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Conductive ultrahigh-molecular-weight polyethylene (UHMWPE) composite with segregated nickel (Ni) structure which exhibited highly efficient electromagnetic interference (EMI) shielding performance was fabricated in this work. By synthesizing nickel coated UHMWPE particles via electroless deposition and then hot compressing, the prearranged thin Ni layer could only selectively locate at the boundary between UHMWPE regions due to the specific high melting viscosity of UHMWPE, and thus constructed a well connected segregate Ni conductive network in UHMWPE matrix. Owing to the advantage of segregated network structure, the UHMWPE/Ni composite shows a low percolation threshold and high conductivity, and exhibits an EMI shielding effectiveness (SE) of average 55 dB with Ni content of only 2.58 vol% in X-band. This result indicates the segregated UHMWPE/Ni composite can serve as an ultra-efficient material for EMI shielding applications. [ABSTRACT FROM AUTHOR]

Abstract: Urchin-like FeNi3 microstructures were hydrothermally synthesized at 170°C for 24h without using any template or external magnetic field. The morphology and size of final products strongly depended on the reaction time and temperature. The microstructures and shapes of as-prepared samples were investigated in details by XRD, EDS, TEM, SEM techniques. The formation mechanism of such novel FeNi3 was discussed on the basis of controlled experiments. Compared to FeNi3 bulk material and submicrometre spheres, urchin-like FeNi3 microstructures exhibited a decreased saturation magnetization (M s , 70.7emu/g) but an enhanced coercivity (H c , 78.4Oe) due to their peculiar morphology. [Copyright &y& Elsevier]