Direct DLP-based 3D-printing of metallopolymers featuring shape-memoryabilities

This study presents for the first time the direct digital light processing (DLP) based three-dimensional (3D) printing of metallopolymers featuring different kinds of metal complexes. 2-Phenoxyethyl acrylate and ligand-containing monomers based on terpyridine, andtriphenylmethyl(trt)-histidine are utilised. After successful complexation of zinc(II) and nickel(II)salts, respectively, within the monomer mixture the polymerisation via photo-induced printingis performed. The hereby obtained smart materials can be printed in any form ranging fromsimple rectangular rods to complex hollow structures. Inductively coupled plasma opticalemission spectroscopy (ICP-OES) and Fourier-transform (FT) Raman spectroscopy reveal thesuccessful imbedding and implementation into the polymeric structure. Additionally, animaging across the 3D-printed structure could be performed indicating the equal distribution ofthe complexes in the structure. Furthermore, the 3D-printed specimens feature excellent shape-memory behaviour. Thermo-mechanical analysis (TMA) reveals fixity rates after mechanicaldeformation up to 100% and recovery rates up to 99%.