title: Facile preparation of lightweight microcellular polyetherimide/graphene composite foams for electromagnetic interference shielding.
abstract: We report a facile approach to produce lightweight microcellular polyetherimide (PEI)/graphene nanocomposite foams with a density of about 0.3 g/cm3 by a phase separation process. It was observed that the strong extensional flow generated during cell growth induced the enrichment and orientation of graphene on cell walls. This action decreased the electrical conductivity percolation from 0.21 vol % for PEI/graphene nanocomposite to 0.18 vol % for PEI/graphene foam. Furthermore, the foaming process significantly increased the specific electromagnetic interference (EMI) shielding effectiveness from 17 to 44 dB/(g/cm3). In addition, PEI/graphene nanocomposite foams possessed low thermal conductivity of 0.065-0.037 W/m·K even at 200 °C and high Young's modulus of 180-290 MPa.
authors: Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang Province, 315201, China.
authors: Jianqiang
authors: J
authors: Ling
authors: Wentao
authors: W
authors: Zhai
authors: Weiwei
authors: W
authors: Feng
authors: Bin
authors: B
authors: Shen
authors: Jianfeng
authors: J
authors: Zhang
authors: Wen ge
authors: Wg
authors: Zheng