Flexible and Transformable Ceramic Aerogels via a Fire‐Reborn Strategy for Thermal Superinsulation in Extreme Conditions

Abstract

AbstractEffective thermal superinsulation in extremely high temperatures (EHT) is crucial for aerospace, industrial, and civilization activities. However, current strategies relying on ceramic materials face limitations due to their high thermal conductivity and brittleness in specific conditions. In this study, a feasible and scalable method for synthesizing a flexible, lightweight, and transformable fire‐reborn silica‐alumina hybrid ceramic aerogel (FR‐SACA) is presented, which is achieved by rearranging silica aerogel microparticles and Al2O3 ceramic fibers using a self‐sacrifice polymer, resulting in a bio‐inspired bird nest structured FR‐SACA. The SACA exhibits exceptional properties, including an ultra‐low density of 0.01 g cm−3, a low thermal conductivity of 0.029 W m−1 K−1, and a reversible compression of up to 80%. Notably, a 20 mm‐thick FR‐SACA demonstrates a remarkable temperature reduction of 1179.6 °C when exposed directly to a 1300 °C flame, suggesting its potential as a thermal superinsulation material in EHT environments. Furthermore, the transformability of SACA enables in situ fabrication on surfaces with diverse heteromorphic structures, such as flat, bent, and angled shapes, thereby providing thermal superinsulation for various constructions. The Phoenix Nirvana process opens up new possibilities for synthesizing ceramic aerogels with desirable flexibility and adaptive properties, facilitating effective thermal management under extreme conditions.