Three-dimensional printing of complex structured silica glass based on high-strength green parts

Abstract

Three-dimensional (3D) printing of silica glass provides significant advantages for the fabrication of silica glass with complex structures. However, auxiliary support structures are generally needed due to the low stiffness and strength of green parts, which limits the flexibility of the structure design. It is imperative to increase the strength of the green part and remove the support structures for improving the molding capacity and printing quality. This study introduces an approach for 3D printing of silica glass with complex structures by digital light processing (DLP) based on the high-strength green parts, which exhibits superior molding capacity. By comparing three monomers of 2-hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate (HEA), and 4-hydroxybutyl acrylate (4-HBA), it was demonstrated that high photopolymerization reactivity is a key factor for improving the mechanical properties of green parts. Green parts printed with 4-HBA exhibit a combination of high modulus, high strength, and high conversion degree. Following heat treatment, these complex-structured green parts transform into dense, transparent silica glass. The specific compressive strength of silica glass with a lattice meta-structure reaches 4.94 × 10⁴ N m kg⁻¹. This study enhances structural design flexibility in the 3D printing of silica glass, providing a novel perspective for future research.