Cotton-Inspired Phase Change Fiber Aerogels with Dual-Functional Thermal Protection for Personal Thermal Management

Phase change fibers demonstrate abundant latent heat exchange, yet lack sufficient insulation against cold environments due to structural limits. Existing fluffy variants are hindered by PCM leakage, poor mechanical properties, and complex fabrication. Inspired by cotton’s high porosity, mechanical durability, and practical applicability, we developed the phase change fiber aerogel (PCFA) by a simple strategy, combining a fibrous aerogel framework with microencapsulated phase change components. The PCFA exhibits outstanding thermal insulation (2.84 × 10 −2 ± 1.53 × 10 −4 W/m·K), further enhanced by low air permeability and moisture resistance. It presents a suitable phase change temperature (26.2 °C), appropriate latent heat density (43.5 J/g), and thermal cycling stability (1000 cycles). Notably, the PCFA demonstrates robust mechanical performance that withstands repeated bending, compression, stretching, and washing. The PCFA outperforms phase change fiber film and cotton in stabilizing skin temperature under various cold conditions, offering a promising solution for next-generation phase change textiles integrating thermal insulation and adaptive thermoregulation.