多孔木炭/Fe_(3)O_(4)复合吸波材料的制备与性能  

Preparation and microwave absorption properties of porous charcoal/Fe_(3)O_(4) composites

作　　者：杨喜[1] 曹敏 简煜 庞晓娜 李贤军[1] YANG Xi;CAO Min;JIAN Yu;PANG Xiaona;LI Xianjun(College of Materials Science and Engineering,Central South University of Forestry and Technology,Changsha 410004,China)

机构地区：[1]中南林业科技大学材料科与工程学院,长沙410004

出　　处：《复合材料学报》2022年第10期4590-4601,共12页Acta Materiae Compositae Sinica

基　　金：中南林科大人才启动基金(2018YJ033);湖南省教育厅科研项目(18B173)。

摘　　要：为了改善Fe_(3)O_(4)吸波材料密度大和吸波频带窄等问题,以马尾松木材为原料,采用去木质素及高温原位生长法制备了多孔木炭(WPC)/Fe_(3)O_(4)复合材料,通过变化碳化温度来调控复合材料的电磁特性与微波吸收性能。微观形貌、结构和电磁参数等结果表明:WPC/Fe_(3)O_(4)复合材料保有木材天然的三维孔结构,Fe_(3)O_(4)粒子均匀负载于多孔木炭的炭壁与孔道中;升高碳化温度(630~690℃)可增强材料的电导率与电磁衰减能力,但温度过高会引起材料阻抗失配。670℃制备的复合材料微波衰减能力强且阻抗匹配特性好,最小反射损耗为-49.5 dB,有效吸收频宽为6.24 GHz(9.04~15.28 GHz),主要衰减机制归结于复合材料的电导损耗、极化弛豫及介电与磁损耗的协同作用。WPC/Fe_(3)O_(4)复合材料优异的吸波性能在电磁波吸收领域具有良好前景,可促进速生木材的高值化与功能化应用。In order to improve the shortages of big density and narrow absorption bandwidth of Fe_(3)O_(4)absorbing material, in this study, wood-based porous charcoal(WPC)/Fe_(3)O_(4)composites were prepared from fast-growing masson pine wood by delignification and high temperature in-situ growth methods. The microwave absorption properties of the composites were regulated by tailoring the carbonization temperature. The results of micromorphology, structure and electromagnetic parameters show that, the WPC/Fe_(3)O_(4)composites retain the natural threedimensional porous structure of wood with Fe_(3)O_(4)particles evenly loaded in the carbon walls and channels of WPC.The increment of carbonization temperature(630-690℃) can enhance the electric conductivity and microwave attenuation capacity of the composites, but too high temperature causes the impedance mismatching. The composite prepared at 670℃ exhibits excellent microwave absorption performance with a minimum reflection loss of-49.5 dB and an effective absorption bandwidth of 6.24 GHz(9.04-15.28 GHz), due to its strong attenuation capability and good impedance matching characteristics. The main dissipation mechanism includes conductive loss, polarization relaxation, and synergistic effect of dielectric and magnetic loss. The strong reflection loss and wide effective absorption bandwidth of WPC/Fe_(3)O_(4)composite suggest a good prospect in electromagnetic absorption field, which can promote the value-added and functional application of fast-growing wood.

关 键 词：松木 Fe_(3)O_(4) 多孔结构 阻抗匹配 吸波性能 衰减机制 

分 类 号：TB332[一般工业技术—材料科学与工程] S785[农业科学—林学]