Temasek Laboratories, Nanyang Technological University, 50 Nanyang Drive, 637553 Singapore, Singapore.
Temasek Laboratories, Nanyang Technological University, 50 Nanyang Drive, 637553 Singapore, Singapore.
J Colloid Interface Sci. 2017 May 1;493:327-333. doi: 10.1016/j.jcis.2017.01.046. Epub 2017 Jan 16.
3D graphene foam was recently demonstrated to exhibit excellent electromagnetic interference (EMI) shielding performance. In this work, we prepared 3D graphene foams by incorporating a surface modification process of graphene via self-polymerization of dopamine with a subsequent foaming process. The multiple roles played by polydopamine (PDA), including as nitrogen doping source and as an enhancement tool to achieve higher extent of reduction of the graphene through providing wider pathways and larger accessible surface areas were discussed in detail. Despite the presence of the PDA which acted as barriers among the graphene layers that hindered the electrons movement, the enhanced reduction of graphene sheets and the polarization effects introduced by PDA decoration compensated the negative effect of the barrier on EMI shielding effectiveness (SE). As a result, the PDA decorated 3D graphene foams showed improved EMI shielding effectiveness (SE) compared to PDA-free graphene foam (from 23.1 to 26.5dB). More significantly, the EMI shielding performance of the PDA decorated graphene foam was much superior to all existing carbon-based porous materials when the thickness of the specimen was considered.
3D 石墨烯泡沫最近被证明具有优异的电磁干扰（EMI）屏蔽性能。在这项工作中，我们通过将多巴胺自聚合与随后的发泡过程结合，对石墨烯进行表面改性处理，制备了 3D 石墨烯泡沫。详细讨论了聚多巴胺（PDA）的多种作用，包括作为氮掺杂源以及作为增强工具，通过提供更宽的途径和更大的可及表面积，实现石墨烯还原程度的提高。尽管 PDA 充当了石墨烯层之间的障碍，阻碍了电子的运动，但石墨烯片的增强还原和 PDA 修饰引入的极化效应补偿了障碍对 EMI 屏蔽效能（SE）的负面影响。结果，与无 PDA 的石墨烯泡沫相比，PDA 修饰的 3D 石墨烯泡沫的 EMI 屏蔽效能（SE）得到了提高（从 23.1dB 提高到 26.5dB）。更重要的是，当考虑样品厚度时，PDA 修饰的石墨烯泡沫的 EMI 屏蔽性能远远优于所有现有的碳基多孔材料。
