CN113929964A - Preparation method of 5G waveband aerogel and polymer interpenetrating wave-absorbing material - Google Patents
Preparation method of 5G waveband aerogel and polymer interpenetrating wave-absorbing material Download PDFInfo
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- H05K9/0073—Shielding materials
- H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
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Abstract
The invention discloses a preparation method of a 5G waveband aerogel and polymer interpenetrating wave-absorbing material, which comprises the following steps: firstly, preparing a carbon nano tube/graphene/chitosan mixed dispersion liquid, then filling the mixed dispersion liquid into polyurethane open-cell foam under a vacuum condition, then forming hydrogel in the open-cell foam by the mixed dispersion liquid through a freeze-thaw method, and finally obtaining the 5G waveband aerogel and polymer interpenetrating wave-absorbing material through low-temperature freezing, sublimation drying and post-treatment in sequence.
Description
Technical Field
The invention relates to a preparation method of a 5G waveband aerogel and polymer interpenetrating wave-absorbing material, belonging to the technical field of wave-absorbing materials.
Background
With the rapid development of new-generation information communication technologies such as 5G technology, artificial intelligence, internet of things and the like and the large-scale popularization of electronic equipment, the problems of electromagnetic pollution, electromagnetic compatibility and the like caused by the rapid development are valued by governments and manufacturing enterprises of various countries. The living environment, the device working environment, the military electromagnetic environment and the like of human beings put forward higher requirements on the electromagnetic protection of equipment, and the research and development and the application of the wave-absorbing material of the 5G frequency band become vital.
In recent years, carbon-based electromagnetic shielding and wave absorbing materials are rapidly developed. Compared with metal materials, the carbon-based material has the advantages of light weight, chemical corrosion resistance, high temperature resistance, easiness in processing and the like, and is an ideal material for preparing light, thin and high-performance wave-absorbing materials. The carbon-based aerogel is a porous carbon material with high specific surface area and high porosity, which is prepared from carbon materials such as graphene and carbon nanotubes by a template method or a self-assembly method. Currently, the most predominant method for preparing carbon-based aerogels is the freeze-drying method. The freeze-drying method has the advantage that materials with different porous structures can be obtained by controlling the freezing mode of the solution.
Chinese patent CN109851284A proposes a preparation method of a multi-component composite aerogel material. According to the preparation method, firstly, a graphene/NiO compound is subjected to ultrasonic dispersion in water to prepare turbid liquid, then soluble alginate is added, the obtained mixed solution is poured into a mold for freeze drying after vigorous stirring, and then the freeze-dried block material is placed into a curing agent solution for curing and then is further subjected to freeze drying to obtain the multi-element composite aerogel material.
Chinese patent CN113086965A proposes a preparation method of a chitosan-based nitrogen-doped aerogel wave-absorbing material. In this patent, chitosan is first dissolved in a dilute acetic acid solvent to obtain a chitosan precursor solution. And then pouring the chitosan precursor solution into a chill casting mold for directional chill casting, and freeze-drying after the chill casting is finished to obtain the chitosan aerogel. And finally, carbonizing the chitosan aerogel to obtain the chitosan-based nitrogen-doped carbon aerogel.
Chinese patent CN113148996A provides a preparation method of a three-dimensional porous graphene aerogel wave-absorbing material. Firstly, respectively measuring a graphene oxide aqueous solution, a reducing agent and an antifreeze agent, and obtaining a mixed solution after magnetic stirring and ultrasonic dispersion; transferring the mixed solution into a glass bottle, sealing and placing the glass bottle in an oven for pre-reduction to obtain pre-reduced graphene hydrogel; freezing the pre-reduced graphene hydrogel, and then thawing at room temperature to obtain the pre-reduced graphene hydrogel after freeze thawing; sealing the pre-reduced graphene hydrogel subjected to freeze thawing, placing the pre-reduced graphene hydrogel in an oven for continuous reduction to obtain graphene hydrogel; and (3) putting the graphene hydrogel into an ethanol/water mixed solution for aging, and freeze-drying to obtain the three-dimensional graphene oxide aerogel. However, the document needs to be subjected to two times of reduction treatment, and the hydrogel needs to be aged in an ethanol/water mixed solution for a certain time, so that the defects of long time and complex operation exist.
