Preparation and heat‐insulating properties of biomorphic ZrO ₂ hollow fibers derived from a cotton template

Zirconia (ZrO 2 ) fibers are lightweight polycrystalline refractory materials that have long service life, and are suitable for use at ultra‐high temperatures (above 1600°C). In this study, biomorphic ZrO 2 ceramic fibers were prepared by a simple impregnation method using a zirconic solution using cotton fibers as a biomaterial template. First, cotton fibers were immersed in a zirconyl chloride octahydrate (Zr OC l 2 ·8H 2 O) solution, which also contained yttrium nitrate hexahydrate [Y( NO 3 ) 3 ·6H 2 O], stannic chloride (SnCl 4 ·5H 2 O), and polyvinyl pyrrolidone. The precursor fibers were sintered at different temperatures to produce the final biomorphic ZrO 2 ceramic fibers in air. Phase analysis, microstructures, thermoanalysis, and thermal conductivity were investigated. The experimental results show that these ZrO 2 ceramic fibers faithfully retain the morphologies of the cotton fibers: parts of the fibers are hollow, allowing greater heat insulation than traditional ZrO 2 fibers. In this study, we utilized the morph‐genetic theory to prepare insulation material, providing a new and effective way to fabricate materials with excellent heat‐insulating properties.