Investigation on the electromagnetic interference shielding performance of hydrochloric acid doped polyaniline: an insight into the protonation

The protonation process is a key factor affecting the electrical properties of conductive polyaniline and determines its application in high efficiency and light weight electromagnetic shielding materials. Herein, the PANIs doped with different concentrations of HCl were synthesized via chemical oxidative polymerization, the influence of protonic acid concentration on morphology, electrical conductivity, dielectric loss and electromagnetic shielding performance of doped PANI are investigated in detail. The resultant PANI doped with the HCl at concentration of 1.5 mol/L displays the highest SE R which was chiefly originated from its conductivity at 105.48 S·cm −1 and expectable value of SE T at 20–25 dB in the whole X-band. All the impedance matching degrees of doped PANIs is far from 1, indicating electromagnetic waves are difficult to enter the interior of the PANIs, but mainly reflect on the surface of the shielding material.