Hybrid direct ink writing of silicone-based emulsions for advanced Biosilicate® scaffolds

Preceramic polymer emulsions have recently shown great potential in the production of ceramics featuring a glassy matrix owing to their ability to achieve a high degree of homogenization of fillers, here introduced as aqueous solutions. The present study seeks to extend this strategy to the class of glass-ceramic materials, specifically targeting the Biosilicate® composition. Silicone blends are successfully developed and combined with Direct Ink Writing and thermal treatment in air to fabricate highly porous biosilicate-like scaffolds (up to 94% total porosity) with outstanding strength-to-density ratios. Firing under nitrogen atmosphere is also explored focusing on its effects on the crystalline phase assemblage, morphology, and physical properties of the scaffolds. Lastly, two post-processing strategies, involving bioresin coating and infiltration respectively, are investigated to mechanically reinforce the air-synthesized polymer-derived scaffolds.