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CN-122002773-A - Transition metal sulfur carbide composite film with electromagnetic shielding effect and preparation method and application thereof

CN122002773ACN 122002773 ACN122002773 ACN 122002773ACN-122002773-A

Abstract

The invention belongs to the technical field of electromagnetic shielding materials, and relates to a transition metal sulfur carbide composite film with electromagnetic shielding effect, and a preparation method and application thereof. The invention discloses a transition metal sulfur carbide composite film with electromagnetic shielding effect, which has a three-layer structure and sequentially comprises a first cellulose-polyvinyl alcohol supporting layer, a transition metal sulfur carbide layer and a second cellulose-polyvinyl alcohol supporting layer, wherein the transition metal sulfur carbide in the transition metal sulfur carbide layer is M 2 X 2 C, M is a transition group metal element comprising at least one of Ti, V, cr, zr, nb, mo, hf, ta, W, and X is a chalcogen element comprising at least one of S, se. The transition metal sulfur carbide composite film with high flexibility and high electromagnetic shielding effect is successfully prepared through the layer-by-layer stacking structure of the cellulose-polyvinyl alcohol supporting layer/the transition metal sulfur carbide layer/the cellulose-polyvinyl alcohol supporting layer.

Inventors

  • LI MIAN
  • WANG YU
  • HUANG QING

Assignees

  • 中国科学院宁波材料技术与工程研究所
  • 宁波杭州湾新材料研究院

Dates

Publication Date
20260508
Application Date
20251222

Claims (16)

