Comparative studies on physical and chemical routes for animal waste-derived activated carbon for microwave absorption in the X-band

Khasnabis, S and Hs, MJ and Bora, PJ and Ramamurthy, PC (2022) Comparative studies on physical and chemical routes for animal waste-derived activated carbon for microwave absorption in the X-band. In: Journal of Materials Science: Materials in Electronics, 33 (7). pp. 3425-3437.

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Abstract

Electromagnetic pollution is a great concern in the present day. Activated carbon derived from waste sources can prove to be a green and cost-effective solution in this situation. In this work, a comparative study has been conducted to explore the potential of cowdung (animal waste)-derived activated carbon towards microwave absorption. Cowdung, which is abundantly available in the environment as a source of biomass, is used as the filler after being activated through two different routes, physical (carbonization) and chemical (acid and base activation). Due to the properties of being lightweight, flexible, corrosion resistive and having ease of large area fabrication, polydimethyl siloxane (PDMS) elastomer has been chosen as a matrix for the composites. Characterizations such as SEM, XRD and FTIR were performed to investigate the morphological and the functionalities present in the porous carbon structure. BET was further performed to investigate parameters such as specific surface area and pore volumes of the samples. Apart from the contribution from interfacial polarization owing to the dielectric properties of the filler material, the induced porosity resulted in hollow carbon structures which contributed to the microwave absorbing properties by scattering and reflecting the incident radiation. In the systems studied, the physically activated samples and the H2SO4-activated sample amongst chemical-activated samples are seen to reach values of ~ − 25 dB thickness as low as 4 mm. The best result is seen correspond to the composite carbonized at 600 °C, which shows ~ − 26 dB of microwave absorption with a bandwidths below − 10 dB (which corresponds to 90% absorption) ranging over 2 GHz. Hence these results indicate the suitability of these systems for real-time applications electronic system shielding.

Item Type:	Journal Article
Publication:	Journal of Materials Science: Materials in Electronics
Publisher:	Springer
Additional Information:	The copyright for this article belongs to the Springer.
Keywords:	Animals; Carbonization; Corrosion; Cost effectiveness; Electromagnetic shielding; Fillers; Microwaves; Pollution; Real time systems, Animal wastes; Carbon structures; Carbonisation; Chemical routes; Comparatives studies; Cost-effective solutions; Cow dung; Electro magnetic pollution; Microwave absorption; X bands, Activated carbon
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	18 Nov 2021 10:03
Last Modified:	30 Jun 2022 05:19
URI:	https://eprints.iisc.ac.in/id/eprint/70579

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