Aerogels are known for their high porosity and very low density and can be made from a range of materials, but are limited by structural instability under extreme thermomechanical conditions. We report on 194 types of dome-celled ultralight aerogels that maintain superior elasticity spanning from 4.2 kelvin (K) to 2273 K, realized by a two-dimensional channel–confined chemistry method. Such aerogels exhibit superelasticity under 99% strain for 20,000 cycles and thermal shock resistance at 2273 K over 100 cycles. The high-entropy carbide aerogel achieves a thermal conductivity of 53.4 mW·m ⁻¹ ·K ⁻¹ at 1273 K and 171.1 mW·m ⁻¹ ·K ⁻¹ at 2273 K. The combination of temperature-invariant elasticity and chemical diversity makes such aerogels highly promising for extreme thermomechanics, from heat-insulated industries to deep space exploration.

The MX₂Y₄ (M = Cr, Hf, Mo, Ti, W, Zr; X = Si, Ge; Y = N, P, As) monolayers possess potential advanced applications such as photocatalytic, electrocatalytic, and photovoltaic devices.

In this work, the heat transport properties of Janus MoSSe and WSSe monolayers are systematically investigated using non-equilibrium molecular dynamics simulations. Strong size dependence of the thermal conductivity is found in the Janus MoSSe and WSSe monolayers. In the two-dimensional limit, the Mo-based Janus MoSSe monolayer shows a higher thermal conductivity but similar phonon mean free path as MoS₂, while the W-based Janus WSSe monolayer shows a similar thermal conductivity but longer phonon mean free path than WSe₂. These two Janus monolayers also present quite different temperature dependencies. With temperature increasing from 100 K to 350 K, the reduction in thermal conductivity of MoSSe is up to 28.4%, but only 12.75% in WSSe, because of the weak temperature dependence in the phonon density of states. With 2% vacancy density, the thermal conductivity of defective MoSSe is only 16.03% that of pristine MoSSe, while for defective WSSe, the thermal conductivity is 14.04% that of pristine WSSe. The strong dependence on vacancy is explained by atomic heat flux vector analysis. The present study demonstrates rich physical phenomena in the thermal transport properties of Janus transition metal dichalcogenide monolayers, which may offer a new degree of freedom for manipulating their thermal conductivity for applications including thermal management and thermoelectric devices.