Solution blow spinning of elastic 3D complex ZrO2@mullite nanofibrous aerogels toward customized thermal insulation

Abstract

High-performance aerogel materials hold significant potential for thermal management applications. However, the widespread utilization of conventional ceramic granular aerogels is constrained by their inherent brittleness and rigidity. Herein, an additive blow spinning strategy is introduced for fabricating 3D ZrO₂@mullite nanofibrous aerogels with complex morphologies and lamellar structures. A spinnable solution comprising polysiloxane and polyaluminum was synthesized and blow spinning was carried out at a high flow rate, typically ranging from 10 to 30 mL h⁻¹. By incorporating ZrO₂ nanocrystals as a reinforcing phase, ZrO₂@mullite nanofibers with enhanced mechanical properties are produced through pyrolysis. Utilizing a customized additive spinning strategy, 3D ZrO₂@mullite fibrous aerogels with various complex morphologies (such as conical and cubic) and lamellar structures are achieved. Inter-layer spaces of fibrous aerogels can be controlled within 20–100 μm, while the fiber diameter varies in the 0.5–1.5 μm range. These 3D ZrO₂@mullite fibrous aerogels showcase remarkable attributes including high compressibility over 60%, high-temperature resistance up to 1300 °C and remarkable bendability of around 360°, and their thermal conductivity remains between 0.01 and 0.026 W m⁻¹ K⁻¹, which paves the way for further advancements in tailored fibrous aerogels.