CN-121992531-A - Spot MoO3/MoxC/C wave-absorbing fiber and preparation method thereof

Abstract

The invention provides a spot MoO 3 /Mo x C/C wave-absorbing fiber, which effectively improves the electromagnetic wave absorption performance of the fiber by actively constructing the spot MoO 3 /Mo x C which is uniformly distributed on the surface of the fiber. Meanwhile, the invention also provides a preparation method of the fiber, and the unique spotted MoO 3 /Mo x C/C fiber is synthesized through four steps of electrostatic spinning, solidification, high-temperature carbonization and controllable oxidation treatment.

Inventors

• FANG CHENG
• BAO YING
• LONG XU
• WANG LIXUAN
• YANG JIANGPO
• LI XUYANG
• YAO MINGYU
• JIANG XIAOYI
• ZHANG QINGFENG
• Meng Dongxu

Assignees

• 郑州大学

Dates

Publication Date

20260508

Application Date

20260122

Claims (8)

1. 1. A preparation method of a spot MoO 3 /Mo x C/C wave-absorbing fiber comprises the following steps: S1, uniformly mixing a carbon source, a molybdenum source and a solvent to obtain a spinning solution, carrying out electrostatic spinning, and drying to obtain precursor fibers; s2, sequentially carrying out low-temperature curing and high-temperature carbonization on the precursor fiber in an air atmosphere to obtain Mo x C/C fiber; S3, completely coating the Mo x C/C fibers with carbon paper, and performing controllable oxidation to enable the surfaces of the fibers to generate MoO 3 in situ, so as to obtain the spotted MoO 3 /Mo x C/C fibers.
2. 2. The preparation method according to claim 1, wherein in the step S1, the molybdenum source is ammonium molybdate, phosphomolybdic acid or molybdenum acetylacetonate, the carbon source is polyacrylonitrile or polyvinylpyrrolidone, and the solvent is N-N dimethylformamide or a mixed solution of N-N dimethylformamide and acetylacetone.
3. 3. The method according to claim 1, wherein the carbon source content of the spinning solution is 10 wt to 15 wt% and the molybdenum source content is 10 wt to 15 wt% in step S1.
4. 4. The method according to claim 3, wherein in step S2, the low-temperature curing temperature is 250-300 ℃, the low-temperature curing time is 1-3 h, the high-temperature carbonization temperature is 1500 ℃, and the carbonization time is 1-3 h.
5. 5. The method of claim 4, wherein in step S3, the controlled oxidation is performed in an air atmosphere at a temperature of 500-650 ℃ for a time of 2-5 min at a temperature-rising rate of 10 ℃ per minute before the predetermined oxidation temperature is reached.
6. 6. The method of claim 1, wherein in step S1, the spinning voltage of the electrostatic spinning is +20 kV- +26 kV, -0.5- (-1.5) kV, the spinning speed is 1-2 mL/h, and the collector rotating speed is 1000-1600 r/min.
7. 7. A patch-like MoO 3 /Mo x C/C wave-absorbing fiber, characterized in that it is produced by the production method according to any one of claims 1 to 6.
8. 8. The wave-absorbing fiber according to claim 7, comprising a carbon fiber body and spot MoO 3 /Mo x C uniformly protruding from the surface of the carbon fiber body.

Description

Spot MoO 3/Mox C/C wave-absorbing fiber and preparation method thereof Technical Field The invention relates to an electromagnetic wave absorbing material, in particular to a spot MoO 3/Mox C/C wave absorbing fiber and a preparation method thereof. Background In recent decades, advances in electronic technology have led to the intelligent information age. However, the ubiquitous electromagnetic wave radiation and pollution interfere with the proper functioning of precision instruments, constituting a potential threat to human health. Therefore, development of a novel electromagnetic wave absorbing material having both strong absorption, wide band and light weight characteristics is a problem to be solved. Among various material systems, one-dimensional carbon-based nanofibers prepared by electrospinning exhibit unique advantages. By precisely controlling the diameter of the nanofiber and the three-dimensional network structure formed by interweaving the nanofiber, a continuous conductive framework and a plurality of scattering interfaces can be constructed, and an ideal physical basis is provided for electromagnetic wave attenuation. However, pure carbon nanofibers have the disadvantages of poor impedance matching, weak absorption strength, narrow effective absorption bandwidth, single loss mechanism and the like. The introduction of transition metal carbides is an effective strategy for achieving synergy of various loss mechanisms and improving charge transport capacity. Among various transition metal carbides, molybdenum-based carbide (Mo 2 C, moC) has a rich polarization relaxation ability and excellent thermal stability, and can significantly enhance the conductive loss and polarization loss of the carbon-based composite material. The MoC/Mo 2 C heterostructure formed by the two has a large number of molybdenum vacancies, and the induced interface polarization and dipole polarization of the molybdenum vacancies obviously enhance the electromagnetic wave absorption performance. However, the system still has certain limitations, such as insufficient absorption performance at high frequency bands and relatively narrow effective bandwidth. This means that it is difficult to achieve co-optimization of both impedance matching and strong broadband absorption by carbide-only phase tuning. In order to solve the above problems, an ideal technical solution is always sought. Disclosure of Invention The invention aims at overcoming the defects of the prior art, and provides a spot MoO 3/Mox C/C wave-absorbing fiber and a preparation method thereof. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a spot MoO 3/Mox C/C wave-absorbing fiber and a preparation method thereof comprise the following steps: s1, uniformly mixing a carbon source, a molybdenum source and a solvent to obtain a spinning solution, carrying out electrostatic spinning, and drying to obtain precursor fibers; s2, sequentially carrying out low-temperature curing and high-temperature carbonization on the precursor fiber in an air atmosphere to obtain Mo x C/C fiber; S3, completely coating the Mo x C/C fibers with carbon paper, and performing controllable oxidation to enable the surfaces of the fibers to generate MoO 3 in situ, so as to obtain the spotted MoO 3/Mox C/C fibers. In the step S1, the molybdenum source is ammonium molybdate ((NH 4)6Mo7O24·4H2 O), phosphomolybdic acid (H 3(PMo12O40)) or molybdenum acetylacetonate (MoO 2(acac)2), the carbon source is Polyacrylonitrile (PAN) or polyvinylpyrrolidone (PVP), and the solvent can be N-N Dimethylformamide (DMF) or a mixed solution of N-N Dimethylformamide (DMF) and acetylacetone (C 5H8O2). In the step S1, the content of the carbon source in the spinning solution is 10 wt-15 wt percent, and the content of the molybdenum source is 10 wt-15 wt percent. In the step S2, the low-temperature curing temperature is 250-300 ℃, the low-temperature curing time is 1-3 h, the high-temperature carbonization temperature is 1500 ℃, and the carbonization time is 1-3 h. In the step S3, controllable oxidization is carried out under the air atmosphere, the oxidization temperature is 500-650 ℃, the oxidization time is 2-5 min, and the temperature rising rate before reaching the preset oxidization temperature is 10 ℃ per minute. In the step S1, the spinning voltage of electrostatic spinning is +20 kV- +26 kV, -0.5- (-1.5) kV, the spinning speed is 1-2 mL/h, and the collector rotating speed is 1000-1600 r/min. A spot MoO 3/Mox C/C wave-absorbing fiber is prepared by the preparation method. The wave-absorbing fiber comprises a carbon fiber main body and spot MoO 3/Mox C which uniformly protrudes on the surface of the carbon fiber main body. Compared with the prior art, the invention has outstanding substantial characteristics and remarkable progress, in particular to the spot MoO 3/Mox C/C wave-absorbing fiber, which not only effectively adjusts the overall conductivity of t