Electrical-Field Induced Nonlinear Conductive Characteristics of Polymer Composites Containing SiO_2-Decorated Silver Nanowire Hybrids

摘要

Environment adaptive electromagnetic protection for electronic systems with transmitting and receiving electromagnetic information is increasingly important because of rapid development of information technology and the application of strong electromagnetic pulse. Easy-to-prepare materials with stable electrical-field induced nonlinear conductive characteristics are strongly desired. In this study, the core-shell hybrid nanoparticles of SiO2-decorated silver nanowire hybrids (AgNWs@SiO2) were synthesized via a sol-gel process employed in a polyvinyl alcohol (PVA) matrix material to prepare composites. Microstructure analysis demonstrated that SiO2 insulating layer was well-bonded to the surface of AgNWs. The AgNWs@SiO2/PVA composites exhibited stable and excellent nonlinear conductive behavior under increasingly applied voltage with high filling concentration of the hybrid nanoparticles, the switching threshold voltage of proposed composites can be tuned by optimizing the loading amount of AgNWs@SiO2 hybrid fillers and the thickness of the SiO2 insulating layer. The mechanism of the nonlinear conductive characteristic of the composites was discussed. The shielding effectiveness (SE) of the developed material against the square-wave electromagnetic pulse up to 15 dB, which verified the adaptive protection function of the AgNWs@SiO2/PVA composite.