Role of Precursors and Doping Agents in Producing 3D-Printed PEGDA–PDANI Electroactive Composites by an In Situ Polymerization Approach

The methodologies for producing composite materials based on conducting polymers (CPs) and 3D-printed polymeric materials are promising to combine the complex geometries of 3D objects with the charge transport properties of CPs. Among the latter, polyaniline (PANI) has an edge because of its peculiar electrochemical behavior. Synthesis protocols starting from the aniline (ANI) monomer to produce the PANI phase are consolidated; however, a series of controversies are related to the use of this reactant, including a potential toxicity. To obtain safer synthetic procedures for fabricating electrical and electrochemically active 3D composite materials, this research exploits an alternative precursor, namely, the aniline dimer (DANI), for the in situ synthesis of polydianiline (PDANI) via oxidative polymerization within 3D-printed polyethylene glycol diacrylate (PEGDA) objects. Factors such as the molecular weight and swelling degree of PEGDA matrix, as well as the nature of PDANI's doping agents, are found to be crucial to modulate the type of redox mechanism, the charge transport properties, and the impedimetric response of 3D-printed PEGDA-PDANI composites. The possibility to produce PEGDA objects in complex 3D shapes (discs, dumbbell, and trabecular structures), coupled with the charge transport and electroactive performances of the PDANI filler, are promising for exploiting PEGDA-PDANI systems as active interfaces in a wide range of electronic applications.