Lightweight and Construable Magnetic Wood for Electromagnetic Interference Shielding
Lightweight and Construable Magnetic Wood for Electromagnetic Interference Shielding
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DOI：
10.1002/adem.202000257
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发表时间：
2020-06-17
影响因子：
3.6
通讯作者：
Zhu, Hongli
中科院分区：
文献类型：
--
作者：
Cheng, Zheng;Wei, Yuyi;Zhu, Hongli
目前，由于通信技术的快速发展，电磁干扰（EMI）和辐射已成为一种新兴的环境污染物。在本文中，分级和多孔结构的木材被用作轻质三维有机支架，用于通过原位矿化过程掺入磁性氧化铁纳米颗粒，该原位矿化过程赋予木块有利的外观以及磁性和EMI屏蔽性能。两步法包括通过蒸煮和漂白从天然木材中去除木质素，然后进行无机矿化。所得磁性木材外观呈棕色，具有典型的磁滞行为，其饱和磁化强度为4.5emu g（-1）。更重要的是，获得的磁性木材比传统磁性金属轻得多，并且可用于多种应用。值得注意的是，与具有相同厚度的磁性木材相比，3 mm厚的磁性木材在8-12 GHz的X波段上显示出5-10 dB（或7- 10倍）增强的电磁波衰减。磁性木材对电磁波的吸收增强主要是由于磁性木材的磁损耗角正切比普通木材大。这项工作提供了一个鼓舞人心的战略，以开发可持续的，轻质的，环保的木材多功能磁性应用。
Currently, due to the rapid development of communication technology, electromagnetic interference (EMI) and irradiation have become an emerging environmental pollutant. Herein, hierarchical and porous structured wood is used as the lightweight three-dimensional organic scaffold for the incorporation of magnetic iron oxide nanoparticles through an in situ mineralization process that endows the woodblock with favorable appearance as well as magnetic and EMI shielding properties. The two-step process involves the removal of lignin from natural wood via cooking and bleaching followed by inorganic mineralization. The resultant magnetic wood displays an optical brown appearance and possesses a typical magnetic hysteresis behavior with a saturation magnetization of 4.5 emu g(-1)for the whole wood. More importantly, the obtained magnetic wood is much lighter than traditional magnetic metal and construable for versatile applications. Notably, the 3 mm thick magnetic wood shows 5-10 dB (or 7-10x) enhanced electromagnetic wave attenuation across the X-band of 8-12 GHz compared with nonmagnetic wood with the same thickness. The enhanced electromagnetic wave absorption of magnetic wood is mainly due to its enhanced magnetic loss tangent compared with nonmagnetic wood. This work provides an inspiring strategy to develop sustainable, lightweight, and environmentally friendly wood for multifunctional magnetic applications.