Silicone Rubber-Based Flexible Nanocomposite Sheets with Iron–nickel Electrodeposited Nanographite for Microwave Absorption

This paper describes the improvements in microwave absorbency and other functional properties of silicone rubber-based nanocomposite sheets with iron (Fe)- and nickel (Ni)-deposited nanographite (NG). NG was synthesized using the ball milling method and then acid functionalized. The deposition was performed on acid-functionalized NG dispersed in an electrochemical bath containing Fe and Ni salts in a designed fluidized bed reactor system. The electrolyte concentration, stirring speed, applied current, and time of electrolysis were optimized. X-ray diffraction, Fourier transform infrared spectroscopy, Brenner–Emmet–Teller analysis, transmission electron microscopy, scanning electron microscopy, and atomic force microscopy were used to characterize the structural as well as morphological properties of the material. The applied current, average particle size, and density of the electrolyte–powder suspension have a significant impact on the material’s morphology and microwave absorption capabilities. To measure tensile strength, electrical impedance, and microwave absorption in the 2–20 GHz range, co-deposited nanographite was mixed in a silicone rubber matrix and molded into 1.00–2.00 mm thick nanocomposite sheets. The nanocomposite sheets demonstrated a − 15 dB reflection loss in the 9–13 GHz frequency band with an absorber thickness of 1.24 mm.