The method can be seen that the existing carbon-based aerogel wave-absorbing material is designed only aiming at the wave-absorbing performance of the material, and the defects that the aerogel has poor mechanical strength and is difficult to deal with a complex stress environment are not considered.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provides a preparation method of a 5G waveband aerogel and polymer interpenetrating wave-absorbing material, and the prepared composite material has good wave-absorbing performance and excellent mechanical property.
The technical scheme adopted by the invention is as follows:
a preparation method of 5G waveband aerogel and polymer interpenetrating wave-absorbing material comprises the following steps:
step one, preparing a carbon nanotube/graphene/chitosan mixed dispersion liquid: adding reduced graphene oxide into a chitosan acetic acid solution, performing ultrasonic dispersion, adding carbon nanotubes, and performing mechanical stirring and ultrasonic dispersion to be uniform to obtain a carbon nanotube/graphene/chitosan mixed dispersion solution;
step two, preparing the mixed dispersion filled foam material: placing the polymer open-cell foam into the mixed dispersion liquid obtained in the step one, and filling the mixed dispersion liquid into the open-cell foam through vacuum degassing, and then recovering the normal pressure;
step three, preparing the hydrogel filling foam material by a freeze-thaw method: freezing and unfreezing the mixed dispersion filling foam material obtained in the step two at a low temperature in sequence to obtain a hydrogel filling foam material;
step four, preparing the aerogel filling foam material: sequentially freezing the hydrogel filling foam composite material obtained in the step three at a low temperature, and carrying out sublimation drying to obtain an aerogel filling foam material;
and step five, carrying out aftertreatment on the aerogel filling foam material: and D, recovering the aerogel filling foam material obtained in the step four to a normal temperature and normal pressure state after vacuum heat treatment, and obtaining the 5G waveband aerogel and polymer interpenetrating wave-absorbing material.
The polymeric open-cell foam is a polyurethane open-cell foam.
Further, a preparation method of the 5G waveband aerogel and polymer interpenetrating wave-absorbing material comprises the following steps:
step one, preparing a carbon nanotube/graphene/chitosan mixed dispersion liquid: adding reduced graphene oxide into a chitosan acetic acid solution, performing ultrasonic dispersion for 10min, and then adding carbon nanotubes into the solution, and performing mechanical stirring for 5-10 min and ultrasonic dispersion for 10-30 min in sequence to uniformly disperse the carbon nanotubes to obtain a carbon nanotube/graphene/chitosan mixed dispersion solution;
step two, preparing the mixed dispersion filled foam material: placing the mixed dispersion liquid obtained in the step one into an unsealed container, placing the cut polyurethane open-cell foam into the mixed dispersion liquid, degassing in a vacuum container to fill the mixed dispersion liquid into the open-cell foam, and then recovering the normal pressure;
step three, preparing the hydrogel filling foam material by a freeze-thaw method: freezing the mixed dispersion filling foam material prepared in the step two at low temperature, and thawing the mixed dispersion filling foam material at room temperature after the mixed dispersion filling foam material is completely frozen to form hydrogel in the mixed dispersion filling foam material to obtain hydrogel filling foam material;
step four, preparing the aerogel filling foam material: freezing the hydrogel filling foam composite material prepared in the third step again at a low temperature, transferring the hydrogel filling foam composite material to a freeze dryer for sublimation and drying for 1-5 days after the hydrogel filling foam composite material is completely frozen until ice in the material is completely sublimated, and obtaining an aerogel filling foam material;
and step five, carrying out aftertreatment on the aerogel filling foam material: and (4) carrying out heat treatment on the aerogel filling foam material obtained in the fourth step for 0.5-3 h under the vacuum condition at the temperature of 80-100 ℃, and recovering to the normal temperature and normal pressure state after the heat treatment is finished, so as to obtain the 5G waveband aerogel and polymer interpenetrating wave-absorbing material.
