Preparation and thermal‐insulating properties of Ce‐doped ZrO ₂ hollow fibers derived from a metaplexis template

Abstract ZrO ₂ is an attractive thermal‐insulating material for high‐temperature applications owing to its low heat conductivity and corrosion resistance. The seed hair in metaplexis is a natural fiber with a hollow structure that endows it with outstanding thermal‐insulating properties. In this paper, we describe a procedure for preparing CeO ₂ ‐stabilized tetragonal ZrO ₂ hollow fibers obtained by imitating a metaplexis template. The metaplexis fibers were first immersed in a mixed solution of ZrOCl ₂ and Ce(NO ₃ ) ₃ to prepare the precursor fibers. The fibers thus produced were subsequently dried in vacuum and sintered under the standard atmospheric pressure in aerobic atmosphere at temperature values of 900, 1100, and 1300°C. The microstructures, phase composition, pore size distribution, and thermal conductivities of the fibers were investigated. Results showed that the Ce‐stabilized ZrO ₂ fiber inherited the hollow structure of the metaplexis, consequently exerting a significant effect on its thermal‐insulating properties. Compared to conventional ZrO ₂ fibers, the thermal conductivities of Ce‐stabilized ZrO ₂ fibers can decrease by approximately 12%‐24.3%.