WO2022242256A1 - Light-weight porous mxene-based composite thin film electromagnetic shielding material and preparation method therefor - Google Patents

Light-weight porous mxene-based composite thin film electromagnetic shielding material and preparation method therefor Download PDF

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WO2022242256A1
WO2022242256A1 PCT/CN2022/077223 CN2022077223W WO2022242256A1 WO 2022242256 A1 WO2022242256 A1 WO 2022242256A1 CN 2022077223 W CN2022077223 W CN 2022077223W WO 2022242256 A1 WO2022242256 A1 WO 2022242256A1
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mxene
preparation
dispersion
electromagnetic shielding
thin film
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French (fr)
Chinese (zh)
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王子成
刘天西
唐新伟
曹国洋
李双双
张亚伟
胡志伟
鲁士杰
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江南大学
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0073—Shielding materials
    • H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A30/00—Adapting or protecting infrastructure or their operation

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  • the invention relates to a lightweight porous MXene-based composite thin-film electromagnetic shielding material and a preparation method thereof, and belongs to the technical field of thin-film electromagnetic shielding materials and preparation thereof.
  • Electromagnetic shielding material as a functional protective material that effectively isolates incident electromagnetic waves by means of reflection loss outside the material and absorption loss inside the material, has been widely used in the field of electromagnetic protection.
  • the problems of electromagnetic leakage and interference in electrical equipment have become increasingly prominent. Therefore, people put forward higher performance requirements for electromagnetic shielding materials, requiring them to be thin, light, wide, and strong.
  • MXene is gradually becoming a class of electromagnetic shielding materials with very competitive advantages due to its ultra-high electrical conductivity, easy processing and low cost, and has attracted extensive attention.
  • the high density also results in less multiple scattering/reflection losses of electromagnetic waves inside the material, which is not conducive to the improvement of electromagnetic shielding effectiveness. Oxidation also leads to a decrease in its electrical conductivity, which reduces the electromagnetic shielding performance.
  • foaming agents to assist in the construction of the internal pore structure of MXene, the pore structure is often uneven due to problems such as dispersion, and it will also have a certain impact on the conductivity and stability of MXene.
  • the present invention provides a light porous MXene-based composite thin film electromagnetic shielding material and its preparation method, the purpose is to overcome the compactness inside the current MXene thin film, which is not conducive to multiple scattering/reflection of electromagnetic waves inside the thin film material, thus causing There are disadvantages such as poor absorption of electromagnetic waves inside the film.
  • high-temperature annealing treatment can effectively remove MXene surface groups, thereby achieving the purpose of improving the stability of MXene and increasing the durability of electromagnetic shielding materials.
  • the present invention firstly provides a kind of preparation method of lightweight porous MXene-based composite thin film electromagnetic shielding material, said method comprising:
  • MXene/GO dispersion Disperse MXene and GO (graphene oxide) in water to obtain a dispersion of MXene and GO, add a cationic surface modifier to the MXene dispersion and remove excess cationic surface by high-speed centrifugation After the modifier, the prepared positively charged MXene dispersion is prepared by mixing the positively charged MXene dispersion with the GO dispersion to obtain the MXene/GO dispersion;
  • step (2) Preparation of M/rGO thin film: the dispersion of MXene/GO obtained in step (1) was drop-coated on the polymer base sheet, dried at low temperature to remove moisture, and then the MXene/GO composite film was obtained from the sheet, and then The obtained MXene/GO composite film was annealed to obtain the M/rGO composite film.
  • the size of the precursor MAX used to prepare MXene is 200 to 400 meshes, and MXene is prepared by etching the MAX phase, and the etching solution is hydrochloric acid (HCl) and A mixture of lithium fluoride (LiF).
  • HCl hydrochloric acid
  • LiF lithium fluoride
  • step (1) after in-situ etching of MAX with HCl and LiF, single-layer or few-layer Mxene (Ti 3 C 2 T X ) is obtained by ultrasonic stripping, and the MXene The concentration of the dispersion is 2-10mg/mL.
  • step (1) the size of the original flake graphite used to prepare graphene oxide is 100-400 mesh, and the GO powder is prepared by the improved Hummers method, and the concentration of the GO dispersion is Control in 2 ⁇ 10mg/mL.
  • the GO accounts for 5-15% of the total mass of MXene and GO.
  • the positively charged MXene dispersion described in step (1) is specifically prepared by the following method: adding an excessive amount of cationic surface modifier in the MXene dispersion and passing through multiple high-speed Centrifugal washing removes excess cationic surface modifier, and then takes the sludge-like slurry at the bottom of centrifugation and adds water to disperse to obtain a positively charged MXene dispersion.
  • the cationic surface modifier described in step (1) is any one of polyethyleneimine, dopamine, 2,5-dimercapto-134-thiadiazole, etc. or several.
  • the speed of the high-speed centrifugation in step (1) is 8000-12000 r/min
  • the centrifugation time is 0.5-2 h
  • the centrifugation frequency is 2-5 times.
  • magnetic stirring is required when preparing the MXene/GO dispersion in step (1), the magnetic stirring time is 6-10 hours, and the magnetic stirring speed is 400-800r/min; The concentration of the MXene/GO dispersion is 2-10 mg/mL.
  • step (2) the low-temperature drying is carried out under vacuum, the temperature is 40-60°C, the drying time is 3-10h; the vacuum degree of the vacuum oven is -0.08-0.1MPa .
  • the polymer-based sheet is polyethylene terephthalate (PET), polystyrene (PS), polyvinyl chloride (PVC), Any one of polycarbonate (PC), etc., with a thickness of 0.1 to 1 mm.
  • the gas atmosphere used in the annealing treatment is hydrogen-argon mixed gas, wherein the hydrogen volume ratio is 5% to 20%, and the annealing temperature is 800°C to 1000°C, The time is 0.5-2 hours.
  • the second object of the present invention is to provide a lightweight porous MXene-based composite thin film electromagnetic shielding material prepared by the above preparation method.
  • the third object of the present invention is to provide aerospace devices, military equipment or precision electronic instruments comprising the above-mentioned lightweight porous MXene-based composite thin film electromagnetic shielding material.
  • the fourth object of the present invention is to provide the application of the above-mentioned lightweight porous MXene-based composite thin film electromagnetic shielding material in the field of electromagnetic protection.
  • the applications include applications in electromagnetic protection fields such as aerospace, military equipment, and precision electronic instruments.
  • the preparation method of the present invention is easy to operate and environmentally friendly.
  • the present invention realizes self-assembly by utilizing electrostatic interaction force to prepare MXene/GO dispersion liquid, and obtains MXene/GO nanocomposite film by vacuum drying in a vacuum oven.
  • High-temperature annealing treatment under argon mixed gas to obtain a porous MXene-based composite film with ultra-high specific efficiency.
  • GO is evenly dispersed in the interlayer of MXene.
  • CO 2 , CO and other gases will be generated during the high-temperature treatment of GO.
  • rGO reduced graphene oxide
  • the introduction of rGO with relatively low conductivity can cooperate with MXene heat treatment products to construct a gradient gradient structure of impedance, thereby improving the absorption capacity of the composite material for incident electromagnetic waves, providing an efficient preparation of lightweight porous ultra-high specific efficiency electromagnetic New approach to shielding composite films;
  • the present invention constructs a porous structure inside the composite film, so that the incident electromagnetic wave can be efficiently attenuated when it enters the material, and the shielding effect of the electromagnetic wave can cover the entire X-band.
  • the introduction of the porous structure makes the density of the composite material greatly reduced while maintaining the electromagnetic shielding performance.
  • the composite film material prepared by the present invention has excellent electromagnetic shielding performance and specific performance. When the thickness is only 15 ⁇ m, the porous MXene-based composite film obtained by adding 5wt% graphene oxide can maintain more than 49dB of electromagnetic shielding in the entire X-band.
  • Shielding efficiency, and the specific efficiency can reach 51551dB cm 2 g -1 on average.
  • the density is only 0.41g cm -3 under the condition that the electromagnetic shielding efficiency declines very little (>44dB).
  • the performance has reached 72316dB cm 2 g -1 , far exceeding similar materials.
  • the preparation process is simple and easy to operate, and is expected to be applied to fields requiring electromagnetic shielding, such as aerospace, military equipment, microelectronic equipment, and civilian electrical appliances.
  • the present invention uses a cationic surface modifier to modify the negatively charged MXene.
  • the modified MXene is positively charged and can be self-sustained with negatively charged GO nanosheets. assembly to achieve the purpose of uniform compounding.
  • the cationic surface modifier can be further decomposed into CO, CO 2 and other gases at high temperatures. While contributing to the generation of pore structures, the composite film after annealing is not Containing the cationic surface modifying agent can maintain the electrical conductivity of the composite film and contribute to the improvement of electromagnetic shielding performance.
  • the present invention is based on the principle that polar groups are unstable at high temperatures. Due to the existence of a large number of polar functional groups (-OH, -F, -O-, etc.) in MXene, it has good dispersibility and also To make the stability worse, the MXene/GO nanocomposite film is placed in a hydrogen-argon mixed gas environment for high-temperature heat treatment, and the polar groups in MXene are removed so that the heat-treated MXene/rGO nanocomposite film has better stability in the air. stability. At the same time, the presence of hydrogen can further reduce the oxidized part of MXene, so that the conductivity of MXene can be further recovered, which is helpful to improve the electromagnetic shielding performance.
  • polar functional groups -OH, -F, -O-, etc.
  • Figure 1 is a schematic diagram of the electromagnetic shielding mechanism of lightweight porous MXene-based composite films.
  • Figure 2(a) is a comparison of the conductivity of MXene and MXene (MX) after high temperature annealing and M-rG5 in air with time and the initial conductivity
  • Figure 2(b) is after 12 months in air Electromagnetic shielding performance comparison of M-rG5 before and after.
  • FIG. 3 are the scanning electron microscope images of the lightweight porous MXene-based composite film before and after high-temperature annealing, respectively.
  • Figure 4 shows the electrical conductivity diagrams of MX, M-rG0, M-rG5, M-rG10, M-rG15, and rGO after annealing at 800°C.
  • Figure 5 is the electromagnetic shielding effectiveness diagram of M-rG5 when the thickness is 15 ⁇ m.
  • Fig. 6 is an electromagnetic shielding effectiveness diagram of M-rG5, M-rG10, and M-rG15 when the thickness is 15 ⁇ m.
  • Figure 7 is the density and specific performance diagrams of M-rG5, M-rG10, and M-rG15 when the thickness is 15 ⁇ m.
  • Agilent E5063A vector network analyzer is used to measure the S parameters of the composite film by waveguide method in the frequency range of 8.2-12.4GHz.
  • MXene Dissolve 2g LiF in a hydrochloric acid solution prepared by 10mL water and 30mL concentrated hydrochloric acid by magnetic stirring in a polytetrafluoroethylene beaker, then add 2g 400 mesh aluminum carbon titanium oxide (Ti 3 AlC 2 ,MAX) powder, and The reactor was placed in a water bath at 35° C. and kept stirring for 24 hours, and then washed with absolute ethanol and ultrapure water by ultrasonication and centrifugation several times to remove residual impurities. The obtained MXene dispersion was freeze-dried for later use.
