浸渍法制备磁性木材的磁性和电磁波吸收性能
发布时间：2019-05-12 12:10
【摘要】：研究了通过浸渍法制得的磁性木材产物不同部位对产物中磁性物质的分布、磁性和电磁波吸收性能的影响。利用金属盐离子尺寸小、在木材中渗透性优于纳米颗粒的特点,将经过预处理的木材先后浸渍于三价铁和二价铁的混合溶液以及氨水溶液中,通过化学共沉淀的方法在木材中原位制备Fe_3O_4纳米颗粒,从而得到磁性木材。对样品成分和结构进行红外光谱和X射线衍射光谱分析;将环境扫描电子显微镜与EDS mapping模式联用研究样品中磁性颗粒的分布;使用振动样品磁强计对所得样品的磁性进行了测量;并使用网络矢量分析仪对杨木试样的电磁波吸收能力进行了测试。铁盐浸渍液中Fe~(3+)和Fe~(2+)的物质的量之比为2∶1,氨水质量分数为25%,浸渍液通过导管传输和纹孔渗透两种方式进入木材内部,最终生成磁性颗粒。磁性颗粒的粒径在13 nm左右,磁性木材不同部位的铁含量按照角、边和中心的顺序依次递减,角部位的磁性强度最高,为24.75 emu/g,而中心部位仅为1.64 emu/g。同时,不同部位的磁矫顽力均较大,分别为137.60(中心),28.15(边)和10.11 Oe(角),表明制得的磁性木材改变了原来磁性颗粒(Fe_3O_4)的软磁性特征,为硬磁材料。此外,它们在5.0 GHz处的电磁波吸波强度分别为-0.63(中心),-3.93(边)和-17.12 d B(角)。采用铁盐与氨水逐步浸渍和原位共沉淀的方法可以成功制备磁性木材。在固定的浸渍液配比浓度和铁盐浸渍时间下,磁性木材内部不同部位所含磁性颗粒的量按中心、边和角的顺序逐渐增加,分布更加均匀,相应的磁性逐渐增强。同时,制得的磁性木材为硬磁材料,但从磁性木材的中心部位到边和角部位呈现出向软磁材料转变的趋势。而制得的磁性木材不同部位电磁波吸收性能按中心、边和角的顺序逐渐增强。铁盐浸渍6 d得到的3 mm厚磁性木材的角部位电磁波吸收能力最强,且对5.0 GHz波段的电磁波吸收性能满足吸波材料的要求。
[Abstract]:The effects of different parts of magnetic wood products prepared by dipping method on the distribution, magnetism and electromagnetic wave absorption properties of magnetic materials in the products were studied. Based on the fact that the metal salt ion size is small and the permeability of the wood is better than that of nanoparticles, the pretreated wood is dipped in the mixed solution of trivalent iron and divalent iron and ammonia solution. Fe_3O_4 nanoparticles were prepared in situ in wood by chemical coprecipitation, and magnetic wood was obtained. The composition and structure of the samples were analyzed by infrared spectroscopy and X-ray diffraction, and the distribution of magnetic particles in the samples was studied by means of environmental scanning electron microscope (SEM) and EDS mapping mode. The magnetic properties of the samples were measured by vibrating sample magnetometer and the electromagnetic wave absorption capacity of poplar samples was measured by network vector analyzer. The ratio of Fe~ (3) to Fe~ (2) in iron salt immersion solution is 2 鈮，
本文编号：2475381
[Abstract]:The effects of different parts of magnetic wood products prepared by dipping method on the distribution, magnetism and electromagnetic wave absorption properties of magnetic materials in the products were studied. Based on the fact that the metal salt ion size is small and the permeability of the wood is better than that of nanoparticles, the pretreated wood is dipped in the mixed solution of trivalent iron and divalent iron and ammonia solution. Fe_3O_4 nanoparticles were prepared in situ in wood by chemical coprecipitation, and magnetic wood was obtained. The composition and structure of the samples were analyzed by infrared spectroscopy and X-ray diffraction, and the distribution of magnetic particles in the samples was studied by means of environmental scanning electron microscope (SEM) and EDS mapping mode. The magnetic properties of the samples were measured by vibrating sample magnetometer and the electromagnetic wave absorption capacity of poplar samples was measured by network vector analyzer. The ratio of Fe~ (3) to Fe~ (2) in iron salt immersion solution is 2 鈮，
本文编号：2475381
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