Ultra-porous and lightweight microwave absorber based on epoxy foam loaded with long carbon fibers

H. Breiss (1, 2) , A. El Assal (1) , R. Benzerga (1) , A. Sharaiha (1) , A. Jrad (2) , A. Harmouch (2)

1 IETR - Institut d'Électronique et des Technologies du numéRique
2 LU / ULB - الجامعة اللبنانية [بيروت] = Lebanese University [Beirut] = Université libanaise [Beyrouth]

A simple methodology to fabricate ultra-porous and lightweight epoxy foam composites loaded with carbon fibers is presented. These materials are proposed for microwave absorbing application. The elaborated composite density can be controlled via proper proportioning of carbon fiber/solvent/surfactant/epoxy components constituting the absorber composites. The influence of the weight percentage of these different components, on the composite structure, is studied. The density of the composites can be reduced to 0.05g‧cm−3 while the density of the neat epoxy foam is about 0.12g‧cm−3. Dielectric characterization of composites elaborated with low weight percentages of carbon fibers (from 0.0125 wt.% to 0.075 wt.%) is conducted using free space method. The simulation of a multilayer absorber is conducted and predicts a promising absorption performance (reflection coefficient andlt;-10 dB) for the wide studied frequency band; this result was confirmed by the measurement of a multilayer absorber prototype. Finally, these performances are compared to commercial absorber materials having same dimensions. © 2020 Elsevier Ltd

Mots clés: Carbon fibers; Composite absorber; Dielectric properties; Lightweight epoxy foam; Microwave absorber

Domaines: Sciences de l'ingénieur [physics]

H. Breiss, A. El Assal, R. Benzerga, A. Sharaiha, A. Jrad, et al.. Ultra-porous and lightweight microwave absorber based on epoxy foam loaded with long carbon fibers. Materials Research Bulletin, 2021, 137, pp.111188. ⟨10.1016/j.materresbull.2020.111188⟩. ⟨hal-03130003⟩