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Inorganic aerogels with low density, high porosity, large specific surface area, and superior mechanical properties are excellent candidate materials in fields such as thermal management, energy, catalysis, and biomedical applications. A comprehensive overview of existing elastic inorganic aerogels is provided, covering their structural units, preparation methods, mechanical performances, and applications. Meanwhile, based on the constituent building blocks and microstructures, a detailed analysis of the mechanical properties and guidelines for elastic design of aerogels is presented. Concluding with a succinct summary of prospective developmental direction, this review deliberates on the challenges and potential opportunities of elastic inorganic aerogels, with the intent of providing a versatile platform for designing new types of elastic inorganic aerogels for various applications. [ABSTRACT FROM AUTHOR]

Carbon aerogels (CAs) are desirable for thermal protection in aerospace because of their lightweight and high‐temperature insulation characteristic; however, their intrinsic brittleness and flaw sensitivity easily trigger catastrophic failure when resisting high‐frequency thermal shocks or complex mechanical stresses. Compression is the predominant load applied on aerogels by aerodynamic pressure and pre‐tightening force; therefore, the structural elasticity and exceptional capability to keep thermal performance under impact stress are crucial in deciding the actual availability of aerogels. This review presents the recent progress in newly resilient CAs for thermal protection, focusing on reliable structural stability, thermal stability, and thermal superinsulation property. The influence law of microstructures on heat transfer behaviors is first investigated, followed by construction strategies for adiabatic CAs, emphasizing the recoverable deformability resulting from increased continuity of building blocks from 0D nanoparticles to 1D nanofibers/nanotubes and then to 2D nanosheets. Moreover, the optimization of thermal stability in high‐temperature aerobic environments and thermal insulation performance are discussed. Finally, it raises current challenges and further opportunities for CAs toward better properties and brighter prospects. [ABSTRACT FROM AUTHOR]

Ceramic aerogels are attractive for many applications due to their ultralow density, high porosity, and multifunctionality but are limited by the typical trade-off relationship between mechanical properties and thermal stability when used in extreme environments. In this work, we design and synthesize ceramic nanofibrous aerogels with three-dimensional (3D) interwoven crimped-nanofibre structures that endow the aerogels with superior mechanical performances and high thermal stability. These ceramic aerogels are synthesized by a direct and facile route, 3D reaction electrospinning. They display robust structural stability with structure-derived mechanical ultra-stretchability up to 100% tensile strain and superior restoring capacity up to 40% tensile strain, 95% bending strain and 60% compressive strain, high thermal stability from −196 to 1400 °C, repeatable stretchability at working temperatures up to 1300 °C, and a low thermal conductivity of 0.0228 W m−1 K−1 in air. This work would enable the innovative design of high-performance ceramic aerogels for various applications. Ceramic aerogels are generally brittle and often tend to structurally collapse under large external tensile strain. Here the authors synthesize large-scale stretchable ceramic aerogels with interwoven crimped nanofibers by combining electrohydrodynamic method and 3D reaction electrospinning. [ABSTRACT FROM AUTHOR]

Ceramic aerogels are attractive candidates for thermal insulation systems in spaceships, missiles, and aircrafts. However, the general lack of mechanical stability in conventional ceramic aerogels presents a major challenge for their practical applications. To date, the creation of mechanically robust ceramic aerogels has not made significant progress. Herein, a universal strategy is presented to fabricate ceramic nanofibrous aerogels with both superior bendability and compressibility, by assembling flexible silica nanofibers with a high length‐to‐diameter ratio into a highly continuous interwoven cellular structure. The resulting aerogels, with improved structural continuity, exhibit enhanced mechanical properties including large compression and buckling strain recovery (85%), temperature‐invariant superelasticity (from −196 °C to 1100 °C), and robust fatigue tolerance up to 100 000 cycles. In parallel, the low thermal conductivity (0.0223 W m−1 K−1), as well as exceptional high‐temperature thermal insulation performance enable them to be ideal candidates for thermal insulation in extreme environments. The successful synthesis of this material may shed light on the development of other mechanically robust ceramic aerogels. [ABSTRACT FROM AUTHOR]

Industrial thermal energy management or space exploration requires thermal insulating materials with features of low thermal conductivity, low bulk density and robust mechanical properties. However, the use of traditional organic insulation materials is hampered by their poor fire resistance while inorganic insulation ones are either stiff or display a high thermal conductivity. Herein, we design and synthesize binary-network structured silica nanofibrous aerogels (BSAs) by in situ assembly of nanoporous silica aerogels on a cellular structured silica fibrous framework. The resulting BSAs can completely recover from 80% compressive strain, displaying temperature-invariant superelasticity and robust fatigue-resistance up to 100 000 compression-release cycles. Moreover, the unique binary-network structure provides BSAs with ultralow thermal conductivity (21.96 mW m−1 K−1), robust fire retardancy, and superior high-temperature thermal insulation performance. BSAs with a thickness of 20 mm are shown to protect bare hands placed on the opposite side, when directly exposed to butane blowtorch flame (∼1000 °C). These superior performances lead to their appealing practical application potential in energy management, thermal isolation or fire protection fields. [ABSTRACT FROM AUTHOR]