  • a hydrochloric acid solution prepared by 10mL water and 30mL concentrated hydrochloric acid by magnetic stirring in a polytetrafluoroethylene beaker
  • MXene/GO dispersion Dissolve 133mg of MXene in an appropriate amount of water, disperse MXene evenly after ultrasonic and magnetic stirring, then add 5mL of 50% polyethyleneimine aqueous solution, mix well after fully stirring, after 1.5h 11000r After high-speed centrifugation at /min, remove the sediment from the lower layer, and then continue to add an appropriate amount of ultrapure water to disperse evenly. Mix well under stirring, and name it as M-G5 dispersion.
  • Preparation of MXene/GO film Take 5mL of the MXene/GO dispersion obtained in step (1), drop-coat it on a polyethylene terephthalate (PET) sheet leveled by a leveler, and vacuum it in a vacuum oven. Drying at a vacuum degree of -0.08MPa and a temperature of 50°C. After drying for 10 hours, the film was peeled off from the PET sheet to obtain a MXene/GO composite film, which was named M-G5 film.
  • PET polyethylene terephthalate
  • porous MXene-based composite film The MXene/GO composite film obtained above was subjected to high-temperature annealing treatment in a hydrogen-argon mixed gas atmosphere, wherein the volume ratio of hydrogen gas was 10%, the high-temperature annealing treatment temperature was 800 ° C, and the time was 30 minutes to obtain porous MXene Based composite film, named M-rG5 film.
  • Dissolve 126mg of MXene in an appropriate amount of ultrapure water After ultrasonic and magnetic stirring, the MXene is uniformly dispersed. Then add 4.7mL of 50% polyethyleneimine aqueous solution. After fully stirring, it is dispersed evenly and placed in a high-speed centrifuge After 1.5h 11000r/min high-speed centrifugation, remove the lower layer of sediment, and then continue to add ultrapure water to disperse evenly. After repeating 4 times, add 25mL ultrapure water, and then add 2mL 7mg/mL graphene oxide that has been evenly dispersed by ultrasonic stirring The dispersion liquid was mixed evenly under magnetic stirring, and it was named M-G10 dispersion liquid.
  • Preparation of MXene/GO film Take 5mL of the MXene/GO dispersion obtained in step (1), drop-coat it on a polyethylene terephthalate (PET) sheet leveled by a leveler, and vacuum it in a vacuum oven. Drying at a vacuum of -0.08MPa and a temperature of 50°C. After drying for 10 hours, the film was peeled off from the PET sheet to obtain an MXene/GO composite film, which was named M-G10 film.
  • PET polyethylene terephthalate
  • MXene-based composite film The MXene/GO composite film obtained above was subjected to high-temperature annealing treatment in a hydrogen-argon mixed gas atmosphere, wherein the volume ratio of hydrogen gas was 10%, the high-temperature annealing treatment temperature was 800 ° C, and the time was 30 minutes to obtain porous MXene Based composite film, named M-rG10 film.
  • Dissolve 119mg of MXene in an appropriate amount of ultrapure water After ultrasonic and magnetic stirring, the MXene is dispersed evenly. Then add 4.5mL of 50% polyethyleneimine aqueous solution. After fully stirring, it is dispersed evenly and placed in a high-speed centrifuge After 1.5h 11000r/min high-speed centrifugation, remove the lower layer of sediment, and then continue to add ultrapure water to disperse evenly. After repeating 4 times, add 24mL ultrapure water, and then add 3mL 7mg/mL graphene oxide that has been evenly dispersed by ultrasonic stirring The dispersion liquid was mixed evenly under magnetic stirring, and it was named M-G15 dispersion liquid.
  • MXene/GO film Get 5ml of the MXene/GO dispersion obtained in step (1), drop-coat it on a polyethylene terephthalate (PET) sheet leveled by a leveler, and vacuum it in a vacuum oven. Drying, the vacuum degree is -0.08MPa, and the temperature is 50°C. After drying, the film is peeled off from the PET sheet to obtain an MXene/GO composite film, which is named M-G15 film.
  • PET polyethylene terephthalate
  • porous MXene-based composite film The MXene/GO composite film obtained above was subjected to high-temperature annealing treatment in a hydrogen-argon mixed gas atmosphere, wherein the volume ratio of hydrogen gas was 10%, the high-temperature annealing treatment temperature was 800 ° C, and the time was 30 minutes to obtain porous MXene Based composite film, named M-rG15 film.
  • FIG. 1 is a schematic diagram of the electromagnetic shielding of the lightweight porous MXene-based composite film in this example.
  • the present invention uses electrostatic interaction as the driving force to realize the self-assembly between MXene and GO nanosheets, and obtains porous film formation and annealing treatment by casting MXene-based composite film, with graphene as the skeleton, MXene is uniformly loaded on the graphene skeleton, through the formation of porous structure inside the material to achieve the purpose of reducing the material density and improving the multiple scattering/reflection loss of electromagnetic waves inside the material, thereby increasing the composite Material electromagnetic shielding specific effectiveness.
  • the introduction of reduced graphene oxide can also cooperate with highly conductive MXene cracking products to construct a gradient structure of impedance gradient, thereby increasing the introduction and attenuation of electromagnetic waves by the composite material.
  • Figure 2 is a comparison chart of the electrical conductivity of MXene and MXene (MX) after high temperature annealing and M-rG5 in the air with time and the initial electrical conductivity, and a comparison chart of the electromagnetic shielding performance before and after being placed in the air for 12 months.
  • MX MXene
  • M-rG5 MXene
  • the present invention can significantly improve the stability of the composite film and MXene through high-temperature annealing treatment. Even after being placed in the air for 12 months, the electromagnetic shielding performance is still well maintained, mainly because high-temperature annealing can The effective removal of MXene surface active groups enhances the stability of MXene and increases the oxidation resistance of electromagnetic shielding materials.
  • Fig. 3 is the scanning electron microscope picture of M-G5 and M-rG5 in the embodiment 1
  • Fig. 3 (a) and Fig. 3 (b) are the scanning electron microscope picture before and after annealing respectively, it can be seen that after 800 °C, 0.5h After high-temperature annealing, the internal porous structure of the film is obvious, and the small sheets of MXene are evenly loaded on the sheets of reduced graphene oxide, forming a uniform internal structure.
  • Fig. 4 is the variation diagram of the electrical conductivity that produces along with the graphene oxide addition difference in embodiment 1,2 and 3, because the electrical conductivity of reduced graphene oxide is lower than MXene, along with the increase of graphene oxide addition, The conductivity showed a gradually decreasing trend.
  • Fig. 5 is the electromagnetic shielding performance diagram of the MXene-based composite film (M-rG5) when the graphene oxide addition amount is 5wt% in embodiment 1, when the film thickness is 15 ⁇ m, the electromagnetic shielding performance is all above 49dB, covering the whole X band. At 8.263GHz, the electromagnetic shielding effectiveness reaches a maximum value of 58.361dB.
  • Figure 6 is a comparison chart of the electromagnetic shielding effectiveness of M-rG5, M-rG10 and M-rG15 when the sample thickness is the same (15 ⁇ m) in Examples 1, 2 and 3. It can be seen that M-rG5 has the highest electromagnetic shielding effectiveness value.
  • the inside of the film becomes more fluffy, and the density decreases; also because the electromagnetic shielding efficiency gradually decreases with the increase of the graphene oxide content, but the final specific performance shows a completely opposite result, which is mainly attributed to the composite material with the The rate at which the density of the material decreases with increasing GO content is much higher than the rate at which the electromagnetic shielding effectiveness decreases.
  • Preparation of MXene/GO film Take 5mL of the MXene/GO dispersion obtained in step (1), drop-coat it on a polyethylene terephthalate (PET) sheet leveled by a leveler, and vacuum it in a vacuum oven. Drying, the vacuum degree is -0.08MPa, and the temperature is 50°C. After drying for 10 hours, the film is peeled off from the PET sheet to obtain the MXene/GO composite film.
  • PET polyethylene terephthalate
  • porous MXene-based composite film The MXene/GO composite film obtained above was subjected to high-temperature annealing treatment in a hydrogen-argon mixed gas atmosphere, wherein the hydrogen volume ratio was 20%, the high-temperature annealing treatment temperature was 900 ° C, and the time was 30 minutes to obtain porous MXene base composite film.
  • the electromagnetic shielding effect of the porous MXene-based composite film prepared in this example can cover the entire X-band, and the density of the composite material is greatly reduced while maintaining the electromagnetic shielding performance.
  • the composite film material prepared in this example has excellent Electromagnetic shielding effectiveness and specific effectiveness.
  • Preparation of MXene/GO film Take 5mL of the MXene/GO dispersion obtained in step (1), drop-coat it on a polystyrene (PS) sheet leveled by a leveler, and vacuum-dry it in a vacuum oven with a vacuum degree of - 0.08MPa, the temperature is 50°C, after drying for 10h, the film is peeled off from the PS sheet to obtain the MXene/GO composite film.
  • PS polystyrene
  • porous MXene-based composite film The MXene/GO composite film obtained above was subjected to high-temperature annealing treatment in a hydrogen-argon mixed gas atmosphere, wherein the volume ratio of hydrogen gas was 5%, the high-temperature annealing treatment temperature was 800 ° C, and the time was 60 minutes to obtain porous MXene base composite film.
  • the electromagnetic shielding performance of the porous MXene-based composite film prepared in this example is above 47.5 dB in the entire X-band.
  • the density (0.4g/cm 3 ) of the composite material is greatly reduced while maintaining the electromagnetic shielding performance.
  • the composite thin film material prepared in this embodiment has excellent electromagnetic shielding performance and specific performance.
  • Preparation of MXene/rGO composite film take the M-G5 film obtained in Example 1 and carry out high-temperature treatment under a hydrogen-argon mixed gas atmosphere, wherein the hydrogen volume ratio is 10%, the high-temperature annealing treatment temperature is 1000 ° C, and the time is 0.5h. After treatment, the brittleness of the composite film increases, but the electromagnetic shielding effect can still cover the entire X-band, and the electromagnetic shielding performance in the entire X-band is above 35dB.
  • the film was peeled off from the PET sheet to obtain MXene/GO
  • the composite film is subjected to high temperature treatment in a hydrogen-argon mixed gas atmosphere, wherein the hydrogen volume ratio is 10%, the high temperature annealing treatment temperature is 800°C, and the time is 0.5h. Due to the high concentration of the dispersion liquid, the viscosity is relatively high. The resulting film is thicker and has poor thickness uniformity.
  • the film was removed from the PET sheet to obtain the MXene/GO composite film, which was subjected to high-temperature treatment in a hydrogen-argon mixed gas atmosphere, wherein the hydrogen volume ratio was 10%, and the high-temperature annealing treatment temperature was 800 °C, and the time For 0.5h, due to the low concentration of dispersion liquid and low solid content, the obtained film is thinner (10 ⁇ m) and more brittle, and its electromagnetic shielding performance in the entire X-band is above 42dB
  • the M-G5 film was treated under hydrogen-argon mixed gas, in which the volume ratio of hydrogen gas was 10%, the high-temperature annealing treatment temperature was 800°C, and the time was 10min, 30min, and 60min respectively.
  • the electromagnetic shielding performance test was carried out on the M-rG5 composite film treated with different annealing times.
  • the M-rG5 composite film with an annealing time of 10 minutes has excellent electromagnetic shielding performance in the entire X-band, with an average of 52dB and a density of 0.97g/cm 3 ;
  • the M-rG5 composite film with an annealing time of 30min has excellent electromagnetic shielding performance in the entire X-band, with an average of 52dB and a density of 0.67g/cm 3 ;
  • the M-rG5 composite film with an annealing time of 60min has excellent electromagnetic shielding performance in the entire X-band It has excellent electromagnetic shielding performance, the average can reach 49dB, and the density is 0.4g/cm 3 .

