Self-Healing, Antibacterial, and 3D-Printable Polymerizable Deep Eutectic Solvents Derived from Tannic Acid

Polymerizable deep eutectic solvents (PDESs) have received great attention in the field of sustainable materials due to their green synthesis process and convenient designability. In this work, we developed a novel ternary PDES based on natural tannic acid (TA), choline chloride (ChCl), and hydroxyethyl methacrylate (HEMA). Density functional theory analysis indicated that hydrogen bonds and van der Waals forces are the main driving forces for the formation of the PDESs. The obtained TA-based PDESs not only showed high biobased content (40.13–52.96%) and superior thermal/mechanical properties (a Tg of 56.08–78.72 °C, tensile stress of 5.45–13.71 MPa, toughness of 13.40–23.29 MJ/m3, etc.), but also demonstrated excellent self-healing and antibacterial properties. Furthermore, the developed TA-based PDESs without any UV-photoblocker can be directly used in LCD 3D printing. The optimal PDES sample (ChCl/HEMA/TA20) showed a low penetration depth (0.192 mm); thus, different structures with high resolution were successfully printed using this sample. In general, the developed TA-based PDESs can be used as green and multifunctional materials for a high-resolution UV-curable 3D printing process.