Temperature-triggered oxidative polymerization for high conductive poly(3,4-ethylenedioxythiophene) sheets at millimeter scale

Poly(3,4-ethylenedioxythiophene) (PEDOT) is one of the most widely used conductive polymers extensively applied in the electronic components and optoelectronic devices. However, its insolubility and infusibility lead to a complex in situ polymerization process or a sacrificed conductivity in practice. In this paper, we report a facile preparation method of high conductive PEDOT sheets through in situ oxidative polymerization of stable EDOT one-pot prepolymerization solution. The prepolymerization solution is solvent-free and can be maintained for more than 30 days at about -20 degrees C. The oxidative polymerization can be triggered by temperature to achieve uniform PEDOT sheets with a thickness ranging from 200 nm to over 2 mm. The thick PEDOT sheets obtained through a mold exhibitl a conductivity over 1 S cm(-1) depending on the thickness. For electromagnetic shielding applications, PEDOT sheets of 500 mu m thickness are capable of shielding over 99% of electromagnetic waves. The thin PEDOT sheets prepared by spin-coating display high conductivity with a sheet resistance as low as 110 Omega sq(-1), superior to those prepared by the oxidant-triggered oxidative polymerization. The temperature-triggered oxidative polymerization can be a promising strategy for the preparation of high conductive PEDOT sheets.