Résumé
3D printing techniques such as digital light processing (DLP) have gained significant interest in material science for the fabrication of complex structures that could not be produced using conventional approaches (Fig.1a). With DLP, the printed structures can be tailored to address specific needs, for instance through the implementation of complex macroporous and controlled networks such as gyroids for enhanced fluid transport (Fig.1b). To design meso/macroporous monoliths, we have developed a new nano-ink based on mesoporous silica nanocages (10 nm) functionalized with methacrylate ligands (Fig.1c) [1,2]. In this contribution, we will demonstrate how such nano-ink formulations with low organic content and compatible with commercial 3D printers enable the direct printing of mesoporous or meso/macroporous monoliths without any calcination step required (Fig.1d).This intrinsic porosity further creates opportunities to incorporate functionalities during printing or through post-printing treatments (Fig.1e). For instance, a variety of metal nanoparticles were integrated to the silica framework by adding the corresponding salt to the ink formulation. The printed structures can also be infiltrated post-fabrication with various precursors. This was demonstrated through the in-situ growth of MOF crystals (HKUST-1) within the silica scaffold, as well as through its conversion into zeolites (LTA, FAU-X) by a pseudomorphic-transformation method [3]. Both approaches add microporosity to the scaffold, resulting in hierarchically porous complex structures. These rational designs hence allow for the fabrication of MOF and zeolites supported monoliths with complex geometry and shapes with high potential in environmental applications, such as CO2 capture.[1] T. Aubert, J. Huang, K. Ma, T. Hanrath, U. Wiesner, Nat. Commun., 2020, 11, 4695.[2] A. Vashishtha, A. Phimphachanh, T. Gaillard, J. Schmitt, C. Gerardin, G. Rydzek, T. Aubert, ACS Nano, doi:10.1021/acsnano.4c09887.[3] Y. Didi, B. Said, M. Micolle, T. Cacciaguerra, D. Cot , A. Geneste, F. Fajula, A. Galarneau, Microporous Mesoporous Mater., 2019, 285, 185-194.