發(fā)布時間：2019-05-12 12:10

【摘要】：研究了通過浸漬法制得的磁性木材產(chǎn)物不同部位對產(chǎn)物中磁性物質(zhì)的分布、磁性和電磁波吸收性能的影響。利用金屬鹽離子尺寸小、在木材中滲透性優(yōu)于納米顆粒的特點,將經(jīng)過預處理的木材先后浸漬于三價鐵和二價鐵的混合溶液以及氨水溶液中,通過化學共沉淀的方法在木材中原位制備Fe_3O_4納米顆粒,從而得到磁性木材。對樣品成分和結(jié)構(gòu)進行紅外光譜和X射線衍射光譜分析;將環(huán)境掃描電子顯微鏡與EDS mapping模式聯(lián)用研究樣品中磁性顆粒的分布;使用振動樣品磁強計對所得樣品的磁性進行了測量;并使用網(wǎng)絡矢量分析儀對楊木試樣的電磁波吸收能力進行了測試。鐵鹽浸漬液中Fe~(3+)和Fe~(2+)的物質(zhì)的量之比為2∶1,氨水質(zhì)量分數(shù)為25%,浸漬液通過導管傳輸和紋孔滲透兩種方式進入木材內(nèi)部,最終生成磁性顆粒。磁性顆粒的粒徑在13 nm左右,磁性木材不同部位的鐵含量按照角、邊和中心的順序依次遞減,角部位的磁性強度最高,為24.75 emu/g,而中心部位僅為1.64 emu/g。同時,不同部位的磁矯頑力均較大,分別為137.60(中心),28.15(邊)和10.11 Oe(角),表明制得的磁性木材改變了原來磁性顆粒(Fe_3O_4)的軟磁性特征,為硬磁材料。此外,它們在5.0 GHz處的電磁波吸波強度分別為-0.63(中心),-3.93(邊)和-17.12 d B(角)。采用鐵鹽與氨水逐步浸漬和原位共沉淀的方法可以成功制備磁性木材。在固定的浸漬液配比濃度和鐵鹽浸漬時間下,磁性木材內(nèi)部不同部位所含磁性顆粒的量按中心、邊和角的順序逐漸增加,分布更加均勻,相應的磁性逐漸增強。同時,制得的磁性木材為硬磁材料,但從磁性木材的中心部位到邊和角部位呈現(xiàn)出向軟磁材料轉(zhuǎn)變的趨勢。而制得的磁性木材不同部位電磁波吸收性能按中心、邊和角的順序逐漸增強。鐵鹽浸漬6 d得到的3 mm厚磁性木材的角部位電磁波吸收能力最強,且對5.0 GHz波段的電磁波吸收性能滿足吸波材料的要求。
[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，

本文編號：2475381