Hydro-tunable CZTO/SWCNT/PVA/PDMS hybrid composites for smart green EMI shielding

Abstract

Despite numerous available materials, the advancement of core high-end electronic technologies in automation, defense, etc. created an urgent demand for the development of external stimulus tunable smart electromagnetic interference (EMI) shielding materials with green shielding capability. However, externally tunable high shielding efficiency along with eco-friendliness still poses several challenges. Here we introduce a unique strategy that uses an active guest in a passive host to prepare a polyvinyl alcohol (PVA)/single-walled carbon nanotube (SWCNT)/carbon-doped zinc stannate (CZTO)/polydimethylsiloxane (PDMS) hybrid polymer composite with both superior shielding capability and externally tunable hydro-smart EMI shielding efficiency. In this composite, the electromagnetically transparent PVA particles act as a hydro-active phase, revealing 17.7 dB externally hydro-tunable and 30.66 dB excluded volume-based total green EMI SEs in the extended Ku frequency band. Along with the highest ∼92 dB SE among externally stimulated shielding composite systems and green index (g_s) > 1, this composite architecture indicates absorption-based ecofriendly shielding efficiency with minimal reflection.