Effect of Barium Hexaferrites and Thermally Reduced Graphene Oxide on EMI Shielding Properties in Polymer Composites

Barium hexaferrites (BaFe) and thermally reduced graphene oxide (TRGO) were successfully prepared by co-precipitation and improved hummer’s method, respectively. Nanocomposite films based on the thermoplastic polyurethane (TPU) matrix with different compositions of TRGO and BaFe were prepared by a solution casting method with a thickness of 0.25 mm. Electromagnetic interference (EMI) shielding is the key application area of these nanocomposites in the microwave frequency range of 0.1–20GHz and near infrared (NIR) wavelength range of 700–2500 nm. A maximum of 3.5*10⁻⁵ S/cm AC conductivity and 4.8*10⁻⁶ S/cm DC conductivity was achieved. The dielectric constant and dielectric loss also enhanced 2–3 times with respect to the pure TPU matrix. Less than 0.5% transmission in the NIR region and −40 dB shielding were observed in the microwave region. The highest shielding of −61 dB was achieved at frequency 12.5GHz.