【摘要】：隨著電子科學(xué)技術(shù)不斷發(fā)展,不論是軍事雷達(dá)隱身領(lǐng)域還是民用電磁污染防護(hù)領(lǐng)域,對(duì)吸波材料性能的要求越來(lái)越高,發(fā)展新型"薄、輕、寬、強(qiáng)"的吸波材料已是勢(shì)在必行。本文以獲得"薄、輕、寬、強(qiáng)"的吸波材料為目標(biāo),以噴霧干燥法制備的中孔炭微球?yàn)榛A(chǔ),制備了一系列磁性復(fù)合吸波材料,并對(duì)相應(yīng)的吸波機(jī)理進(jìn)行了探討。(1)采用噴霧干燥法制備了粒徑分布在1-10μm的中孔炭微球(MCMSs),比表面積和孔容最高分別可達(dá)到1221 m2/g和2.5 cm3/g。且單純的MCMSs具有一定的吸波效果,最大反射峰峰值可為-12dB,匹配厚度為2mm。但是非磁性的中孔炭微球阻抗匹配較弱,導(dǎo)致了其吸波效果有限。(2)為提高材料的磁損耗能力,采用濕法浸漬-熱處理的方法成功制備了 Fe_3O_4/MCMSs復(fù)合材料。復(fù)合材料具有優(yōu)異的流動(dòng)性和低密度(0.24-0.39 g/cm3)特征,四氧化三鐵的納米顆粒高度分散在MCMSs中孔孔道內(nèi);復(fù)合材料仍具有較高的比表面積(266-735 m2/g);在2-18 GHz范圍內(nèi),復(fù)合材料以介電損耗為主,12.6 GHz處具有最大反射率-25 dB,小于-10 dB的帶寬達(dá)4.7 GHz。其優(yōu)異的吸波性能歸結(jié)于均相分布的Fe_3O_4納米顆粒及其和中孔炭微球之間的協(xié)同作用,同時(shí)改善了阻抗匹配。(3)為在低頻下獲得較好的電磁波吸收效果,通過化學(xué)共沉淀法制備了 NiFe2O4/MCMSs復(fù)合材料,其在匹配厚度5mm時(shí),在5.9 GHz處具有最大反射峰,峰值為-21 dB,小于-10 dB的帶寬2.1 GHz;且涂層厚度為2-5 mm時(shí)最大反射損耗都超過了-10 dB。對(duì)比Fe_3O_4/MCMSs復(fù)合材料,其在低頻下的吸收能力得到了一定程度的提升,這主要?dú)w功于鎳鐵氧體優(yōu)良的軟磁性質(zhì)以及極低的共振頻率,使得復(fù)合材料在較低的頻率范圍內(nèi)出現(xiàn)了多個(gè)共振損耗峰。(4)探索用化學(xué)鍍鎳的方法對(duì)中孔炭微球進(jìn)行包覆,確定了化學(xué)鍍鎳的前處理以及施鍍過程的優(yōu)化工藝條件。成功的在中孔炭微球表面包覆了一層均勻的鎳磷合金鍍層。鍍鎳后保持了中孔炭微球原本較大的介電損耗,同時(shí)磁損耗有大幅增加。在涂層厚度2-5 mm時(shí)鍍鎳中孔炭微球的反射損耗都超過了-10dB,在匹配厚度3mm時(shí),其在7.4GHz處最大反射峰峰值為-20 dB,小于-10 dB的帶寬為2.0 GHz(6.4-8.4 GHz)。結(jié)果表明化學(xué)鍍鎳的方法可以有效的提高中孔炭微球的吸波能力。
[Abstract]:With the development of electronic science and technology, whether in the field of military radar stealth or in the field of civil electromagnetic pollution protection, it is imperative to develop new "thin, light, wide and strong" absorbing materials. In this paper, a series of magnetic composite absorbing materials were prepared on the basis of mesoporous carbon microspheres prepared by spray drying with the aim of obtaining "thin, light, wide and strong" absorbing materials. The corresponding absorbing mechanism was also discussed. (1) the (MCMSs), surface area and pore volume of mesoporous carbon microspheres with particle size distribution of 1-10 渭 m were prepared by spray drying method. The specific surface area and pore volume of mesoporous carbon microspheres were up to 1221 m2 / g and 2.5 cm3/g., respectively. The pure MCMSs has a certain absorbing effect, the maximum reflection peak value can be -12 dB, and the matching thickness is 2 mm. However, the impedance matching of non-magnetic mesoporous carbon microspheres is weak, which leads to the limited effect of absorbing waves. (2) in order to improve the magnetic loss, Fe_3O_4/MCMSs composites were successfully prepared by wet impregnation and heat treatment. The composites have excellent fluidity and low density (0.24-0.39 g/cm3), the nano-particles of Fe _ 2O _ 4 are highly dispersed in the pore channels of MCMSs, and the composites still have high specific surface area (266-735 m2 / g). In the range of 2-18 GHz, the dielectric loss is dominant in the composite, and the bandwidth of -25 dB, less than -10 dB at 12.6 GHz has a bandwidth of 4.7 GHz.. Its excellent wave absorption performance is attributed to the synergistic effect between homogeneous Fe_3O_4 nanoparticles and mesoporous carbon microspheres, and the impedance matching is improved. (3) in order to obtain better electromagnetic wave absorption effect at low frequency, NiFe2O4/MCMSs composites were prepared by chemical coprecipitation method. The maximum reflection peak at 5.9 GHz was obtained when the thickness of 5mm was matched, and the peak bandwidth of -21 dB, less than -10 dB was 2.1 GHz;. And the maximum reflection loss of the coating is more than -10 dB. when the thickness of coating is 2-5 mm. Compared with Fe_3O_4/MCMSs composites, the absorption capacity of Fe_3O_4/MCMSs composites at low frequency is improved to some extent, which is mainly due to the excellent soft magnetic properties of nickel ferrite and the extremely low resonance frequency. The composite has many resonance loss peaks in the lower frequency range. (4) the electroless nickel plating method is explored to coat the mesoporous carbon microspheres, and the pretreatment of electroless nickel plating and the optimum process conditions of the plating process are determined. A uniform Ni-P alloy coating was successfully coated on the surface of mesoporous carbon microspheres. After nickel plating, the dielectric loss of mesoporous carbon microspheres was maintained, and the magnetic loss increased significantly. When the coating thickness is 2-5 mm, the reflection loss of Ni-coated mesoporous carbon microspheres exceeds -10 dB. When the thickness is matched, the maximum reflection peak at 7.4GHz is -20 dB,. Bandwidth less than -10 dB is 2.0 GHz (6.4-8.4 GHz).) The results show that the method of electroless nickel plating can effectively improve the absorbing ability of mesoporous carbon microspheres.
【學(xué)位授予單位】：華東理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TB332

