Vigilancia Tecnológica

Hybrid polymeric materials with outstanding microwave absorbing properties were prepared by in situ polymerization of aniline in the presence of EVA/CNT/GNP suspension.AbstractMicrowave?absorbing materials are widely used for electromagnetic interference shielding and stealth technology. However, most existing materials are heavy, rigid, and expensive, limiting their practical applications. Therefore, there is a need to develop new materials that are flexible, lightweight, and cost effective. This study aimed to synthesize and characterize a novel ternary composite material based on polyaniline (PAni), carbon nanotubes (CNTs), and graphene nanoplatelets (GNPs) in an ethylene?vinyl acetate (EVA) copolymer matrix. PAni?based ternary composites were prepared by in situ polymerization of aniline in toluene dispersion of CNT/GNP hybrids and EVA. The microwave absorption properties were evaluated using a vector network analyzer in the frequency range of 8.2–18?GHz. The presence of as little as 0.8?wt% of CNT/GNP hybrid with appropriate mass ratio increased the conductivity by more than four orders of magnitude compared to the EVA@PAni blend. The minimum reflection loss corresponded to ?40.55?dB at 16.31?GHz for the system containing CNT/GNP?=?0.3:0.7, whereas those with CNT/GNP?=?0.0:1.0 and 0.7:0.3 presented the widest effective absorption bandwidths (RL < ?10 dB), covering almost the entire Ku?band. Due to the excellent flexibility, low weight, and high microwave absorption performance, these composites are potential candidates for microwave absorption applications.