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Metal-doped polymer derived ceramics (PDCs) exhibits multifunctional properties due to the introduction of special metal element; however as one of the cheapest metal element carriers, metal inorganic salts have rarely been reported for the fabrication of metal-doped PDCs. In this article, a novel hydrophilic photosensitive γ-methacryloxypropyl trimethoxy modified polyhydroxymethylsiloxane preceramic polymer was firstly synthesised and three different metal-doped SiOC ceramic lattices with a strut thickness of 200 μm were successfully fabricated using inorganic metal salts as the metal source by digital light processing. The photosensitive coefficient, initial photocuring coefficient and the corresponding working curves were employed to evaluate the photocurable ability of preceramic polymers with different recipes. Results showed that both the metal-containing polymer lattices and the metal-doped SiOC ceramic lattices exhibited high-resolution microstructure and homogeneous metal element distribution, indicating that the inorganic metal salt is an effective metal source for the fabrication of metal-doped PDCs. [ABSTRACT FROM AUTHOR]

To satisfy the ever-increasing demand for aluminum borate porous ceramics with complex shapes and tunable pore structures in a diverse set of fields, aluminum borate whisker-based lattices with hierarchical pore structures were fabricated by a combination of in situ reaction and digital light processing three-dimensional (3D) printing. The optimal dispersant concentration and exposure parameters for 3D printing were determined based on analyses of the rheological properties and working curves of the Al 2 O 3 –B 2 O 3 photosensitive slurries. The effects of the B 2 O 3 /Al 2 O 3 molar ratio on the morphology and properties of aluminum borate lattices were investigated. The results showed that the addition of an excess of B 2 O 3 was beneficial to the growth of aluminum borate whiskers. When the B 2 O 3 /Al 2 O 3 molar ratio was set to 6:9, the resultant aluminum borate lattices exhibited a typical hierarchical pore structure, including inherent large pores in the lattices and small pores formed by interlocked aluminum borate whiskers generated in situ within the struts. This unique hierarchical pore structure endowed the ceramic lattices with a high compressive strength (1.18 MPa) and porosity (82.58%), as well as non-brittle fracture characteristics. Owing to these outstanding properties, aluminum borate whisker-based lattices are promising candidates for high-temperature thermal insulation, catalyst supports, acoustic absorption, and particle filtration. [ABSTRACT FROM AUTHOR]

Explorations in the stereolithography fabricated polymer-derived ceramics are still far from maturity. Herein, a novel preceramic slurry, which consists of a photocurable epoxy-acrylic siloxane and particle-size gradated ZrO 2 fillers, was digital light processing shaped into 3D preceramic precursors. By taking advantage of the high reactivity of in-situ formed silica from the polysiloxane, 3D-zircon product can be synthesized through the sintering reaction between the polysiloxane and ZrO 2 particles in the precursor at a low temperature. During the sintering process, ZrSiO 4 phase starts to appear at the temperature of 1200 °C. A proper particle-size distribution of the ZrO 2 filler, 20 wt% of micropartciles and 4 wt% of nanoparticles, not only endowed the ceramic slurry with a low viscosity but also increase the purity of the zircon products. Besides, the addition of sintering aid NaF can promote the sintering reaction between the polysiloxane and ZrO 2 particles while increase the crystalize degree of the 3D-zircon products. [ABSTRACT FROM AUTHOR]

• A high solid loading polysiloxane (PSO)/SiO 2 slurry had been developed and DLP printed into 3D-PSO/SiO 2 precursor. • More ceramic content can be preserved in the PSO/SiO 2 precursor through a two-step argon-air sintering process. • Si-based composite ceramics can be obtained through the two-step argon-air sintering process. • Bulk 3D-silica ceramics can be DLP fabricated from the PSO/SiO 2 slurry. • The introduction of sintering aid NaF can promote the sintering between the PSO and SiO 2 powders. Nowadays, 3D polymer-derived silicon oxycarbide ceramics (SiOC) can be fabricated by the stereolithography method successfully. However, due to their intrinsically poor ceramic content and the large thermal shrinkage during the pyrolysis, it is difficult for the bulk 3D polysiloxane precursors to be pyrolyzed into dense 3D-ceramics. Herein, the ceramic content of the photocurable polysiloxane precursors was increased by adding a large amount of SiO 2 powders into the low solid content epoxy-acrylic siloxane. After being added with proper dispersant, the viscosity of the high solid loading polysiloxane/SiO 2 slurry can reach a proper level. Bulk 3D-silica ceramics with the wall-thickness around 8 mm can be conveniently fabricated from the polysiloxane/SiO 2 slurry by stereolithography and a two-step sintering process. The addition of a proper sintering aid NaF can promote the 3D-PSO/SiO 2 precursor to be converted into dense and crack-free 3D-silica ceramics with good mechanical proprieties. [ABSTRACT FROM AUTHOR]

• Complex-shaped mullite components were DLP printed based on a hydroxysiloxane/Al 2 O 3 preceramic precursor strategy. • The introduction of hydroxysiloxane can improve the homogeneity and rheological properties of mullite slurry. • The introduction of hydroxysiloxane can reduce the sintering temperature of 3D-mullite precursor. • A sintering aid AlF 3 was employed to promote the sintering reaction between the hydroxysiloxane and the Al 2 O 3 filler. By taking advantage of the low sintering temperatures of the preceramic polymers, stereolithography printed mullite components derived from preceramic polymer precursor containing alumina particles can be sintered at low temperatures. However, due to their high specific surface, nano alumina particles are difficult to be dispersed into the photocurable polysiloxane. Herein, to prepare mullite slurry, a photosensitive hydroxysiloxane was employed as the preceramic polymer matrix while γ-Al 2 O 3 nanoparticle was added as the active filler. The introduction of photocurable hydroxysiloxane not only improved the homogeneity and rheological properties of mullite slurry but also shorted the ionic diffusion distance of Si-ion and Al-ion during the sintering process. Therefore, 3D mullite preceramic precursor stereolithography printed from hydroxysiloxane-Al 2 O 3 slurry was endowed with a low sintering temperature around 1400 °C. During the sintering process of preceramic precursor, sintering aid AlF 3 can participate in the reaction and further promote the formulation of mullite grains. [ABSTRACT FROM AUTHOR]