Abstract

The present invention belongs to the technical field of thin film electromagnetic shielding materials and preparation therefor. Disclosed are a light-weight porous MXene-based composite thin film electromagnetic shielding material and a preparation method therefor. By means of the present invention, an electrostatic interaction force as a driving force is applied to MXene modified by means of a cationic surface modifier, and graphene oxide, so as to realize self-assembly of the MXene and the graphene oxide, and a light-weight porous MXene-based composite electromagnetic shielding material having ultra-high specific effectiveness is then obtained by means of casting into a film and high-temperature annealing. When the thickness of the composite thin film material in the present invention is only 15 μm, the porous MXene-based composite thin film can maintain electromagnetic shielding effectiveness of 49 dB or above across the entire X-band, and after 12 months, the electromagnetic shielding effectiveness is maintained to a great extent and is maintained at 47 dB or above across the entire X-band. The preparation process is simple and is easy to operate, and is expected to be applied to the fields of aerospace, military devices, miniature electronic devices, civil electric appliances, etc.

Description

一种轻质多孔MXene基复合薄膜电磁屏蔽材料及其制备方法A kind of lightweight porous MXene-based composite thin film electromagnetic shielding material and preparation method thereof 技术领域technical field
本发明涉及一种轻质多孔MXene基复合薄膜电磁屏蔽材料及其制备方法，属于薄膜电磁屏蔽材料及其制备技术领域。The invention relates to a lightweight porous MXene-based composite thin-film electromagnetic shielding material and a preparation method thereof, and belongs to the technical field of thin-film electromagnetic shielding materials and preparation thereof.
背景技术Background technique
随着信息技术的飞速发展，电子设备在日常生活中的应用也逐渐增多，电子设备在给人类生活带来便利的同时，也带来了一系列电磁干扰等问题，因此，迫切需要一种轻质高效的电磁屏蔽薄膜材料。With the rapid development of information technology, the application of electronic equipment in daily life is gradually increasing. While electronic equipment brings convenience to human life, it also brings a series of problems such as electromagnetic interference. Therefore, there is an urgent need for a light High-quality and efficient electromagnetic shielding film material.
电磁屏蔽材料作为一种以在材料外部的反射损耗和材料内部的吸收损耗方式对入射电磁波进行有效隔离的功能防护材料，在电磁防护领域获得了广泛的应用。同时，随着电子元器件的小型化和高度集成化程度越来越高，也使得电气设备中电磁泄露和干扰问题日益突出。因此，人们对于电磁屏蔽材料提出了更高的性能要求，要求其兼具薄、轻、宽、强的特性。MXene以其超高的电导率、易加工性能和低成本等特点正逐渐成为一类极具竞争优势的电磁屏蔽材料而受到广泛的关注。然而，对于常规密堆积结构的纯MXene薄膜材料来说，当入射电磁波(Electromagneticwave,EW)进入材料内部时，内部多重散射/反射较少，无法实现对进入材料内部电磁波进行有效的衰减。除此之外，传统的MXene薄膜材料因其结构中含有大量的极性官能团(-OH,-F,-O-等)使其稳定性较差，不利于在正常环境下应用，长时间暴露在空气中MXene极易发生氧化，导致导电性变差，使得电磁屏蔽性能快速衰退，严重影响电磁屏蔽材料的耐久性。Electromagnetic shielding material, as a functional protective material that effectively isolates incident electromagnetic waves by means of reflection loss outside the material and absorption loss inside the material, has been widely used in the field of electromagnetic protection. At the same time, with the increasing miniaturization and high integration of electronic components, the problems of electromagnetic leakage and interference in electrical equipment have become increasingly prominent. Therefore, people put forward higher performance requirements for electromagnetic shielding materials, requiring them to be thin, light, wide, and strong. MXene is gradually becoming a class of electromagnetic shielding materials with very competitive advantages due to its ultra-high electrical conductivity, easy processing and low cost, and has attracted extensive attention. However, for pure MXene thin film materials with a conventional close-packed structure, when the incident electromagnetic wave (Electromagnetic wave, EW) enters the material, there is less internal multiple scattering/reflection, and it is impossible to effectively attenuate the electromagnetic wave entering the material. In addition, the traditional MXene thin film material has poor stability due to the large number of polar functional groups (-OH, -F, -O-, etc.) in its structure, which is not conducive to application in normal environments. MXene is easily oxidized in the air, resulting in poor electrical conductivity, causing rapid decline in electromagnetic shielding performance and seriously affecting the durability of electromagnetic shielding materials.
发明内容Contents of the invention
【技术问题】【technical problem】
纯MXene薄膜由于内部密实不含孔结构，密度较大的同时也致使电磁波在材料内部发生的多重散射/反射损耗较少，从而不利于电磁屏蔽效能的提升，另外由于MXene在空气条件下容易发生氧化，也导致其电导率的下降，使得电磁屏蔽性能的降低。然而通过加入发泡剂等来辅助构造MXene内部孔结构，往往由于分散性等问题使其孔结构不均匀，同时也会对MXene的导电性与稳定性产生一定的影响。Due to the dense and non-porous structure inside the pure MXene film, the high density also results in less multiple scattering/reflection losses of electromagnetic waves inside the material, which is not conducive to the improvement of electromagnetic shielding effectiveness. Oxidation also leads to a decrease in its electrical conductivity, which reduces the electromagnetic shielding performance. However, by adding foaming agents to assist in the construction of the internal pore structure of MXene, the pore structure is often uneven due to problems such as dispersion, and it will also have a certain impact on the conductivity and stability of MXene.
【技术方案】【Technical solutions】
为解决上述问题，本发明提供了一种轻质多孔MXene基复合薄膜电磁屏蔽材料及其制备方法，目的在于克服当下MXene薄膜内部密实，不利于电磁波在薄膜材料内部进行多重散射/反射，从而造成在薄膜内部对电磁波的吸收较差等缺点，同时，高温退火处理能够对MXene 表面基团进行有效去除，从而达到提升MXene稳定性，增加电磁屏蔽材料耐久性的目的。In order to solve the above problems, the present invention provides a light porous MXene-based composite thin film electromagnetic shielding material and its preparation method, the purpose is to overcome the compactness inside the current MXene thin film, which is not conducive to multiple scattering/reflection of electromagnetic waves inside the thin film material, thus causing There are disadvantages such as poor absorption of electromagnetic waves inside the film. At the same time, high-temperature annealing treatment can effectively remove MXene surface groups, thereby achieving the purpose of improving the stability of MXene and increasing the durability of electromagnetic shielding materials.
具体的，本发明首先提供了一种轻质多孔MXene基复合薄膜电磁屏蔽材料的制备方法，所述方法包括：Concrete, the present invention firstly provides a kind of preparation method of lightweight porous MXene-based composite thin film electromagnetic shielding material, said method comprising:
(1)制备MXene/GO分散液：将MXene和GO(氧化石墨烯)分别分散在水中得到MXene和GO的分散液，在MXene分散液中加入阳离子表面改性剂经高速离心洗涤去除多余阳离子表面改性剂后，制备得到的带正电的MXene分散液，将带正电的MXene分散液与GO分散液混合后制备得到MXene/GO分散液；(1) Preparation of MXene/GO dispersion: Disperse MXene and GO (graphene oxide) in water to obtain a dispersion of MXene and GO, add a cationic surface modifier to the MXene dispersion and remove excess cationic surface by high-speed centrifugation After the modifier, the prepared positively charged MXene dispersion is prepared by mixing the positively charged MXene dispersion with the GO dispersion to obtain the MXene/GO dispersion;
(2)制备M/rGO薄膜：将步骤(1)得到的MXene/GO的分散液滴涂在高分子基薄板上，低温干燥去除水分，之后从薄板上揭取得到MXene/GO复合薄膜，然后将得到的MXene/GO复合薄膜进行退火处理，得到M/rGO复合薄膜。(2) Preparation of M/rGO thin film: the dispersion of MXene/GO obtained in step (1) was drop-coated on the polymer base sheet, dried at low temperature to remove moisture, and then the MXene/GO composite film was obtained from the sheet, and then The obtained MXene/GO composite film was annealed to obtain the M/rGO composite film.
在本发明的一种实施方式中，步骤(1)中，用于制备MXene的前驱体MAX的尺寸为200～400目，通过刻蚀MAX相来制备MXene，刻蚀液为盐酸(HCl)与氟化锂(LiF)的混合物。In one embodiment of the present invention, in step (1), the size of the precursor MAX used to prepare MXene is 200 to 400 meshes, and MXene is prepared by etching the MAX phase, and the etching solution is hydrochloric acid (HCl) and A mixture of lithium fluoride (LiF).
在本发明的一种实施方式中，步骤(1)中，采用HCl与LiF原位刻蚀MAX后，再通过超声剥离得到单层或少层Mxene(Ti 3C 2T X)，所述MXene分散液浓度为2-10mg/mL。 In one embodiment of the present invention, in step (1), after in-situ etching of MAX with HCl and LiF, single-layer or few-layer Mxene (Ti 3 C 2 T X ) is obtained by ultrasonic stripping, and the MXene The concentration of the dispersion is 2-10mg/mL.
在本发明的一种实施方式中，步骤(1)中，用于制备氧化石墨烯的原始鳞片石墨的尺寸为100～400目，通过改进的Hummers法制备得到GO粉末，所述GO分散液浓度控制在2～10mg/mL。In one embodiment of the present invention, in step (1), the size of the original flake graphite used to prepare graphene oxide is 100-400 mesh, and the GO powder is prepared by the improved Hummers method, and the concentration of the GO dispersion is Control in 2 ~ 10mg/mL.
在本发明的一种实施方式中，所述GO占MXene和GO总质量的5～15％。In one embodiment of the present invention, the GO accounts for 5-15% of the total mass of MXene and GO.
在本发明的一种实施方式中，步骤(1)中所述带正电的MXene分散液具体通过以下方法制备得到的：在MXene分散液中加入过量的阳离子表面改性剂并通过多次高速离心洗涤去除多余的阳离子表面改性剂，之后取离心后底部淤泥状浆料加入水分散后得到带正电的MXene分散液。In one embodiment of the present invention, the positively charged MXene dispersion described in step (1) is specifically prepared by the following method: adding an excessive amount of cationic surface modifier in the MXene dispersion and passing through multiple high-speed Centrifugal washing removes excess cationic surface modifier, and then takes the sludge-like slurry at the bottom of centrifugation and adds water to disperse to obtain a positively charged MXene dispersion.
在本发明的一种实施方式中，步骤(1)中所述的阳离子表面改性剂为聚乙烯亚胺、多巴胺、2,5-二巯基-1 3 4-噻二唑等中任一种或几种。In one embodiment of the present invention, the cationic surface modifier described in step (1) is any one of polyethyleneimine, dopamine, 2,5-dimercapto-134-thiadiazole, etc. or several.
在本发明的一种实施方式中，步骤(1)中所述高速离心的速率为8000～12000r/min，离心时间为0.5～2h，离心次数为2～5次。In one embodiment of the present invention, the speed of the high-speed centrifugation in step (1) is 8000-12000 r/min, the centrifugation time is 0.5-2 h, and the centrifugation frequency is 2-5 times.
在本发明的一种实施方式中，制备步骤(1)中MXene/GO的分散液时需进行磁力搅拌，所述磁力搅拌时间为6～10h，磁力搅拌速度为400～800r/min；所述的MXene/GO分散液浓度为2～10mg/mL。In one embodiment of the present invention, magnetic stirring is required when preparing the MXene/GO dispersion in step (1), the magnetic stirring time is 6-10 hours, and the magnetic stirring speed is 400-800r/min; The concentration of the MXene/GO dispersion is 2-10 mg/mL.
在本发明的一种实施方式中，步骤(2)中，所述低温干燥在真空下进行，温度为40～60 ℃，干燥时间为3～10h；真空烘箱真空度为-0.08～-0.1MPa。In one embodiment of the present invention, in step (2), the low-temperature drying is carried out under vacuum, the temperature is 40-60°C, the drying time is 3-10h; the vacuum degree of the vacuum oven is -0.08-0.1MPa .
在本发明的一种实施方式中，步骤(2)中，所述高分子基薄板为聚对苯二甲酸乙二醇酯(PET)、聚苯乙烯(PS)、聚氯乙烯(PVC)、聚碳酸酯(PC)等中的任一种，厚度为0.1～1mm。In one embodiment of the present invention, in step (2), the polymer-based sheet is polyethylene terephthalate (PET), polystyrene (PS), polyvinyl chloride (PVC), Any one of polycarbonate (PC), etc., with a thickness of 0.1 to 1 mm.
在本发明的一种实施方式中，步骤(2)中，所述退火处理所用的气体氛围为氢氩混合气，其中氢气体积比为5％～20％，退火温度为800℃～1000℃，时间为0.5～2h。In one embodiment of the present invention, in step (2), the gas atmosphere used in the annealing treatment is hydrogen-argon mixed gas, wherein the hydrogen volume ratio is 5% to 20%, and the annealing temperature is 800°C to 1000°C, The time is 0.5-2 hours.
