期刊
CHEMICAL ENGINEERING JOURNAL
卷 450, 期 -, 页码 -出版社
ELSEVIER SCIENCE SA
DOI: 10.1016/j.cej.2022.137943
关键词
Chitin nanofibers; Carbon aerogels; Anisotropic porous channels; Defective carbon; Microwave absorption
资金
- JST SPRING Program [JPMJSP2138]
- JST FOREST Program [JPMJFR2003]
- Japan Society for the Promotion of Science [20 K21334]
- Ministry of Education, Culture, Sports, Science and Technology, Japan [JPMXP09S21OS0029]
This research proposes the fabrication of anisotropic porous channels and defective carbon structures within chitin-derived carbon nano-fibrous aerogels, which achieve good impedance matching and high polarization loss for strong microwave absorption. The resulting aerogel exhibits superior microwave absorption performance compared to existing carbon-based absorbers. These findings provide guidance for the development of high-performance and sustainable microwave absorbers.
With the increasing use of microwaves, the functional design of carbon-based microwave absorbers has gained attention toward overcoming severe electromagnetic pollution, owing to the lightweight and broadband ab-sorption properties of these absorbers. The key functions for realizing strong microwave absorption include good impedance matching to the impedance of free air, moderate conductive loss, and high polarization loss. How-ever, it remains challenging to incorporate these complex functions into a single microwave absorber. Herein, the tailoring of anisotropic porous channels and defective carbon structures within chitin-derived carbon nano -fibrous aerogels is proposed to overcome this challenge. Honeycomb-like anisotropic porous channels were fabricated by the unidirectional freeze drying of crab-shell-derived chitin nanofiber/water suspensions. There-after, temperature-controlled carbonization was performed to tailor the defective carbon structures. Anisotropic porous channels and the as-tailored N-and O-doped defective carbon provide good impedance matching and high polarization loss, respectively. Both strategies moderate the conductive loss. The resulting aerogel had strong microwave absorption of-82.2 dB at 8.9 GHz and-92.8 dB at 11.6 GHz when the incident microwave radiation was parallel and perpendicular to the anisotropic channels, respectively. This performance surpasses that of state-of-the-art carbon-based microwave absorbers. These findings could guide the fabrication of high-performance and sustainable microwave absorbers.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据