Biodegradable deep-eutectic mixtures as electrolytes for the electrochemical synthesis of conducting polymers

The use of inexpensive and biodegradable deep-eutectic ionic mixtures as solvents for the electrochemical synthesis of conducting polymers could potentially improve the sustainability of these processes and reduce their economic cost. Such an unexplored approach was investigated in this communication by growing a model polymer such as polyaniline from a 1:2 mixture of choline chloride and 1,2-ethanediol (the so-called Propeline) using potentiodynamic and potentiostatic electrochemical procedures. Beyond a preparation method, cyclic voltammetry was also used to characterize the growth of the polymers. The morphology of the films, and their optical properties, were assessed ex-situ by means of scanning electron microscopy and spectroscopic measurements in the UV-vis. The polyanilines thus prepared exhibited nanoparticulated morphology and high reversibility to doping/dedoping which evidences fast charge transport across the films. Excellent conductivities higher than 50 S cm(-1) were found under this approach.