Fabrication of expanded carbon microspheres/ZnAl2O4 nanocomposite and investigation of its microwave, magnetic, and optical performance

Abstract

In this research the expanded carbon microspheres (ECMS)s were architected using citric acid and sucrose as novel raw materials, as well as ZnAl2O4 nanoparticles were prepared by the sol-gel route using citric acid and they were composited based on a modified sol-gel method. All of the applied analyses including X-ray powder diffraction (XRD), Fourier transform infrared (FTIR), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FE-SEM) attested that the pure ECMS/ZnAl2O4 nanocomposite has been synthesized. Besides, the magnetic, optical, and microwave performance of prepared structures were evaluated by vibrating sample magnetometer (VSM), diffuse reflection spectroscopy (DRS), and vector network analyzer (VNA), respectively. Moreover, the medium and interfacial effects on the microwave characteristics were investigated by polystyrene (PS) and polyvinylidene fluoride (PVDF) matrices. It is found that ECMSs could diminish the energy band gap of nanoparticles, confirmed by the result of ECMS/ZnAl2O4 nanocomposite. Additionally, ZnAl2O4/PVDF nanocomposite demonstrated a significant maximum reflection loss (RL) of 84.95 dB at 13.63 GHz with a thickness of 2.00 mm, whereas ECMS/ZnAl2O4/PS illustrated a considerable efficient bandwidth as wide as 7.47 GHz (RL > 10 dB) with 2.00 mm in thickness. Noteworthy, an eye-catching efficient bandwidth of 3.10 GHz (RL > 20 dB) was achieved by ECMS/ZnAl2O4/PVDF nanocomposite.