title: Polydopamine decoration on 3D graphene foam and its electromagnetic interference shielding properties.
abstract: 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.
authors.affiliation: Temasek Laboratories, Nanyang Technological University, 50 Nanyang Drive, 637553 Singapore, Singapore. Electronic address: ly.zhang@ntu.edu.sg.
authors.forename: Liying
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Temasek Laboratories, Nanyang Technological University, 50 Nanyang Drive, 637553 Singapore, Singapore.
authors.forename: Ming
authors.initials: M
authors.lastname: Liu
authors.affiliation: Temasek Laboratories, Nanyang Technological University, 50 Nanyang Drive, 637553 Singapore, Singapore.
authors.forename: Shuguang
authors.initials: S
authors.lastname: Bi
authors.affiliation: Institute of Chemical and Engineering Sciences, A*STAR (Agency for Science, Technology and Research), 1 Pesek Road, Jurong Island, 627833 Singapore, Singapore.
authors.forename: Liping
authors.initials: L
authors.lastname: Yang
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore, Singapore.
authors.forename: Sunanda
authors.initials: S
authors.lastname: Roy
authors.affiliation: School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore, Singapore.
authors.forename: Xiu-Zhi
authors.initials: XZ
authors.lastname: Tang
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore, Singapore.
authors.forename: Chenzhong
authors.initials: C
authors.lastname: Mu
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore, Singapore. Electronic address: ASXHU@ntu.edu.sg.
authors.forename: Xiao
authors.initials: X
authors.lastname: Hu
keywords: Electromagnetic interference shielding behavior; Graphene foam; Nitrogen-doping; Polydopamine