Robust, lightweight, thermally-insulating felt assembled by hollow and continuous yttria-stabilized ZrO₂ fibers

Advanced hollow ceramic fiber materials with excellent thermal insulation and lightweight characteristics are urgently needed in rapidly developing areas such as aerospace. However, creating such hollow ceramic fiber materials has proven to be extremely challenging for current synthetic techniques. Here, we introduce a facile approach for the production of hollow yttria-stabilized zirconia (YSZ) fiber felts through sol–gel solution centrifugal spinning. It is found that the hollow structure can be effectively controlled by adjusting the mass ratios of inorganic salts and PVP, as well as the calcination temperatures. The resulting hollow YSZ felts exhibit low density (38 mg cm⁻³), robust tensile strength (439.56±24.23 kPa), significant stretchability (>10 %), exceptional oxidation and high-temperature resistance, refractory properties, and outstanding thermal insulation characteristics (0.019 W m⁻¹ K⁻¹ at room temperature and 0.103 W m⁻¹ K⁻¹ at 1000℃). The successful synthesis of such fascinating materials may provide new insights into the design and development of hollow ceramic fibers.