Ultralight electrospun nanofibrous aerogels as shape-stabilizing matrices for high-loading paraffin-based phase change materials

Electrospun nanofibrous aerogels (NFAs) were strategically employed as a lightweight, porous supporting matrix to fabricate shape-stabilized composite phase change materials (PCMs) with exceptionally high paraffin wax (PW) loading. NFAs of tunable density were fabricated via a synergistic process combining high-speed emulsification, freeze-drying, and thermal crosslinking, using electrospun polyacrylonitrile (PAN)/benzoxazine (BA-a) nanofibrous membranes integrated with carbon nanotubes (CNTs) as precursors. The microstructure, shape stability, thermal energy storage capacity, thermal reliability, and thermal conductivity of the resulting PW/NFA composites were systematically evaluated. The NFAs exhibit an ultralow-density, hierarchically interconnected three-dimensional porous architecture, which enables effective control over PW incorporation by adjusting aerogel density. Notably, a maximum PW mass fraction of 98% was achieved without any leakage. Thermal analysis confirms that the composite PCMs exhibit excellent thermal energy storage and release capabilities, with phase change enthalpies approaching those of pure PW, along with outstanding thermal reliability and stability. Furthermore, the incorporation of CNT-reinforced NFAs enhances the thermal conductivity of the composite by 125.30% relative to pure PW. Infrared thermal imaging and time–temperature response tests collectively validate the superior heat transfer efficiency and practical applicability of these shape-stabilized PCMs in thermal management systems.