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CN-117024833-B - Preparation method of MXene@LM composite wave-absorbing material with natural wood-like oriented pore structure

CN117024833BCN 117024833 BCN117024833 BCN 117024833BCN-117024833-B

Abstract

The invention belongs to the technical field of composite materials, and relates to a preparation method of an MXene@LM composite wave-absorbing material with a natural wood-like oriented pore structure, which comprises the steps of adding LiF into a polytetrafluoroethylene container containing HCl solution, stirring uniformly, adding Ti 3 AlC 2 , centrifuging, adding deionized water into precipitate, dispersing into Ti 3 C 2 T x lamellar collecting liquid, regulating the pH value of a dispersion liquid system to be more than 6 with tris, adding dopamine hydrochloride, stirring uniformly to obtain polydopamine modified Ti 3 C 2 T x lamellar dispersion liquid, adding liquid metal particles into the polydopamine modified Ti 3 C 2 T x lamellar dispersion liquid, stirring uniformly, adding nanocellulose, freeze-drying the mixed system, and demoulding. The invention has the advantages of cheap and easily obtained raw materials, simple preparation method, safety and no pollution, meets the requirements of green chemical production, and has the value of industrial production and potential application. The multiple pore canal structure obviously improves the conductive path, greatly improves the electromagnetic wave absorption performance and can effectively solve the electromagnetic wave pollution problem.

Inventors

  • CHEN XIAO
  • LI YUNLONG
  • YU CHAO
  • WU KANGJIE
  • XIE AMING

Assignees

  • 江苏科技大学

Dates

Publication Date
20260512
Application Date
20230613

Claims (9)

  1. 1. The preparation method of the MXene@LM composite wave-absorbing material with the natural wood-like oriented pore structure is characterized by comprising the following steps of: (1) Adding LiF into a polytetrafluoroethylene container containing an HCl solution, stirring uniformly, adding Ti 3 AlC 2 , stirring for 20-40 h at 25-50 ℃ until the mixture is uniform, centrifugally washing until the pH is more than 6, dissolving the precipitate in ethanol, performing ultrasonic treatment, centrifugally removing the ethanol, adding deionized water, centrifuging, collecting an upper liquid, centrifuging the upper liquid, adding the precipitate into deionized water, and dispersing the precipitate into Ti 3 C 2 T x sheet collection liquid; (2) Adding tris into the collected solution to adjust the pH of a dispersion system to be more than 6, adding dopamine hydrochloride to carry out coating modification, and uniformly stirring to obtain polydopamine modified Ti 3 C 2 T x lamellar dispersion, wherein the mass ratio of the dopamine hydrochloride to the Ti 3 C 2 T x lamellar is 1:10-50; (3) Placing liquid metal in a container, adding deionized water, performing ultrasonic crushing to obtain liquid metal particles, adding the liquid metal particles into polydopamine modified Ti 3 C 2 T x sheet dispersion, stirring uniformly, adding nanocellulose, continuously stirring uniformly, and pouring the obtained product into a planar disk, wherein the liquid metal is gallium-indium alloy, the gallium is 75wt% and the indium is 25wt%, the mass ratio of polydopamine modified Ti 3 C 2 T x sheet to nanocellulose is 5-1:1, and the mass ratio of polydopamine modified Ti 3 C 2 T x sheet to liquid metal is 30-1:1; (4) Rapidly freezing until the product is solid, lyophilizing, and demolding.
  2. 2. The method for preparing the MXene@LM composite wave-absorbing material with the natural wood-like oriented pore structure, which is disclosed in claim 1, is characterized in that in the step (1), the concentration of the HCl solution is 10mol/L.
  3. 3. The preparation method of the MXene@LM composite wave-absorbing material with the natural wood-like oriented pore structure, which is disclosed in claim 1, is characterized in that in the step (1), liF is added into a polytetrafluoroethylene container containing HCl solution and stirred uniformly, then Ti 3 AlC 2 is added, and stirring is carried out for 20-40 h at 35 ℃ until uniform.
  4. 4. The method for preparing the MXene@LM composite wave-absorbing material with the natural wood-like oriented pore structure, which is disclosed in claim 1, is characterized in that in the step (1), the molar ratio of HCl, liF and Ti 3 AlC 2 is 9-3:1-0.5:1-0.5.
  5. 5. The method for preparing the MXene@LM composite wave-absorbing material with the natural wood-like oriented pore structure, which is disclosed in claim 4, is characterized in that in the step (1), the molar ratio of HCl, liF and Ti 3 AlC 2 is 7:1:1.
  6. 6. The method for preparing the MXene@LM composite wave-absorbing material with the natural wood-like oriented pore structure according to claim 1, wherein in the step (1), the rotational speed of centrifugal washing is 5000rpm, ultrasonic treatment is carried out for 1h at 325W, the rotational speed of centrifugation for removing ethanol is 10000rpm, the rotational speed of centrifugation during collection is 3500rpm, and the rotational speed of centrifugation for removing water is 10500rpm.
  7. 7. The method for preparing the MXene@LM composite wave-absorbing material with the natural wood-like oriented pore structure, which is disclosed in claim 1, is characterized in that in the step (2), tris is added until the pH of the whole dispersion system is more than 6, and the stirring rotation speed is kept at 600rpm.
  8. 8. The method for preparing the MXene@LM composite wave-absorbing material with the natural wood-like oriented pore structure, which is disclosed in the claim 1, is characterized in that in the step (3), the ultrasonic crushing time is 30min, and the ultrasonic treatment is stopped for 1s.
  9. 9. The MXene@LM composite wave-absorbing material with a natural wood-like oriented pore structure, which is prepared by the method according to any one of claims 1-8.

