MXene-MWCNTs-ANF@PPy复合薄膜的制备及其电磁屏蔽与电热转换性能

Preparation of MXene-MWCNTs-ANF@PPy composite films and their electromagnetic shielding and electrothermal conversion properties

  • 摘要: 二维MXene材料在电磁屏蔽领域具有显著潜力,但其实际应用受限于阻抗失配导致的强二次反射污染、导热通路匮乏引起的电热响应迟滞,以及纳米片自堆叠造成的力学脆性。该研究通过真空辅助过滤将一维多壁碳纳米管(MWCNTs)和原位聚合芳纶@聚吡咯纳米纤维(ANF@PPy)差异化地引入MXene层间,构筑了仿生“砖(MXene)-砂浆(ANF@PPy和MWCNTs)”层状复合薄膜。研究发现,MWCNTs的引入使反射系数从0.953(MXene/ANF@PPy)降至0.908,缓解了因反射造成的二次电磁污染问题。同时,MWCNTs贯穿形成的连续导热通道使薄膜在3 V驱动下10 s内升温至120.5℃,并在多次通电-断电循环和长时间连续工作中均表现出良好的温度稳定性和可逆响应能力。ANF@PPy纤维则通过空间阻隔与氢键交联将拉伸强度提升至19.32 MPa(较纯MXene提升近9倍)。当MXene与MWCNTs质量比为4∶1时,薄膜电导率达1296.4 S/cm,X波段电磁屏蔽效能为49.61 dB。该工作揭示了多组分间的功能协同机制,为突破MXene基材料在柔性电磁屏蔽-热管理一体化应用中的性能瓶颈提供了新思路。

     

    Abstract: Two-dimensional MXene materials have significant potential in electromagnetic interference (EMI) shielding. However, their practical applications are limited by several issues. Strong secondary reflection pollution arises from impedance mismatch. Poor thermal conduction pathways cause slow electrothermal response. Nanosheet self-stacking leads to mechanical brittleness. This study used vacuum-assisted filtration to introduce one-dimensional multi-walled carbon nanotubes (MWCNTs) and in-situ polymerized aramid@polypyrrole nanofibers (ANF@PPy) into MXene interlayers. The approach constructed a bio-inspired layered composite film with a "brick (MXene)-mortar (ANF@PPy and MWCNTs)" structure. The results showed that the addition of MWCNTs reduced the reflection coefficient from 0.953 (for MXene-ANF@PPy) to 0.908. This alleviated secondary electromagnetic pollution caused by reflection. Meanwhile, the MWCNTs formed continuous thermal conduction channels. These channels enabled the film to heat up to 120.5℃ within 10 s under a 3 V driving voltage. ANF@PPy fibers increased the tensile strength to 19.32 MPa through spatial separation and hydrogen bonding crosslinking. This value is nearly eight times that of pure MXene. When the mass ratio of MXene to MWCNTs was 4∶1, the film achieved an electrical conductivity of 1296.4 S/cm. Its EMI shielding effectiveness in the X-band reached 49.61 dB. This work reveals the synergistic functional mechanism among the multiple components. It also provides a new strategy to break the performance bottlenecks of MXene-based materials in flexible EMI shielding and thermal management applications.

     

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