CN104464712A - Preparation method of nano-fiber-foam-based acoustic material - Google Patents

Abstract

The invention provides a method for preparing a nanofiber foam-based sound-absorbing material, which is characterized in that the specific steps include: the first step: activate the surface of the nanofiber foam; the second step: at a temperature of 32°C to 35°C, Under the condition of a pressure of 7.39×10 ⁶ Pa to 8.0×10 ⁶ Pa, the nanofiber foam obtained in the previous step is treated with a mixture of supercritical carbon dioxide fluid, adhesive agent and surface roughness modified particles, and then the pressure is reduced. The nanofiber foam is desorbed from the supercritical carbon dioxide fluid, so that the adhesive agent and the surface roughness modified particles are uniformly dispersed on the surface of the fiber; the third step: the adhesive agent is cured and crosslinked by the thermal crosslinking method, and the surface roughness modified particles Combined with the fiber surface, the nanofiber foam-based sound-absorbing material is obtained. The invention has better sound-absorbing performance.

Description

A kind of preparation method of nanofiber foam-based sound-absorbing material

technical field

The invention belongs to the technical field of noise pollution control, and in particular relates to a nanofiber foam-based sound-absorbing material and a preparation method thereof.

Background technique

Noise pollution has caused great harm to people's physical and mental health. Effectively preventing noise pollution and reducing the harm of noise are necessary measures to ensure people's normal work and life. Sound-absorbing materials can control noise pollution from three aspects: the source of noise generation, the process of transmission, and the protection of terminal victims. It is the most effective means of applying noise pollution. Sound-absorbing materials can be divided into porous sound-absorbing materials, resonant sound-absorbing materials and special-structure sound-absorbing materials according to their sound-absorbing characteristics. Among them, porous sound-absorbing materials have the characteristics of light weight and good sound-absorbing effect. Widely used in vehicles, studio halls, theaters and other places. With the rapid development of the sound-absorbing material industry, only good sound-absorbing effects can no longer fully meet the needs of the current market. People have put forward higher requirements for sound-absorbing materials. Materials must not only have good sound-absorbing performance, but also require light weight. Therefore, in recent years, ultra-light and high-efficiency sound-absorbing materials have become one of the hot spots of global development.

At present, the light and high-efficiency sound-absorbing materials are mainly traditional non-woven sound-absorbing cotton, and researchers have also done corresponding research work in this area and developed a series of sound-absorbing materials. Domestic patent CN101471070A discloses a high-performance sound-absorbing material and its preparation method. The preparation method is to first mix 1D and 15D polyester staple fibers with 1.5D hot-melt polyester staple fibers in a certain proportion and prepare a three-dimensional net by hot pressing. shape mixed short fiber layer, and then use 10g/cm ² polypropylene spunbond cloth to sandwich multiple layers of the above-mentioned three-dimensional network mixed short fiber layer to prepare sound-absorbing materials. The TAI-2047 series sound-absorbing cotton products produced by 3M are currently the most representative sound-absorbing products in the world. This product is a non-woven material composed of polyester fibers with a diameter of 25 μm and polypropylene fibers with a diameter of 2 μm. The volume density is 20mg/cm ³ , the thickness is 10mm. Domestic patent CN101903434A discloses a vibration-damping sound-absorbing material and its manufacturing method. The sound-absorbing material described in the patent is obtained by foaming polyurethane. The materials and products provided by the above-mentioned patents have large internal pore sizes and narrow pore size distribution, which cannot effectively absorb low-frequency noise, and the bulk density of materials is generally too high. Aiming at the problem of high volume density of sound-absorbing materials, the domestic patent CN101807394Y discloses a layered sound-absorbing material composed of micro-nano fibers. Superimposed and combined with each other, the sound absorption and flame retardancy of the overall material can be adjusted by adjusting the micro-nano fiber components, thickness, bulk density and functional fillers of different layers of materials, although the patent introduces nanofibers as a lightweight component of the material. However, the bulk density of the material is still relatively large, and the internal fillers including powdered fillers only play a role of single filling modification, and cannot be tightly bonded to the fiber surface to improve the pore structure of the material, so the sound absorption performance of the material Especially low frequency sound absorption performance is poor. To sum up, the above-mentioned patents and products all have the disadvantages of poor sound-absorbing performance, especially low-frequency sound-absorbing performance, and excessive bulk density, which severely limits the extensive application of sound-absorbing materials in aerospace, high-end automobiles and other fields.

Contents of the invention

The purpose of the present invention is to propose a method for preparing a nanofiber foam-based sound-absorbing material in order to solve the problems existing in the above-mentioned materials.

In order to achieve the above object, the present invention provides a method for preparing a nanofiber foam-based sound-absorbing material, characterized in that the specific steps include:

The first step: activate the nanofiber foam surface;

The second step: under the conditions of temperature 32℃～35℃ and pressure 7.39×10 ⁶ Pa～8.0×10 ⁶ Pa, the mixture of supercritical carbon dioxide fluid, adhesive agent and surface roughness modified particles is used for the previous step The obtained nanofiber foam is processed, and then the pressure is reduced to desorb the supercritical carbon dioxide fluid from the nanofiber foam, so that the adhesive agent and surface roughness modified particles are uniformly dispersed on the surface of the fiber;

The third step: using thermal cross-linking method to cure and cross-link the adhesive agent, so that the surface roughness modified particles are combined on the surface of the fiber to obtain a nanofiber foam-based sound-absorbing material.

Preferably, the nanofiber foam is a three-dimensional network-like material formed by interpenetrating and interlacing nanofibers.

