Facile Fabrication of PEDOT:PSS‐Based Free‐Standing Conducting Film for Highly Efficient Electromagnetic Interference Shielding

Abstract With the growing popularity of portable and wearable smart electronics, the electromagnetic shielding materials with high shielding effectiveness (SE) as well as light weight and excellent mechanical strength are in high. In this work, the PEDOT:PSS‐based free‐standing conducting film with superior conductivity and mechanical strength is prepared through a facile fabrication. The cellulose nanofibers (CNFs) are first introduced to induce an orderly grow and stack of the PEDOT grains. A phosphoric acid immersion process is then employed to remove the insulating CNF and PSS in the film. The obtained free‐standing conducting film shows a record conductivity of 3508 S cm −1 and its elongation at break reaches 3.75%. Encouragingly, the film delivers an excellent electromagnetic interference (EMI) shielding behavior with a SE of 49 dB in the X‐band (8.2–12.4 GHz) at a thickness of 4 µm. The superior conductivity, mechanical strength, and high SE as well as its facile solution processability make this free‐standing conducting film to be an attractive EMI material for portable and wearable smart electronics.