The reduced graphene oxide is obtained by chemically reducing graphene oxide.
The chitosan acetic acid solution is prepared by using acetic acid as a solvent and chitosan as a solute, wherein the concentration of the chitosan is 1-10 mg/mL.
The concentration of the carbon nano tubes in the mixed dispersion liquid is 1-5 mg/mL.
The mass ratio of the carbon nanotubes to the reduced graphene oxide in the carbon nanotube/graphene/chitosan mixed dispersion liquid is 5: 1-1: 1, and the mass ratio of the carbon nanotubes to the chitosan is 1: 5-2: 1.
The temperature of the low-temperature freezing in the third step is lower than-10 ℃.
And step four, the low-temperature freezing temperature is lower than-40 ℃.
The 5G wave band aerogel prepared by the method of any one of claims 1 to 5 and the polymer interpenetrating wave-absorbing material are applied to absorbing electromagnetic wave signals in a 5G mobile communication frequency band.
The invention has the beneficial effects that:
the material prepared by the method has excellent electromagnetic wave absorption performance and excellent mechanical property.
The method is simple and easy to implement, the manufacturing conditions are easy to control, and the dispersion liquid filled in the polyurethane pores forms hydrogel through a freeze-thaw method, so that the filling rate of the dispersion liquid in the open-pore foam is improved, and the sedimentation of the nano particles in the freezing process is effectively avoided. And the freezing-sublimation is combined to generate the aerogel, the hydrogel aging process is not needed, the flow is greatly saved, and the operation requirement is reduced. In the conventional method, however, it is impossible to form a dispersion of a carbon material into hydrogel inside polymer cells by a freeze-thaw method because: the aqueous dispersion of the carbon material can be used for producing hydrogel only by the steps of in-situ thermal reduction, solvent exchange or aging and the like; and the steps of thermal reduction, solvent exchange or aging, etc. cannot be omitted in the conventional method because the conventional method requires formation of a network structure of gel by means of self-assembly during thermal reduction of a carbon material or solvent exchange; by adjusting the proportion of the carbon nano tube, the graphene and the chitosan and selecting proper concentration, the method for promoting the formation of the carbon material gel network in the freezing process is realized, the aging steps are reduced, and the high-efficiency generation of the carbon material hydrogel is realized.
Drawings
FIG. 1 is a flow chart of a preparation process of 5G wave band aerogel and polymer interpenetrating wave-absorbing material;
FIG. 2 is a scanning electron microscope photograph of the 5G waveband aerogel and polymer interpenetrating wave-absorbing material in example 1;
FIG. 3 is a scanning electron microscope photograph with high magnification of the 5G wave band aerogel and polymer interpenetrating wave-absorbing material in example 1;
FIG. 4 is a 100-cycle compressive stress-strain curve of the 5G wave band aerogel and polymer interpenetrating wave-absorbing material under 40% strain in example 1.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The invention provides a preparation method of a 5G waveband aerogel and polymer interpenetrating wave-absorbing material, which comprises the following steps:
step S1: preparing a carbon nano tube/graphene/chitosan mixed dispersion liquid: dispersing reduced graphene oxide in 1-10 mg/mL chitosan acetic acid solution for 10min under the action of ultrasound, then adding carbon nanotubes into the solution to enable the concentration of the carbon nanotubes to be 1-5 mg/mL, controlling the mass ratio of the carbon nanotubes to the reduced graphene oxide in the dispersion to be 5: 1-1: 1 and the mass ratio of the carbon nanotubes to the chitosan to be 1: 5-2: 1, and then mechanically stirring for 5-10 min and ultrasonically dispersing for 10-30 min to uniformly disperse the carbon nanotubes/graphene/chitosan mixed dispersion to obtain the carbon nanotube/graphene/chitosan mixed dispersion;
step S2: preparation of mixed dispersion filled foam: placing the mixed dispersion liquid obtained in the step S1 in an unsealed container, placing the cut polyurethane open-cell foam in the mixed dispersion liquid, degassing in a vacuum container to fill the mixed dispersion liquid into the polyurethane open-cell foam, and then recovering the normal pressure;
