Dielectric characterization of white birch–activated biochar composites: A sustainable alternative to radar-absorbing materials
| Autor: | Guilherme Fb Lenz e Silva, Maurício Ribeiro Baldan, Ariane At Souza, Alan Fn Boss, Hassine Bouafif, G. Amaral-Labat, Flavia Lega Braghiroli, Ahmed Koubaa |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
020209 energy Mechanical Engineering 02 engineering and technology Dielectric 010501 environmental sciences 7. Clean energy 01 natural sciences Reflectivity law.invention Characterization (materials science) Mechanics of Materials law Biochar 0202 electrical engineering electronic engineering information engineering Materials Chemistry Ceramics and Composites Composite material Radar Radar-absorbent material 0105 earth and related environmental sciences |
| Zdroj: | Journal of Composite Materials. 54:1233-1244 |
| ISSN: | 1530-793X 0021-9983 |
| DOI: | 10.1177/0021998319877493 |
| Popis: | Sustainability can be defined as the ability of meet presents needs without compromise the ability of future generations to find their own needs. In this matter, scientists have been warning about natural resource scarcity, and now several researchers are aiming their efforts to develop sustainable technologies. Here, we focus on finding novel uses to biochar, a carbon rich material made from biomass that is usually applied on soil amendment. To expand its applications, biochars were activated using two different methods: a physical activation using CO2; and a chemical one using KOH. We investigate here the dielectric properties of composites made with both activated biochars from white birch, where composites were made using silicone rubber matrix. It was also investigated the influence of composites made with biochar in powder and in flakes. All samples were characterized over the X-band frequency range. Composites made with powder presented a linear permittivity over the frequency range, while composites made with flakes presented oscillations on different frequencies. These oscillations are related to the composite surface, which induces reflection effects because of flakes arrangement in the top surface. Such effects widen opportunities to engineer new materials to be explored as radar-absorbing materials. |
| Databáze: | OpenAIRE |
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