Preferably, the nanofiber foam has a bulk density of 0.1-50 mg/cm ³ , a pore diameter of 0.01-10 μm, and a specific surface area of 10-2000 m ² /g.

Preferably, the nanofiber foam is a nanofiber foam material with a uniform overall density, or a nanofiber foam material with a uniform density change along the thickness direction, or a nanofiber foam material with a gradient change density along the thickness direction.

Preferably, the activation treatment method is: a combination of one or more of alkali reduction method, solvent extraction method, hydrothermal growth method, vapor phase growth method and magnetic field induced self-assembly method.

Preferably, the adhesive is a benzoxazine monomer, and the mass fraction of the adhesive in the mixture of the supercritical carbon dioxide fluid, the adhesive and the surface roughness modified particles is 0.01-10%.

Preferably, the surface roughness modified particles are one or more of metal particles, metal oxide particles, inorganic non-metal oxide particles, organic nanocrystalline particles, graphene sheets and graphene oxide sheets Combination; the average particle diameter of the surface roughness modified particles is 0.002-100 μm, and the mass fraction of the surface roughness modified particles in the mixture of the supercritical carbon dioxide fluid, the adhesive agent and the surface roughness modified particles is 0.1 ~20%.

Preferably, the thermal cross-linking is a temperature-programmed segmented thermal cross-linking method.

Preferably, the volume density of the nanofiber foam-based sound-absorbing material is 0.2-60 mg/cm ³ .

The nanofiber foam-based sound-absorbing material is a sound-absorbing material obtained by modifying a three-dimensional nanofiber foam material. It is a three-dimensional network-shaped material in which nanofibers interpenetrate and interlace, and is obtained by constructing a secondary rough structure on the surface. The high-density modified particles are evenly dispersed on the surface of the fiber material and exhibit effective bonding with the fiber to build a secondary rough structure and increase the reflection and attenuation area of the sound wave.

Compared with prior art, the beneficial effect of the present invention is:

(1) The nanofiber open-cell foam used in the present invention is different from traditional foam materials. Its frame structure is composed of nanofibers, which makes the material have higher specific surface area, high porosity, high pore connectivity and excellent mechanical properties. Through the secondary rough structure on the surface of the modified fiber, the reflection and absorption area for sound waves and the resonance attenuation for low-frequency noise are increased, giving the material better sound-absorbing properties.

(2) The present invention utilizes the characteristics of a wide range of nanofiber materials to broaden the types of raw materials for sound-absorbing materials, and can control the preparation process during the material preparation process, and prepare sound-absorbing materials with density gradient structures in one step to improve the sound-absorbing performance of the materials .

(3) The preparation process of the nanofiber foam-based sound-absorbing material provided by the present invention is simple, the material structure design is strong, the product volume density is small, the thickness is small, and the cost is low. It has great application prospect and commercial value.

Detailed ways

The present invention will be further described below in combination with specific embodiments. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application. The nanofiber foam in the following examples is a three-dimensional network-shaped material formed by interpenetrating and interlacing nanofibers, which can be purchased from Shanghai Dongxiang Nano Technology Co., Ltd. High-purity carbon dioxide gas (purity is 99.99%) can be purchased from Shanghai Jiaya Chemical Industry Co., Ltd. Co., Ltd., VW-6/2-6 air-cooled carbon dioxide compressor can be purchased in Anhui Jufeng Compressor Manufacturing Co., Ltd.

Example 1

A preparation method of nanofiber foam-based sound-absorbing material, the specific steps are:

The first step: the surface of the nanofiber foam is activated by an alkali reduction method, wherein the alkali solution is a 2% sodium hydroxide solution by mass fraction, and the nanofiber foam is immersed in a 2% sodium hydroxide solution, and after 1 hour Take it out and wash it to neutral, and then put it into a blast oven to dry; the nanofiber foam has a volume density of 0.1mg/cm ³ , an average pore diameter of 0.01μm, and a specific surface area of 10m ² /g; the nanofiber foam is Nanofiber foam with uniform overall density;

The second step: under the conditions of a temperature of 32°C and a pressure of 7.39×10 ⁶ Pa, the nanofiber foam obtained in the previous step is treated with a mixture of supercritical carbon dioxide fluid, adhesive agent and surface roughness modified particles, and then Reduce the pressure to 1.01×10 ⁵ Pa to desorb the supercritical carbon dioxide fluid from the nanofiber foam, so that the adhesive agent and surface roughness modified particles are uniformly dispersed on the fiber surface; the supercritical carbon dioxide fluid is made of VW-6/ 2-6 The air-cooled carbon dioxide compressor compresses ultra-pure carbon dioxide gas to 7.39×10 ⁶ Pa and raises the temperature to 32°C; the adhesive is benzoxazine monomer, and the supercritical carbon dioxide fluid The mass fraction of the adhesive in the mixture with the adhesive and the surface roughness modified particles is 0.01%; the surface roughness modified particles are Al ₂ O ₃ nanoparticles with an average particle diameter of 0.002 μm, and the super The mass fraction of surface roughness modified particles in the mixture of critical carbon dioxide fluid, adhesive agent and surface roughness modified particles is 0.1%:

The third step: use thermal cross-linking method to solidify and cross-link the adhesive agent, so that the surface roughness modified particles are closely combined on the surface of the fiber, and a secondary rough structure is constructed to obtain a composite three-dimensional nanofiber-based foam sound-absorbing material with excellent sound-absorbing performance; The temperature-programmed segmental thermal crosslinking method is to program the temperature at a heating rate of 5°C/min, and keep the temperature at 80°C, 100°C, 120°C, 160°C, 180°C, 200°C, and 220°C for 10 minutes, and the obtained The bulk density of the nanofiber foam-based sound-absorbing material is 0.2mg/cm ³ .

