To obtain high‐performance electromagnetic microwave (EM) absorption materials with broad effective absorption bandwidth (EAB) and reduced thickness, designing structures has proved to be a promising way. Herein, ultra‐broadband multilayer bidirectional MXene/polyimide EM absorption aerogels containing multi‐structures on scales ranging from the micro‐ to the macroscale are produced with the aid of electric and temperature fields. On the microscale, under the action of electric force and temperature gradient, the ordered structures made of aligned Ti3C2Tx MXene nanosheets and the microscale layered aerogel walls enable the bidirectional aerogel to achieve a wide EAB of 8.58 GHz at a thickness of 2.1 mm. This is ascribed to the numerous aligned nanosheets and layered aerogel walls perpendicular to the incident EMs, facilitating the conversion of electromagnetic energy into electrical energy. Furthermore, on the macroscale, the multilayer bidirectional aerogel with non‐gradient structures effectively resolves the conflict between impedance matching and energy loss, resulting in an ultrawide EAB of 9.41 GHz at a thickness of 3 mm. This innovative design of electric‐field‐assisted multilayer bidirectional aerogels with multiscale structural coupling may provide feasible and effective pathways for the development of advanced EM absorption materials.

中文翻译：

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用于超宽带微波吸收的双向多层 MXene/聚酰亚胺气凝胶


为了获得具有宽有效吸收带宽（EAB）和减小厚度的高性能电磁微波（EM）吸收材料，设计结构已被证明是一种有前途的方法。在此，借助电场和温度场制备了包含从微观到宏观尺度的多重结构的超宽带多层双向 MXene/聚酰亚胺电磁吸收气凝胶。在微观尺度上，在电力和温度梯度的作用下，由排列整齐的Ti3C2TX MXene纳米片和微米级层状气凝胶壁组成的有序结构使双向气凝胶能够在2.1 mm的厚度下实现8.58 GHz的宽EAB。这归因于垂直于入射电磁的大量排列的纳米片和分层气凝胶壁，促进电磁能转化为电能。此外，在宏观尺度上，具有非梯度结构的多层双向气凝胶有效解决了阻抗匹配和能量损失之间的矛盾，在3 mm的厚度下实现了9.41 GHz的超宽EAB。这种具有多尺度结构耦合的电场辅助多层双向气凝胶的创新设计可能为先进电磁吸收材料的开发提供可行有效的途径。