Polar conjugated polymers: eco-friendly materials as new platform for advanced applications

The development of new materials is pivotal for the exploitation of the new technologies. One important class of emerging semiconducting materials is represented by conjugated polyelectrolytes (CPEs) comprising an electronically delocalized ?-conjugated backbone with pendant groups bearing polar or ionic functionalities [1]. CPEs combine the typical properties of polymeric semiconductors,such as chemical tunability, easy processability, lightness and flexibility with the growing demand for environmentally friendly materials. In fact, the incorporation of polar/ionic side groups increases the solubility in water and alcohols, which can potentially provide increased biocompatibility for sensor applications and more environmentally friendly manufacturing options. Moreover, the possibility for orthogonal solvent processability opens the way to all-solution-processed organic multilayer devices. We have shown that the insertion of a thin film of a properly synthesized CPE between active layer and electrode in organic electronic devices like OLED[2], OPV[3] and recently OLET[4] is crucial for achieving a high-performance device, due to the formation of permanent dipoles. In this view, we have designed, synthesized and tested CPEs combining different monomers in the conjugated backbone as fluorene, thiophene, benzodithiazole and cyclopentadithiophene with pendant polar and/or cationic or anionic groups The same class of CPEs, thanks to their conjugated backbone and ionic functionality have shown to remarkably enhance the pseudocapacitance of MXene-based hybrid 2D materials [5].Interfacial engineering has been identified recently as an essential approach for maximizing efficiency and stability of electronic devices. In this contest, the intrinsic hybrid characteristics of CPEs make them promising candidates for tuning the interface properties of inorganic materials too. Moreover the use of CPE in biological applications seem to be very promising thanks to their high tunability, water solubility and good biocompatibility [1] Hu Z., Zhang K., Huang F. & Cao Y. (2015). Chem. Commun., 51, 5572-5585. [2] Giovanella, U., Pasini, M., Lorenzon, M., Galeotti, F., Lucchi, C., Meinardi, F., ... & Brovelli, S. (2018). Nano letters, 18(6), 3441- 3448. [3] Carulli, F., Mróz, W., Lassi, E., Sandionigi, C., Squeo, B., Pasini, M.., ... & Galeotti, F. (2018). Chemical Papers, 1-7 [4] Prosa, M., Benvenuti, E., Pasini, M., Giovanella, U., Bolognesi, M., Meazza, L., ... & Toffanin, S. (2018). ACS applied materials & interfaces [5].Boota, M., Pasini, M., Galeotti, F., Porzio, W., Zhao, M. Q., Halim, J., & Gogotsi, Y. (2017).. Chemistry of Materials, 29(7), 2731- 2738.