  1. 1. The transition metal sulfur carbide composite film with electromagnetic shielding effect is characterized by comprising a first cellulose-polyvinyl alcohol supporting layer, a transition metal sulfur carbide layer and a second cellulose-polyvinyl alcohol supporting layer in sequence; The transition metal sulfur carbide in the transition metal sulfur carbide layer is M 2 X 2 C, wherein M is a transition group metal element including at least one of Ti, V, cr, zr, nb, mo, hf, ta, W, and X is a chalcogen element including at least one of S, se; The preparation method comprises the following steps: (1) Adding lithium salt and transition metal sulfur carbon powder with the molar ratio of (2-10) of 1 into an organic solvent, stirring and reacting, ultrasonically centrifuging to collect precipitate, dispersing the precipitate in water after cleaning, ultrasonically centrifuging again, and taking supernatant to obtain a transition metal sulfur carbide few-layer dispersion liquid; (2) Mixing a cellulose aqueous solution with a polyvinyl alcohol aqueous solution to obtain a cellulose-polyvinyl alcohol mixed solution; (3) And (3) sequentially preparing a film by adopting a cellulose-polyvinyl alcohol mixed solution and a transition metal sulfur carbide few-layer dispersion liquid to obtain the metal sulfur carbide composite film.
  2. 2. The transition metal sulfur carbide composite film with electromagnetic shielding effectiveness according to claim 1, wherein in the step (1), the preparation method of the transition metal sulfur carbon powder comprises the steps of mixing transition metal powder, chalcogen powder and carbon powder to obtain mixed powder, adding a catalyst into the mixed powder, transferring the mixed powder into a vacuum sealing container, and heating the vacuum sealing container to obtain the transition metal sulfur carbide composite film; The transition metal powder comprises at least one of Ti, V, cr, zr, nb, mo, hf, ta, W powder, the chalcogen powder comprises at least one of S, se, and the catalyst is carbon tetrabromide.
  3. 3. The method for producing a transition metal sulfur carbide composite film having electromagnetic shielding effectiveness according to claim 1, wherein in the step (1), the molar ratio of the lithium salt to the transition metal sulfur carbon powder is (5-8): 1.
  4. 4. The transition metal sulfur carbide composite membrane with electromagnetic shielding effectiveness of claim 2, wherein in step (1) the lithium salt comprises one or more of lithium trifluoromethane sulfonyl imide, lithium bis (fluorosulfonyl) imide, lithium bis (pentafluoroethylsulfonyl) imide, lithium hexafluorophosphate, n-butyllithium, lithium perchlorate, lithium chloride.
  5. 5. The transition metal sulfur carbide composite film having electromagnetic shielding effectiveness according to claim 1, wherein in step (1), the organic solvent is dimethylsulfoxide.
  6. 6. The transition metal sulfur carbide composite film with electromagnetic shielding effectiveness according to claim 1, wherein in the step (1), the transition metal sulfur carbide minority dispersion has a minority nano-sheet with an average thickness of 1 to 10nm.
  7. 7. The transition metal sulfur carbide composite film with electromagnetic shielding effectiveness according to claim 1, wherein in the step (2), the mass ratio of cellulose in the aqueous cellulose solution to polyvinyl alcohol in the aqueous polyvinyl alcohol solution is 1 (0.1-10).
  8. 8. The transition metal sulfur carbide composite film with electromagnetic shielding effectiveness according to claim 1, wherein the thickness of the transition metal sulfur carbide composite film with electromagnetic shielding effectiveness is 1-100 μm.
  9. 9. The transition metal sulfur carbide composite film with electromagnetic shielding effectiveness of claim 8, wherein the transition metal sulfur carbide layer in the transition metal sulfur carbide composite film with electromagnetic shielding effectiveness has a thickness ratio of >65%.
  10. 10. The transition metal sulfur carbide composite film with electromagnetic shielding effectiveness of claim 1, wherein the electromagnetic shielding effectiveness of the transition metal sulfur carbide composite film with electromagnetic shielding effectiveness is >40 dB.
  11. 11. The transition metal sulfur carbide composite film with electromagnetic shielding effectiveness according to claim 1, wherein the retention rate of electromagnetic shielding effectiveness is >80% after the transition metal sulfur carbide composite film with electromagnetic shielding effectiveness is left standing for 30 days in an air environment at a temperature of 20-30 ℃ and a humidity of 80-90%.
  12. 12. A method for producing a transition metal sulfur carbide composite film having electromagnetic shielding effectiveness according to claim 1, comprising: (1) Mixing transition metal powder, chalcogen powder and carbon powder with the molar ratio of (1-5) 1 to obtain mixed powder, adding 1-20wt% of catalyst into the mixed powder, transferring the mixed powder into a vacuum sealing container, and heating the mixture at 1000-1300 ℃ for 1-60 hours to obtain transition metal sulfur-carbon powder; (2) Adding lithium salt and transition metal sulfur carbon powder with the molar ratio of (2-10) of 1 into an organic solvent, stirring and reacting, ultrasonically centrifuging to collect precipitate, dispersing the precipitate in water after cleaning, ultrasonically centrifuging again, and taking supernatant to obtain a transition metal sulfur carbide few-layer dispersion liquid; (3) Mixing a cellulose aqueous solution with a polyvinyl alcohol aqueous solution to obtain a cellulose-polyvinyl alcohol mixed solution; (4) And (3) sequentially dripping the cellulose-polyvinyl alcohol mixed solution, the transition metal sulfur carbide few-layer dispersion liquid and the cellulose-polyvinyl alcohol mixed solution into a suction filtration device, and drying after suction filtration to obtain the metal sulfur carbide composite film.
  13. 13. The method for preparing a transition metal sulfur carbide composite film with electromagnetic shielding effectiveness according to claim 1, wherein the transition metal sulfur carbide composite film with electromagnetic shielding effectiveness has a three-layer structure and sequentially comprises a first cellulose-polyvinyl alcohol supporting layer, a transition metal sulfur carbide layer and a second cellulose-polyvinyl alcohol supporting layer; The transition metal sulfur carbide in the transition metal sulfur carbide layer is M 2 X 2 C, wherein M is a transition group metal element including at least one of Ti, V, cr, zr, nb, mo, hf, ta, W, and X is a chalcogen element including at least one of S, se.
  14. 14. Use of the transition metal sulfur carbide composite film with electromagnetic shielding effectiveness according to any one of claims 1 to 11 in the field of electromagnetic shielding.
  15. 15. An electromagnetic shielding material, characterized by comprising 0.1-100 wt% of the transition metal sulfur carbide composite film with electromagnetic shielding effectiveness according to any one of claims 1-11.
  16. 16. The electromagnetic shielding material according to claim 15, wherein the electromagnetic shielding material has an electromagnetic shielding effectiveness of >40dB, and an electromagnetic shielding effectiveness retention rate of >80% after the electromagnetic shielding material is left to stand in an air environment for 30 days at a temperature of 20-30 ℃ and a humidity of 80-90%.

