Polyaniline : from preparation to application in printing processes

With the discovery of electrically conductive polymers (ECPs) an attractive object of research has begun. ECPs combine the electrical properties of metals with the advantages of plastics (flexibility, lightness, stability, etc.). Among them polyaniline (PANI) is unique for its high thermal and environmental stability, ease of synthesis and interesting redox properties. The combination of electrical conductivity and tunable processability of PANI make this polymer particularly tempting for application in numerous sectors, included printing processes. Even though many methods have developed to synthesized PANI of good quality in terms of conductivity, stability and solubility, all these approaches are based on the use of toxic stoichiometric oxidants (typically metals in high oxidation state) and lead to the production of carcinogenic coproducts (i. e. benzidine). In line with the growing environmental sensitivity and the necessity of clean products, we have recently addressed our efforts on the development of environmentally friendly protocols to produce “green” PANI. Herein, we report a brief overview of the state of the art on the PANI synthesis by environmentally friendly approaches, our results in the PANI preparation by clean processes and our recent goals in their used for printable PANI-based inks fabrication. The electronic, chemical and physical properties of printed devices will be also discussed.