Hydrothermally grown uniform TiO2 coatings on ZrO2 fibers and their infrared reflective and thermal conductive properties

Abstract

Improving the infrared reflectivity of ZrO2 polycrystalline fibers is of great benefit to its thermal applications. In the present research, we cast a highly uniform TiO2 coating with a thickness ranging from dozens to hundreds of nanometers on ZrO2 fibers by utilizing hydrothermal growth. The coating bonds tightly to the ZrO2 fibers via Zr–O–Ti chemical linkages, and the thickness of the coating can be tailored by varying the hydrothermal growth time. The TiO2 coating, acting as a sheath towards electromagnetic radiation, not only reflected light with wavelengths ranging from the visible region to the infrared region and up to 8 μm but also shielded the Raman signals of the ZrO2 fibers. The present research provides an efficient way to cast controllable and uniform coatings on flexible fiber materials. The obtained ZrO2 fibers coated with TiO2 may have applications such as reinforcement for bulk ceramics, thermal barrier coatings, aerogels, etc., thus performing the dual functions of mechanical strengthening and thermal insulation.