Electromagnetic Shielding Effectiveness of Carbon Nanotubes Hydrogel Nanocomposites in the Frequency Range from 1.7 to 6.0 GHz

Carbon nanotube-based nanocomposites are being increasingly utilized in materials for electromagnetic shielding purposes due to their exceptional electrical and mechanical properties. The current study optimizes a simple procedure to prepare multi-wall carbon nanotubes (MWCNTs)-based hydrogel nanocomposites out of water, gelatin, and glycerol. The content ratio of each component in the hydrogel composite is carefully selected to optimize the dielectric properties over the electromagnetic (EM) wave frequency of 0.5 to 20 GHz. The hydrogel nanocomposites were prepared with MWCNT concentrations ranging from 0.1 to 0.9 wt%. The dispersion of MWCNTs in the nanocomposites was investigated and confirmed using a scanning electron microscope (SEM). The dielectric parameters, including the real dielectric constant ε′, imaginary dielectric constant ε″, and tangent loss tan δ along with the DC and AC electrical conductivity (σDC,σAC) were investigated. The study shows a significant enhancement in the dielectric parameters of the prepared nanocomposites as the MWCNT concentration is increased. The shielding effectiveness (SE) of the hydrogel nanocomposites against electromagnetic waves in the frequency range from 1.7 to 6.0 GHz is investigated and found to be enhanced as the concentration of MWCNTs and frequency have increased. The shielding effectiveness of the prepared hydrogel nanocomposites ranges from 10 dB to 26 dB, equivalent to shielding of 90% and more than 99% of incident radiation, respectively.