碳纤维纸基屏蔽材料的制备与性能研究

发布时间：2018-10-15 18:26

【摘要】：随着信息技术和电子技术的快速发展,人们生活中出现了大量的电器设备,各种电器设备在提高人们的工作效率和生活质量的同时,也产生了大量的电磁辐射,给人们的生活带来了不便,对人类的生命健康造成了威胁。因此,对高性能屏蔽材料研究就显得非常重要了。石墨烯拥有独特的结构,超强的导电性能,是很有发展前景的电磁屏蔽材料。同时镍也是一种具有高磁导率物质,可以对电磁波产生很大的吸收损耗,是一种非常有发展潜力的屏蔽材料。本研究主要以碳纤维和植物纤维作为基本骨架原料,通过真空减压抽滤法来制备石墨烯/碳纤维电磁屏蔽纸和化学镀镍植物纤维/碳纤维电磁屏蔽纸,并对导电性能和电磁屏蔽性能进行系统研究,为高性能的电磁屏蔽产品的制备提供一定的理论依据。首先,对碳纤维进行氧化改性处理,使其表面的活性基团数量增多。然后分别对化学镀镍后的植物纤维、碳纤维的混合体系的分散性和石墨烯、植物纤维、碳纤维混合体系的分散性进行了研究。发现混合体系的粘度,随着还原剂二甲基氨硼烷(DMAB)用量的增大,先降低后升高,当还原剂二甲基氨硼烷(DMAB)用量为3g/L时,混合体系的粘度最低,分散性能最好,同时包覆率也较大。同时对石墨烯、植物纤维和碳纤维浆料混合体系分散性的因素进行探究,发现当疏解转数为20000r/min,超声时间为22.5min,加入的CPAM用量为0.5%时,石墨烯、植物纤维和碳纤维浆料的混合体系分散性最好。其次,采用真空抽滤将具有超强导电性的石墨烯材料加入到纸基材料内部,制备出石墨烯/碳纤维纸基屏蔽材料,研究了石墨烯添加量对碳纤维纸基材料的导电性能和屏蔽性能的影响;采用探究得到的最佳实验工艺制备石墨烯/碳纤维纸基材料,采用扫描电镜、抗张强度测试仪、四探针电阻率测试仪和矢量网络分析仪对石墨烯/碳纤维纸基材料进行表面形貌、力学性能、导电性能和电磁屏蔽性能的表征,研究石墨烯添加量对石墨烯纸基材料的影响,发现石墨烯添加量为10wt%时,石墨烯/碳纤维纸的电阻率降低到最小值0.662?·cm,同时,石墨烯/碳纤维纸具有最高的电磁屏蔽效能。此外,使用化学镀的方法在植物纤维表面进行化学镀镍,然后采用真空抽滤制备植物纤维化学镀镍的碳纤维纸基材料,研究了镍的包覆量对纸基材料的力学性能、导电性能和屏蔽性能的影响,并将化学镀镍碳纤维纸基材料和石墨烯/碳纤维纸基材料进行了对比分析研究。综合对比两种碳纤维纸基材料,得到结论:相比于石墨烯/碳纤维纸基材料,化学镀镍的碳纤维纸基材料在力学性能和导电性能方面相差都比较大,但其电磁屏蔽性能却和石墨烯/碳纤维纸基材料无明显差异,相同频率下,相差不超过2dB。综上所述,与化学镀镍碳纤维纸相比较,石墨烯/碳纤维纸更适合应用在电磁屏蔽方面,可以更好地对电磁波进行屏蔽。
[Abstract]:With the rapid development of information technology and electronic technology, a large number of electrical equipment have appeared in people's lives. All kinds of electrical equipment not only improve people's working efficiency and quality of life, but also produce a lot of electromagnetic radiation. It brings inconvenience to people's life and threatens the life and health of human beings. Therefore, it is very important to study high performance shielding materials. Graphene, with its unique structure and excellent electrical conductivity, is a promising electromagnetic shielding material. At the same time, nickel is also a kind of high permeability material, which can cause great absorption loss to electromagnetic wave, and it is a kind of shielding material with great development potential. In this study, carbon fiber and plant fiber were used as basic skeleton materials to prepare graphene / carbon fiber electromagnetic shielding paper and electroless nickel-coated vegetable fiber / carbon fiber electromagnetic shielding paper by vacuum filtration method. The electrical conductivity and electromagnetic shielding performance are systematically studied to provide a theoretical basis for the preparation of high performance electromagnetic shielding products. Firstly, the surface active groups of carbon fiber were increased by oxidation modification. Then the dispersity of plant fiber, carbon fiber mixed system and graphene, plant fiber and carbon fiber mixed system after electroless nickel plating were studied respectively. It was found that the viscosity of the mixed system decreased first and then increased with the increase of the (DMAB) content of dimethylamino borane. When the content of (DMAB) was 3g/L, the viscosity of the mixed system was the lowest and the dispersion property was the best. At the same time, the coating rate is also large. At the same time, the factors of dispersity of graphene, plant fiber and carbon fiber paste were investigated. It was found that when the hydrophobic number was 200r / min, the ultrasonic time was 22.5min and the amount of CPAM added was 0.5g / min, graphene was obtained. The mixture of plant fiber and carbon fiber paste has the best dispersion. Secondly, graphene / carbon fiber paper-base shielding material was prepared by adding graphene material with super conductivity into paper based material by vacuum filtration. The effects of graphene addition on the conductive and shielding properties of carbon fiber paper based materials were studied, and the graphene / carbon fiber paper based materials were prepared by the optimum experimental process, and the tensile strength tester and scanning electron microscope were used to prepare graphene / carbon fiber paper based materials. The surface morphology, mechanical properties, electrical conductivity and electromagnetic shielding properties of graphene / carbon fiber paper-based materials were characterized by four-probe resistivity tester and vector network analyzer. The effect of graphene addition on graphene paper-based materials was studied. It is found that the resistivity of graphene / carbon fiber paper decreases to a minimum of 0.662? cm, when the content of graphene is 10 wt%, and the graphene / carbon fiber paper has the highest electromagnetic shielding efficiency. In addition, electroless nickel plating was carried out on the surface of plant fibers by electroless plating, and carbon fiber paper based materials were prepared by vacuum filtration. The mechanical properties of paper based materials were studied by coating amount of nickel. The effects of electroless nickel coated carbon fiber paper based materials and graphene / carbon fiber paper based materials on the electrical conductivity and shielding properties were compared and studied. Compared with graphene / carbon fiber paper based materials, compared with graphene / carbon fiber paper based materials, electroless nickel coated carbon fiber paper based materials have great difference in mechanical properties and conductive properties. However, there is no obvious difference between the electromagnetic shielding properties and graphene / carbon fiber paper based materials, and the difference is not more than 2 dB at the same frequency. In conclusion, compared with electroless nickel coated carbon fiber paper, graphene / carbon fiber paper is more suitable for electromagnetic shielding and can shield electromagnetic wave better.
【学位授予单位】：陕西科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS761.2

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