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 王濤;張峻銘;王鵬;喬亮;唐麗云;薛德勝;李發(fā)伸;;吸波材料吸波機(jī)制及吸波劑性能優(yōu)劣評(píng)價(jià)方法[J];磁性材料及器件;2016年06期

2 郭亞軍;張龍;后潔瓊;馬泳波;秋虎;張文娟;杜雪巖;;中空結(jié)構(gòu)聚苯胺/Fe_3O_4/炭黑復(fù)合材料的制備及吸波性能[J];高等學(xué)�；瘜W(xué)學(xué)報(bào);2016年06期

3 李慶;陳志萍;楊曉峰;李巧玲;;基于石墨烯吸波材料的研究進(jìn)展[J];材料導(dǎo)報(bào);2015年19期

4 龐建峰;馬喜君;謝興勇;;電磁吸波材料的研究進(jìn)展[J];電子元件與材料;2015年02期

5 劉英華;;移動(dòng)通信基站的電磁輻射水平及其對(duì)人體健康的影響[J];中國(guó)輻射衛(wèi)生;2014年01期

6 李友良;應(yīng)淑妮;陳國(guó)貴;;石墨烯在電磁屏蔽與吸波材料方面的應(yīng)用及研究進(jìn)展[J];新材料產(chǎn)業(yè);2013年09期

7 劉淵;劉祥萱;王煊軍;陳鑫;;鈰離子摻雜鎳基鐵氧體的制備及其吸波性能[J];硅酸鹽學(xué)報(bào);2013年06期

8 李斌鵬;王成國(guó);王雯;;碳基吸波材料的研究進(jìn)展[J];材料導(dǎo)報(bào);2012年07期

9 謝洪波;江冰;陳華三;張來(lái)祥;;化學(xué)鍍鎳規(guī)律及機(jī)理探討[J];電鍍與精飾;2012年02期

10 葉云;李巧玲;;BaTiO_3/鐵氧體復(fù)合材料的制備及性能[J];分析儀器;2011年02期

，

本文編號(hào)：2338122