Electromagnetic interference shielding properties of solid-state polymerization conducting polymer

Abstract

Poly(3,4-ethylenedioxythiophene) (PEDOT) has been synthesized through a facile solid-state polymerization (SSP) approach. The polymerization was simply initiated by sintering the monomer, 2,5-dibro-3,4-ethylenedioxythiophene (DBEDOT), at a temperature of 80 °C. A high performance shield for electromagnetic interference (EMI) protection based on this SSP-PEDOT has been developed. The SSP-PEDOT with a heating time of 24 hours has the maximum value of the dielectric loss tangent (tan δ_ε) in the frequency range of 2–18 GHz, which revealed that this sample has the best electromagnetic energy absorption ability. When the thickness of the sample reached 2 mm, the bandwidth with the reflection loss (RL) deeper than −10 dB was nearly 5.9 GHz (from 10.0 GHz to 15.9 GHz), and the maximum value of RL was about −50.1 dB at 11.2 GHz. The SSP-PEDOT with a heating time of 1 hour had the best EMI shielding effectiveness (SE_total) in the entire frequency range of 2–18 GHz, which was almost contributed to the reflection from the material surface (SE_R). These results demonstrated that SSP initiated at low temperature shows multi-practical EMI shielding application in the areas of military camouflage and electronic devices protection.