本发明的第二个目的是提供上述制备方法制备得到的轻质多孔MXene基复合薄膜电磁屏蔽材料。The second object of the present invention is to provide a lightweight porous MXene-based composite thin film electromagnetic shielding material prepared by the above preparation method.
本发明的第三个目的是提供包含上述轻质多孔MXene基复合薄膜电磁屏蔽材料的航空航天装置、军事装备或精密电子仪器。The third object of the present invention is to provide aerospace devices, military equipment or precision electronic instruments comprising the above-mentioned lightweight porous MXene-based composite thin film electromagnetic shielding material.
本发明的第四个目的是提供上述轻质多孔MXene基复合薄膜电磁屏蔽材料在电磁防护领域中的应用。The fourth object of the present invention is to provide the application of the above-mentioned lightweight porous MXene-based composite thin film electromagnetic shielding material in the field of electromagnetic protection.
在本发明的一种实施方式中，所述应用包括在航空航天、军事装备、精密电子仪器等电磁防护领域中的应用。In one embodiment of the present invention, the applications include applications in electromagnetic protection fields such as aerospace, military equipment, and precision electronic instruments.
[有益效果]：[Beneficial effect]:
(1)本发明制备方法操作简单，绿色环保，本发明通过利用静电相互作用力实现自组装制备MXene/GO分散液，并在真空烘箱中真空干燥获得MXene/GO纳米复合薄膜，再通过在氢氩混合气下高温退火处理，获得超高比效能的多孔MXene基复合薄膜。GO均匀分散在MXene的层间，一方面，GO由于高温处理过程中，会产生CO 2、CO等气体，由于气体的胀开作用，使得薄膜内部孔状结构产生，MXene层间孔结构在赋予材料低密度的同时，其对于入射电磁波多重散射/反射效应也相应增加；另一方面，还原氧化石墨烯(rGO)可以充当骨架结构，对材料内部孔结构起到支撑作用，使得材料获得一定的力学强度和韧性。另外，相对于较低电导率的rGO的引入可以与MXene热处理产物协同构建阻抗渐变梯度结构，进而提高复合材料对于入射电磁波的吸收能力，提供了一种高效制备轻质多孔的超高比效能电磁屏蔽复合薄膜的新方法； (1) The preparation method of the present invention is easy to operate and environmentally friendly. The present invention realizes self-assembly by utilizing electrostatic interaction force to prepare MXene/GO dispersion liquid, and obtains MXene/GO nanocomposite film by vacuum drying in a vacuum oven. High-temperature annealing treatment under argon mixed gas to obtain a porous MXene-based composite film with ultra-high specific efficiency. GO is evenly dispersed in the interlayer of MXene. On the one hand, CO 2 , CO and other gases will be generated during the high-temperature treatment of GO. Due to the expansion of the gas, the internal pore structure of the film is formed, and the MXene interlayer pore structure is endowed While the material has a low density, its multiple scattering/reflection effects on incident electromagnetic waves also increase accordingly; on the other hand, reduced graphene oxide (rGO) can act as a skeleton structure to support the internal pore structure of the material, making the material obtain a certain Mechanical strength and toughness. In addition, the introduction of rGO with relatively low conductivity can cooperate with MXene heat treatment products to construct a gradient gradient structure of impedance, thereby improving the absorption capacity of the composite material for incident electromagnetic waves, providing an efficient preparation of lightweight porous ultra-high specific efficiency electromagnetic New approach to shielding composite films;
(2)本发明根据入射电磁波在材料内部进行多重散射/反射损耗衰减的原则，在复合薄膜内部构筑多孔结构，使入射电磁波在进入材料内部时能够进行高效衰减，并且电磁波的屏蔽效果可以覆盖整个X波段。与此同时，多孔结构的引入，在使得复合材料在保持电磁屏蔽性能的同时，密度也得到大幅度降低。本发明所制备得到的复合薄膜材料具有优异的电磁屏蔽效能和比效能，在厚度仅有15μm时，添加5wt％氧化石墨烯获得的多孔MXene基复合薄膜能够在整个X波段都保持49dB以上的电磁屏蔽效能，并且比效能平均可达到51551dB cm 2g -1，在添加15wt％氧化石墨烯时，在电磁屏蔽效能衰退极小(>44dB)的情况下，密度仅有 0.41g cm -3，比效能达到了72316dB cm 2g -1，远远超过同类材料。该制备过程简单易操作，有望应用于航空航天、军事装备、微型电子设备、民用电器等对电磁屏蔽有需求的领域。 (2) According to the principle of multiple scattering/reflection loss attenuation of the incident electromagnetic wave inside the material, the present invention constructs a porous structure inside the composite film, so that the incident electromagnetic wave can be efficiently attenuated when it enters the material, and the shielding effect of the electromagnetic wave can cover the entire X-band. At the same time, the introduction of the porous structure makes the density of the composite material greatly reduced while maintaining the electromagnetic shielding performance. The composite film material prepared by the present invention has excellent electromagnetic shielding performance and specific performance. When the thickness is only 15 μm, the porous MXene-based composite film obtained by adding 5wt% graphene oxide can maintain more than 49dB of electromagnetic shielding in the entire X-band. Shielding efficiency, and the specific efficiency can reach 51551dB cm 2 g -1 on average. When adding 15wt% graphene oxide, the density is only 0.41g cm -3 under the condition that the electromagnetic shielding efficiency declines very little (>44dB). The performance has reached 72316dB cm 2 g -1 , far exceeding similar materials. The preparation process is simple and easy to operate, and is expected to be applied to fields requiring electromagnetic shielding, such as aerospace, military equipment, microelectronic equipment, and civilian electrical appliances.
(3)本发明根据聚合物在高温下分解的原理，对带负电MXene使用阳离子表面改性剂进行改性，改性后的MXene带有正电，能够与带有负电的GO纳米片进行自组装，达到均匀复合的目的，另外，所述的阳离子表面改性剂在高温下能够进一步分解为CO、CO 2等气体，在有助于孔状结构产生的同时，退火后的复合薄膜由于不含有所述的阳离子表面改性剂，能够使得复合薄膜的电导率得到保持，有助于电磁屏蔽效能的提高。 (3) According to the principle of polymer decomposition at high temperature, the present invention uses a cationic surface modifier to modify the negatively charged MXene. The modified MXene is positively charged and can be self-sustained with negatively charged GO nanosheets. assembly to achieve the purpose of uniform compounding. In addition, the cationic surface modifier can be further decomposed into CO, CO 2 and other gases at high temperatures. While contributing to the generation of pore structures, the composite film after annealing is not Containing the cationic surface modifying agent can maintain the electrical conductivity of the composite film and contribute to the improvement of electromagnetic shielding performance.
(4)本发明根据极性基团在高温下不稳定的原则，由于MXene的存在大量的极性官能团(-OH,-F,-O-等)使其在具有较好分散性的同时也使得稳定性变差，将MXene/GO纳米复合薄膜置于氢氩混合气环境中进行高温热处理，除去MXene中的极性基团使得热处理后的MXene/rGO纳米复合薄膜在空气中具有较好的稳定性。同时，氢气的存在能使得MXene中被氧化的部分被进一步还原，使得MXene的电导率得到进一步的回复，有助于电磁屏蔽性能的提升。(4) The present invention is based on the principle that polar groups are unstable at high temperatures. Due to the existence of a large number of polar functional groups (-OH, -F, -O-, etc.) in MXene, it has good dispersibility and also To make the stability worse, the MXene/GO nanocomposite film is placed in a hydrogen-argon mixed gas environment for high-temperature heat treatment, and the polar groups in MXene are removed so that the heat-treated MXene/rGO nanocomposite film has better stability in the air. stability. At the same time, the presence of hydrogen can further reduce the oxidized part of MXene, so that the conductivity of MXene can be further recovered, which is helpful to improve the electromagnetic shielding performance.
附图说明Description of drawings
图1为轻质多孔MXene基复合薄膜电磁屏蔽机理示意图。Figure 1 is a schematic diagram of the electromagnetic shielding mechanism of lightweight porous MXene-based composite films.
图2(a)为MXene与高温退火后的MXene(MX)以及M-rG5在空气中随时间变化电导率与初始电导率的对比图，图2(b)为经过在空气中放置12个月前后的M-rG5的电磁屏蔽性能对比。Figure 2(a) is a comparison of the conductivity of MXene and MXene (MX) after high temperature annealing and M-rG5 in air with time and the initial conductivity, and Figure 2(b) is after 12 months in air Electromagnetic shielding performance comparison of M-rG5 before and after.
图3中(a)和(b)分别为轻质多孔MXene基复合薄膜高温退火前后的扫描电子显微镜图片。(a) and (b) in Fig. 3 are the scanning electron microscope images of the lightweight porous MXene-based composite film before and after high-temperature annealing, respectively.
图4中分别为MX、M-rG0、M-rG5、M-rG10、M-rG15、rGO在800℃退火后的电导率图。Figure 4 shows the electrical conductivity diagrams of MX, M-rG0, M-rG5, M-rG10, M-rG15, and rGO after annealing at 800°C.
图5为M-rG5在厚度为15μm时的电磁屏蔽效能图。Figure 5 is the electromagnetic shielding effectiveness diagram of M-rG5 when the thickness is 15 μm.
图6为M-rG5、M-rG10、M-rG15在厚度均为15μm时的电磁屏蔽效能图。Fig. 6 is an electromagnetic shielding effectiveness diagram of M-rG5, M-rG10, and M-rG15 when the thickness is 15 μm.
图7为M-rG5、M-rG10、M-rG15在厚度均为15μm时的密度和比效能图。Figure 7 is the density and specific performance diagrams of M-rG5, M-rG10, and M-rG15 when the thickness is 15 μm.
具体实施方式Detailed ways
下面结合具体实施例，进一步阐述本发明。应理解，这些实施例仅用于说明本发明而不用于限制本发明的范围。此外应理解，在阅读了本发明讲授的内容之后，本领域技术人员可以对本发明作各种改动或修改，这些等价形式同样落于本申请所附权利要求书所限定的范围。Below in conjunction with specific embodiment, further illustrate the present invention. 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.
具有超高比效能的多孔MXene基复合薄膜电磁屏蔽性能测定方法：使用Agilent E5063A矢量网络分析仪在8.2～12.4GHz频率范围内通过波导法测得复合薄膜的S参数。Measurement method of electromagnetic shielding performance of porous MXene-based composite film with ultra-high specific efficiency: Agilent E5063A vector network analyzer is used to measure the S parameters of the composite film by waveguide method in the frequency range of 8.2-12.4GHz.
实施例1Example 1
(1)制备MXene/GO分散液：(1) Preparation of MXene/GO dispersion:
制备MXene：在聚四氟乙烯烧杯内通过磁力搅拌将2g LiF溶解于10mL水和30mL浓盐酸配制的盐酸溶液中，随后加入2g 400目的碳钛化铝(Ti 3AlC 2,MAX)粉末，将反应器置于35℃水浴中持续搅拌24h，之后用无水乙醇和超纯水通过多次超声和离心对其进行洗涤，除去残余的杂质。将得到的MXene分散液冷冻干燥后待用。 Preparation of MXene: Dissolve 2g LiF in a hydrochloric acid solution prepared by 10mL water and 30mL concentrated hydrochloric acid by magnetic stirring in a polytetrafluoroethylene beaker, then add 2g 400 mesh aluminum carbon titanium oxide (Ti 3 AlC 2 ,MAX) powder, and The reactor was placed in a water bath at 35° C. and kept stirring for 24 hours, and then washed with absolute ethanol and ultrapure water by ultrasonication and centrifugation several times to remove residual impurities. The obtained MXene dispersion was freeze-dried for later use.
制备氧化石墨烯(GO)：将4g 325目鳞片石墨、480mL浓硫酸和54mL浓磷酸加入到1000mL三口烧瓶中，机械搅拌30min后缓慢加入24g高锰酸钾，继续匀速搅拌，水浴50℃ 12h，待反应结束后将混合液缓慢倒入盛有800mL去离子水的烧杯中，并用玻璃棒搅拌均匀。将过氧化氢水溶液逐滴加入至混合液中，并加以搅拌，直至溶液变成金黄色，静置12h，将混合液进行离心处理，除去混合液中残余的酸、金属离子等；随后分别采用稀HCl溶液、去离子水进行多次洗涤，直至pH值接近5～6。将得到的氧化石墨烯分散液进行冷冻干燥待用。Preparation of graphene oxide (GO): Add 4g of 325 mesh flake graphite, 480mL of concentrated sulfuric acid and 54mL of concentrated phosphoric acid into a 1000mL three-neck flask, mechanically stir for 30min, then slowly add 24g of potassium permanganate, continue to stir at a constant speed, and put in a water bath at 50°C for 12h. After the reaction was completed, the mixture was slowly poured into a beaker containing 800 mL of deionized water, and stirred evenly with a glass rod. Add aqueous hydrogen peroxide solution dropwise to the mixed solution, and stir until the solution turns golden yellow, let it stand for 12 hours, and centrifuge the mixed solution to remove residual acid, metal ions, etc. in the mixed solution; then use Wash with dilute HCl solution and deionized water several times until the pH value is close to 5-6. The obtained graphene oxide dispersion was freeze-dried for use.
制备MXene/GO分散液：取133mg MXene溶解在适量水中，经过超声和磁力搅拌后使MXene分散均匀，之后加入5mL 50％聚乙烯亚胺水溶液，经过充分搅拌后使其混合均匀，经过1.5h 11000r/min高速离心后，取下层沉淀，然后继续加入适量超纯水分散均匀，重复4次后加入26mL超纯水，再加入经过超声搅拌分散均匀的1mL 7mg/mL氧化石墨烯分散液，在磁力搅拌下混合均匀，将其命名为M-G5分散液。Preparation of MXene/GO dispersion: Dissolve 133mg of MXene in an appropriate amount of water, disperse MXene evenly after ultrasonic and magnetic stirring, then add 5mL of 50% polyethyleneimine aqueous solution, mix well after fully stirring, after 1.5h 11000r After high-speed centrifugation at /min, remove the sediment from the lower layer, and then continue to add an appropriate amount of ultrapure water to disperse evenly. Mix well under stirring, and name it as M-G5 dispersion.
