Additive manufacturing of scaffolds from porous glass microspheres via masked stereolithography: Printing challenges and sustainable applications

Additive manufacturing techniques, particularly masked stereolithography (MSLA), enable the creation of intricate and precise porous glass structures. However, preserving slurry stability remains a significant challenge for MSLA. For the first time, this study offers a novel approach to printing highly porous glass microspheres by addressing particle aggregation and sedimentation issues. Particle settling and separation are effectively avoided by coating the porous glass microspheres with polyethylene glycol (PEG) before combining them with photocurable resin. Using this approach, scaffolds with a diamond-shaped cellular structure and 90 % open porosity were fabricated via MSLA. Furthermore, incorporating 7.5 wt% titania nanoparticles enabled the fabrication of 3D composite structures with photocatalytic activity. The printed scaffolds, consisting of pure porous glass microspheres and porous glass microspheres containing titania, were assessed for their capacity to adsorb and photodegrade methylene blue dye. The addition of titania nanoparticles significantly enhanced photocatalytic performance, increasing dye remediation efficiency from 74 % to 100 %. The findings demonstrate the ability of 3D printing technology to repurpose and improve the usefulness of discarded glass, providing a sustainable and effective method for addressing a variety of environmental issues.