Yuan Yang, Qu Zhaoming, Wang Qingguo, Sun Xiaoning
National Key Laboratory on Electromagnetic Environment Effects, Army Engineering University, Shijiazhuang 050003, China.
Polymers (Basel). 2020 Jul 23;12(8):1634. doi: 10.3390/polym12081634.
With the increasing threats arising from the electromagnetic environment, polymeric composites which could exhibit nonlinear conductive characteristics are highly required in the protection of electronic devices against overvoltage. In this research, ZnO nanoparticles are coated onto graphene nanoplatelets (GNPs)-carbon nanotubes (CNTs) hybrid, and then it is embedded in epoxy resin (ER) matrix via solution blending. Based on the characterization results, CNTs are well dispersed across the GNPs which prevent the restacking of GNPs and CNTs. At the same time, ZnO nanoparticles are well-bonded to the surfaces of GNPs-CNTs hybrid. During repeated conductive characteristic measurements, GNPs-CNTs-ZnO/ER composite is able to demonstrate distinctly reversible nonlinear conductive behavior, with high nonlinear coefficients. Especially, the filler content in GNPs-CNTs-ZnO/ER composite is only 12.5% of that in GNPs-ZnO/ER composite reported in our previous work. Moreover, it is shown that the nonlinear coefficients and switching threshold voltage can be modified by controlling the weight ratios of GNPs, CNTs, and ZnO. Finally, the samples with 1:1 weight ratio of GO to MWCNTs (A-6.67 and A-10) exhibit the best reversible nonlinear conductive behavior.
随着电磁环境带来的威胁日益增加，在保护电子设备免受过电压影响方面，迫切需要能够呈现非线性导电特性的聚合物复合材料。在本研究中，将氧化锌纳米颗粒包覆在石墨烯纳米片（GNPs）-碳纳米管（CNTs）杂化物上，然后通过溶液共混将其嵌入环氧树脂（ER）基体中。基于表征结果，碳纳米管在石墨烯纳米片上分散良好，这防止了石墨烯纳米片和碳纳米管的重新堆叠。同时，氧化锌纳米颗粒与石墨烯纳米片-碳纳米管杂化物的表面结合良好。在重复的导电特性测量过程中，石墨烯纳米片-碳纳米管-氧化锌/环氧树脂复合材料能够表现出明显的可逆非线性导电行为，具有高非线性系数。特别是，石墨烯纳米片-碳纳米管-氧化锌/环氧树脂复合材料中的填料含量仅为我们先前工作中报道的石墨烯纳米片-氧化锌/环氧树脂复合材料中填料含量的12.5%。此外，结果表明，通过控制石墨烯纳米片、碳纳米管和氧化锌的重量比，可以改变非线性系数和开关阈值电压。最后，氧化石墨烯与多壁碳纳米管重量比为1:1的样品（A-6.67和A-10）表现出最佳的可逆非线性导电行为。
