Yttria nettings by colloidal processing

• Yttria powders are highest stable at pH = 10.5 (ζ = |56 mV|).
• With 0.5 wt% of poly-acrylic acid stable suspensions can be prepared from pH = 7.0.
• Binder excess promotes high viscous suspensions as well as final products with irregular shape.
• Concentrated suspensions with 30 vol% of yttria and 0.3 wt% of carboximetilcelulose presented shear thinning behavior and thixotropy which are suitable for replica method.
• Yttria nettings with homogeneous shape of cells and struts can be produced with 0.3 wt% of carboximetilcelulose by sintering at 1600 ̊C/1 h.

Porous ceramic burners have been shown as a promising technology to produce heat and lighting by burning low calorific fuels like modern biomass. Among ceramics, yttria (Y2O3) presents considerable luminescent proprieties for gas burner technology. By colloidal processing of yttria, this work aims to produce luminescence ceramic nettings with potential to be used as gas burners. Processing parameters such as mean particle size, zeta potential and flow behavior were evaluated in order to prepare suitable suspensions for replica method. Yttria nanoparticles presented light emission with λ = 550 nm when being thermal stimulated at 150 °C. Besides, the nano sized powders d50 = 113.8 nm and specific surface area of 13.6 m2 g−1 could be highly stabilized at pH 10.5. Suspensions with 30 vol% of solids, pH 10.5, 1 wt% of dispersant and 0.3 wt% of binder presented shear thinning behavior and thixotropy suitable for replica method. As a result, samples sintered at 1600 °C/1 h showed homogeneous morphology of struts and porous microstructure desirable for gas recirculation and burning process.