Rapid three-dimensional structuring of transparent SiO 2 glass using interparticle photo-cross-linkable suspensions

Photo-curable suspensions are important materials for shaping complex-structured ceramic and glass components. However, most systems undergo slow debinding and sintering so to avoid structural collapse by rapid gas generation from polymers. Here, we propose a new strategy to fabricate interparticle photo-cross-linkable suspensions for rapid three-dimensional structuring with short debinding and sintering times. SiO 2 particles modified with polyethyleneimine complexed with oleic acid (PEI-OA) are dispersed into a refractive-index-tuned solvent, where a photo-radical initiator and a lower-than-typical amount of multifunctional acrylates (MAs) were dissolved. The SiO 2 suspension is cured by the photo-radical polymerization of MA and the Michael additive reaction between polymerized MA and amino groups of PEI-OA on SiO 2 particles. These photo-curable suspensions can be employed in various shaping processes, from micro-scale stereolithography to centimeter-scale silicone molding. The SiO 2 green compacts with complex structures are also debinded and sintered into transparent glass components by rapid heating.