the material type, density, pore size, mechanical strength and other performance indexes of the polyurethane open-cell foam are randomly selected according to actual requirements, for example, soft, semi-hard or hard polyurethane open-cell foam can be selected based on the consideration of mechanical properties;
step S3: preparing a hydrogel filling foam material by a freeze-thaw method: freezing the polyurethane open-cell foam filled with the mixed dispersion liquid obtained in the step S2 at a low temperature, and thawing the polyurethane open-cell foam at room temperature after the polyurethane open-cell foam is completely frozen to form hydrogel from the mixed dispersion liquid filled in the polyurethane open-cell foam to obtain a hydrogel filling foam material;
the temperature of the refrigerant or freezing environment used for the low-temperature freezing is lower than-10 ℃, otherwise, hydrogel cannot be obtained;
step S4: preparation of aerogel-filled foam: freezing the hydrogel filling foam material obtained in the step S3 again at low temperature, transferring the hydrogel filling foam material to a freeze dryer for sublimation and drying for 1-5 days after the hydrogel filling foam material is completely frozen, and completely sublimating ice in the material;
the temperature of the refrigerant or the freezing environment used for low-temperature freezing is lower than-40 ℃, otherwise the aperture and the wave-absorbing performance of the aerogel are influenced; the freeze dryer should be able to provide a minimum vacuum of 20kPa below atmospheric pressure.
Step S5: post-treatment of aerogel-filled foam: and (5) carrying out heat treatment on the aerogel filling foam material obtained in the step S4 for 0.5-3 h at 80-100 ℃ under a vacuum condition, and recovering to a normal temperature and normal pressure state after the heat treatment is finished to obtain the 5G waveband aerogel and polymer interpenetrating wave-absorbing material.
Example 1
Step one, 1g of reduced graphene oxide is placed in 500mL of chitosan acetic acid solution with the concentration of 5mg/mL for ultrasonic dispersion for 10min, 2.5g of carbon nano tube is added after uniform dispersion, and the mixture is mechanically stirred for 10min and ultrasonically dispersed for 30min in sequence to be uniformly dispersed, so that carbon nano tube/graphene/chitosan mixed dispersion liquid is obtained;
step two, preparing the mixed dispersion filled foam material: placing the mixed dispersion liquid obtained in the first step into an unsealed container, and cutting the mixed dispersion liquid into pieces with the size of 20mm multiplied by 20mm and the density of 5.0 multiplied by 10-2g/cm3Placing the soft polyurethane open-cell foam in the mixed dispersion, degassing in a vacuum container for 30min to fill the mixed dispersion into the open-cell foam, and then recovering normal pressure;
step three, preparing the hydrogel filling foam material by a freeze-thaw method: placing the mixed dispersion filling foam material obtained in the step two in liquid nitrogen at the temperature of less than or equal to-10 ℃ for low-temperature freezing for 3min, transferring to a room temperature environment after the mixed dispersion filling foam material is completely frozen, and slowly melting the ice crystals in the mixed dispersion filling foam material to form hydrogel, thus obtaining the hydrogel filling foam material;
step four, preparing the aerogel filling foam material: placing the hydrogel filling foam material obtained in the third step on a metal plate with the bottom immersed in liquid nitrogen, freezing for 5min at the temperature of less than or equal to-40 ℃, and transferring to a freeze dryer for sublimation drying for 2 days;
and step five, carrying out aftertreatment on the aerogel filling foam material: and (4) carrying out heat treatment on the aerogel filling foam material obtained in the fourth step for 3 hours at the temperature of 95 ℃ under a vacuum condition, and recovering to a normal-temperature normal-pressure state after the heat treatment is finished, so as to obtain the 5G waveband aerogel and polymer interpenetrating wave-absorbing material.
