Gradient pore-structured Aerogels: Structure, strategies, and applications

Aerogels possess various fascinating properties, such as low density, high porosity, low thermal conductivity, and low dielectric constant, offering promising applications in thermal management, noise absorption, oil/water separation, and beyond. Compared with conventional uniform-pore aerogels, gradient pore-structured aerogels (GPSAs) offer distinct advantages, such as significantly improved mechanical robustness, superior thermal regulation, enhanced sorption/separation performance, and greater potential for multifunctionality. Nevertheless, comprehensive reviews that systematically summarize the structural advantages and emerging applications of GPSAs remain limited. This review systematically presents the main fabrication strategies, characteristic microstructures and the associated formation mechanism of GPSAs. It also summarizes their representative applications—particularly in thermal management, acoustic absorption, and oil–water separation—along with the underlying mechanisms. Finally, major challenges and future research directions are discussed to provide guidance for the development of next-generation, high-performance, multifunctional GPSAs. Overall, this review offers valuable insights into advanced gradient pore-structured aerogels, highlighting their potential to significantly enhance thermal management, acoustic absorption, and solar-driven interfacial evaporation in next-generation aerogel materials.