Light weight and flexible electronic components are extensively being designed and developed due to the miniaturization of electronic devices. Such materials with light weight and low density are highly preferred for EMI shielding applications also. Heavy materials which lack flexibility will not be chosen for practical EMI shielding applications due to their structural limitations, even though they possess exceptional shielding efficiency. Beyond these functional aspects, ensuring the sustainability and environmental compatibility of such material is essential for their broader technological adoption. Low density aerogels which show adequate shielding efficiency are emerging as promising materials for EMI shielding. In addition to low density and strong shielding ability, the sustainability and biodegradability of the material is also vital for assessing its applicability in sophisticated technological applications. Polyvinyl alcohol is a prime member among materials used to fabricate biodegradable materials since it can be availed for the easy fabrication of films, aerogels and hydrogels. Biodegradable lightweight aerogels were fabricated with polyvinyl alcohol/polypyrrole nanotube-GnP (PVA/PPy nT-GnP) composite. The sustainability of the composite arises from the biodegradable PVA matrix, the metal—free and environmentally benign conductive PPy nanotubes and the carbon-based recyclable GnP. All these together ensure the formation of green EMI shielding material without significantly compromising the environmental footprint of the composite. The fabricated aerogels possessed a maximum electrical conductivity of 0.721 S/cm and achieved an outstanding shielding efficiency of nearly ~ 50 dB and specific shielding efficiency (SSE) of ~ 499 dB cm g −1 . More promisingly the fabricated sustainable aerogels exhibited more than 90% of absorption with very minimal reflection. The porous structure of the aerogel facilitated the multiple reflection of EM radiations and contributed to the absorption loss of the material. These results highlight PVA/PPy nT-GnP aerogel as sustainable, biodegradable and high-performance candidate for next generation lightweight EMI shielding applications.
Nair et al. (Wed,) studied this question.