Complex permittivity and electromagnetic interference shielding properties of Ti₃SiC₂/polyaniline composites

Ti3SiC2/insulating polyaniline (Ti3SiC2/PANI) composites were prepared by solution blending and subsequently by hot-pressing process. The dielectric permittivity and electromagnetic interference (EMI) shielding effectiveness (SE) of the composites were determined in the frequency range of 8.2-12.4 GHz (X-band). Both real and imaginary permittivities increase with the increasing Ti3SiC2 content, and which are attributed to the enhanced displacement current and conduction current. The EMI SE of the composites can be greatly improved by addition of Ti3SiC2 filler, which may be ascribed to the increase of electrical conductivity of the composites. It is also found that the reflection of electromagnetic radiation is a dominant mechanism for EMI shielding of the composite. An average EMI SE of 23 dB can be achieved in the X-band range for the composite with 25 wt% Ti3SiC2 content, which shows the potential of the Ti3SiC2/PANI composites as EMI shielding materials for commercial applications.