Description

Preparation method of MXene@LM composite wave-absorbing material with natural wood-like oriented pore structure Technical Field The invention belongs to the technical field of composite materials, relates to a wave-absorbing material, and particularly relates to a preparation method of an MXene@LM composite wave-absorbing material with a natural wood-like oriented pore structure. Background With the rapid development of information technology, more and more electromagnetic signals, such as radar, radio broadcasting, mobile phones, televisions and the like, work by means of electromagnetic waves. However, electromagnetic waves bring about a lot of problems while improving the life quality of people, such as complex processes of generating, transmitting and receiving electronic signals in the environment of everything interconnection, so that the electromagnetic environment becomes more complex, and the problems of electromagnetic pollution, electromagnetic interference and the like are inevitably caused. MXene has great potential for microwave absorption due to: (1) The MXene has a layered structure with controllable quantity, the interlayer structure can realize the repeated reflection and scattering of electromagnetic waves among materials, the adjustment of the interlayer spacing of the multilayer material can be realized through different preparation modes, and the single-layer and multilayer materials can also provide basic conditions for constructing a three-dimensional structure; (2) MXene has high conductivity, which easily results in stronger dielectric loss; (3) Surface defects and functional groups are generated in the MXene etching process, and the defects and the functional groups generate dipoles under the action of an electromagnetic field, so that the dielectric loss capacity of the material is further improved. However, the high conductivity of MXene tends to result in high interfacial reflection and poor impedance matching. Therefore, in order to improve the impedance matching and electromagnetic attenuation capabilities of MXene nanomaterials, MXene is often compounded with other materials to improve microwave absorption properties. In order to break through the bottleneck of wave absorbing performance, the development and research of new material combinations are more important. Disclosure of Invention Aiming at the defects in the prior art, the invention aims to provide a preparation method of an MXene@LM composite wave-absorbing material with a natural wood-like oriented pore structure. The method adopts a brand new material combination, has a regular pore structure and a stable frame structure after freeze drying treatment, and prepares the MXene wave-absorbing composite material with high-quality electromagnetic wave absorption performance and multiple communicating pore channels. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a preparation method of an MXene@LM composite wave-absorbing material with a natural wood-like oriented pore structure comprises the following steps: (1) Adding LiF into a polytetrafluoroethylene container containing an HCl solution, stirring uniformly, adding Ti 3AlC2, stirring at 25-50 ℃ preferably at 35 ℃ for 20-40 hours until the mixture is uniform, centrifugally washing until the pH is more than 6, dissolving the precipitate in ethanol, performing ultrasonic treatment, centrifugally removing the ethanol, adding deionized water, centrifuging, collecting an upper layer liquid, centrifuging the upper layer liquid, adding the precipitate into deionized water, and dispersing the precipitate into Ti 3C2Tx sheet (MXene) collecting liquid; (2) Adding tris into the collected solution to adjust the pH of a dispersion system to be more than 6, adding dopamine hydrochloride to carry out coating modification, and uniformly stirring to obtain polydopamine modified Ti 3C2Tx lamellar (MXene) dispersion; (3) Placing Liquid Metal (LM) in a container, adding deionized water, performing ultrasonic crushing to obtain liquid metal particles, adding the liquid metal particles into polydopamine modified Ti 3C2Tx lamellar dispersion, uniformly stirring, adding nano cellulose, continuously uniformly stirring, and pouring the obtained product into a planar disk; (4) Quick freezing until the product is solid, freeze drying and demolding to obtain the MXene@LM composite wave-absorbing material with a natural wood-like oriented pore structure. In the preferred embodiment of the present invention, in the step (1), the concentration of the HCl solution is 10mol/L, and the molar ratio of HCl, liF to Ti 3AlC2 is 9-3:1-0.5:1-0.5, preferably 7:1:1. In the preferred embodiment of the present invention, in the step (1), the rotational speed of the centrifugal washing is 5000rpm, the ultrasonic treatment is carried out at 325W for 1 hour, the rotational speed of the centrifugation for removing ethanol is 10000rpm, the rotational speed of the c