Author(s):
Lokesh Saini, Priyambada Sahoo, Raj Kumar Jani, Ambesh Dixit
Abstract:
Carbonaceous materials of two different types, viz. spherical nano carbon black (NCB)
powder (Brunauer-Emmett-Teller (BET) surface area ~1400 m2/g) and multiwalled carbon
nanotube (MWCNT) (BET surface area ~75 m2/g), have been impregnated in room temperature
vulcanized (RTV) silicon rubber matrix to study the effect of geometries of filler particles on
microwave absorption characteristics, over X-band frequencies (8.2 -12.4 GHz). The rubber-based
composites are prepared by dispersion of NCB and MWCNT fillers in the liquid rubber with
loading fractions ranging from 0.3-0.9 wt% and 1.1-1.7 wt%, respectively. The dielectric loss
tangent (tanδe) profiles were evaluated for the filler-loaded rubber composites at different
concentrations. The calculated Reflection loss (RL) profiles suggest that NCB-based rubber
provides maximum RL value, (RL)max ~ -20 dB (99.00 % absorption), at a lower filler
concentration of 0.5 wt%, as compared to MWCNT. However, the MWCNT-based rubber
composite shows enhanced (RL)min values of ~ -29 dB (~99.99% absorption) due to multiple
scattering phenomena. The identified NCB and MWCNT-based rubber-based MW absorbers have
potential stealth applications for military aerial vehicles.
Pages: 381-392
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