TY  - EJOU
AU  - Medeiros, Nila Cecília Faria Lopes 
AU  - Amaral-Labat, Gisele 
AU  - Medeiros, Leonardo Iusuti de 
AU  - Boss, Alan Fernando Ney 
AU  - Fonseca, Beatriz Carvalho da Silva 
AU  - Munhoz, Manuella Gobbo de Castro 
AU  - Silva, Guilherme F. B. Lenz e 
AU  - Baldan, Mauricio Ribeiro 
AU  - Braghiroli, Flavia Lega 

TI  - Optimizing Activation Temperature of Sustainable Porous Materials Derived from Forestry Residues: Applications in Radar-Absorbing Technologies
T2  - Journal of Renewable Materials

PY  - 2025
VL  - 13
IS  - 6
SN  - 2164-6341

AB  - Biochar, a carbon-rich material derived from the thermochemical conversion of biomass under oxygen-free conditions, has emerged as a sustainable resource for radar-absorbing technologies. This study explores the production of activated biochars from end-of-life wood panels using a scalable and sustainable physical activation method with CO<sub>2</sub> at different temperatures, avoiding the extensive use of corrosive chemicals and complex procedures associated with chemical or vacuum activation. Compared to conventional chemically or vacuum-activated biochars, the physically activated biochar demonstrated competitive performance while minimizing environmental impact, operational complexity, and energy consumption. Furthermore, activation at 750°C reduces energy consumption by 14% and 28% compared to activations at 850°C and 950°C, respectively, emphasizing the cost-effectiveness of this method for large-scale applications. The composite with 15% of biochar embedded in silicon rubber presented good electromagnetic performance, achieving a measured reflection loss (RL) of −37.2 dB at 11.3 GHz with an 8.4 mm thickness and an effective absorption bandwidth (EAB) of 1.25 GHz. These results highlight the potential of biochar-silicone rubber composites as flexible radar-absorbing materials (RAMs) for applications in electromagnetic shielding, anechoic chambers, and Internet of Things (IoT) devices. This study also shows the importance of forestry residues as sustainable precursors for producing low-cost porous carbon materials, aligning with circular economy principles and the United Nations’ 2030 Agenda for Sustainable Development. This work establishes a framework for scalable, cost-effective, and sustainable biochar production, addressing critical challenges in electromagnetic interference (EMI) mitigation and advancing the global adoption of green technologies.
KW  - Biochar; forestry residues; electromagnetic properties; flexible composites

DO  - 10.32604/jrm.2025.02025-0017