(2)制备轻质多孔MXene基复合薄膜(2) Preparation of lightweight porous MXene-based composite films
制备MXene/GO薄膜：取5mL步骤(1)获得的MXene/GO分散液，滴涂在经水平仪调平后的聚对苯二甲酸乙二醇酯(PET)薄板上，在真空烘箱中进行真空干燥，真空度为-0.08MPa，温度为50℃，待干燥10h后，将薄膜从PET薄板上揭取下来，获得MXene/GO复合薄膜，将其命名为M-G5薄膜。Preparation of MXene/GO film: Take 5mL of the MXene/GO dispersion obtained in step (1), drop-coat it on a polyethylene terephthalate (PET) sheet leveled by a leveler, and vacuum it in a vacuum oven. Drying at a vacuum degree of -0.08MPa and a temperature of 50°C. After drying for 10 hours, the film was peeled off from the PET sheet to obtain a MXene/GO composite film, which was named M-G5 film.
制备多孔MXene基复合薄膜：将上述获得的MXene/GO复合薄膜在氢氩混合气气氛下进行高温退火处理，其中氢气体积比10％，高温退火处理温度为800℃，时间为30min，获得多孔MXene基复合薄膜，将其命名为M-rG5薄膜。Preparation of porous MXene-based composite film: The MXene/GO composite film obtained above was subjected to high-temperature annealing treatment in a hydrogen-argon mixed gas atmosphere, wherein the volume ratio of hydrogen gas was 10%, the high-temperature annealing treatment temperature was 800 ° C, and the time was 30 minutes to obtain porous MXene Based composite film, named M-rG5 film.
实施例2Example 2
(1)制备MXene/GO分散液：(1) Preparation of MXene/GO dispersion:
取126mg MXene溶解在适量超纯水中，经过超声和磁力搅拌后，使MXene均匀分散，之后加入4.7mL 50％的聚乙烯亚胺水溶液，经过充分搅拌后使其分散均匀，置于高速离心机中经过1.5h 11000r/min高速离心后，取下层沉淀，然后继续加入超纯水分散均匀，重复4次 后加入25mL超纯水后，再加入经过超声搅拌分散均匀的2mL 7mg/mL氧化石墨烯分散液，在磁力搅拌下混合均匀，将其命名为M-G10分散液。Dissolve 126mg of MXene in an appropriate amount of ultrapure water. After ultrasonic and magnetic stirring, the MXene is uniformly dispersed. Then add 4.7mL of 50% polyethyleneimine aqueous solution. After fully stirring, it is dispersed evenly and placed in a high-speed centrifuge After 1.5h 11000r/min high-speed centrifugation, remove the lower layer of sediment, and then continue to add ultrapure water to disperse evenly. After repeating 4 times, add 25mL ultrapure water, and then add 2mL 7mg/mL graphene oxide that has been evenly dispersed by ultrasonic stirring The dispersion liquid was mixed evenly under magnetic stirring, and it was named M-G10 dispersion liquid.
(2)制备轻质多孔MXene基复合薄膜(2) Preparation of lightweight porous MXene-based composite films
制备MXene/GO薄膜：取5mL步骤(1)获得的MXene/GO分散液，滴涂在经水平仪调平后的聚对苯二甲酸乙二醇酯(PET)薄板上，在真空烘箱中进行真空干燥，真空度为-0.08MPa，温度为50℃，待干燥10h后，将薄膜从PET薄板上揭取下来，获得MXene/GO复合薄膜，将其命名为M-G10薄膜。Preparation of MXene/GO film: Take 5mL of the MXene/GO dispersion obtained in step (1), drop-coat it on a polyethylene terephthalate (PET) sheet leveled by a leveler, and vacuum it in a vacuum oven. Drying at a vacuum of -0.08MPa and a temperature of 50°C. After drying for 10 hours, the film was peeled off from the PET sheet to obtain an MXene/GO composite film, which was named M-G10 film.
制备多孔MXene基复合薄膜：将上述获得的MXene/GO复合薄膜在氢氩混合气气氛下进行高温退火处理，其中氢气体积比10％，高温退火处理温度为800℃，时间为30min，获得多孔MXene基复合薄膜，将其命名为M-rG10薄膜。Preparation of porous MXene-based composite film: The MXene/GO composite film obtained above was subjected to high-temperature annealing treatment in a hydrogen-argon mixed gas atmosphere, wherein the volume ratio of hydrogen gas was 10%, the high-temperature annealing treatment temperature was 800 ° C, and the time was 30 minutes to obtain porous MXene Based composite film, named M-rG10 film.
实施例3Example 3
(1)制备MXene/GO分散液：(1) Preparation of MXene/GO dispersion:
取119mg MXene溶解在适量超纯水中，经过超声和磁力搅拌后，使MXene分散均匀，之后加入4.5mL 50％的聚乙烯亚胺水溶液，经过充分搅拌后使其分散均匀，置于高速离心机中经过1.5h 11000r/min高速离心后，取下层沉淀，然后继续加入超纯水分散均匀，重复4次后加入24mL超纯水后，再加入经过超声搅拌分散均匀的3mL 7mg/mL氧化石墨烯分散液，在磁力搅拌下混合均匀，将其命名为M-G15分散液。Dissolve 119mg of MXene in an appropriate amount of ultrapure water. After ultrasonic and magnetic stirring, the MXene is dispersed evenly. Then add 4.5mL of 50% polyethyleneimine aqueous solution. After fully stirring, it is dispersed evenly and placed in a high-speed centrifuge After 1.5h 11000r/min high-speed centrifugation, remove the lower layer of sediment, and then continue to add ultrapure water to disperse evenly. After repeating 4 times, add 24mL ultrapure water, and then add 3mL 7mg/mL graphene oxide that has been evenly dispersed by ultrasonic stirring The dispersion liquid was mixed evenly under magnetic stirring, and it was named M-G15 dispersion liquid.
(2)制备轻质多孔MXene基复合薄膜(2) Preparation of lightweight porous MXene-based composite films
制备MXene/GO薄膜：取5ml步骤(1)获得的MXene/GO分散液，滴涂在经水平仪调平后的聚对苯二甲酸乙二醇酯(PET)薄板上，在真空烘箱中进行真空干燥，真空度为-0.08MPa，温度为50℃，待干燥后，将薄膜从PET薄板上揭取下来，获得MXene/GO复合薄膜，将其命名为M-G15薄膜。Preparation of MXene/GO film: Get 5ml of the MXene/GO dispersion obtained in step (1), drop-coat it on a polyethylene terephthalate (PET) sheet leveled by a leveler, and vacuum it in a vacuum oven. Drying, the vacuum degree is -0.08MPa, and the temperature is 50°C. After drying, the film is peeled off from the PET sheet to obtain an MXene/GO composite film, which is named M-G15 film.
制备多孔MXene基复合薄膜：将上述获得的MXene/GO复合薄膜在氢氩混合气气氛下进行高温退火处理，其中氢气体积比10％，高温退火处理温度为800℃，时间为30min，获得多孔MXene基复合薄膜，将其命名为M-rG15薄膜。Preparation of porous MXene-based composite film: The MXene/GO composite film obtained above was subjected to high-temperature annealing treatment in a hydrogen-argon mixed gas atmosphere, wherein the volume ratio of hydrogen gas was 10%, the high-temperature annealing treatment temperature was 800 ° C, and the time was 30 minutes to obtain porous MXene Based composite film, named M-rG15 film.
电磁屏蔽性能测试Electromagnetic shielding performance test
对实施例1、2和3制备得到的复合薄膜材料进行分析测试，结果见图1～7。The composite film materials prepared in Examples 1, 2 and 3 were analyzed and tested, and the results are shown in Figs. 1-7.
图1为本实施例中轻质多孔MXene基复合薄膜电磁屏蔽示意图，本发明以静电相互作用力为驱动力实现MXene与GO纳米片间的自组装，通过流延成膜和退火处理，获得多孔MXene基复合薄膜，以石墨烯为骨架，MXene均匀的负载在石墨烯骨架上，通过材料内部多孔结构的形成实现降低材料密度和提高电磁波在材料内部的多重散射/反射损耗的目的，进而增加复 合材料电磁屏蔽比效能。与此同时，还原氧化石墨烯的引入也能起到与高导电MXene裂解产物间协同构建阻抗渐变型的梯度结构从而增加复合材料对电磁波的引入和衰减。Figure 1 is a schematic diagram of the electromagnetic shielding of the lightweight porous MXene-based composite film in this example. The present invention uses electrostatic interaction as the driving force to realize the self-assembly between MXene and GO nanosheets, and obtains porous film formation and annealing treatment by casting MXene-based composite film, with graphene as the skeleton, MXene is uniformly loaded on the graphene skeleton, through the formation of porous structure inside the material to achieve the purpose of reducing the material density and improving the multiple scattering/reflection loss of electromagnetic waves inside the material, thereby increasing the composite Material electromagnetic shielding specific effectiveness. At the same time, the introduction of reduced graphene oxide can also cooperate with highly conductive MXene cracking products to construct a gradient structure of impedance gradient, thereby increasing the introduction and attenuation of electromagnetic waves by the composite material.
图2为MXene与高温退火后的MXene(MX)以及M-rG5在空气中随时间变化电导率与初始电导率的对比图和经过在空气中放置12个月前后的电磁屏蔽性能对比图，由图中可以看出，本发明通过高温退火处理能够显著提高复合薄膜以及MXene的稳定性，即使在空气中放置12个月后，电磁屏蔽性能仍然得到了很好的保持，主要是由于高温退火能够对MXene表面活性基团进行有效的去除，从而MXene的稳定性得到增强，增加电磁屏蔽材料的抗氧化能力。Figure 2 is a comparison chart of the electrical conductivity of MXene and MXene (MX) after high temperature annealing and M-rG5 in the air with time and the initial electrical conductivity, and a comparison chart of the electromagnetic shielding performance before and after being placed in the air for 12 months. It can be seen from the figure that the present invention can significantly improve the stability of the composite film and MXene through high-temperature annealing treatment. Even after being placed in the air for 12 months, the electromagnetic shielding performance is still well maintained, mainly because high-temperature annealing can The effective removal of MXene surface active groups enhances the stability of MXene and increases the oxidation resistance of electromagnetic shielding materials.
图3为实施例1中的M-G5和M-rG5的扫描电子显微镜图片，图3(a)和图3(b)分别为退火前后的扫描电子显微镜图片，可见，经过800℃，0.5h高温退火后薄膜内部明显的多孔结构，MXene的小片层均匀的负载在还原氧化石墨烯的片层上，形成均匀的内部结构。Fig. 3 is the scanning electron microscope picture of M-G5 and M-rG5 in the embodiment 1, and Fig. 3 (a) and Fig. 3 (b) are the scanning electron microscope picture before and after annealing respectively, it can be seen that after 800 ℃, 0.5h After high-temperature annealing, the internal porous structure of the film is obvious, and the small sheets of MXene are evenly loaded on the sheets of reduced graphene oxide, forming a uniform internal structure.
图4为实施例1、2和3中随着氧化石墨烯加入量不同所产生的电导率的变化图，由于还原氧化石墨烯的电导率低于MXene，随着氧化石墨烯加入量的增加，电导率呈现逐渐降低的趋势。Fig. 4 is the variation diagram of the electrical conductivity that produces along with the graphene oxide addition difference in embodiment 1,2 and 3, because the electrical conductivity of reduced graphene oxide is lower than MXene, along with the increase of graphene oxide addition, The conductivity showed a gradually decreasing trend.
图5为实施例1当氧化石墨烯添加量为5wt％时的MXene基复合薄膜(M-rG5)的电磁屏蔽效能图，当薄膜厚度为15μm时，电磁屏蔽效能均在49dB以上，覆盖整个X波段。在8.263GHz时，电磁屏蔽效能值达到最大值58.361dB。Fig. 5 is the electromagnetic shielding performance diagram of the MXene-based composite film (M-rG5) when the graphene oxide addition amount is 5wt% in embodiment 1, when the film thickness is 15 μ m, the electromagnetic shielding performance is all above 49dB, covering the whole X band. At 8.263GHz, the electromagnetic shielding effectiveness reaches a maximum value of 58.361dB.
图6为实施例1、2和3当样品厚度相同时(15μm)，M-rG5、M-rG10和M-rG15的电磁屏蔽效能对比图，可见，M-rG5电磁屏蔽效能值最高。Figure 6 is a comparison chart of the electromagnetic shielding effectiveness of M-rG5, M-rG10 and M-rG15 when the sample thickness is the same (15 μm) in Examples 1, 2 and 3. It can be seen that M-rG5 has the highest electromagnetic shielding effectiveness value.
为了探究薄膜的轻质和高效电磁屏蔽效能之间的关系，对氧化石墨烯添加量不同的薄膜的密度和比效能进行比较，结果如图7所示，当不同氧化石墨烯含量的15μm复合薄膜，随着氧化石墨烯含量的增加，密度呈现逐渐下降的趋势，主要是由于氧化石墨烯含量的增加，在高温退火处理过程中，释放的小分子气体相应的也随之增加，同时产生的孔状结构孔径也就更大、更多。从而导致薄膜内部变得更加蓬松，密度随之下降；同样由于随着氧化石墨烯含量增加电磁屏蔽效能逐渐降低，但最终比效能却呈现出截然相反的结果，这主要归因于复合材料随着氧化石墨烯含量增加材料密度降低的速度远高于电磁屏蔽效能降低的速率。In order to explore the relationship between light weight and high-efficiency electromagnetic shielding performance of the film, the density and specific performance of the films with different additions of graphene oxide were compared. The results are shown in Figure 7. When the 15 μm composite film with different graphene oxide content , with the increase of graphene oxide content, the density presents a gradually decreasing trend, mainly due to the increase of graphene oxide content, during the high-temperature annealing process, the small molecular gas released correspondingly increases accordingly, and the pores generated at the same time The pore size of the shape structure is larger and more. As a result, the inside of the film becomes more fluffy, and the density decreases; also because the electromagnetic shielding efficiency gradually decreases with the increase of the graphene oxide content, but the final specific performance shows a completely opposite result, which is mainly attributed to the composite material with the The rate at which the density of the material decreases with increasing GO content is much higher than the rate at which the electromagnetic shielding effectiveness decreases.
