Fluorinated functionalized EDOT-based conducting films

Abstract

Three ethylenedioxithiophene (EDOT) derivatives bearing either perfluoro- or ether perfluoro-alkyl chains were synthesized with the objective to prepare films with dry and chemically immobilized lubrication properties. The corresponding fluorinated PEDOT films were deposited on platinum surface by electropolymerization. Cyclic voltammetry (CV) and electrochemical quartz crystal microbalance (EQCM) analyses (both quartz resonant frequency and resonant admittance) of the growing steps are described. The electroactive behavior of the films versus their doping level was followed by electrochemical impedance spectroscopy (EIS) through equivalent circuit fitting procedure and compared to their CV responses. Hysteresis in fit parameters corresponding to capacity and film resistance between the forward and the backward scans are observed and discussed. Control of the chemical structures and charge effects on PEDOT chains are followed by an XPS analysis. From these analyses, it appears that the fluorinated side-arm does not alter both the growing and the electrical properties of the films in respect to the pristine PEDOT taken as reference.