TY  - EJOU
AU  - Boss, Alan F.N. 
AU  - Munhoz, Manuella G.C. 
AU  - Amaral-Labat, Gisele 
AU  - Lima, Rodrigo G.A. 
AU  - Medeiros, Leonardo I. 
AU  - Medeiros, Nila C.F.L. 
AU  - Fonseca, Beatriz C.S. 
AU  - Braghiroli, Flavia L. 
AU  - Silva, Guilherme F.B. Lenz e 

TI  - Why Sustainable Porous Carbon Should be Further Explored as Radar-Absorbing Material? A Comparative Study with Different Nanostructured Carbons
T2  - Journal of Renewable Materials

PY  - 2024
VL  - 12
IS  - 10
SN  - 2164-6341

AB  - Radar Absorbing Materials (RAM) are a class of composites that can attenuate incident electromagnetic waves to avoid radar detection. Most carbon allotropes that have the potential to be used as RAM are either carbon nanotubes (CNTs), graphene, carbon black (CB) and ultimately, sustainable porous carbon (SPC). Here, black wattle bark waste (following tannin extraction) was used as a sustainable source to produce SPC made from biomass waste. It was characterized and used as a filler for a silicone rubber matrix to produce a flexible RAM. The electromagnetic performance of this composite was compared with composites made with commercial CB and CNT through reflection loss (RL), where −10 dB is equivalent to 90% of attenuation. These composites were evaluated in single-layer, double-layer, and as radar absorbing structures (RAS) with the aim of improving their effective absorption bandwidth (EAB) performances and a reduction in costs. The CNT composite presented a RL of −26.85 dB at 10.89 GHz and an EAB of 2.6 GHz with a 1.9 mm thickness, while the double-layer structures using CNT and SPC provided a RL of −19.74 dB at 10.75 GHz and an EAB of 2.51 GHz. Furthermore, the double-layer structures are ~42% cheaper than the composite using only CNT since less material is used. Finally, the largest EAB was achieved with a RAS using SPC, reaching ~2.8 GHz and a RL of −49.09 dB at 10.4 GHz. Summarizing, SPC made of black wattle bark waste can be a competitive, alternative material for use as RAM and RAS since it is cheaper, sustainable, and suitable for daily life uses such as absorbers for anechoic chambers, sensors, and electromagnetic interference shields for electronics, wallets, vehicles, and others.
KW  - Microwave absorption material; tannin waste; dielectric constant; carbon composite; reflectivity

DO  - 10.32604/jrm.2024.056004