The sound-absorbing material with a thickness of 5mm was used as the test sample, and based on the measurement method of "Measurement of Sound Absorption Coefficient and Acoustic Impedance in Acoustic Impedance Tube Part 2: Transfer Function Method" described in ISO10534-2, Beijing Shengshengsheng Co., Ltd. The low-frequency sound absorption coefficient of the sample measured by the produced SW260 impedance tube is above 0.20, and the maximum sound absorption coefficient is above 0.90. Example 2

A preparation method of nanofiber foam-based sound-absorbing material, the specific steps are:

Step 1: Use solvent extraction method to activate the surface of nanofiber foam, wherein the extraction solvent is dichloromethane, the extraction time is 30min, and the number of extractions is 3 times, so that the surface soluble functional groups are removed by dichloromethane to form active sites point; the nanofiber foam has a volume density of 50 mg/cm ³ , an average pore diameter of 10 μm, and a specific surface area of 2000 m ² /g; the nanofiber foam is a nanofiber foam whose overall density changes uniformly along the thickness direction;

The second step: under the conditions of a temperature of 35°C and a pressure of 7.4×10 ⁶ Pa, the nanofiber foam obtained in the previous step is treated with a mixture of supercritical carbon dioxide fluid, adhesive agent and surface roughness modified particles, and then Reduce the pressure to 1.01×10 ⁵ Pa to desorb the supercritical carbon dioxide fluid from the nanofiber foam, so that the adhesive agent and surface roughness modified particles are uniformly dispersed on the fiber surface; the supercritical carbon dioxide fluid is made of VW-6/ 2-6 The air-cooled carbon dioxide compressor compresses ultra-pure carbon dioxide gas to 7.39×10 ⁶ Pa and raises the temperature to 32°C; the adhesive is benzoxazine monomer, and the supercritical carbon dioxide fluid The mass fraction of the adhesive in the mixture with the adhesive and the surface roughness modified particles is 10%; the surface roughness modified particles are iron particles with an average particle diameter of 100 μm, and the supercritical carbon dioxide fluid and the adhesive The mass fraction of the surface roughness modified particles in the mixture of the agent and the surface roughness modified particles is 20%;

The third step: use thermal cross-linking method to cure and cross-link the adhesive, so that the surface roughness modified particles are firmly combined on the surface of the fiber, and a secondary rough structure is constructed to obtain a composite three-dimensional nanofiber-based foam sound-absorbing material with excellent sound-absorbing properties ; The temperature-programmed segmental thermal cross-linking method is to program the temperature at a heating rate of 5°C/min, and keep the temperature at 80°C, 100°C, 120°C, 160°C, 180°C, 200°C, and 220°C for 10 minutes, The volume density of the obtained nanofiber foam-based sound-absorbing material was 60 mg/cm ³ . The sound-absorbing material with a thickness of 5mm was used as the test sample, and based on the measurement method of "Measurement of Sound Absorption Coefficient and Acoustic Impedance in Acoustic Impedance Tube Part 2: Transfer Function Method" described in ISO10534-2, Beijing Shengshengsheng Co., Ltd. The low-frequency sound absorption coefficient of the sample measured by the produced SW260 impedance tube is above 0.4, and the maximum sound absorption coefficient is above 0.99.

Example 3

A preparation method of nanofiber foam-based sound-absorbing material, the specific steps are:

Step 1: Activate the surface of the nanofiber foam by using the hydrothermal growth method, wherein the solution used in the hydrothermal growth method is a glucose solution with a mass fraction of 5%, the heating temperature is 200°C, the pressure is 10MPa, and the treatment time is 2 hours; The volume density of the nanofiber foam is 5 mg/cm ³ , the average pore diameter is 1 μm, and the specific surface area is 1000 m ² /g; the nanofiber foam is a nanofiber foam material whose overall density changes gradiently along the thickness direction.

The second step: under the conditions of a temperature of 34°C and a pressure of 7.5×10 ⁶ Pa, the nanofiber foam obtained in the previous step is treated with a mixture of supercritical carbon dioxide fluid, adhesive agent and surface roughness modified particles, and then Reduce the pressure to 1.01×10 ⁵ Pa to desorb the supercritical carbon dioxide fluid from the nanofiber foam, so that the adhesive agent and surface roughness modified particles are uniformly dispersed on the fiber surface; the supercritical carbon dioxide fluid is made of VW-6/ 2-6 The air-cooled carbon dioxide compressor compresses ultra-pure carbon dioxide gas to 7.39×10 ⁶ Pa and raises the temperature to 32°C; the adhesive is benzoxazine monomer, and the supercritical carbon dioxide fluid The massfraction of adhesive agent in the mixture with adhesive agent and surface roughness modified particle is 5%; Described surface roughness modified particle is SiO ₂ particles, average particle diameter is 5 μ m, described supercritical carbon dioxide fluid and The mass fraction of the surface roughness modified particles in the mixture of the adhesive agent and the surface roughness modified particles is 5%;

The third step: use thermal cross-linking method to solidify and cross-link the adhesive agent, so that the surface roughness modified particles are closely combined on the surface of the fiber, and a secondary rough structure is constructed to obtain a composite three-dimensional nanofiber-based foam sound-absorbing material with excellent sound-absorbing performance; The temperature-programmed segmental thermal crosslinking method is to program the temperature at a heating rate of 5°C/min, and keep the temperature at 80°C, 100°C, 120°C, 160°C, 180°C, 200°C, and 220°C for 10 minutes, and the obtained The bulk density of the nanofiber foam-based sound-absorbing material is 6mg/cm ³ .