实施例4Example 4
(1)制备MXene/GO分散液：(1) Preparation of MXene/GO dispersion:
取133mg MXene溶解在适量水中，经过超声和磁力搅拌后使MXene分散均匀，之后加入1.33g2,5-二巯基-1 3 4-噻二唑，经过充分搅拌后使其混合均匀，经过1.5h 11000r/min高速离心后，取下层沉淀，然后继续加入适量超纯水分散均匀，重复3次后加入26mL超纯水， 再加入经过超声搅拌分散均匀的1mL 7mg/mL氧化石墨烯分散液，在磁力搅拌下混合均匀，得到MXene/GO分散液。Dissolve 133mg of MXene in an appropriate amount of water, and disperse the MXene evenly after ultrasonic and magnetic stirring, then add 1.33g of 2,5-dimercapto-1 3 4-thiadiazole, and mix it evenly after fully stirring. After 1.5h 11000r After high-speed centrifugation at /min, remove the lower layer of sediment, and then continue to add an appropriate amount of ultrapure water to disperse evenly. Mix well under stirring to obtain MXene/GO dispersion.
(2)制备轻质多孔MXene基复合薄膜(2) Preparation of lightweight porous MXene-based composite films
制备MXene/GO薄膜：取5mL步骤(1)获得的MXene/GO分散液，滴涂在经水平仪调平后的聚对苯二甲酸乙二醇酯(PET)薄板上，在真空烘箱中进行真空干燥，真空度为-0.08MPa，温度为50℃，待干燥10h后，将薄膜从PET薄板上揭取下来，获得MXene/GO复合薄膜。Preparation of MXene/GO film: Take 5mL of the MXene/GO dispersion obtained in step (1), drop-coat it on a polyethylene terephthalate (PET) sheet leveled by a leveler, and vacuum it in a vacuum oven. Drying, the vacuum degree is -0.08MPa, and the temperature is 50°C. After drying for 10 hours, the film is peeled off from the PET sheet to obtain the MXene/GO composite film.
制备多孔MXene基复合薄膜：将上述获得的MXene/GO复合薄膜在氢氩混合气气氛下进行高温退火处理，其中氢气体积比20％，高温退火处理温度为900℃，时间为30min，获得多孔MXene基复合薄膜。Preparation of porous MXene-based composite film: The MXene/GO composite film obtained above was subjected to high-temperature annealing treatment in a hydrogen-argon mixed gas atmosphere, wherein the hydrogen volume ratio was 20%, the high-temperature annealing treatment temperature was 900 ° C, and the time was 30 minutes to obtain porous MXene base composite film.
本实施例制备得到的多孔MXene基复合薄膜电磁屏蔽效果可以覆盖整个X波段，复合材料在保持电磁屏蔽性能的同时，密度也得到大幅度降低，本实施例所制备得到的复合薄膜材料具有优异的电磁屏蔽效能和比效能。The electromagnetic shielding effect of the porous MXene-based composite film prepared in this example can cover the entire X-band, and the density of the composite material is greatly reduced while maintaining the electromagnetic shielding performance. The composite film material prepared in this example has excellent Electromagnetic shielding effectiveness and specific effectiveness.
实施例5Example 5
(1)制备MXene/GO分散液：(1) Preparation of MXene/GO dispersion:
取133mg MXene分散在适量超纯水中，经过超声和磁力搅拌后使MXene分散均匀，之后加入0.5g盐酸多巴胺，经过充分搅拌后使其混合均匀，经过1.5h 11000r/min高速离心后，取下层沉淀，然后继续加入适量超纯水分散均匀，重复3次后加入26mL超纯水，再加入经过超声搅拌分散均匀的1mL 7mg/mL氧化石墨烯分散液，在磁力搅拌下混合均匀，得到MXene/GO分散液。Take 133mg MXene and disperse it in an appropriate amount of ultrapure water, and disperse MXene evenly after ultrasonic and magnetic stirring, then add 0.5g dopamine hydrochloride, mix it evenly after thorough stirring, and after 1.5h 11000r/min high-speed centrifugation, remove the lower layer Precipitate, then continue to add an appropriate amount of ultrapure water to disperse evenly, repeat 3 times, add 26mL ultrapure water, then add 1mL 7mg/mL graphene oxide dispersion that has been uniformly dispersed by ultrasonic stirring, and mix evenly under magnetic stirring to obtain MXene/ GO dispersion.
(2)制备轻质多孔MXene基复合薄膜(2) Preparation of lightweight porous MXene-based composite films
制备MXene/GO薄膜：取5mL步骤(1)获得的MXene/GO分散液，滴涂在经水平仪调平后的聚苯乙烯(PS)薄板上，在真空烘箱中进行真空干燥，真空度为-0.08MPa，温度为50℃，待干燥10h后，将薄膜从PS薄板上揭取下来，获得MXene/GO复合薄膜。Preparation of MXene/GO film: Take 5mL of the MXene/GO dispersion obtained in step (1), drop-coat it on a polystyrene (PS) sheet leveled by a leveler, and vacuum-dry it in a vacuum oven with a vacuum degree of - 0.08MPa, the temperature is 50°C, after drying for 10h, the film is peeled off from the PS sheet to obtain the MXene/GO composite film.
制备多孔MXene基复合薄膜：将上述获得的MXene/GO复合薄膜在氢氩混合气气氛下进行高温退火处理，其中氢气体积比5％，高温退火处理温度为800℃，时间为60min，获得多孔MXene基复合薄膜。Preparation of porous MXene-based composite film: The MXene/GO composite film obtained above was subjected to high-temperature annealing treatment in a hydrogen-argon mixed gas atmosphere, wherein the volume ratio of hydrogen gas was 5%, the high-temperature annealing treatment temperature was 800 ° C, and the time was 60 minutes to obtain porous MXene base composite film.
本实施例制备得到的多孔MXene基复合薄膜在整个X波段的电磁屏蔽性能均在47.5dB以上。复合材料在保持电磁屏蔽性能的同时，密度(0.4g/cm 3)也得到大幅度降低，本实施例所制备得到的复合薄膜材料具有优异的电磁屏蔽效能和比效能。 The electromagnetic shielding performance of the porous MXene-based composite film prepared in this example is above 47.5 dB in the entire X-band. The density (0.4g/cm 3 ) of the composite material is greatly reduced while maintaining the electromagnetic shielding performance. The composite thin film material prepared in this embodiment has excellent electromagnetic shielding performance and specific performance.
对比例1Comparative example 1
制备MXene/rGO复合薄膜：取实施例1中得到的M-G5薄膜在氢氩混合气气氛下进行高温处理，其中氢气体积比10％，高温退火处理温度为1000℃，时间为0.5h，退火处理后复合薄膜脆性增加，但电磁屏蔽效果仍可覆盖整个X波段，在整个X波段电磁屏蔽性能均在35dB以上。Preparation of MXene/rGO composite film: take the M-G5 film obtained in Example 1 and carry out high-temperature treatment under a hydrogen-argon mixed gas atmosphere, wherein the hydrogen volume ratio is 10%, the high-temperature annealing treatment temperature is 1000 ° C, and the time is 0.5h. After treatment, the brittleness of the composite film increases, but the electromagnetic shielding effect can still cover the entire X-band, and the electromagnetic shielding performance in the entire X-band is above 35dB.
对比例2Comparative example 2
探究氧化石墨烯含量对电导率的影响：将氧化石墨烯含量不同的薄膜在氢氩混合气下处理，其中氢气体积比10％，高温退火处理温度为800℃，时间为30min，随着氧化石墨烯含量的增加，如图3所示，电导率大致呈现逐渐降低的趋势，退火处理过后的MXene(命名为MX)的电导率为1958S/cm；rGO电导率为53S/cm，而M-rG10和M-rG15电导率变化不大，可能的原因是在此阶段到达电导率变化的平台期。To explore the effect of graphene oxide content on electrical conductivity: films with different graphene oxide contents were treated under a hydrogen-argon gas mixture, in which the volume ratio of hydrogen gas was 10%, the high-temperature annealing treatment temperature was 800°C, and the time was 30 minutes. With the increase of ene content, as shown in Figure 3, the electrical conductivity generally shows a gradually decreasing trend. The electrical conductivity of MXene (named MX) after annealing treatment is 1958 S/cm; the electrical conductivity of rGO is 53 S/cm, while the electrical conductivity of M-rG10 The conductivity of M-rG15 and M-rG15 did not change much, the possible reason is that the plateau period of conductivity change was reached at this stage.
对比例3Comparative example 3
探究MXene/GO分散液浓度对复合薄膜的影响：取实施例1中经过高速离心洗涤过后的MXene沉淀加入13mL超纯水和1mL 7mg/mL的GO分散液，经磁力搅拌后混和均匀，取上述5mL分散液滴涂在PET薄板上，经在真空烘箱中进行真空干燥，真空度为-0.08MPa，温度为50℃，待干燥10h后，将薄膜从PET薄板上揭取下来，获得MXene/GO复合薄膜，并将其在氢氩混合气气氛下进行高温处理，其中氢气体积比为10％，高温退火处理温度为800℃，时间为0.5h，由于分散液浓度过高，致使粘度较大，得到的薄膜较厚，且厚度均匀性变差。Explore the influence of MXene/GO dispersion concentration on the composite film: Take the MXene precipitate after high-speed centrifugal washing in Example 1, add 13mL ultrapure water and 1mL 7mg/mL GO dispersion, mix evenly after magnetic stirring, take the above 5mL of the dispersion liquid was drop-coated on a PET sheet, and then vacuum-dried in a vacuum oven with a vacuum degree of -0.08MPa and a temperature of 50°C. After drying for 10 hours, the film was peeled off from the PET sheet to obtain MXene/GO The composite film is subjected to high temperature treatment in a hydrogen-argon mixed gas atmosphere, wherein the hydrogen volume ratio is 10%, the high temperature annealing treatment temperature is 800°C, and the time is 0.5h. Due to the high concentration of the dispersion liquid, the viscosity is relatively high. The resulting film is thicker and has poor thickness uniformity.
将上述得到的MXene/GO分散液取3mL加入2mL超纯水稀释后，滴涂在PET薄板上，经在真空烘箱中进行真空干燥，真空度为-0.08MPa，温度为50℃，待干燥12h后，将薄膜从PET薄板上揭取下来，获得MXene/GO复合薄膜，并将其在氢氩混合气气氛下进行高温处理，其中氢气体积比为10％，高温退火处理温度为800℃，时间为0.5h，由于分散液浓度较低，固含量低，致使得到的薄膜较薄(10μm)，脆性较大，其在整个X波段的电磁屏蔽性能均在42dB以上Take 3mL of the MXene/GO dispersion obtained above and add 2mL of ultrapure water to dilute it, drop-coat it on a PET sheet, and dry it in a vacuum oven with a vacuum degree of -0.08MPa and a temperature of 50°C for 12 hours. Finally, the film was removed from the PET sheet to obtain the MXene/GO composite film, which was subjected to high-temperature treatment in a hydrogen-argon mixed gas atmosphere, wherein the hydrogen volume ratio was 10%, and the high-temperature annealing treatment temperature was 800 °C, and the time For 0.5h, due to the low concentration of dispersion liquid and low solid content, the obtained film is thinner (10μm) and more brittle, and its electromagnetic shielding performance in the entire X-band is above 42dB
探究退火时间对电磁屏蔽性能和密度的影响：将M-G5薄膜在氢氩混合气下处理，其中氢气体积比10％，高温退火处理温度为800℃，时间分别为10min，30min，60min。对不同退火时间处理后的M-rG5复合薄膜进行电磁屏蔽性能测试，退火时间为10min的M-rG5复合薄膜在整个X波段具有优异的电磁屏蔽性能，平均可达52dB，密度为0.97g/cm 3；退火时间为30min的M-rG5复合薄膜在整个X波段具有优异的电磁屏蔽性能，平均可达52dB，密度为0.67g/cm 3；退火时间为60min的M-rG5复合薄膜在整个X波段具有优异的电磁屏蔽性能，平均可达49dB，密度为0.4g/cm 3。对于上述结果我们可以看到，改变退火时间对电磁 屏蔽性能的影响不大，但是密度会大幅度降低，主要是由于随着退火时间的延长，GO热处理过程中产生的气体变多，发泡程度变大，密度逐渐降低，电磁波在薄膜内部的多重散射增强，使得密度降低得情况下，电磁屏蔽性能基本不变。 To explore the effect of annealing time on the electromagnetic shielding performance and density: the M-G5 film was treated under hydrogen-argon mixed gas, in which the volume ratio of hydrogen gas was 10%, the high-temperature annealing treatment temperature was 800°C, and the time was 10min, 30min, and 60min respectively. The electromagnetic shielding performance test was carried out on the M-rG5 composite film treated with different annealing times. The M-rG5 composite film with an annealing time of 10 minutes has excellent electromagnetic shielding performance in the entire X-band, with an average of 52dB and a density of 0.97g/cm 3 ; The M-rG5 composite film with an annealing time of 30min has excellent electromagnetic shielding performance in the entire X-band, with an average of 52dB and a density of 0.67g/cm 3 ; the M-rG5 composite film with an annealing time of 60min has excellent electromagnetic shielding performance in the entire X-band It has excellent electromagnetic shielding performance, the average can reach 49dB, and the density is 0.4g/cm 3 . From the above results, we can see that changing the annealing time has little effect on the electromagnetic shielding performance, but the density will be greatly reduced, mainly because the gas generated during the heat treatment of GO increases with the prolongation of the annealing time, and the degree of foaming increases. When the density becomes larger, the density gradually decreases, and the multiple scattering of electromagnetic waves inside the film is enhanced, so that the electromagnetic shielding performance is basically unchanged when the density is reduced.
虽然本发明已以较佳实施例公开如上，但其并非用以限定本发明，任何熟悉此技术的人，在不脱离本发明的精神和范围内，都可做各种的改动与修饰，因此本发明的保护范围应该以权利要求书所界定的为准。Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore The scope of protection of the present invention should be defined by the claims.

