Lightweight and Resilient ZrO₂–TiO₂ Fiber Sponges with Layered Structure for Thermal Insulation

Abstract

Low density, heat‐resistant sponge‐like fiber assembly materials are considered as promising high‐temperature insulation materials. However, the poor structural stability, infrared radiation heat transfer, and complex preparation process limit its further application. Herein, a facile method to create ultralow‐density ZrO2–TiO2 fiber sponges by the electrospinning method followed by heat treatment is presented. The layered structure sponges treated at 1200 °C have a low density of 9.5 mg cm−3. Moreover, the sponges possess high compressibility and good compression resistance over a wide temperature range from −196 to 1200 °C. In addition, the sponges exhibit low thermal conductivity of 27 mW m−1 K−1, robust fire resistance, and high near‐infrared reflectance, making them an ideal alternative for high‐temperature thermal insulation materials.

Dual-Phasic, Well-Aligned, and Strong Flexible Hydrophobic Ceramic Membranes for Efficient Thermal Insulation in Extreme Conditions

“…(a) Density and corresponding room-temperature thermal conductivity of ZSNFMs and H-ZSNFMs. (b) Statistical diagram of density and corresponding thermal conductivity of various materials. ,,,,− (c) Schematic diagram of the heat insulation test device with a butane spray gun as a heat source. (d) Cold surface temperature curve of time.…”

“…Moreover, the ordered structure of the fibers made λ s along the direction of the arrangement of the fibers. The structure of stacked fibers was vertically arranged with the heat source to the maximum extent so that the heat was transmitted in the plane, which can reduce the λ s. The λ r dominates at high temperatures; according to the Wien displacement law, λ r is mainly concentrated in the near-infrared band Figure e shows that the average near-infrared reflectance of ZSNFMs and H-ZSNFMs (700–2500 nm) is 93 and 90%, respectively.…”

Recent advances in ZrO2 nanofibers: From structural design to emerging applications

“…Zhang's group [56] synthesized an ultralight and fluffy ZrO 2 -TiO 2 NF sponge by direct electrostatic spraying and summarized the formation mechanism of the sponge (Fig. 6a, b).…”

“…However, these materials suffer from low oxidation resistance. Therefore, Zhang's group [56] added the TiO 2 component to ZrO 2 NFs, and thermal conductivity was successfully reduced to 0.027 W m −1 K −1 using the high-temperature reflective TiO 2 component to reduce the radiative heat transfer of the entire material.…”

“…1D ZrO 2 nanofibers (NFs), considered one of the most attractive ZrO 2 nanomaterials, have attracted increasing interest because of their capability to combine the inherited properties of ZrO 2 with those of NFs, such as high continuity, low bulk density, and excellent flexibility [32]. Over the past few decades, various advanced techniques, such as the biotemplate method [33][34][35], phase inversion method [36][37][38], centrifugal spinning [39][40][41], and electrospinning [42][43][44], have been developed to synthesize ZrO 2 NFs in solid [45,46], porous [47][48][49], hollow [50][51][52], hierarchical [53][54][55], and 3D assembled structures [56].…”