【作者】 张杰；

【导师】 陈玉金；

【作者基本信息】 哈尔滨工程大学 ， 光学微纳材料与器件， 2023， 硕士

【摘要】 无线电通讯和电子产品的高速发展,不仅给我们生活带来很多便利,同时产生的电磁干扰以污染问题也愈发突出,因此,为了解决目前面临的电磁干扰与污染问题,开发具有高吸收、低厚度、宽频带和轻质量的吸波材料成为当下的研究热点之一。过渡金属族氧化物或硫化物等材料可以用来吸收电磁波,同时它们具备廉价、稳定以及制造工艺简单等特点。但是它们在制备的过程中易发生团聚现象,而且导电性差,这些缺点限制了它们在电磁波吸收领域的应用。石墨烯气凝胶具有独特的三维网络形态、丰富的孔隙、较好的导电导热特性以及较大的机械强度等特点使得其在各个领域都有着潜在的应用价值。但是石墨烯气凝胶作为吸波材料应用时存在阻抗匹配性差、损耗机制单一等缺点。对于纳米材料而言,结构对它性能有着至关重要的影响。其中,中空的纳米结构通常由于具有较大的比表面积以及较低的质量密度,使得其在锂电池、催化、生物医学、电磁吸收等领域具有广阔的应用前景。因此本文通过模板法、水热法以及高温热处理等方法制备合成了具有中空结构四氧化三铁/硫化铁-氧化石墨烯（Fe₃O₄/Fe S_x-GO）气凝胶,并详细研究了该类材料作为电磁波吸收体的吸波性能和机制。主要研究内容如下:首先对样品就行了扫描、透射、X射线衍射分析（XRD）等表征测试,证明了中空结构以及气凝胶结构的成功合成;对材料的电磁波吸收性能测试结果表明,硫化温度为400℃,再与氧化石墨烯混合得到的气凝胶性能最好。在添加量为30 wt%,厚度为2.0 mm时,最小反射损耗值达到-43.03 d B,且厚度在1.6 mm时最大有效吸收带宽达到4.24 GHz。Fe₃O₄/Fe S_x-GO气凝胶优异的电磁波吸收性能来源于复合材料的中空结构、三维网络结构以及异质界面等共同作用的结果。综上所述,本文通过组成成分、晶化程度以及结构的多重调控成功制备了具有“薄、轻、宽、强”特性的新型吸波材料,该复合材料在电磁波吸收领域具有良好的应用前景,也可为其他新型的电磁波吸收材料的制备提供参考。更多还原

【Abstract】 The rapid development of radio communication and electronic products not only brings a lot of convenience to our lives,but also causes electromagnetic interference and pollution problems.Therefore,in order to solve the current electromagnetic interference and pollution problems,the development of high absorption,low thickness,wide band and light weight absorbing materials has become one of the current research hotspots.Materials such as transition metal oxides or sulfides can be used to absorb electromagnetic waves,and they are cheap,stable and simple to manufacture.However,they are easy to agglomerate in the process of preparation and have poor electrical conductivity,which limits their application in the field of electromagnetic wave absorption.Graphene aerogel has the characteristics of unique three-dimensional network shape,abundant pores,good electrical and thermal conductivity and high mechanical strength,which makes it have potential application value in various fields.However,when graphene aerogel is used as a wave absorbing material,it has some disadvantages such as poor impedance matching and single loss mechanism.For nanomaterials,structure has a crucial effect on their properties.Among them,the hollow nanostructure usually has a large specific surface area and a low mass density,so that it has a broad application prospect in lithium batteries,catalysis,biomedics,electromagnetic absorption and other fields.Therefore,aerogels with hollow structure ferrioxide/Ferrisulfide graphene oxide（Fe₃O₄/Fe S_x-GO）were synthesized by template method,hydrothermal method and high temperature heat treatment,and the wave absorption properties and mechanism of these materials as electromagnetic wave absorbers were studied in detail.The main research contents are as follows:Firstly,the sample was characterized by scanning,transmission and X-ray diffraction（XRD）,which proved that the hollow structure and aerogel structure were successfully synthesized.The results of electromagnetic wave absorption test show that the aerogel obtained by mixing with graphene oxide at 400℃has the best performance.When the addition amount is 30 wt%and the thickness is 2.0 mm,the minimum reflection loss value reaches-43.03 d B,and the maximum effective absorption bandwidth reaches 4.24 GHz when the thickness is 1.6 mm.The excellent electromagnetic wave absorption performance of Fe₃O₄/Fe S_x-GO aerogel is the result of the joint action of the hollow structure,three-dimensional network structure and heterogeneous interface of the composite material.In summary,this paper successfully prepared a new wave absorbing material with the characteristics of"thin,light,wide and strong"through the multiple regulation of composition,crystallization degree and structure.The composite material has a good application prospect in the field of electromagnetic wave absorption,and can also provide a reference for the preparation of other new electromagnetic wave absorbing materials.更多还原