Claims (17)

  1. 一种轻质多孔MXene基复合薄膜电磁屏蔽材料的制备方法，其特征在于，所述方法包括：A kind of preparation method of lightweight porous MXene-based composite thin film electromagnetic shielding material, is characterized in that, described method comprises:
    (1)制备MXene/GO分散液：将MXene和GO分别分散在水中得到MXene和GO的分散液，在MXene分散液中加入阳离子表面改性剂经高速离心洗涤去除多余阳离子表面改性剂后，制备得到的带正电的MXene分散液，将带正电的MXene分散液与GO分散液混合后制备得到MXene/GO分散液；(1) Preparation of MXene/GO dispersion: Disperse MXene and GO in water to obtain a dispersion of MXene and GO, add a cationic surface modifier to the MXene dispersion, and remove excess cationic surface modifier by high-speed centrifuge washing, The prepared positively charged MXene dispersion is prepared by mixing the positively charged MXene dispersion with the GO dispersion to obtain the MXene/GO dispersion;
    (2)制备M/rGO薄膜：将步骤(1)得到的MXene/GO的分散液滴涂在高分子基薄板上，低温干燥去除水分，之后从薄板上揭取得到MXene/GO复合薄膜，然后将得到的MXene/GO复合薄膜进行退火处理，得到M/rGO复合薄膜。(2) Preparation of M/rGO thin film: the dispersion of MXene/GO obtained in step (1) was drop-coated on the polymer base sheet, dried at low temperature to remove moisture, and then the MXene/GO composite film was obtained from the sheet, and then The obtained MXene/GO composite film was annealed to obtain the M/rGO composite film.
  2. 根据权利要求1所述的制备方法，其特征在于，步骤(1)中，所述MXene分散液浓度为2～10mg/mL，所述GO分散液浓度控制在为2～10mg/mL。The preparation method according to claim 1, characterized in that, in step (1), the concentration of the MXene dispersion is 2 to 10 mg/mL, and the concentration of the GO dispersion is controlled at 2 to 10 mg/mL.
  3. 根据权利要求1所述的制备方法，其特征在于，所述GO占MXene和GO总质量的5～15％。The preparation method according to claim 1, characterized in that the GO accounts for 5-15% of the total mass of MXene and GO.
  4. 根据权利要求1～3任一项所述的制备方法，其特征在于，步骤(1)中所述的阳离子表面改性剂为聚乙烯亚胺、多巴胺、2,5-二巯基-1 3 4-噻二唑中任一种或几种。According to the preparation method described in any one of claims 1 to 3, it is characterized in that the cationic surface modifier described in step (1) is polyethyleneimine, dopamine, 2,5-dimercapto-134 - Any one or more of thiadiazoles.
  5. 根据权利要求1～3任一项所述的制备方法，其特征在于，所述的MXene/GO分散液浓度为2～10mg/mL。The preparation method according to any one of claims 1-3, characterized in that the concentration of the MXene/GO dispersion is 2-10 mg/mL.
  6. 根据权利要求4所述的制备方法，其特征在于，所述的MXene/GO分散液浓度为2～10mg/mL。The preparation method according to claim 4, characterized in that the concentration of the MXene/GO dispersion is 2-10 mg/mL.
  7. 根据权利要求1～3或6任一项所述的制备方法，其特征在于，步骤(2)中，所述高分子基薄板包括聚对苯二甲酸乙二醇酯、聚苯乙烯、聚氯乙烯、聚碳酸酯中的任一种。The preparation method according to any one of claims 1-3 or 6, characterized in that, in step (2), the polymer-based sheet comprises polyethylene terephthalate, polystyrene, polychloride Any of vinyl and polycarbonate.
  8. 根据权利要求4所述的制备方法，其特征在于，步骤(2)中，所述高分子基薄板包括聚对苯二甲酸乙二醇酯、聚苯乙烯、聚氯乙烯、聚碳酸酯中的任一种。The preparation method according to claim 4, characterized in that, in step (2), the polymer-based sheet comprises polyethylene terephthalate, polystyrene, polyvinyl chloride, polycarbonate any kind.
  9. 根据权利要求5所述的制备方法，其特征在于，步骤(2)中，所述高分子基薄板包括聚对苯二甲酸乙二醇酯、聚苯乙烯、聚氯乙烯、聚碳酸酯中的任一种。The preparation method according to claim 5, characterized in that, in step (2), the polymer-based sheet comprises polyethylene terephthalate, polystyrene, polyvinyl chloride, polycarbonate any kind.
  10. 根据权利要求1～3、6或8～9任一项所述的制备方法，其特征在于，步骤(2)中，所述退火处理所用的气体氛围为氢氩混合气，其中氢气体积比为5％～20％，退火温度为800℃～1000℃，时间为0.5～2h。According to the preparation method described in any one of claims 1-3, 6 or 8-9, it is characterized in that, in step (2), the gas atmosphere used in the annealing treatment is hydrogen-argon mixed gas, wherein the hydrogen volume ratio is 5%-20%, the annealing temperature is 800°C-1000°C, and the time is 0.5-2h.
  11. 根据权利要求4所述的制备方法，其特征在于，步骤(2)中，所述退火处理所用的气体氛围为氢氩混合气，其中氢气体积比为5％～20％，退火温度为800℃～1000℃，时间为0.5～2h。The preparation method according to claim 4, characterized in that, in step (2), the gas atmosphere used in the annealing treatment is hydrogen-argon mixed gas, wherein the hydrogen volume ratio is 5% to 20%, and the annealing temperature is 800°C ～1000℃, the time is 0.5～2h.
  12. 根据权利要求5所述的制备方法，其特征在于，步骤(2)中，所述退火处理所用的气体氛围为氢氩混合气，其中氢气体积比为5％～20％，退火温度为800℃～1000℃，时间为0.5～2h。The preparation method according to claim 5, characterized in that, in step (2), the gas atmosphere used in the annealing treatment is hydrogen-argon mixed gas, wherein the hydrogen volume ratio is 5% to 20%, and the annealing temperature is 800°C ～1000℃, the time is 0.5～2h.
  13. 根据权利要求7所述的制备方法，其特征在于，步骤(2)中，所述退火处理所用的气体氛围为氢氩混合气，其中氢气体积比为5％～20％，退火温度为800℃～1000℃，时间为0.5～2h。The preparation method according to claim 7, characterized in that, in step (2), the gas atmosphere used in the annealing treatment is hydrogen-argon mixed gas, wherein the volume ratio of hydrogen is 5% to 20%, and the annealing temperature is 800°C ～1000℃, the time is 0.5～2h.
  14. 根据权利要求1～13任一项所述的制备方法制备得到的轻质多孔MXene基复合薄膜电磁屏蔽材料。The light porous MXene-based composite thin film electromagnetic shielding material prepared according to the preparation method described in any one of claims 1-13.
  15. 一种航空航天装置、军事装备或精密电子仪器，其特征在于，包含权利要求14所述的轻质多孔MXene基复合薄膜电磁屏蔽材料。An aerospace device, military equipment or precision electronic instrument, is characterized in that, comprises the electromagnetic shielding material of lightweight porous MXene-based composite thin film described in claim 14.
  16. 权利要求14所述的轻质多孔MXene基复合薄膜电磁屏蔽材料在电磁防护领域中的应用。The application of the lightweight porous MXene-based composite thin film electromagnetic shielding material in claim 14 in the field of electromagnetic protection.
  17. 根据权利要求16所述的应用，其特征在于，所述应用包括在航空航天、军事装备、精密电子仪器等电磁防护领域中的应用。The application according to claim 16, characterized in that the application includes applications in electromagnetic protection fields such as aerospace, military equipment, and precision electronic instruments.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115746392A (en) * 2022-11-25 2023-03-07 中国科学院海洋研究所 Modified friction power generation sponge, single-electrode sponge friction power generation device, and preparation and application thereof
CN117641872A (en) * 2023-11-27 2024-03-01 山东省地质科学研究院 Hollow manganese dioxide nanotube loaded MXene material and preparation method thereof

