Nacre‐Mimetic Nanocomposite Aerogels with Exceptional Mechanical Performance for Thermal Superinsulation at Extreme Conditions

Abstract

Thermal protection under extreme conditions requires materials with excellent thermal insulation properties and exceptional mechanical properties to withstand a variety of complex external stresses. Mesoporous silica aerogels are the most widely used insulation materials due to their ultralow thermal conductivity. However, they still suffer from mechanical fragility and structural instability in practical applications. Herein, a nacre‐mimetic nanocomposite aerogel, synthesized via in situ growth of inorganic minerals in a lamellar cellulose nanofibrous network, is reported. The multiscale structural adaptation of the inorganic–organic components endows nanocomposite aerogels with rapid configuration recovery during ambient pressure drying. The resulting aerogels show ultralow thermal conductivities (17.4 mW m−1 K−1 at 1.0 atm). These aerogels also integrate challenging mechanical properties, including high compressive stiffness to resist deformation under the pressure of an adult, superelasticity to prevent static and dynamic stress cracking even under the crushing of a vehicle (1.6 t), and high bending flexibility to adapt to any surface. Moreover, they exhibit excellent structural stability under fatigue stress/strain cycles over a wide temperature range (−196 to 200 °C). The combination of high thermal insulation performance and excellent mechanical properties offers a potential material system for robust thermal superinsulation under extreme conditions, especially for aerospace applications.

Rapid Thermochromic and Highly Thermally Conductive Nanocomposite Based on Silicone Rubber for Temperature Visualization Thermal Management in Electronic Devices

“…These reductions can be attributed to the poor thermal conductivity of OTM . In this study, the higher the OTM content, the lower the thermal conductivity of the OTM-GO/Al 2 O 3 /PDMS nanocomposites. , …”

“…39 In this study, the higher the OTM content, the lower the thermal conductivity of the OTM-GO/Al 2 O 3 /PDMS nanocomposites. 40,41 As shown in Figure 3a the thermal response time of the OTM-GO/Al 2 O 3 /PDMS nanocomposites is positively correlated with their thermal conductivity: the higher the thermal conductivity, the faster the response. 42 Figure 3d depicts the thermal response processes of the different samples.…”

Synchronous Radiative Cooling and Thermal Insulation in SiO2/Poly(vinyl alcohol) Composite Aerogel for Energy Savings in Building Thermal Management

“…High porosity and low density of aerogels with nanomicro–multistage porous structure often result in good thermal insulation and thus are widely used as thermal insulation materials , or radiative cooling materials. ,,, It was found that adding acetone reduced the thermal conductivity of the PVA aerogel from 0.0492 to 0.0421 W/mK and reduced the thermal diffusion coefficient from 0.5815 to 0.5490 mm 2 /s (Figure f) resulting from the structural changes which increased the proportion of micro- and nanopores inside the aerogel and reduced the macro-gaps . Further, the incorporation of SiO 2 particles made the thermal conductivity decreased to 0.0390 W/mK and decreased the thermal diffusion coefficient to 0.4770 mm 2 /s.…”

Guidelines derived from biomineralized tissues for design and construction of high-performance biomimetic materials: from weak to strong

“…The BMT-mimetic structures are expected to solve this problem. Recently, Zhang et al 769 prepared a nacre-mimetic nanocomposite aerogel via in situ growth of the inorganic mineral in a lamellar cellulose nanofibrous network. The preparation process involved sol–gel preparation of mesoporous polymethylsilsesquioxane in a layered bacterial cellulose gel network, followed by ambient pressure drying.…”