Multiwalled carbon nanotubes/nickel/poly(ether-ketone) nanohybrids for electromagnetic interference shielding applications

As the modern world progresses, concerns regarding electromagnetic pollution are raised by the ever-increasing use of wireless communication technology and electronic devices. EMI shielding materials are therefore crucial for reducing electromagnetic pollution and safeguarding both organisms and gadgets. This work discusses the synergistic effect of multiwalled carbon nanotubes (MWCNT) on the electrical and electromagnetic interference (EMI) shielding properties of the nickel (Ni)/poly(ether-ketone) (PEK) nanocomposites. Both Ni/PEK nanocomposites and MWCNT/Ni/PEK nanohybrids were fabricated using the planetary ball mill followed by hot pressing. Scanning electron microscopy revealed uniform dispersion of Ni nanoparticles in the matrix. The 4.7 vol% Ni/PEK nanocomposite with a density of 1.65 g/cm³ exhibited dc electrical conductivity of ~ 10^–3 S/cm. However, the addition of 0.69 vol% MWCNT into 1.63 vol% Ni/PEK nanocomposite (density: 1.436 g/cm³) decreased the percolation threshold significantly without compromising electrical conductivity. Furthermore, the addition of 3.5 vol% MWCNT into 1.63 vol% Ni/PEK nanocomposite (called nanohybrid) increased the electrical conductivity to ~ 0.082 S/cm, which is 44% higher than the 4.7 vol% Ni/PEK nanocomposite. Similarly, the nanohybrids exhibited better ac conductivity and dielectric constant than the nanocomposites. The MWCNT/Ni/PEK nanohybrid with 3.5 vol% MWCNT exhibited electromagnetic interference shielding of 32 dB in the X-band, which is 60% higher than the Ni/PEK nanocomposites without MWCNT. Interestingly, the nanohybrid has a very low density of ~ 1.45 g/cm³. Thus, these hybrid nanocomposites with high EMI-SE at low density could be used for defence, space, and aerospace applications.