RT journal article T1 3D-printable ionic liquid formulations for filler-free, transparent ion-conducting soft materials A1 Carmenini, Rosario A1 Sanz de León, Alberto Darío A1 Comes Franchini, Mauro A1 Molina Rubio, Sergio Ignacio A1 Maturi, Mirko A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica K1 Vat photopolymerization K1 Photocurable ionic liquids K1 Ion-conducting polymers K1 Transparent soft materials K1 Process–structure–property relationships AB This work presents a family of photocurable ionic liquids (pILs) based on a polymerizable methacrylate anion and readily available organic cations, designed for vat photopolymerization (VP) of soft ion-conducting networks. The pILs were synthesized by straightforward ion exchange, providing liquid salts that are fully compatible with commercial acrylate resins and enable filler-free 3D printing of transparent ionic polymers. By systematically mapping the resin compositions as a function of the total acrylate content and the fraction of crosslinking species, a clear printability window was identified, allowing prediction of the maximum printable ionic liquid concentration from the molecular weight of the chosen cation. Mechanical properties were shown to be governed primarily by network architecture, with imidazolium-based systems displaying linear correlations between stiffness and crosslinking density, while tetraalkylammonium cations introduced exponential softening due to their plasticizing effect. In contrast, ionic conductivity was largely dictated by cation size, hydrophobicity, and charge shielding, enabling conductivity values in the 10–6–10–4 S/cm range without the need for conductive fillers. These results demonstrate a chemically simple and generalizable approach to obtain printable, filler-free ion-conducting materials, opening opportunities for applications in antistatic coatings, electrostatic discharge protection, flexible and stretchable sensors, and low-voltage energy harvesting devices. PB Elsevier SN 2352-9415 YR 2026 FD 2026 LK http://hdl.handle.net/10498/39078 UL http://hdl.handle.net/10498/39078 LA eng DS Repositorio Institucional de la Universidad de Cádiz RD 11-nov-2026