The density of the 5G wave band aerogel and polymer interpenetrating wave-absorbing material is 6.2 multiplied by 10 < -2 > G/cm3Adopting two-probe method to pass through Jishili 2400 digitsThe average volume conductivity measured by a source meter is 7.8S/m, the wave-absorbing performance test is carried out by adopting a waveguide method through Agilent N5234A, and the maximum absorption loss of the electromagnetic waves in two frequency ranges of 8-12 GHz and 26.5-40 GHz is-21.5 dB and-20.0 dB respectively; the compressive strength of the material at 40% strain was 40.0KPa after 100 cycles of compression at 40% strain under the Instron 3365 Universal Material testing machine using the test standards GB/T8813-2020.
FIG. 2 is a scanning electron microscope photograph of the 5G waveband aerogel and polymer interpenetrating wave-absorbing material in example 1, from which the pore structure of the aerogel can be clearly observed and is in a completely filled state in the polyurethane pores;
FIG. 3 is a scanning electron microscope photograph with high magnification of the 5G waveband aerogel and polymer interpenetrating wave-absorbing material in example 1, from which the aerogel wall formed by the carbon nanotubes in the rolled state can be seen, and many pulled single carbon nanotubes can be observed at the fracture;
fig. 4 is a 100-cycle compressive stress-strain curve of the 5G waveband aerogel and polymer interpenetrating wave-absorbing material in example 1 under 40% strain, and it can be seen that the obtained material has excellent resilience.
Example 2
Step one, placing 1.25g of reduced graphene oxide in 500mL of chitosan acetic acid solution with the concentration of 5mg/mL for ultrasonic dispersion for 10min, adding 1.25g of carbon nano tubes after uniform dispersion, and sequentially mechanically stirring for 10min and ultrasonically dispersing for 15min to uniformly disperse the carbon nano tubes, the graphene and the chitosan to obtain a carbon nano tube/graphene mixed dispersion solution;
step two, preparing the mixed dispersion filled foam material: placing the mixed dispersion liquid obtained in the first step into an unsealed container, and cutting the mixed dispersion liquid into pieces with the size of 20mm multiplied by 20mm and the density of 5.0 multiplied by 10-2g/cm3Placing the soft polyurethane open-cell foam in the mixed dispersion, degassing in a vacuum container for 30min to fill the mixed dispersion into the open-cell foam, and then recovering normal pressure;
step three, preparing the hydrogel filling foam material by a freeze-thaw method: placing the mixed dispersion filling foam material obtained in the step two in liquid nitrogen at the temperature of less than or equal to-10 ℃ for low-temperature freezing for 3min, transferring to a room temperature environment after the mixed dispersion filling foam material is completely frozen, and slowly melting the ice crystals in the mixed dispersion filling foam material to form hydrogel, thus obtaining the hydrogel filling foam material;
step four, preparing the aerogel filling foam material: placing the hydrogel filling foam material obtained in the third step on a metal plate with the bottom immersed in liquid nitrogen, freezing for 5min at the temperature of less than or equal to-40 ℃, and transferring to a freeze dryer for sublimation drying for 2 days;
step five, carrying out aftertreatment on the aerogel/foam material: and (4) carrying out heat treatment on the aerogel filling foam material obtained in the fourth step for 3 hours at the temperature of 95 ℃ under a vacuum condition, and recovering to a normal-temperature normal-pressure state after the heat treatment is finished, so as to obtain the 5G waveband aerogel and polymer interpenetrating wave-absorbing material.
The density of the 5G wave band aerogel and polymer interpenetrating wave-absorbing material is 5.9 multiplied by 10-2g/cm3The average volume conductivity is 4.6S/m, and the maximum absorption loss of the electromagnetic waves in two frequency ranges of 8-12 GHz and 26.5-40 GHz is-14.8 dB and-15.6 dB respectively; after 100 cycles of compression at 40% strain, the material had a compressive strength of 40.0KPa at 40% strain.
