Abstract: The booming development of the 5G era has facilitated the rapid growth of electronic information technology, providing efficiency and convenience, but inevitably giving rise to electromagnetic pollution, which poses irreversible harms to human health and the environment. To address this issue, microwave absorption materials (MAMs) have been developed and utilized. In civilian applications, MAMs are commonly used as patches in mobile devices and computers to prevent interference and minimize the electromagnetic radiation leakage. In military contexts, stealth technology enhances the survivability and defensive capabilities of weapons, providing a strategic advantage in modern warfare. Thus, MAMs play a crucial role in both military stealth operations and civilian protection. Traditional MAMs, such as ferrites, conductive carbon black, and magnetic metals, are typically incorporated into polymer matrices as powder fillers. However, they suffer from various drawbacks, including poor mechanical properties, inability to function as load-bearing components, high density hindering integration, and limited flexibility to meet the demands of modern electronics. One-dimensional fiber materials offer promising alternatives due to their lightweight, flexibility, and design versatility. However, most microwave absorbing fibers are produced by using methods such as chemical plating, coating, and impregnation. Addressing these challenges, this paper focuses on integrating modern textile techniques to produce flexible composite fibers with superior mechanical properties and exceptional absorption capabilities.
The PEDOT:PSS/sodium alginate@MXene (PA@M) composite fibers with core-shell structure were successfully fabricated by coaxial wet spinning process, to realize the integration of strong and efficient wave-absorbing functions. This paper mainly explored the effects of Ti3C2Tx MXene content on the morphology, mechanical properties, electrical conductivity and electromagnetic characteristics of the PA@M composite fibers. The results showed that because of the interactions between the MXene layers in the core and the PA components in the shell, the PA@M composite fibers exhibited remarkable mechanical properties, with a single-fiber breaking strength reaching (63.13±2.56) MPa and a corresponding elongation at break of (23.28±1.67)%, which can be originated from the interactions between the Ti3C2Tx MXene core layers and the PA shell components. Furthermore, the conductivity of PA@M composite fibers was increased from 0.71 S/m to 3.42 S/m due to the efficient electron transfer between MXene nanolayers. Meanwhile, the component modulation and microstructure design could effectively regulate the electromagnetic properties of the PA@M composite fibers, so that PA@M-1.0 composite fibers achieved the minimum reflection loss of –63.39 dB and effective absorption bandwidth of 3.20 GHz. This research presents a novel and efficient approach for the design and development of microwave absorption fibers.

Key words: composite fiber, core-shell structure, microwave absorption performance, Ti3C2Tx MXene, wet spinning

摘要： 针对吸波纤维制备工艺复杂、力学承载性差、性能不稳定等问题，文章以聚(3,4-乙烯二氧噻吩):聚苯乙烯磺酸(PEDOT:PSS)和海藻酸钠(SA)的复配液为纤维壳层纺丝液，以二维过渡金属碳氮化物(Ti3C2Tx MXene)分散液为纤维芯层纺丝液，通过同轴湿法纺丝一体化成型工艺制备了具有核壳结构的PEDOT:PSS/SA@MXene(PA@M)复合纤维，并对复合纤维的形貌、结构、力学特性及电磁参数等进行详细的测试分析。结果表明：通过组分调控和结构优化，PA@M复合纤维可保持良好的力学性能，纤维最大断裂强度和断裂伸长率分别达到(63.12±2.56) MPa和(23.28±1.67)%；当芯层分散液的质量浓度为1.0 mg/mL时，所制备的PA@M复合纤维具有最优的吸波性能，其最小反射损耗可达63.39 dB，有效吸收带宽为3.20 GHz。研究结果可为新型高性能吸波纤维的设计、制备提供新思路。

关键词: 复合纤维, 核壳结构, 吸波性能, Ti3C2Tx MXene, 湿法纺丝