The sound-absorbing material with a thickness of 5mm was used as the test sample, and based on the measurement method of "Measurement of Sound Absorption Coefficient and Acoustic Impedance in Acoustic Impedance Tube Part 2: Transfer Function Method" described in ISO10534-2, Beijing Shengshengsheng Co., Ltd. The low-frequency sound absorption coefficient of the sample measured by the produced SW260 impedance tube is above 0.26, and the maximum sound absorption coefficient is above 0.93.

Example 4

A preparation method of nanofiber foam-based sound-absorbing material, the specific steps are:

Step 1: The surface of the nanofiber foam is activated by the vapor phase growth method, in which ethylene is used as the carbon source, ferrocene is used as the catalyst, high-purity nitrogen is used as the protective gas, the treatment temperature is 250°C, and the treatment time is 1 hour; The volume density of the nanofiber foam is 15 mg/cm ³ , the average pore diameter is 5 μm, and the specific surface area is 1500 m ² /g; the nanofiber foam is a nanofiber foam with uniform overall density.

The second step: the nanofiber foam obtained in the previous step was treated with a mixture of supercritical carbon dioxide fluid, adhesive agent and surface roughness modified particles at a temperature of 34°C and a pressure of 7.6×10 ⁶ Pa, and then reduced The minimum pressure is 1.01×10 ⁵ Pa, so that the nanofiber foam desorbs the supercritical carbon dioxide fluid, so that the adhesive agent and the surface roughness modified particles are uniformly dispersed on the surface of the fiber; the supercritical carbon dioxide fluid is made of VW-6/2 -6 obtained by compressing ultra-pure carbon dioxide gas to 7.39×10 ⁶ Pa with an air-cooled carbon dioxide compressor and raising the temperature to 32°C; the adhesive is benzoxazine monomer, and the supercritical carbon dioxide fluid is combined with The mass fraction of the adhesive agent in the mixture of the adhesive agent and the surface roughness modified particles is 10%; the described surface roughness modified particles are organic silica gel particles with an average particle diameter of 10 μm, and the supercritical carbon dioxide fluid and the adhesive The mass fraction of the surface roughness modified particles in the mixture of the agent and the surface roughness modified particles is 10%;

The third step: use thermal cross-linking method to solidify and cross-link the adhesive agent, so that the surface roughness modified particles are closely combined on the surface of the fiber, and a secondary rough structure is constructed to obtain a composite three-dimensional nanofiber-based foam sound-absorbing material with excellent sound-absorbing performance; The temperature-programmed segmental thermal crosslinking method is to program the temperature at a heating rate of 5°C/min, and keep the temperature at 80°C, 100°C, 120°C, 160°C, 180°C, 200°C, and 220°C for 10 minutes, and the obtained The bulk density of the nanofiber foam-based sound-absorbing material is 20mg/cm ³ .

The sound-absorbing material with a thickness of 5mm was used as the test sample, and based on the measurement method of "Measurement of Sound Absorption Coefficient and Acoustic Impedance in Acoustic Impedance Tube Part 2: Transfer Function Method" described in ISO10534-2, Beijing Shengshengsheng Co., Ltd. The low-frequency sound absorption coefficient of the sample measured by the produced SW260 impedance tube is above 0.32, and the maximum sound absorption coefficient is above 0.97.

Example 5

A preparation method of nanofiber foam-based sound-absorbing material, the specific steps are:

The first step: Activate the surface of the nanofiber foam by using the magnetic field-induced self-assembly method. The magnetic field generator used in the magnetic field-induced self-assembly method is PEM-80AC constant stability produced by Litian Magnetic Technology Co., Ltd., Mianyang City, Sichuan Province A magnetic field generator, the magnetic field strength is 1.5T, the activation modifier is Fe ₃ O ₄ nanoparticles, the diameter is 20-200nm; the self-assembly method is to immerse the magnetized nanofibers in the Fe ₃ O ₄ nano particle suspension 40 min; the volume density of the nanofiber foam is 25 mg/cm ³ , the average pore diameter is 10 μm, and the specific surface area is 1000 m ² /g; the nanofiber foam is a nanofiber foam with uniform overall density.

The second step: under the conditions of a temperature of 33°C and a pressure of 8×10 ⁶ Pa, the nanofiber foam obtained in the previous step is treated with a mixture of supercritical carbon dioxide fluid, an adhesive agent and surface roughness modified particles, and then Reduce the pressure to 1.01×10 ⁵ Pa to desorb the supercritical carbon dioxide fluid from the nanofiber foam, so that the adhesive agent and surface roughness modified particles are uniformly dispersed on the fiber surface; the supercritical carbon dioxide fluid is made of VW-6/ 2-6 The air-cooled carbon dioxide compressor compresses ultra-pure carbon dioxide gas to 7.39×10 ⁶ Pa and raises the temperature to 32°C; the adhesive is benzoxazine monomer, and the supercritical carbon dioxide fluid The mass fraction of the adhesive agent in the mixture with the adhesive agent and the surface roughness modified particles is 10%; the described surface roughness modified particles are graphene sheets with an average particle diameter of 10 μm, and the supercritical carbon dioxide fluid The mass fraction of the surface roughness modified particles in the mixture with the adhesive and the surface roughness modified particles is 20%;

The third step: use thermal cross-linking method to solidify and cross-link the adhesive agent, so that the surface roughness modified particles are closely combined on the surface of the fiber, and a secondary rough structure is constructed to obtain a composite three-dimensional nanofiber-based foam sound-absorbing material with excellent sound-absorbing performance; The temperature-programmed segmental thermal crosslinking method is to program the temperature at a heating rate of 5°C/min, and keep the temperature at 80°C, 100°C, 120°C, 160°C, 180°C, 200°C, and 220°C for 10 minutes, and the obtained The volume density of the nanofiber foam-based sound-absorbing material is 30mg/cm ³ .

