMF, slowly add 0.2 ml of glacial acetic acid dropwise to the mixed solution, and fully stir to form solution B; slowly add solution B to solution A, mix evenly to obtain a clear and transparent solution; after aging for 1 hour, start spinning, Electrospinning conditions are as follows: adjust the distance between the needle tip of the syringe and the receiving plate to 12 cm, set the high-voltage DC power supply voltage at 20 kV, and set the propulsion speed of the micro-syringe pump at 0.8 ml / hour; after spinning, take Precursor samples on the lower receiver plate. The precursor was placed in a tube furnace and calcined at 1390°C for 6 hours in an argon atmosphere with a heating rate of 5°C / min; then baked at 650°C for 4 hours in an oxygen atmosphere at a heat...

Embodiment 2

[0031]Add 1.4g of polyacrylonitrile (PAN, molecular weight 22,600) into 10ml of N,N-dimethylformamide (DMF), stir well to form solution A; In 10 ml of DMF, slowly add 0.4 ml of glacial acetic acid dropwise to the mixture, and stir fully to form solution B; slowly add solution B to solution A, mix well to obtain a clear and transparent solution; after aging for 1 hour, start spinning, Electrospinning conditions are as follows: adjust the distance between the needle tip of the syringe and the receiving plate to 12 cm, set the high-voltage DC power supply voltage at 20 kV, and set the propulsion speed of the micro-injection pump at 1 ml / hour; after spinning, take Precursor samples on the lower receiver plate. The precursor was placed in a tube furnace and calcined in an argon atmosphere at 1300°C for 15 hours with a heating rate of 5°C / min; then calcined in an oxygen atmosphere at 650°C for 4 hours at a heating rate of 5°C / min; the above samples were After cooling to room temper...

Embodiment 3

[0033] Take 1.4 grams of polyvinyl alcohol (PVA, molecular weight 90,000) and add it to 10 milliliters of absolute ethanol, stir well to form solution A; take another 1.5 milliliters of tetraethyl silicate (TEOS) and add it to 6 milliliters of absolute ethanol, slowly add to Add 0.2 milliliters of glacial acetic acid dropwise to the mixed solution, stir well to form solution B; slowly add solution B to solution A, mix well to obtain a clear and transparent solution; after aging for 0.5 hours, start spinning, and the electrospinning conditions are as follows: The distance between the needle tip of the syringe and the receiving plate is 12 cm, the high-voltage DC power supply voltage is set at about 22 kV, and the propulsion speed of the micro-injection pump is set at 1.2 ml / hour; after spinning, remove the precursor on the receiving plate object samples. The precursor was placed in a tube furnace and calcined at 1350°C for 5 hours in an argon atmosphere with a heating rate of 5...

technical field

[0001] The invention belongs to the field of preparation of high-performance inorganic functional materials, and in particular relates to a low-density SiC nanofiber and a preparation method thereof. Background technique

[0002] One-dimensional nanomaterials have unique properties and broad application prospects, and have developed into an important branch of functional materials in recent years. At present, there are many methods for synthesizing one-dimensional nanomaterials, and the prepared shapes are too numerous to enumerate, such as nanofibers, nanowires, nanoribbons, nanotubes, etc. Among the wide variety of synthetic methods, electrospinning technology (a process based on electrostatic interaction) stands out as one of the focuses of people's research. One-dimensional nanofibers prepared by electrospinning are based on uniaxial stretching of a polymer solution or a viscoelastic jet of melt. This method is similar to the mechanical stretching techn...

Examples

Embodiment 1

[0029] Add 2.8 grams of polyacrylonitrile (PAN, molecular weight 22600) into 16 ml of N,N-dimethylformamide (DMF), stir well to form solution A; take another 1.5 ml of tetraethyl orthosilicate (TEOS) and add In 6 ml of DMF, slowly add 0.2 ml of glacial acetic acid dropwise to the mixed solution, and fully stir to form solution B; slowly add solution B to solution A, mix evenly to obtain a clear and transparent solution; after aging for 1 hour, start spinning, Electrospinning conditions are as follows: adjust the distance between the needle tip of the syringe and the receiving plate to 12 cm, set the high-voltage DC power supply voltage at 20 kV, and set the propulsion speed of the micro-syringe pump at 0.8 ml / hour; after spinning, take Precursor samples on the lower receiver plate. The precursor was placed in a tube furnace and calcined at 1390°C for 6 hours in an argon atmosphere with a heating rate of 5°C / min; then baked at 650°C for 4 hours in an oxygen atmosphere at a heat...

Embodiment 2

[0031]Add 1.4g of polyacrylonitrile (PAN, molecular weight 22,600) into 10ml of N,N-dimethylformamide (DMF), stir well to form solution A; In 10 ml of DMF, slowly add 0.4 ml of glacial acetic acid dropwise to the mixture, and stir fully to form solution B; slowly add solution B to solution A, mix well to obtain a clear and transparent solution; after aging for 1 hour, start spinning, Electrospinning conditions are as follows: adjust the distance between the needle tip of the syringe and the receiving plate to 12 cm, set the high-voltage DC power supply voltage at 20 kV, and set the propulsion speed of the micro-injection pump at 1 ml / hour; after spinning, take Precursor samples on the lower receiver plate. The precursor was placed in a tube furnace and calcined in an argon atmosphere at 1300°C for 15 hours with a heating rate of 5°C / min; then calcined in an oxygen atmosphere at 650°C for 4 hours at a heating rate of 5°C / min; the above samples were After cooling to room temper...

Embodiment 3

[0033] Take 1.4 grams of polyvinyl alcohol (PVA, molecular weight 90,000) and add it to 10 milliliters of absolute ethanol, stir well to form solution A; take another 1.5 milliliters of tetraethyl silicate (TEOS) and add it to 6 milliliters of absolute ethanol, slowly add to Add 0.2 milliliters of glacial acetic acid dropwise to the mixed solution, stir well to form solution B; slowly add solution B to solution A, mix well to obtain a clear and transparent solution; after aging for 0.5 hours, start spinning, and the electrospinning conditions are as follows: The distance between the needle tip of the syringe and the receiving plate is 12 cm, the high-voltage DC power supply voltage is set at about 22 kV, and the propulsion speed of the micro-injection pump is set at 1.2 ml / hour; after spinning, remove the precursor on the receiving plate object samples. The precursor was placed in a tube furnace and calcined at 1350°C for 5 hours in an argon atmosphere with a heating rate of 5...

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