Description

Transition metal sulfur carbide composite film with electromagnetic shielding effect and preparation method and application thereof Technical Field The invention belongs to the technical field of electromagnetic shielding materials, and relates to a transition metal sulfur carbide composite film with electromagnetic shielding effect, and a preparation method and application thereof. Background With the popularization of electronic equipment and the arrival of the 5G communication age, the influence caused by electromagnetic radiation and interference is more and more obvious, namely, on one hand, a large amount of electromagnetic radiation can be generated in the operation process of the electronic equipment to influence the operation of surrounding electronic equipment, and on the other hand, long-term electromagnetic radiation can damage the health of a human body and pollute the environment. Therefore, the application value of the electromagnetic shielding material is remarkable. The current diversified application scenes not only require the electromagnetic shielding material to have good shielding parameters, but also provide requirements for mechanical properties (such as flexibility) and environmental stability (such as high temperature resistance and oxidation resistance). Therefore, the development of the electromagnetic shielding material with comprehensive performance has important application value. The traditional metal electromagnetic shielding materials such as copper, aluminum, silver and the like have the defects of high weight, easy corrosion, lack of flexibility and the like, and are difficult to adapt to the electromagnetic shielding requirements of various environments, although the traditional metal electromagnetic shielding materials have higher shielding efficiency. In recent years, two-dimensional materials represented by layered transition metal carbide (MXene) exhibit great potential as electromagnetic shielding materials due to high point conductivity and good flexible device manufacturability. Although MXene is excellent in electromagnetic shielding performance, it faces a challenge of insufficient environmental stability in a practical application scenario. This is because MXene is obtained by chemically etching an a-site atomic layer in a MAX phase of its precursor, and the etching process inevitably forms crystal defects, resulting in a decrease in oxidation resistance of the MXene material. In general, without special protection, MXene undergoes significant oxidative degradation within days of exposure to air or water, and the critical properties, such as electrical conductivity and mechanical properties, are significantly reduced. Chinese patent application publication No. CN112812338a proposes a composite electromagnetic shielding film, which includes a bacterial cellulose film layer and an MXene film layer, wherein the bacterial cellulose film layer and the MXene film layer are alternately arranged, and both outer surfaces of the composite electromagnetic shielding film are the bacterial cellulose film layer. The Chinese patent application (publication No. CN 119031684A) proposes a flexible electromagnetic shielding film, which comprises a two-dimensional film layer, a first cellulose film layer and a second cellulose film layer which are respectively arranged on two sides of the two-dimensional film layer, wherein the two-dimensional film layer is made of at least one of NbSe 2、TiSe2、MoTe2、TaSe2 and VSe 2. These designs improve the flexibility and mechanical support of the material to some extent, but the combination of electromagnetic shielding properties, especially the balance of long-term stability in harsh environments and high-efficiency shielding capabilities, remains to be further improved. Disclosure of Invention The invention aims at solving the problems in the prior art and provides a preparation method of a transition metal sulfur carbide composite film with electromagnetic shielding effect, which successfully prepares the transition metal sulfur carbide composite film with high flexibility and high electromagnetic shielding effect through a layer-by-layer stacking structure of a cellulose-polyvinyl alcohol supporting layer/a transition metal sulfur carbide layer/a cellulose-polyvinyl alcohol supporting layer. One object of the invention is achieved by the following technical scheme: The transition metal sulfur carbide composite film with electromagnetic shielding effect has a three-layer structure and sequentially comprises a first cellulose-polyvinyl alcohol supporting layer, a transition metal sulfur carbide layer and a second cellulose-polyvinyl alcohol supporting layer; The transition metal sulfur carbide in the transition metal sulfur carbide layer is M 2X2 C, wherein M is a transition group metal element including at least one of Ti, V, cr, zr, nb, mo, hf, ta, W, and X is a chalcogen element including at least one of S, se; The preparation method compr