The sound-absorbing material with a thickness of 5mm was used as the test sample, and based on the measurement method of "Measurement of Sound Absorption Coefficient and Acoustic Impedance in Acoustic Impedance Tube Part 2: Transfer Function Method" described in ISO10534-2, Beijing Shengshengsheng Co., Ltd. The low-frequency sound absorption coefficient of the sample measured by the produced SW260 impedance tube is above 0.34, and the maximum sound absorption coefficient is above 0.98.

Example 6

A preparation method of nanofiber foam-based sound-absorbing material, the specific steps are:

The first step: Activate the surface of the nanofiber foam by using the magnetic field-induced self-assembly method. The magnetic field generator used in the magnetic field-induced self-assembly method is PEM-80AC constant stability produced by Litian Magnetic Technology Co., Ltd., Mianyang City, Sichuan Province A magnetic field generator, the magnetic field strength is 1.5T, the activation modifier is Fe ₃ O ₄ nanoparticles, the diameter is 20-200nm; the self-assembly method is to immerse the magnetized nanofibers in the Fe ₃ O ₄ nano particle suspension 30 minutes; the volume density of the nanofiber foam is 35 mg/cm ³ , the average pore diameter is 10 μm, and the specific surface area is 2000 m ² /g; the nanofiber foam is a nanofiber foam with uniform overall density;

The second step: under the conditions of a temperature of 34°C and a pressure of 7.9×10 ⁶ Pa, the nanofiber foam obtained in the previous step is treated with a mixture of supercritical carbon dioxide fluid, adhesive agent and surface roughness modified particles, and then Reduce the pressure to 1.01×10 ⁵ Pa to desorb the supercritical carbon dioxide fluid from the nanofiber foam, so that the adhesive agent and surface roughness modified particles are uniformly dispersed on the fiber surface; the supercritical carbon dioxide fluid is made of VW-6/ 2-6 The air-cooled carbon dioxide compressor compresses ultra-pure carbon dioxide gas to 7.39×10 ⁶ Pa and raises the temperature to 32°C; the adhesive is benzoxazine monomer, and the supercritical carbon dioxide fluid The mass fraction of the adhesive in the mixture with the adhesive and the surface roughness modified particles is 1%; the surface roughness modified particles are graphene oxide sheets with an average particle diameter of 10 μm, and the supercritical carbon dioxide The mass fraction of the surface roughness modified particles in the mixture of the fluid, the adhesive agent and the surface roughness modified particles is 20%;

The third step: use thermal cross-linking method to solidify and cross-link the adhesive agent, so that the surface roughness modified particles are closely combined on the surface of the fiber, and a secondary rough structure is constructed to obtain a composite three-dimensional nanofiber-based foam sound-absorbing material with excellent sound-absorbing performance; The temperature-programmed segmental thermal crosslinking method is to program the temperature at a heating rate of 5°C/min, and keep the temperature at 80°C, 100°C, 120°C, 160°C, 180°C, 200°C, and 220°C for 10 minutes, and the obtained The volume density of the nanofiber foam-based sound-absorbing material is 40mg/cm ³ .

The sound-absorbing material with a thickness of 5mm was used as the test sample, and based on the measurement method of "Measurement of Sound Absorption Coefficient and Acoustic Impedance in Acoustic Impedance Tube Part 2: Transfer Function Method" described in ISO10534-2, Beijing Shengshengsheng Co., Ltd. The low-frequency sound absorption coefficient of the sample measured by the produced SW260 impedance tube is above 0.34, and the maximum sound absorption coefficient is above 0.99.

Example 7

A preparation method of nanofiber foam-based sound-absorbing material, the specific steps are:

Step 1: The surface of nanofiber foam is activated by solvent extraction and magnetic field-induced self-assembly method. First, the surface of nanofiber foam is activated by solvent extraction. The extraction solvent is dichloromethane, and the extraction time is is 30min, and the number of extractions is 3 times so that the surface soluble functional groups are removed by dichloromethane to form active sites; The magnetic field generator is a PEM-80AC constant magnetic field generator produced by Litian Magnetic Technology Co., Ltd. in Mianyang City, Sichuan Province. The magnetic field strength is 1.5T. The activation modifier is Fe ₃ O ₄ nanoparticles with a diameter of 20-200nm; The self-assembly method is to immerse magnetized nanofibers in Fe ₃ O ₄ nanoparticle suspension for 30 minutes; the nanofiber foam has a volume density of 18 mg/cm ³ , an average pore diameter of 10 μm, and a specific surface area of 2000 m ² /g; The nanofiber foam is a nanofiber foam with uniform overall density;

