Microwave properties of polyvinyl chloride/oxidized activated carbon thin-film composites in the Ka-band

Thin-film composites (TFCs) composed of poly(vinyl chloride) (PVC) and hydrogen peroxide-oxidized activated carbon (AC-H₂O₂) were fabricated via rapid thermal pressing, with filler loadings (<i>x</i>) ranging from 0.2 to 30 wt%. Characterization using SEM/EDX, FTIR, TGA, and Boehm titration confirmed the enhanced surface functionality of AC-H₂O₂. Microwave measurements in the Ka-band demonstrated radiotransparency at <i>x</i> ≤ 10 wt%, whereas higher <i>x</i> increased reflection (up to ∽27%) and decreased transmission (down to ∽48%). The electromagnetic response of the TFCs was tunable by adjusting <i>x</i>, with low <i>x</i> favoring transparency and high <i>x</i> providing effective shielding. These flexible TFCs show promising potential for scalable, lightweight applications in Ka-band electromagnetic inference shielding.