Combining Fast Wicking Capability With Mechanical Robustness in Aerogel for Capillary-Driven Evaporative Cooling

Capillary-driven evaporative cooling offers a compact and energy-efficient solution to the challenges of high heat flux and high temperature. Porous material serves as both liquid transport carrier and major weight contributor. However, conventional metallic or ceramic materials fail to combine lightweight, flexibility, and fast capillarity. In contrast, aerogels with high porosity and hydrophilized skeletons are ideal alternatives, but the weak micro/nano-sheet interactions lead to pore collapse or blockage, compromising both mechanical and wicking properties. In this study, strong and flexible aerogels with fast wicking capability were prepared by non-covalently immobilizing graphene oxide on melamine foam. Benefiting from the micro-arched structures, the aerogel exhibited a specific elastic modulus of 207.0 kPa kg⁻¹ m³ and a specific compressive strength of 5.4 kPa kg⁻¹ m³. Meanwhile, the aerogel achieved a high wicking flux of 8.4 kg m⁻² s⁻¹, exceeding reported wicking materials by one to two orders of magnitude. Furthermore, the aerogel surface temperature was maintained at 100.0°C during evaporative cooling under a heat flux of 1.0 MW m⁻². The integration of aerogel in a cooling device reduced the areal density by at least 26.8%. This work challenges the paradigm of conventional materials and expands the applicability of aerogels in harsh environments.