Example 3
Step one, 1g of reduced graphene oxide is placed in 500mL of chitosan acetic acid solution with the concentration of 2mg/mL for ultrasonic dispersion for 10min, 1g of carbon nano tube is added after uniform dispersion, and the mixture is mechanically stirred for 5min and ultrasonically dispersed for 10min in sequence to be uniformly dispersed, so that carbon nano tube/graphene/chitosan mixed dispersion liquid is obtained;
step two, preparing the mixed dispersion filled foam material: placing the mixed dispersion liquid obtained in the first step into an unsealed container, and cutting into pieces with the size of 20mm multiplied by 20mm and the density of 0.30g/cm3Placing the semi-rigid polyurethane open-cell foam into the mixed dispersion, degassing in a vacuum container for 30min to fill the mixed dispersion into the open-cell foam, and then recovering normal pressure;
step three, preparing the hydrogel filling foam material by a freeze-thaw method: placing the mixed dispersion filling foam material obtained in the step two in liquid nitrogen at the temperature of less than or equal to-10 ℃ for low-temperature freezing for 3min, transferring to a room temperature environment after the mixed dispersion filling foam material is completely frozen, and slowly melting the ice crystals in the mixed dispersion filling foam material to form hydrogel, thus obtaining the hydrogel filling foam material;
step four, preparing the aerogel filling foam material: placing the hydrogel filling foam material obtained in the third step on a metal plate with the bottom immersed in liquid nitrogen, freezing for 5min at the temperature of less than or equal to-40 ℃, and transferring to a freeze dryer for sublimation drying for 2 days;
and step five, carrying out aftertreatment on the aerogel filling foam material: and (4) carrying out heat treatment on the aerogel filling foam material obtained in the fourth step for 1h under the vacuum condition at the temperature of 90 ℃, and recovering to the normal temperature and normal pressure state after the heat treatment is finished, thus obtaining the 5G waveband aerogel and polymer interpenetrating wave-absorbing material.
The density of the 5G wave band aerogel and polymer interpenetrating wave-absorbing material is 0.30G/cm3The average volume conductivity is 6.4S/m, and the maximum absorption loss of the electromagnetic waves in two frequency ranges of 8-12 GHz and 26.5-40 GHz is-16.2 dB and-17.4 dB respectively; after 100 cycles of compression at 40% strain, the material had a compressive strength of 212KPa at 40% strain.
Example 4
Step one, 1g of reduced graphene oxide is placed in 500mL of chitosan acetic acid solution with the concentration of 10mg/mL for ultrasonic dispersion for 10min, 2.5g of carbon nano tube is added after uniform dispersion, and the mixture is mechanically stirred for 10min and ultrasonically dispersed for 30min to be uniformly dispersed, so that carbon nano tube/graphene/chitosan mixed dispersion liquid is obtained;
step two, preparing the mixed dispersion filled foam material: placing the mixed dispersion liquid obtained in the first step into an unsealed container, and cutting into pieces with the size of 20mm multiplied by 20mm and the density of 0.30g/cm3Placing the semi-rigid polyurethane open-cell foam into the mixed dispersion, degassing in a vacuum container for 30min to fill the mixed dispersion into the open-cell foam, and then recovering normal pressure;
step three, preparing the hydrogel filling foam material by a freeze-thaw method: placing the mixed dispersion filling foam material obtained in the step two in liquid nitrogen at the temperature of less than or equal to-10 ℃ for low-temperature freezing for 3min, transferring to a room temperature environment after the mixed dispersion filling foam material is completely frozen, and slowly melting the ice crystals in the mixed dispersion filling foam material to form hydrogel, thus obtaining the hydrogel filling foam material;
step four, preparing the aerogel filling foam material: placing the hydrogel filling foam material obtained in the third step on a metal plate with the bottom immersed in liquid nitrogen, freezing for 5min at the temperature of less than or equal to-40 ℃, and transferring to a freeze dryer for sublimation drying for 2 days;
and step five, carrying out aftertreatment on the aerogel filling foam material: and (4) carrying out heat treatment on the aerogel filling foam material obtained in the fourth step for 3 hours at the temperature of 95 ℃ under a vacuum condition, and recovering to a normal-temperature normal-pressure state after the heat treatment is finished, so as to obtain the 5G waveband aerogel and polymer interpenetrating wave-absorbing material.
