Polyaniline/MoS₂/MWCNT Ternary Nanocomposite for Effective Electromagnetic Interference Shielding

To advance electromagnetic interference (EMI) shielding in high-frequency electronic systems, a ternary polyaniline (PANI)/multiwalled carbon nanotube (MWCNT)/molybdenum disulfide (MoS2) composite is proposed, and its shielding effectiveness (SE) is presented by varying MoS2 concentrations in this paper. A four-step in situ polymerization was employed to synthesize the proposed composite, with 5, 10, and 20 wt % MoS2, while maintaining a constant 5 wt % MWCNT content. The composite samples were tested using VNA in the microwave frequency range of 8.2–12.4 GHz, and their EMI SE and complex permittivity were analyzed. Notably, the PANI/MoS2/MWCNT composite, with 10 wt % MoS2, exhibited the highest SE of 48.98 dB with a sample thickness of 2.8 mm, compared to lower shielding values for the other compositions. The significant enhancement in EMI SE is attributed to the synergistic effect of MoS2 and MWCNTs, which facilitate better impedance matching, high electrical conductivity, and dissipation of electromagnetic (EM) waves. Various physical phenomena, such as binding and agglomeration during in situ polymerization, involved in EM absorption and multiple scattering mechanisms were studied in detail. Key findings indicate that the optimized PANI/MoS2/MWCNT composite can serve as an efficient EMI shielding material with potential applications in advanced electronic and communication devices.