本文關(guān)鍵詞：碳磁異質(zhì)結(jié)構(gòu)吸收劑的設(shè)計(jì)、制備與電磁特性　出處：《浙江師范大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 碳/磁雜化材料 異質(zhì)結(jié)構(gòu) 化學(xué)氣相沉積 靜磁性能 微波吸收性能

【摘要】：理想的吸波劑要求質(zhì)量輕,厚度薄,吸收強(qiáng),頻帶寬,吸收頻帶可調(diào)及多功能性,傳統(tǒng)的吸波材料難以滿足當(dāng)前民用和軍用的高要求。目前,研究?jī)?yōu)良的吸波劑面臨兩大難題： (1)高吸收和阻抗匹配是矛盾體； (2)復(fù)合吸波劑的界面是影響性能的關(guān)鍵,但仍然難以控制�？v觀前人的研究與吸波機(jī)理,將碳納米管與納米磁性金屬?gòu)?fù)合成異質(zhì)結(jié)構(gòu)吸波劑可以摒棄傳統(tǒng)單一碳材料和磁性金屬材料吸波劑的自身限制,進(jìn)而獲得具有成分、結(jié)構(gòu)和性能完全可控的新異質(zhì)結(jié)構(gòu)復(fù)合吸波材料�；诋�(dāng)前碳磁復(fù)合吸波材料的研究現(xiàn)狀,本論文設(shè)計(jì)和制備了紅毛丹狀Ni/MWCNTs異質(zhì)結(jié)構(gòu)、蜈蚣狀Fe/Fe3C/MWCNT異質(zhì)結(jié)構(gòu)和EG/Ni/MWCNT雜化異質(zhì)結(jié)構(gòu)三類雜化吸波材料,通過(guò)調(diào)節(jié)實(shí)驗(yàn)工藝條件,實(shí)現(xiàn)了成分、物相、形貌和性能的可控,深入地探究了異質(zhì)結(jié)構(gòu)吸波材料的形成過(guò)程及微波吸收機(jī)理。主要成果如下：(1)采用催化CVD法制備了形態(tài)和組成可控的紅毛丹狀Ni/MWCNT異質(zhì)結(jié)構(gòu),詳盡地研究了異質(zhì)結(jié)構(gòu)的靜磁性能及微波吸收特性;研究發(fā)現(xiàn),當(dāng)PEG20000與NiO的投料比δ從3增到15,隨著樣品的C含量增加,形貌從Ni/C膜核殼結(jié)構(gòu)演變?yōu)榧t毛丹狀Ni/MWCNT異質(zhì)結(jié)構(gòu)；同時(shí),δ的變化導(dǎo)Ms降低和介電常數(shù)增加,當(dāng)δ=7.5時(shí)獲得的Ni/MWCNT異質(zhì)結(jié)構(gòu)具有優(yōu)異的吸波性能,其在12.8 GHz處有最小RL值為-37.9 dB,且在5.0至9.2 GHz內(nèi)RL均低于-20 dB。(2)首次采用一種簡(jiǎn)便的氣流誘導(dǎo)兩步CVD法制備了成分和形貌可控的蜈蚣狀Fe/Fe3C/MWCNTs異質(zhì)結(jié)構(gòu),并且詳盡地研究了該異質(zhì)結(jié)構(gòu)的靜磁性能及微波吸收特性；蜈蚣狀異質(zhì)結(jié)構(gòu)的形成歸因于氣流與自發(fā)磁化的協(xié)同作用；與Fe納米纖維相比,蜈蚣狀Fe/Fe3C/MWCN異質(zhì)結(jié)構(gòu)因其特殊的結(jié)構(gòu),具有多重共振特性、更高的介電損耗和微波吸收特性。(3)采用浸漬法和CVD法成功地制備了形態(tài)和成分可控的輕質(zhì)EG/Ni/CNT雜化材料。研究了鎳鹽的濃度及不同碳源與前驅(qū)物比例對(duì)產(chǎn)物的組成、結(jié)構(gòu)和形貌的影響。靜磁和電磁特性的研究表明：控制Ni顆粒的含量、晶粒尺寸能有效地調(diào)節(jié)軟磁和微波吸收特性。
[Abstract]:Ideal absorbent requires light weight, thin thickness, strong absorption, frequency bandwidth, adjustable absorption band and multifunction. Traditional absorbing materials are difficult to meet the high requirements of civil and military. There are two problems in the study of excellent absorbers: (1) High absorption and impedance matching are contradictions; The interface of composite absorbent is the key to influence the performance, but it is still difficult to control. The composite of carbon nanotubes and magnetic nanometallic materials to form heterogeneous structure microwave absorbers can abandon the limitations of traditional single carbon materials and magnetic metal materials and then obtain the components. Based on the current research status of carbon-magnetic composite absorbing materials, this paper designs and fabricates a novel red-wool Ni/MWCNTs heterostructure with completely controllable structure and properties. Three kinds of hybrid absorbing materials, centipede Fe/Fe3C/MWCNT heterostructure and EG/Ni/MWCNT hybrid heterostructure, were obtained by adjusting the experimental conditions. The morphology and properties are controllable. The formation process and microwave absorption mechanism of heterostructure absorbing materials are studied in depth. The main results are as follows: 1). Ni/MWCNT heterostructures with controllable morphology and composition were prepared by catalytic CVD method. The magnetostatic properties and microwave absorption characteristics of heterostructures are studied in detail. It is found that when the feed ratio 未 of PEG20000 to NiO increases from 3 to 15, the C content of the sample increases. The morphology changed from the core shell structure of Ni/C film to the Ni/MWCNT heterostructure. At the same time, the conductance Ms decreases and the dielectric constant increases. The Ni/MWCNT heterostructure obtained by 未 -7. 5 has excellent absorbing property. The minimum RL value at 12.8 GHz is -37.9 dB. Between 5.0 and 9.2 GHz, RL was lower than -20 dB. For the first time, a simple two-step CVD method was used to prepare the centipede-like Fe/Fe3C/MWCNTs heterostructure with controllable composition and morphology. The magnetostatic properties and microwave absorption characteristics of the heterostructure are studied in detail. The formation of centipede-like heterostructure is attributed to the synergistic effect of airflow and spontaneous magnetization. Compared with Fe nanofibers, centipede Fe/Fe3C/MWCN heterostructure has multiple resonance characteristics because of its special structure. Higher dielectric loss and microwave absorption. Lightweight EG/Ni/CNT hybrid materials with controllable morphology and composition were successfully prepared by impregnation and CVD. The concentration of nickel salt and the composition of the products with different carbon source to precursor ratio were studied. The effects of structure and morphology on the magnetostatic and electromagnetic properties show that the soft magnetic and microwave absorption characteristics can be effectively adjusted by controlling the content of Ni particles and grain size.
【學(xué)位授予單位】：浙江師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TB33;O611.3

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