木基多孔炭/铁氧体复合吸波材料的制备与性能表征

Preparation and Characterization of Wood-based Porous Carbon/Ferrite Composite Microwave Absorbing Materials

以马尾松木材为原料,使用低温预处理、真空浸注和高温原位生长等手段制备了性能优异的木基多孔炭/铁氧体复合吸波材料(WPC/Fe_(3)O_(4)),采用XRD、XPS、SEM、VNA等技术对复合材料的物相、成分、形貌和电磁特性等进行表征分析,初步阐述了其吸波机理。结果表明:制备的WPC/Fe3O4具有优异的吸波性能,其反射损耗峰值达-35.6 dB,有效吸波频带宽超过5.6 GHz,并且在3~4.3 mm厚度范围内均可实现对全部Ku频段电磁波的有效吸收;WPC/Fe_(3)O_(4)具有规则通直的孔隙结构和丰富的异质界面,高温下Fe_(3)O_(4)纳米粒子均匀生长于木基多孔炭的孔隙和炭壁中;随着碳化温度的升高,WPC/Fe_(3)O_(4)的介电常数显著增大而磁导率变化较小;WPC/Fe_(3)O_(4)的电磁损耗机制主要为导电损耗、磁损耗和界面极化损耗。复合材料表现出对Ku频段电磁波的高效与宽频吸收,有望实现其在电子通讯或目标隐身等微波领域的应用。

In this paper,wood-based porous carbon/ferrite composite microwave absorbing materials(WPC/Fe_(3)O_(4))with excellent properties were prepared by low-temperature pretreatment,vacuum impregnation and high-temperature in-situ growth using masson pine as raw materials.The phase,composition,morphology,and electromagnetic properties were investigated by XRD,XPS,SEM,and VNA.And the mechanism of its absorption was preliminarily explained.The results showed that the WPC/Fe_(3)O_(4) has excellent absorption performance,with the peak reflection loss reaching-35.6 dB,the effective absorption band width exceeding 5.6 GHz,and the effective absorption of all Ku band electromagnetic waves within the thickness range of 3—4.3 mm.WPC/Fe_(3)O_(4) has a regular straight pore structure and a rich heterogeneous interface.Fe_(3)O_(4) nanoparticles grow uniformly in the pores and carbon walls of wood-based porous carbon at high temperatures.As the carbonization temperature increases,the dielectric constant of WPC/Fe_(3)O_(4) increases significantly,but small change in permeability.The electromagnetic loss mechanisms of WPC/Fe3O4 are mainly conductive loss,magnetic loss and interfacial polarization loss.The composite materials show high efficiency of Ku band electromagnetic wave,which is expected to achieve its application in the microwave field such as electronic communication or target stealth.