## 12 Porous Polyimide Nanocomposites for Electromagnetic Interference Shielding
 } & **Specific** & \multirow{2}{*}{**Ref**} \\  & **Composition** & **Technique** & **(mm)** & **(g/cm\({}^{3}\))** & & & **Conductivity** & **(dB)** & **EMI SE** & **Ref** \\ \hline \multirow{2}{*}{27} & Graphene/PDMS & \multirow{2}{*}{ coaxial} & \multirow{2}{*}{-1} & \multirow{2}{*}{0.06} & \multirow{2}{*}{1.5–30} & \multirow{2}{*}{200} & \multirow{2}{*}{-30} & \multirow{2}{*}{500} & \multirow{2}{*}{[135]} \\  & foam & & & & & & & & \\ \hline \multirow{2}{*}{28} & GN/CNA & coaxial & 2 & 52.1 & 8.2–12.4 & 19.1 & 58.4 & & [136] \\ \hline \multirow{2}{*}{29} & Polypropylene/carbon & \multirow{2}{*}{Coaxial} & \multirow{2}{*}{-} & \multirow{2}{*}{8.0–12.4} & \multirow{2}{*}{-} & \multirow{2}{*}{24.9} & \multirow{2}{*}{-} & \multirow{2}{*}{[137]} \\  & fiber composite foams & & & & & & & \\ \hline \multirow{3}{*}{30} & Porous & \multirow{2}{*}{2.5} & \multirow{2}{*}{0.45} & \multirow{2}{*}{8.2–12.4} & \multirow{2}{*}{1.25} & \multirow{2}{*}{29} & \multirow{2}{*}{64.4} & \multirow{2}{*}{[138]} \\  & graphene/polystyrene & & & & & & & \\  & foam composite & & & & & & & \\ \hline \multirow{3}{*}{31} & Polypropylene/ & \multirow{2}{*}{Coaxial} & \multirow{2}{*}{-} & \multirow{2}{*}{8.2–12.4} & \multirow{2}{*}{-} & \multirow{2}{*}{47.6} & \multirow{2}{*}{75} & \multirow{2}{*}{[139]} \\  & stabilines-steel fiber & composite foams & & & & & & \\ \hline \multirow{3}{*}{32} & Silver Nanowire & \multirow{3}{*}{Vayeguide} & \multirow{3}{*}{5.0} & \multirow{2}{*}{0.014–0.022} & \multirow{2}{*}{30 MHz–1.5 GHz} & \multirow{2}{*}{-} & \multirow{2}{*}{17} & \multirow{2}{*}{772} & \multirow{2}{*}{[140]} \\  & Hybrid Polyimide & Composite foams & & & & & & \\ \hline \multirow{3}{*}{33} & Polyimide/reduced & \multirow{2}{*}{Waveguide} & \multirow{2}{*}{0.8} & \multirow{2}{*}{0.28} & \multirow{2}{*}{8.2–12.4} & \multirow{2}{*}{0.8} & \multirow{2}{*}{17-21} & \multirow{2}{*}{75} & \multirow{2}{*}{[141]} \\  & graphene oxide & & & & & & & \\ \hline \multirow{3}{*}{34} & Graphene foam/ & \multirow{3}{*}{poly (3,4-  ethylenedioxythiophene):} & \multirow{3}{*}{-} & \multirow{3}{*}{0.0182} & \multirow{3}{*}{8.2–12.4} & \multirow{3}{*}{43.2} & \multirow{3}{*}{91.9} & \multirow{3}{*}{3124} & \multirow{3}{*}{[142]} \\  & poly(tytyremsulfonate) & & & & & & & & \\ \hline \multirow{3}{*}{35} & Polyetherimide/ & \multirow{3}{*}{Waveguide} & \multirow{3}{*}{2.5} & \multirow{3}{*}{0.28–0.4} & \multirow{3}{*}{8.2–12.4} & \multirow{3}{*}{-} & \multirow{3}{*}{14.3–18.2} & \multirow{3}{*}{41.5} & \multirow{3}{*}{[120]} \\  & graphene@FeO340 & composite foams & & & & & & \\ \hline \multirow{3}{*}{36} & Reduced graphene & \multirow{3}{*}{ coaxial} & \multirow{3}{*}{1} & \multirow{3}{*}{-} & \multirow{3}{*}{8.2–12.4} & \multirow{3}{*}{16.8} & \multirow{3}{*}{34} & \multirow{3}{*}{-} & \multirow{3}{*}{[143]} \\  & oxide/waterborne & & & & & & & & \\ \hline \multirow{3}{*}{37} & Polyurethane & \multirow{3}{*}{3.8} & \multirow{3}{*}{1.2} & \multirow{3}{*}{8.2–12.4} & \multirow{3}{*}{-} & \multirow{3}{*}{50} & \multirow{3}{*}{-} & \multirow{3}{*}{[145]} \\  & polyurethane & & & & & & & \\ \hline \multirow{3}{*}{39} & Polyyrrole and & \multirow{3}{*}{Freduced graphene oxide} & \multirow{3}{*}{1.5–5} & \multirow{3}{*}{-} & \multirow{3}{*}{2–18} & \multirow{3}{*}{-} & \multirow{3}{*}{-54.4} & \multirow{3}{*}{-} & \multirow{3}{*}{[146]} \\  & graphene oxide & & & & & & & \\ \hline \multirow{3}{*}{40} & Natural rubber/ & \multirow{3}{*}{-} & \multirow{3}{*}{1.6} & \multirow{3}{*}{-} & \multirow{3}{*}{8.2–12.4} & \multirow{3}{*}{6.1} & \multirow{3}{*}{42.4} & \multirow{3}{*}{26.4} & \multirow{3}{*}{[147]} \\  & (Fe3 XO) and reduced & & & & & & & \\ \cline{1-1}  & graphene oxide & & & & & & & \\ \hline \multirow{3}{*}{41} & Multilayered & \multirow{3}{*}{waveguide} & \multirow{3}{*}{6.5} & \multirow{3}{*}{0.42} & \multirow{3}{*}{12–18} & \multirow{3}{*}{3} & \multirow{3}{*}{24} & \multirow{3}{*}{-} & \multirow{3}{*}{[111]} \\  & polyurethane (graphene & & & & & & & \\ \cline{1-1}  & composite foams & & & & & & & \\ \hline \multirow{3}{*}{42} & Polymer-derived & \multirow{3}{*}{Coaxial} & \multirow{3}{*}{2-4.5} & \multirow{3}{*}{0.19} & \multirow{3}{*}{2–18} & \multirow{3}{*}{-} & \multirow{3}{*}{-} & \multirow{3}{*}{[43.37]} & \multirow{3}{*}{-} & \multirow{3}{*}{[148]} \\  & ceramic aerogels & & & & & & & \\ \cline{1-1}  & (PDCA) & & & & & & & \\ \hline \multirow{3}{*}{43} & Polystyrene/ & \multirow{3}{*}{functionalized & \multirow{3}{*}{-} & \multirow{3}{*}{-} & \multirow{3}{*}{8.2–12.4} & \multirow{3}{*}{0.1} & \multirow{3}{*}{18} & \multirow{3}{*}{-} & \multirow{3}{*}{[149]} \\  & graphene & & & & & & & \\ \cline{1-1}  & nanocomposite foams & & & & & & & \\ \hline \multirow{3}{*}{44} & polycarbonate/ & \multirow{3}{*}{Waveguide} & \multirow{3}{*}{-} & \multirow{3}{*}{8.2–12.4} & \multirow{3}{*}{-} & \multirow{3}{*}{-} & \multirow{3}{*}{39} & \multirow{3}{*}{[150]} \\  & graphene & & & & & & & & \\ \cline{1-1}  & nanocomposite foams & & & & & & & & \\ \hline \multirow{3}{*}{45} & Epoxy/ \multirow{3}{*}{functionalized \multirow{3}{*}{nauti-walled carbon  nanotube}} & \multirow{3}{*}{Waveguide} & \multirow{3}{*}{2.5} & \multirow{3}{*}{-} & \multirow{3}{*}{12–18} & \multirow{3}{*}{\(1.04