Avanish K. Srivastava; Bhumika Samaria; Smita Soni; Virendra S Chauhan; Jitendra Singh; Rajesh K Shukla; Anuj Shukla; Narendra Kumar
Abstract
In the ongoing search for newer materials for microwave absorption applications, the graphene merits a special consideration owing to its outstanding mechanical, thermal and electrical properties. Here, we report investigation on microwave absorption properties of Fe-Co oxide- thermally exfoliated graphene ...
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In the ongoing search for newer materials for microwave absorption applications, the graphene merits a special consideration owing to its outstanding mechanical, thermal and electrical properties. Here, we report investigation on microwave absorption properties of Fe-Co oxide- thermally exfoliated graphene oxide (Fe-Co oxide-TEGO) composite in a frequency range of 8-18 GHz. Fe-Co oxide was synthesized by thermal decomposition of Fe-Co oxide/aniline- formaldehyde copolymer at 900 0C in air. Fe-Co oxide-TEGO hybrid was prepared by physical mixing of Fe-Co oxide and TEGO. Thereafter, hybrid was characterized using scanning electron microscope, energy dispersive X-ray, Fourier transform infrared spectrometer and X-ray diffractrometer. Thereafter, Fe-Co oxide-TEGO composites were prepared by intermixing in different weight % in PU (polyurethane) resin and their electromagnetic and microwave absorption properties were studied. The effect of varying the weight % of Fe-Co oxide in Fe-Co oxide-TEGO composite on electromagnetic properties was also studied. The absorption bandwidth of 3.5 GHz (8.5-12.0 GHz, X-band) and 5.0 GHz (13.0-18.0 GHz, Ku -band) has been achieved using Fe-Co oxide-TEGO composite (50 wt%) with 2.2 and 1.6 mm thickness, respectively. Microwave absorption studies show Fe-Co oxide- TEGO composite as a potential candidate for microwave absorption applications. Copyright© 2018 VBRI Press.
Bhumika Samaria; Avanish K. Srivastava; Virendra S Chauhan; Jitendra Singh; Smita Soni; Manoj K Dhaka; Rajesh K Shukla; Anuj Shukla; Narendra Kumar
Abstract
The discovery of graphene and subsequent development of graphene-based nanocomposites in different matrices including that in polymer is an important addition in the area of nanoscience and technology. This work deals with the studies on the dielectric properties of the nanocomposites of graphite, graphite ...
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The discovery of graphene and subsequent development of graphene-based nanocomposites in different matrices including that in polymer is an important addition in the area of nanoscience and technology. This work deals with the studies on the dielectric properties of the nanocomposites of graphite, graphite oxide (GO) and thermally exfoliated graphene oxide (TEGO) in epoxy matrix. GO was synthesized using modified Hummers method which on heat treatment at ~300 0C resulted into formation of graphene oxide termed as TEGO. The synthesized GO and TEGO were characterized using scanning electron microscope, energy dispersive X-ray, Fourier transform infrared spectrophotometer, Raman spectrometer, X-ray diffractometer, UV-Vis spectrometer, CHNSO analyzer, surface area analyzer, and dc electrical conductivity. Composites using graphite powder (GP), GO and TEGO individually were prepared in epoxy resin. The dielectric (dielectric permittivity, dielectric loss tangent) properties of composites were studied in frequency range of 8 - 12 GHz. Dielectric tangent loss (tande) vary from 0.02 for GP to 0.35 for TEGO. The effect of addition of GP to GO and TEGO composite on dielectric properties was investigated. The order of tandevalues of composites is: TEGO > GP-TEGO > GP-GO> GO >GP. TEGO composite showed significant dielectric loss among the reported composites. The results thus indicate TEGO as filler for epoxy based composites to afford specific dielectric properties, especially as an alternative of much more expensive carbon nanotubes. Copyright © 2018 VBRI Press.