Multiple Stimuli-Triggered Self-Healing Aerogels with Efficient Photothermal Conversion and Humidity Response Performance

Aerogels are widely utilized due to their high porosity, low density, and ease of functionalization, containing sensing and photothermal conversion. However, their susceptibility to damage, due to their fragile porous structure, often hinders their application in complex scenarios. Herein, this study proposes a facile strategy to fabricate a multifunctional composite aerogel with self-healing performance to extend the service life and broaden the application. In the composite system, poly(vinyl alcohol) (PVA) served as a supporting framework to maintain the structural stability, while PCL acted as a low-melting repair agent to enable damage restoration. Three distinct stimuli strategies, involving direct thermal stimuli, hydrothermal stimuli, and photothermal stimuli, could realize the effective self-healing of the broken aerogel, which were devised to meet diverse demands. Besides, the composite aerogel was endowed with good humidity response and photothermal conversion performance. It could effectively detect humidity through remarkable electrical signal changes and realize a rapid temperature rise under light irradiation, resulting in a further photothermal antibacterial effect against Escherichia coli and Staphylococcus aureus. This work provided new insights into the design of multifunctional self-healing aerogels, offering broad application prospects in energy conversion, intelligent sensing, and other fields.