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

Improving the infrared reflectivity of ZrO 2 polycrystalline fibers is of great benefit to its thermal applications. In the present research, we cast a highly uniform TiO 2 coating with a thickness ranging from dozens to hundreds of nanometers on ZrO 2 fibers by utilizing hydrothermal growth. The coating bonds tightly to the ZrO 2 fibers via Zr–O–Ti chemical linkages, and the thickness of the coating can be tailored by varying the hydrothermal growth time. The TiO 2 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 ZrO 2 fibers. The present research provides an efficient way to cast controllable and uniform coatings on flexible fiber materials. The obtained ZrO 2 fibers coated with TiO 2 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 .