Solar-Driven Gradient Aerogel Composites for Coupled Seawater Desalination, Thermoelectric Power Generation, and Dual-Mode Camouflage

Abstract

To overcome the limitations of traditional energy systems and enhance the energy utilization diversity, a multifunctional gradient aerogel composite system is designed in this study. This system integrates poly(maleic acid ditetradecyl ester-hexadecyl acrylate) (PMH) as a phase change material, an amino montmorillonite/graphene oxide (N-MMT/GO) hybrid aerogel (GNA) as a support framework, and a thermochromic surface coating. GNA features a unique hierarchical porous structure, where N-MMT mitigates GO restacking and lattice defects. PMH exhibits high thermal stability and enthalpy (99.1 J g⁻¹) and is stably encapsulated in the GNA matrix with a low leakage rate (0.45%). High-temperature carbonization yields reduced GO and N-MMT, forming continuous thermal conduction pathways that enhance phonon and electron transport, thereby improving thermal storage and photothermal conversion efficiency. The resulting composite simultaneously enables four key functions: solar-driven seawater desalination, thermoelectric power generation, infrared camouflage, and visible-light camouflage. Solar energy drives efficient thermal energy storage and triggers a dynamic color transition through the thermochromic layer, enabling an adaptive environmental response. This study presents a comprehensive strategy for designing solar-responsive multifunctional materials with promising applications in seawater desalination, sustainable energy, environmental regulation, and military camouflage.