四氧化三铁复合纤维的制备与吸波性能研究

发布时间：2018-06-26 02:25

本文选题：吸波材料 + 四氧化三铁　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：Fe_3O_4作为一种传统的磁性吸波材料,具有磁导率高、吸波强度高、制备简单等优点,但是相对密度大、吸收频带窄、颗粒分散性差、易腐蚀、高温性差等缺点限制了其进一步的应用。而SiO_2材料化学性能稳定、易功能化、介电常数值小、电导率低,将其作为Fe_3O_4纳米颗粒的包覆层,不仅可以改进四氧化三铁纳米颗粒之间的相互作用,改善其分散性,而且它们之间独特的界面效应能够使阻抗更加匹配。静电纺丝是目前制备微纳米纤维最有效的方法之一,该方法使电纺前驱体在高压电场中被高速拉伸,溶剂挥发固化后制得微纳米纤维。因此本文采用静电纺丝的方法制备了两种不同的Fe_3O_4/SiO_2复合纤维以及纯的Fe_3O_4纤维,并对其形貌、结构、耐酸性、吸波性能进行了分析,主要内容如下:(1)在可纺范围内,通过电纺技术将水热法制备的Fe_3O_4纳米颗粒掺杂到SiO_2纤维中制得两种不同质量分数的Fe_3O_4/SiO_2复合纤维。研究发现,Fe_3O_4纳米颗粒分散性差,团聚现象严重,有效吸收带宽较窄为5.9GHz。而Fe_3O_4/SiO_2复合纤维中的Fe_3O_4纳米颗粒在纤维中长列有序分布,分散性得到了明显改善,且复合纤维密度很低,耐酸性强。样品Fe_3O_4/SiO_2复合纤维(质量比1:10)在匹配厚度6mm,反射损耗峰值在18GHz处达到-14.8dB,其-10dB的有效吸收带宽达到11.0GHz。进一步增加Fe_3O_4的含量,由于颗粒分散性较差,吸波性能并未改善。(2)通过静电纺丝以柠檬酸、硝酸铁和硫酸亚铁为原料制备了Fe_3O_4前驱体纤维,经烧结后得到Fe_3O_4纤维,对其吸波性能分析,其吸收强度很高,但有效吸收带宽相对较窄。在有效结合两种溶胶前驱体的基础上,通过电纺Fe_3O_4前驱体溶胶与SiO_2溶胶的混合前驱体,制备得到两种不同质量分数的Fe_3O_4/SiO_2复合纤维。研究发现:复合纤维密度很低、耐酸性强。Fe_3O_4含量较低的复合纤维在匹配厚度为6mm,反射损耗峰值在频率为18GHz处达到-16.1dB,其-10d B的有效吸收带宽达到11.8GHz。进一步增加Fe_3O_4的含量,由于SiO_2纤维包覆能力有限,使得多于的Fe_3O_4颗粒吸附在纤维外表面,吸波性能并未能得到明显改善。综上,相比于单一组分的Fe_3O_4吸波材料,利用静电纺丝在Fe_3O_4表面包覆SiO_2纤维制得的Fe_3O_4/SiO_2复合纤维,其密度低、耐酸性强,有效吸收频带宽。
[Abstract]:Fe _ 3O _ 4, as a traditional magnetic absorbing material, has the advantages of high permeability, high absorption intensity and simple preparation, but it has high relative density, narrow absorption band, poor dispersion of particles and easy corrosion. Its further application is limited by its disadvantages such as poor high temperature. The SiO2 material has stable chemical properties, easy functionalization, low dielectric constant and low electrical conductivity. Using SiO2 as the coating layer of Fe3O4 nanoparticles can not only improve the interaction between Fe3O4 nanoparticles, but also improve the dispersion of Fe3O4 nanoparticles. And the unique interfacial effect between them can make the impedance more matching. Electrospinning is one of the most effective methods to prepare micro and nano fibers. This method makes the electrospinning precursor be stretched at high speed in high voltage electric field and the solvent volatilizes and solidifies to produce micro and nano fibers. In this paper, two kinds of Fe3O / SiO2 composite fibers and pure Fe3O4 fibers were prepared by electrospinning method. The morphology, structure, acid resistance and absorptivity of the fibers were analyzed. The main contents are as follows: (1) in the spinning range, Two kinds of Fe _ 3O _ 4 / Sio _ 2 composite fibers with different mass fraction were prepared by electrospinning technique by doping the Sio _ 3O _ 4 nanoparticles prepared by hydrothermal method into the Sio _ 2 fibers. It is found that Fe3O4 nanoparticles have poor dispersion, serious agglomeration and narrow effective absorption bandwidth of 5.9 GHz. However, the distribution of Fe3O4 nanoparticles in the Fe3O4 / SiO2 composite fiber has been obviously improved, and the density of the composite fiber is very low and the resistance to acid is strong. The sample Fe3O / SiOs _ 2 composite fiber (mass ratio 1:10) is 6 mm thick, the peak reflection loss is -14.8dB at 18GHz, and its effective absorption bandwidth of -10dB is 11.0GHz. Further increasing the content of Fe3O4, due to the poor dispersion of the particles, the microwave absorption properties have not improved. (2) Fe3O4 precursor fibers were prepared by electrostatic spinning using citric acid, ferric nitrate and ferrous sulfate as raw materials. After sintering, Fe3OS4 fibers were obtained. The absorption intensity is very high, but the effective absorption bandwidth is relatively narrow. On the basis of combining the two kinds of sol precursors effectively, two kinds of Fe3Os / SiO2 composite fibers with different mass fraction were prepared by electrospinning the mixed precursor of Fe3O4 precursor and SiO2 sol. It is found that the composite fibers with low fiber density and low acid resistance. Fe3O _ 4 have a matching thickness of 6mm, a peak reflection loss of -16.1 dB at 18GHz, and an effective absorption bandwidth of -10dB of 11.8 GHz 路min ~ (-1) 路kg ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1). The content of Fe3O4 is further increased. Due to the limited coating ability of SiO2 fibers, more Fe3O4 particles are adsorbed on the outer surface of the fibers. To sum up, compared with the single component of the Snap-Fe3O4 absorbing material, the Fe3O4 / SiO2 composite fiber, which is prepared by electrostatic spinning, is coated with the SiO2 fiber on the surface of the Fe3O4. Its density is low, the acid resistance is strong, and the effective absorption frequency bandwidth is high.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB34

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