The second step: under the conditions of a temperature of 33°C and a pressure of 8×10 ⁶ Pa, the nanofiber foam obtained in the previous step is treated with a mixture of supercritical carbon dioxide fluid, an adhesive agent and surface roughness modified particles, and then Reduce the pressure to 1.01×10 ⁵ Pa to desorb the supercritical carbon dioxide fluid from the nanofiber foam, so that the adhesive agent and surface roughness modified particles are uniformly dispersed on the fiber surface; the supercritical carbon dioxide fluid is made of VW-6/ 2-6 The air-cooled carbon dioxide compressor compresses ultra-pure carbon dioxide gas to 7.39×10 ⁶ Pa and raises the temperature to 32°C; the adhesive is benzoxazine monomer, and the supercritical carbon dioxide fluid The mass fraction of the adhesive in the mixture of the adhesive and the surface roughness modified particles is 6%; the surface roughness modified particles are a mixture of graphene oxide sheets and Al ₂ O ₃ particles, and the super The average particle size of graphene oxide sheets in the mixture of critical carbon dioxide fluid, adhesive agent and surface roughness modified particles is 10 μm, and the mass fraction is 5%. The supercritical carbon dioxide fluid, adhesive agent and surface roughness modified particles Al ₂ O ₃ particles in the mixture, the particle size is 5 μm, the mass fraction is 10%,

The third step: use thermal cross-linking method to solidify and cross-link the adhesive agent, so that the surface roughness modified particles are closely combined on the surface of the fiber, and a secondary rough structure is constructed to obtain a composite three-dimensional nanofiber-based foam sound-absorbing material with excellent sound-absorbing performance; The temperature-programmed segmental thermal crosslinking method is to program the temperature at a heating rate of 5°C/min, and keep the temperature at 80°C, 100°C, 120°C, 160°C, 180°C, 200°C, and 220°C for 10 minutes, and the obtained The bulk density of the nanofiber foam-based sound-absorbing material is 20mg/cm ³ .

The sound-absorbing material with a thickness of 5mm was used as the test sample, and based on the measurement method of "Measurement of Sound Absorption Coefficient and Acoustic Impedance in Acoustic Impedance Tube Part 2: Transfer Function Method" described in ISO10534-2, Beijing Shengshengsheng Co., Ltd. The low-frequency sound absorption coefficient of the sample measured by the produced SW260 impedance tube is above 0.32, and the maximum sound absorption coefficient is above 0.97.

Example 8

A preparation method of nanofiber foam-based sound-absorbing material, the specific steps are:

Step 1: The surface of the nanofiber foam is activated by the composite modification method of vapor phase growth method and magnetic field induced self-assembly method. First, the surface of the nanofiber foam is activated by the vapor phase growth method. Iron is the catalyst, high-purity nitrogen is the protective gas, the treatment temperature is 250°C, and the treatment time is 1 hour; then the nanofiber foam obtained above is treated by the magnetic field-induced self-assembly method, and the magnetic field used in the magnetic field-induced self-assembly method is The generator is a PEM-80AC constant magnetic field generator produced by Litian Magnetic Technology Co., Ltd. in Mianyang City, Sichuan Province. The magnetic field strength is 1.5T. The activation modifier is Fe ₃ O ₄ nanoparticles with a diameter of 20-200nm; The self-assembly method is to immerse magnetized nanofibers in Fe ₃ O ₄ nanoparticle suspension for 30 minutes; the nanofiber foam has a volume density of 8 mg/cm ³ , an average pore diameter of 10 μm, and a specific surface area of 2000 m ² /g; The nanofiber foam is a nanofiber foam with uniform overall density;

The second step: under the conditions of a temperature of 34°C and a pressure of 7.8×10 ⁶ Pa, the nanofiber foam obtained in the previous step is treated with a mixture of supercritical carbon dioxide fluid, adhesive agent and surface roughness modified particles, and then Reduce the pressure to 1.01×10 ⁵ Pa to desorb the supercritical carbon dioxide fluid from the nanofiber foam, so that the adhesive agent and surface roughness modified particles are uniformly dispersed on the fiber surface; the supercritical carbon dioxide fluid is made of VW-6/ 2-6 The air-cooled carbon dioxide compressor compresses ultra-pure carbon dioxide gas to 7.39×10 ⁶ Pa and raises the temperature to 32°C; the adhesive is benzoxazine monomer, and the supercritical carbon dioxide fluid The massfraction of adhesive agent in the mixture with adhesive agent and surface roughness modified particle is 7%; Described surface roughness modified particle is graphene oxide sheet and Fe ₃ O ₄ the mixture of nanoparticle, described The average particle size of graphene oxide sheets in the mixture of supercritical carbon dioxide fluid, adhesive agent and surface roughness modified particles is 10 μm, and the mass fraction is 10%. The supercritical carbon dioxide fluid, adhesive agent and surface roughness modified Al ₂ O ₃ particles in the mixture of particles, the particle size is 5 μm, and the mass fraction is 5%;

The third step: use thermal cross-linking method to solidify and cross-link the adhesive agent, so that the surface roughness modified particles are closely combined on the surface of the fiber, and a secondary rough structure is constructed to obtain a composite three-dimensional nanofiber-based foam sound-absorbing material with excellent sound-absorbing performance; The temperature-programmed segmental thermal crosslinking method is to program the temperature at a heating rate of 5°C/min, and keep the temperature at 80°C, 100°C, 120°C, 160°C, 180°C, 200°C, and 220°C for 10 minutes, and the obtained The volume density of the nanofiber foam-based sound-absorbing material is 10mg/cm ³ .

