부산대학교 도서관

This study aims at designing microwave absorbing composites for controlling electromagnetic (EM) pollution by absorption of EM waves inside the composite material. For this purpose, a light weight and flexible microwave absorber composite was fabricated using reduced graphene oxide (RGO) and W-type barium hexaferrite (BaW) in polyvinylidene fluoride (PVDF) matrix. W-type hexaferrite nanoparticles (BaW) were fabricated by sol–gel auto-combustion method. The fabricated nanoparticles were mixed in PVDF by mechanical grinding. Subsequently, the composites were designed by ultrasonic mixing BaW/PVDF with RGO. The prepared samples were characterized through different techniques for their structural, morphological, and EM properties, as discussed in detail. The X-ray diffractometer results showed the existence of single-phase hexaferrite structure with an average particle size of 48.9 nm. The scanning electron microscope results show that BaW/PVDF is completely embedded in RGO. Dielectric results showed that addition of RGO in BaW/PVDF increases polarization effect, which increases dielectric constant of material. Moreover, RGO decreases the saturation magnetization of composites, which increases the anisotropy constant and hence increases the magnetic loss of material. The composite C3 having RGO to ferrite ratio 15:100 exhibits the maximum reflection loss of −11 dB with broad bandwidth <−10 dB for complete X-band (8.2–12.4 GHz). [ABSTRACT FROM AUTHOR]