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113329603B (en) * 2021-05-17 2023-06-13 江南大学 Light porous MXene-based composite film electromagnetic shielding material and preparation method thereof
CN113998693A (en) * 2021-10-22 2022-02-01 北京石墨烯技术研究院有限公司 Preparation method of graphene nano-roll
CN113979428B (en) * 2021-11-17 2023-05-26 深圳市鸿富诚新材料股份有限公司 Preparation method of heat-conducting wave-absorbing composite film and heat-conducting wave-absorbing composite film
CN114454573A (en) * 2021-12-28 2022-05-10 成都大学 Ti3C2TxMXene/GO heterogeneous membrane and preparation method and application thereof
CN114371200B (en) * 2021-12-31 2023-10-31 上海工程技术大学 High-stain-resistance MXene-ERHG electrochemical sensor and preparation method thereof
CN114478148B (en) * 2022-01-10 2022-07-19 北京理工大学 Blasting multi-mechanism coupling type energetic electromagnetic damage cloud cluster and preparation method and application thereof
CN115521553B (en) * 2022-10-11 2023-03-14 昆明理工大学 Preparation method and application of graphene/MXene/polystyrene composite material
CN115850968A (en) * 2022-10-18 2023-03-28 中科院广州化学有限公司 MXene-based high-thermal-conductivity fireproof composite film and preparation method and application thereof

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109207834A (en) * 2018-11-13 2019-01-15 中国科学院过程工程研究所 A kind of modified MXenes powder and its preparation method and application
CN109897343A (en) * 2019-04-11 2019-06-18 西北工业大学 A kind of MXene aeroge/epoxy resin electromagnetic shielding nanocomposite and preparation method thereof
CN110117431A (en) * 2019-05-16 2019-08-13 哈尔滨工业大学 A kind of preparation method of MXene base electro-magnetic screen coating material
WO2020009627A1 (en) * 2018-07-03 2020-01-09 Per Persson Process for production of a substantially two-dimensional sheet of transition metal carbide, nitride or carbonitride
CN111372435A (en) * 2020-04-25 2020-07-03 郑州大学 MXene-based high-thermal-conductivity fireproof electromagnetic shielding composite film and preparation method thereof
CN111799464A (en) * 2020-07-08 2020-10-20 中国科学院电工研究所 MXene/graphene composite nanosheet, preparation method and application thereof, electrode plate and application thereof
CN111993725A (en) * 2020-09-02 2020-11-27 苏州大学 Method for improving electromagnetic shielding performance of MXene-based composite fabric material
US20210094831A1 (en) * 2017-12-22 2021-04-01 Drexel University Crumpled mesoporous mxene powders synthesized by acid-, base-, or salt-induced crumpling
CN113329603A (en) * 2021-05-17 2021-08-31 江南大学 Light porous MXene-based composite film electromagnetic shielding material and preparation method thereof

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110294857B (en) * 2019-05-08 2022-02-01 广东石油化工学院 Synergistic enhanced electromagnetic shielding film and preparation method thereof
CN111883314A (en) * 2020-09-03 2020-11-03 南京林业大学 Preparation method of oxidized cellulose-graphene nanoribbon-MXene composite conductive film

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210094831A1 (en) * 2017-12-22 2021-04-01 Drexel University Crumpled mesoporous mxene powders synthesized by acid-, base-, or salt-induced crumpling
WO2020009627A1 (en) * 2018-07-03 2020-01-09 Per Persson Process for production of a substantially two-dimensional sheet of transition metal carbide, nitride or carbonitride
CN109207834A (en) * 2018-11-13 2019-01-15 中国科学院过程工程研究所 A kind of modified MXenes powder and its preparation method and application
CN109897343A (en) * 2019-04-11 2019-06-18 西北工业大学 A kind of MXene aeroge/epoxy resin electromagnetic shielding nanocomposite and preparation method thereof
CN110117431A (en) * 2019-05-16 2019-08-13 哈尔滨工业大学 A kind of preparation method of MXene base electro-magnetic screen coating material
CN111372435A (en) * 2020-04-25 2020-07-03 郑州大学 MXene-based high-thermal-conductivity fireproof electromagnetic shielding composite film and preparation method thereof
CN111799464A (en) * 2020-07-08 2020-10-20 中国科学院电工研究所 MXene/graphene composite nanosheet, preparation method and application thereof, electrode plate and application thereof
CN111993725A (en) * 2020-09-02 2020-11-27 苏州大学 Method for improving electromagnetic shielding performance of MXene-based composite fabric material
CN113329603A (en) * 2021-05-17 2021-08-31 江南大学 Light porous MXene-based composite film electromagnetic shielding material and preparation method thereof

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CN115746392A (en) * 2022-11-25 2023-03-07 中国科学院海洋研究所 Modified friction power generation sponge, single-electrode sponge friction power generation device, and preparation and application thereof
CN115746392B (en) * 2022-11-25 2023-12-19 中国科学院海洋研究所 Modified friction power generation sponge, single-electrode sponge friction power generation device, and preparation and application thereof
CN117641872A (en) * 2023-11-27 2024-03-01 山东省地质科学研究院 Hollow manganese dioxide nanotube loaded MXene material and preparation method thereof

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