The sound-absorbing material with a bulk density of 10mg/cm ³ and a thickness of 5mm is used as the test sample, based on the measurement method described in ISO10534-2 "Measurement of Sound Absorption Coefficient and Acoustic Impedance in Acoustic Impedance Tube Part 2: Transfer Function Method" , The low-frequency sound absorption coefficient of the sample was measured by using the SW260 impedance tube produced by Beijing Shengwangsheng Co., Ltd. to be above 0.3, and the maximum sound absorption coefficient was above 0.95.

Example 9

A preparation method of nanofiber foam-based sound-absorbing material, the specific steps are:

Step 1: The surface of the nanofiber foam is activated by the composite modification method of vapor phase growth method and magnetic field induced self-assembly method. First, the surface of the nanofiber foam is activated by the vapor phase growth method. Iron is the catalyst, high-purity nitrogen is the protective gas, the treatment temperature is 250°C, and the treatment time is 1 hour; then the nanofiber foam obtained above is treated by the magnetic field-induced self-assembly method, and the magnetic field used in the magnetic field-induced self-assembly method is The generator is a PEM-80AC constant magnetic field generator produced by Litian Magnetic Technology Co., Ltd. in Mianyang City, Sichuan Province. The magnetic field strength is 1.5T. The activation modifier is Fe ₃ O ₄ nanoparticles with a diameter of 20-200nm; The self-assembly method is to immerse magnetized nanofibers in Fe ₃ O ₄ nanoparticle suspension for 30 minutes; the nanofiber foam has a volume density of 30 mg/cm ³ , an average pore diameter of 10 μm, and a specific surface area of 2000 m ² /g; The nanofiber foam is a nanofiber foam with uniform overall density;

The second step: under the conditions of temperature of 33°C and pressure of 7.7×10 ⁶ Pa, the nanofiber foam obtained in the previous step is treated with a mixture of supercritical carbon dioxide fluid, adhesive agent and surface roughness modified particles, and then Reduce the pressure to 1.01×10 ⁵ Pa to desorb the supercritical carbon dioxide fluid from the nanofiber foam, so that the adhesive agent and surface roughness modified particles are uniformly dispersed on the fiber surface; the supercritical carbon dioxide fluid is made of VW-6/ 2-6 The air-cooled carbon dioxide compressor compresses ultra-pure carbon dioxide gas to 7.39×10 ⁶ Pa and raises the temperature to 32°C; the adhesive is benzoxazine monomer, and the supercritical carbon dioxide fluid The massfraction of adhesive agent in the _mixture with adhesive agent and surface roughness modified particle is 6%; Described surface roughness modified particle is the mixture of iron particle, graphene oxide sheet and _Al2O3 particle, so The diameter of the iron particles in the mixture of the supercritical carbon dioxide fluid, the adhesive agent and the surface roughness modified particles is 5 μm, and the mass fraction is 4%, the average particle diameter of the graphene oxide sheet is 10 μm, and the mass fraction is 5%, Al ₂ O ₃ particles with a particle size of 5 μm and a mass fraction of 10%;

The third step: use thermal cross-linking method to solidify and cross-link the adhesive agent, so that the surface roughness modified particles are closely combined on the surface of the fiber, and a secondary rough structure is constructed to obtain a composite three-dimensional nanofiber-based foam sound-absorbing material with excellent sound-absorbing performance; The temperature-programmed segmental thermal crosslinking method is to program the temperature at a heating rate of 5°C/min, and keep the temperature at 80°C, 100°C, 120°C, 160°C, 180°C, 200°C, and 220°C for 10 minutes, and the obtained The volume density of the nanofiber foam-based sound-absorbing material is 40mg/cm ³ .

The sound-absorbing material with a thickness of 5mm was used as the test sample, and based on the measurement method of "Measurement of Sound Absorption Coefficient and Acoustic Impedance in Acoustic Impedance Tube Part 2: Transfer Function Method" described in ISO10534-2, Beijing Shengshengsheng Co., Ltd. The low-frequency sound absorption coefficient of the sample measured by the produced SW260 impedance tube is above 0.34, and the maximum sound absorption coefficient is above 0.99.

Example 10

A preparation method of nanofiber foam-based sound-absorbing material, the specific steps are:

Step 1: The surface of the nanofiber foam is activated by the composite modification method of vapor phase growth method, magnetic field induced self-assembly method and hydrothermal growth method. Firstly, the surface of the nanofiber foam is activated by the vapor phase growth method. Carbon source, ferrocene as a catalyst, high-purity nitrogen as a protective gas, the treatment temperature is 250 ° C, and the treatment time is 1 hour; then the nanofiber foam obtained in the previous step is treated by a magnetic field-induced self-assembly method, and the magnetic field-induced The magnetic field generator used in the self-assembly method is the PEM-80AC constant magnetic field generator produced by Litian Magnetoelectric Technology Co., Ltd., Mianyang City, Sichuan Province. The magnetic field strength is 1.5T, and the activation modifier is Fe ₃ O ₄ nanoparticles. 20-200nm; the self-assembly method is to immerse the magnetized nanofibers in the Fe ₃ O ₄ nanoparticle suspension for 30 minutes; finally, the nanofiber foam obtained in the previous step is treated by the hydrothermal growth method, wherein the hydrothermal growth method The solution used is a glucose solution with a mass fraction of 5%, the heating temperature is 200°C, the pressure is 10MPa, and the treatment time is 2 hours; the volume density of the nanofiber foam is 4mg/cm ³ , the average pore diameter is 20μm, and the specific surface area is 2000m ² /g; the nanofiber foam is a nanofiber foam material whose overall density changes gradiently along the thickness direction;

