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 0.1-20 GHz 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.