The density of the 5G wave band aerogel and polymer interpenetrating wave-absorbing material is 0.31G/cm3The average volume conductivity is 6.9S/m, and the maximum absorption loss of the electromagnetic waves in two frequency ranges of 8-12 GHz and 26.5-40 GHz is-18.2 dB and-19.5 dB respectively; after 100 cycles of compression at 40% strain, the material had a compressive strength of 218KPa at 40% strain.
Claims (9)
1. A preparation method of 5G waveband aerogel and polymer interpenetrating wave-absorbing material is characterized by comprising the following steps:
step one, preparing a carbon nanotube/graphene/chitosan mixed dispersion liquid: adding reduced graphene oxide into a chitosan acetic acid solution, performing ultrasonic dispersion, adding carbon nanotubes, and performing mechanical stirring and ultrasonic dispersion to be uniform to obtain a carbon nanotube/graphene/chitosan mixed dispersion solution;
step two, preparing the mixed dispersion filled foam material: placing the polymer open-cell foam into the mixed dispersion liquid obtained in the step one, and filling the mixed dispersion liquid into the open-cell foam through vacuum degassing, and then recovering the normal pressure;
step three, preparing the hydrogel filling foam material by a freeze-thaw method: freezing and unfreezing the mixed dispersion filling foam material obtained in the step two at a low temperature in sequence to obtain a hydrogel filling foam material;
step four, preparing the aerogel filling foam material: sequentially freezing the hydrogel filling foam material obtained in the step three at a low temperature, sublimating and drying to obtain an aerogel filling foam material;
and step five, carrying out aftertreatment on the aerogel filling foam material: and D, recovering the aerogel filling foam material obtained in the step four to a normal temperature and normal pressure state after vacuum heat treatment, and obtaining the 5G waveband aerogel and polymer interpenetrating wave-absorbing material.
2. The method for preparing the 5G waveband aerogel and polymer interpenetrating wave-absorbing material of claim 1, wherein the polymer open-cell foam is polyurethane open-cell foam.
3. The preparation method of the 5G waveband aerogel and polymer interpenetrating wave-absorbing material as claimed in claim 1, comprising the following steps:
step one, preparing a carbon nanotube/graphene/chitosan mixed dispersion liquid: adding reduced graphene oxide into a chitosan acetic acid solution, performing ultrasonic dispersion for 10min, and then adding carbon nanotubes into the solution, and performing mechanical stirring for 5-10 min and ultrasonic dispersion for 10-30 min in sequence to uniformly disperse the carbon nanotubes to obtain a carbon nanotube/graphene/chitosan mixed dispersion solution;
step two, preparing the mixed dispersion filled foam material: placing the mixed dispersion liquid obtained in the step one into an unsealed container, placing the cut polyurethane open-cell foam into the mixed dispersion liquid, degassing in a vacuum container to fill the mixed dispersion liquid into the open-cell foam, and then recovering the normal pressure;
step three, preparing the hydrogel filling foam material by a freeze-thaw method: freezing the mixed dispersion filling foam material prepared in the step two at low temperature, and thawing the mixed dispersion filling foam material at room temperature after the mixed dispersion filling foam material is completely frozen to form hydrogel in the mixed dispersion filling foam material to obtain hydrogel filling foam material;
step four, preparing the aerogel filling foam material: freezing the hydrogel filling foam material prepared in the third step again at a low temperature, transferring the hydrogel filling foam material to a freeze dryer for sublimation and drying for 1-5 days after the hydrogel filling foam material is completely frozen until ice in the material is completely sublimated to obtain an aerogel filling foam material;
and step five, carrying out aftertreatment on the aerogel filling foam material: and (4) carrying out heat treatment on the aerogel filling foam material obtained in the fourth step for 0.5-3 h under the vacuum condition at the temperature of 80-100 ℃, and recovering to the normal temperature and normal pressure state after the heat treatment is finished, so as to obtain the 5G waveband aerogel and polymer interpenetrating wave-absorbing material.
