Effect of weak reductant on properties of electroless copper polyacrylonitrile nanocomposites for electromagnetic interference shielding

摘要

In this work, the electroless copper method with different reductant compositions (NaHSO_3/Na_2 S_2O _3·5H_2O and Na_2S_2O _3·5H_2O) without sensitizing and activating, was used to deposit copper-sulfide deposition on the polyacrylonitrile (PAN) surface for electromagnetic interference (EMI) shielding materials. The weak reductant, NaHSO_3, in the electroless copper method was used to control the phase of copper-sulfide deposition. The Cu_(x(x=1-1.8))S was deposited on the PAN (Cu_xS-PAN) by reductant composition (NaHSO _3/Na_2S_2O_3·5H_2O) and the Cu_(x(x=1-1.8))S deposition of Cu_xS-PAN possesses three kinds of coppersulfide phases (CuS, Cu_(1.75)S and Cu _(1.8)S). However, the electrolesscopper with reductant was only Na _2S_2O_3·5H_2O (without weak reductant, NaHSO_3), the hexagonal CuS deposition was plated on the PAN (CuS-PAN) and increased the EMI shielding effectiveness of CuS-PAN composites about 10-15 dB. In this study, the best EMI SE of CuS-PAN and Cu _xS-PAN composites were about 27-30 dB and 15-17 dB respectively, as the cupric ion concentration was 0.24 M. The volume resistivity of CuS-PAN composite was about 1000 times lower than that of Cu_xS-PAN composite and lowest volume resistivity of CuS-PAN composites was 0.012 ω cm, as the cupric ion concentration was 0.24 M.