Enhancing the thermal insulating properties of lanthanum zirconate porous ceramics via pore structure tailoring

The potentially useful role of lanthanum zirconate (La2Zr2O7, LZO) porous bulk ceramics has been rarely explored thus far, much less the optimisation of its pore structure. In this study, LZO porous ceramics were successfully fabricated using a tert-butyl alcohol (TBA)-based gelcasting method, and the pore structures were tailored by varying the initial solid loading of the slurry. The as-prepared ceramics exhibited an interconnected pore structure with high porosity (67.9 %-84.2 %), low thermal conductivity (0.083-0.207 W/(m.K)), and relatively high compressive strength (1.56-7.89 MPa). The LZO porous ceramics with porosity of 84.2 % showed thermal conductivity as low as 0.083 W/(m.K) at room temperature and 0.141 W/(m.K) at 1200 degrees C, which is much lower than the counterparts fabricated from particle-stabilized foams owing to its unique pore structure with a smaller size, exhibiting better thermal insulating performance.

Automated summary

This study successfully fabricated LZO porous ceramics with tailored pore structures by adjusting the solid loading of the slurry. The ceramics exhibited high porosity, low thermal conductivity, and relatively high compressive strength. The ceramics with the highest porosity showed significantly lower thermal conductivity compared to counterparts, due to its unique pore structure with smaller size and better thermal insulating performance.