4. The preparation method of the 5G waveband aerogel and polymer interpenetrating wave-absorbing material as claimed in claim 1 or 3, wherein the chitosan acetic acid solution is prepared by taking acetic acid as a solvent and chitosan as a solute, wherein the concentration of the chitosan is 1-10 mg/mL.
5. The preparation method of the 5G waveband aerogel and polymer interpenetrating wave-absorbing material as claimed in claim 1 or 3, wherein the concentration of the carbon nanotubes in the mixed dispersion liquid is 1-5 mg/mL.
6. The preparation method of the 5G waveband aerogel and polymer interpenetrating wave-absorbing material as claimed in claim 1 or 3, wherein the mass ratio of the carbon nanotubes to the reduced graphene oxide in the carbon nanotube/graphene/chitosan mixed dispersion liquid is 5: 1-1: 1, and the mass ratio of the carbon nanotubes to the chitosan is 1: 5-2: 1.
7. The preparation method of the 5G waveband aerogel and polymer interpenetrating wave-absorbing material as claimed in claim 1 or 3, wherein the low-temperature freezing temperature in the third step is lower than-10 ℃.
8. The preparation method of the 5G waveband aerogel and polymer interpenetrating wave-absorbing material as claimed in claim 1 or 3, wherein the low-temperature freezing temperature in the fourth step is lower than-40 ℃.
9. The application of the 5G waveband aerogel prepared by the method of any one of claims 1 to 8 and the polymer interpenetrating wave-absorbing material in absorbing electromagnetic wave signals of a 5G mobile communication frequency band.
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| CN114804078A (en) * | 2022-03-18 | 2022-07-29 | 安徽建筑大学 | Polydicyclopentadiene-based carbon nanotube/graphene nanosheet aerogel flame-retardant electromagnetic shielding composite material and preparation method thereof |
| CN115109313A (en) * | 2022-07-09 | 2022-09-27 | 南通恒光大聚氨酯材料有限公司 | Preparation method of special auxiliary agent for polyurethane sponge based on increase of tensile force |
| CN116322007A (en) * | 2023-02-23 | 2023-06-23 | 之江实验室 | NiFe-CNTs-RGO composite aerogel material with three-dimensional interconnected pore structure, and preparation method and application thereof |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114804078A (en) * | 2022-03-18 | 2022-07-29 | 安徽建筑大学 | Polydicyclopentadiene-based carbon nanotube/graphene nanosheet aerogel flame-retardant electromagnetic shielding composite material and preparation method thereof |
| CN114804078B (en) * | 2022-03-18 | 2023-07-04 | 安徽建筑大学 | Poly-dicyclopentadienyl carbon nano tube/graphene nano sheet aerogel flame-retardant electromagnetic shielding composite material and preparation method thereof |
| CN115109313A (en) * | 2022-07-09 | 2022-09-27 | 南通恒光大聚氨酯材料有限公司 | Preparation method of special auxiliary agent for polyurethane sponge based on increase of tensile force |
| CN116322007A (en) * | 2023-02-23 | 2023-06-23 | 之江实验室 | NiFe-CNTs-RGO composite aerogel material with three-dimensional interconnected pore structure, and preparation method and application thereof |
| CN116322007B (en) * | 2023-02-23 | 2023-12-29 | 之江实验室 | NiFe-CNTs-RGO composite aerogel material with three-dimensional interconnected pore structure, and preparation method and application thereof |
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