The second step: under the conditions of a temperature of 32°C and a pressure of 7.5×10 ⁶ Pa, the nanofiber foam obtained in the previous step is treated with a mixture of supercritical carbon dioxide fluid, adhesive agent and surface roughness modified particles, and then Reduce the pressure to 1.01×10 ⁵ Pa to desorb the supercritical carbon dioxide fluid from the nanofiber foam, so that the adhesive agent and surface roughness modified particles are uniformly dispersed on the fiber surface; the supercritical carbon dioxide fluid is made of VW-6/ 2-6 The air-cooled carbon dioxide compressor compresses ultra-pure carbon dioxide gas to 7.39×10 ⁶ Pa and raises the temperature to 32°C; the adhesive is benzoxazine monomer, and the supercritical carbon dioxide fluid The massfraction of adhesive agent in the _mixture with adhesive agent and surface roughness modified particle is 6%; Described surface roughness modified particle is the mixture of iron particle, graphene oxide sheet and _Al2O3 particle, so The diameter of the iron particles in the mixture of the supercritical carbon dioxide fluid, the adhesive agent and the surface roughness modified particles is 5 μm, and the mass fraction is 4%, the average particle diameter of the graphene oxide sheet is 10 μm, and the mass fraction is 5%, Al ₂ The particle size of _O3 particles is 5 μm, and the mass fraction is 10%;

The third step: use thermal cross-linking method to solidify and cross-link the adhesive agent, so that the surface roughness modified particles are closely combined on the surface of the fiber, and a secondary rough structure is constructed to obtain a composite three-dimensional nanofiber-based foam sound-absorbing material with excellent sound-absorbing performance; The temperature-programmed segmental thermal crosslinking method is to program the temperature at a heating rate of 5°C/min, and keep the temperature at 80°C, 100°C, 120°C, 160°C, 180°C, 200°C, and 220°C for 10 minutes, and the obtained The bulk density of the nanofiber foam-based sound-absorbing material is 5mg/cm ³ .

The sound-absorbing material with a thickness of 5mm was used as the test sample, and based on the measurement method of "Measurement of Sound Absorption Coefficient and Acoustic Impedance in Acoustic Impedance Tube Part 2: Transfer Function Method" described in ISO10534-2, Beijing Shengshengsheng Co., Ltd. The low-frequency sound absorption coefficient of the sample measured by the produced SW260 impedance tube is above 0.25, and the maximum sound absorption coefficient is above 0.92.

Claims (9)

1. A preparation method for nanofiber foam-based sound-absorbing material, characterized in that, the specific steps include: The first step: activate the nanofiber foam surface; The second step: under the conditions of temperature 32℃～35℃ and pressure 7.39×10 ⁶ Pa～8.0×10 ⁶ Pa, the mixture of supercritical carbon dioxide fluid, adhesive agent and surface roughness modified particles is used for the previous step The obtained nanofiber foam is processed, and then the pressure is reduced to desorb the supercritical carbon dioxide fluid from the nanofiber foam, so that the adhesive agent and surface roughness modified particles are uniformly dispersed on the surface of the fiber; The third step: using thermal cross-linking method to cure and cross-link the adhesive agent, so that the surface roughness modified particles are combined on the surface of the fiber to obtain a nanofiber foam-based sound-absorbing material. 2. The preparation method of nanofiber foam-based sound-absorbing material according to claim 1, characterized in that, the nanofiber foam is a three-dimensional network-shaped material formed by interpenetrating and interlacing nanofibers. 3. The preparation method of nanofiber foam-based sound-absorbing material according to claim 1, characterized in that the volume density of the nanofiber foam is 0.1-50 mg/cm ³ , the pore diameter is 0.01-10 μm, and the specific surface area is 10 ~2000m ² /g. 4. The preparation method of nanofiber foam-based sound-absorbing material as claimed in claim 1, characterized in that, said nanofiber foam is a nanofiber foam material with uniform overall density, or a nanofiber whose density uniformly changes along the thickness direction The foam or nanofibrous foam has a density gradient along the thickness. 5. The preparation method of nanofiber foam-based sound-absorbing material as claimed in claim 1, characterized in that, the activation treatment method is: alkali reduction method, solvent extraction method, hydrothermal growth method, vapor phase growth method and magnetic field One or more combinations of induced self-assembly methods. 6. the preparation method of nanofiber foam-based sound-absorbing material as claimed in claim 1, is characterized in that, described adhesive is benzoxazine monomer, and described supercritical carbon dioxide fluid and adhesive and surface roughness The mass fraction of the adhesive in the mixture of modified particles is 0.01-10%. 7. The preparation method of nanofiber foam-based sound-absorbing material as claimed in claim 1, wherein the surface roughness modified particles are metal particles, metal oxide particles, inorganic non-metal oxide particles, organic nano A combination of one or more of crystal particles, graphene sheets and graphene oxide sheets; the average particle size of the surface roughness modified particles is 0.002-100 μm, and the supercritical carbon dioxide fluid and adhesive and The mass fraction of the surface roughness modified particles in the mixture of surface roughness modified particles is 0.1-20%. 8. The method for preparing a nanofiber foam-based sound-absorbing material according to claim 1, wherein the thermal cross-linking is a segmented thermal cross-linking method with temperature programming. 9 . The preparation method of nanofiber foam-based sound-absorbing material according to claim 1 , characterized in that, the volume density of the nanofiber foam-based sound-absorbing material is 0.2-60 mg/cm ³ .