The Preparation and Research on the Electromagnetic Shielding Effectiveness of T-ZnO@Ag/Silicone Rubber Composites

Abstract

This study first conducted surface modification of Ag-plated Tetrapod-like zinc oxide (T-ZnO) whiskers with the use of dopamine and prepared Ag-plated T-ZnO whiskers (T-ZnO@Ag) by means of chemical plating, in which AgNO₃ solutions with different concentrations were used during the preparation. Micro-structures of the prepared T-ZnO@Ag powders were examined to evaluate the effect of AgNO₃ concentration on Ag plating performance. Subsequently, conductive Si rubber samples were prepared, the T-ZnO@Ag powders were used as fillers, and the effectiveness of the related electromagnetic shielding was investigated in detail. The results showed that using AgNO₃ solution with a concentration of 20 g/L, a continuous Ag coating-layer was observed on the surface of T-ZnO whiskers. It was evident that, when used as fillers, T-ZnO@Ag has a conductive threshold and when the mass fraction of the fillers exceeded 50 %, the T-ZnO@Ag whiskers that were uniformly dispersed in the matrix formed interconnected conductive paths. In this condition, the electromagnetic shielding effectiveness of the prepared T-ZnO@Ag/Si rubber composite reached up 90 dB.