基于石墨烯海绵制备的复合材料及薄膜电磁屏蔽性能研究

发布时间：2018-02-23 20:09

本文关键词： 石墨烯海绵电磁屏蔽性能 PDMS 柔性石墨烯薄膜　出处：《哈尔滨工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：石墨烯具有优异的电学性能,在电磁屏蔽领域的应用潜力巨大。在实际应用的过程中,二维石墨烯纳米片不容易操控,影响石墨烯电学性能的发挥。而三维石墨烯海绵比二维石墨烯纳米片更容易操控,是发挥石墨烯优异电学性能的有效途径。本论文基于三维石墨烯海绵制备了石墨烯材料,并且重点研究了他们的电磁屏蔽性能,具体的研究内容如下:利用冷冻干燥的方法制备了氧化石墨烯海绵,并通过水合肼还原得到了石墨烯海绵。通过将聚二甲基硅氧烷(PDMS)与石墨烯海绵复合,制备得到了石墨烯海绵/PDMS复合材料。在复合之前,通过热处理的方法,提高了石墨烯海绵的电学性能。当石墨烯的质量分数为3.07%时,复合材料的电导率达到了103S/m,并且当复合材料的厚度为2mm,在8~12GHz的频率范围,复合材料的平均电磁屏蔽性能可以达到54.26d B。通过对石墨烯海绵/PDMS复合材料的电磁屏蔽机理分析,吸收屏蔽效能占总屏蔽效能的主要部分,表明石墨烯海绵/PDMS复合材料是以吸收为主的电磁屏蔽材料。利用冷冻干燥的方法制备了氧化石墨烯海绵,并通过水合肼还原得到了石墨烯海绵。通过原位热压的工艺制备得到了基于石墨烯三维网络的柔性石墨烯薄膜。对柔性石墨烯薄膜电学、导热、电磁屏蔽性能和对X射线的透过性能进行了研究。柔性石墨烯薄膜的电导率达到1.14×105S/m,热导率达到1073.83 W/(m·K),并且薄膜厚度在50μm的条件,频率在1.7GHz~40GHz的范围内,电磁屏蔽效能最低值超过50d B。通过对柔性石墨烯薄膜的电磁屏蔽机理进行分析,吸收屏蔽效能占总屏蔽效能的主要部分,表明柔性石墨烯薄膜是以吸收为主的电磁屏蔽材料。随着X射线能量的增加,更容易透过柔性石墨烯薄膜。
[Abstract]:Graphene has excellent electrical properties and has great potential in electromagnetic shielding. In practical applications, two-dimensional graphene nanocrystals are not easy to manipulate. It is an effective way to exert the excellent electrical properties of graphene by using 3D graphene sponge, which is easier to manipulate than two-dimensional graphene nanosheet. In this paper, graphene materials were prepared based on 3D graphene sponge. Their electromagnetic shielding properties were studied. The main contents were as follows: graphene oxide sponge was prepared by freeze-drying method. The graphene sponge was synthesized by hydrazine hydrate reduction. The graphene sponge / PDMS composite was prepared by combining polydimethylsiloxane (PDMS) with graphene sponge. The electrical properties of graphene sponges are improved. When the mass fraction of graphene is 3.07, the electrical conductivity of the composites reaches 103 S / m, and when the thickness of the composite is 2 mm, the frequency range is 812 GHz. The average electromagnetic shielding performance of the composite can reach 54.26 dB. By analyzing the electromagnetic shielding mechanism of graphene sponge / PDMS composite, the absorption shielding efficiency accounts for the main part of the total shielding efficiency. The results showed that graphene sponge / PDMS composite was an absorbing electromagnetic shielding material, and graphene oxide sponge was prepared by freeze-drying method. The graphene sponge was prepared by hydrazine hydrate reduction, and the flexible graphene film was prepared by in-situ hot pressing. The electromagnetic shielding properties and X-ray transmittance of flexible graphene thin films are studied. The conductivity of flexible graphene thin films is 1.14 脳 10 ~ 5 S / m, the thermal conductivity is 1073.83 W / m 路K ~ (-1), the thickness of the films is 50 渭 m, and the frequency is within 1.7 GHz. The minimum electromagnetic shielding efficiency is more than 50 dB. By analyzing the electromagnetic shielding mechanism of the flexible graphene film, the absorption shielding efficiency accounts for the main part of the total shielding effectiveness. It is shown that the flexible graphene film is a kind of electromagnetic shielding material which is mainly absorbed, and it is easier to pass through the flexible graphene film with the increase of X-ray energy.
【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】：TB332;O613.71

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