CNC-directed hierarchical porous cellulose/MoS2 shape stabilized PCMs phase change fibers for thermal insulation and infrared stealth

A novel coaxial wet spinning strategy is reported to fabricate shape stabilized phase change aerogel fibers (C f PCF). • The fibers feature hierarchically porous flower-like PUPCM clusters engineered by CNC-directed hydrogen bonding. • The C f PCF exhibits a high phase change enthalpy (115.6 J/g), ultralow thermal conductivity (0.076 W·m −1 ·K −1 ). • The C f PCF fabrics enable outstanding infrared stealth (Infrared detection temperature decreased by 51 °C). The escalating demand for advanced fibrous materials integrating dynamic thermal management and infrared stealth has spurred continuing innovation. Traditional porous phase change fibers (PCFs) suffer from two critical deficiencies: solid-liquid phase change materials (SLPCMs) leakage and gas-solid interface degradation. Herein, we present a novel coaxial wet spinning strategy to fabricate porous shape stabilized phase change fibers (C f PCFs). The aerogel core is prepared via cellulose nanocrystals (CNCs)-directed crystallization of polyurethane-based shape stabilized PCMs (PUPCMs) that were synthesized through crosslinking polyethylene glycol with hexamethylene diisocyanate, inherently eliminating liquid leakage. Thanks to strong intermolecular hydrogen bonding interactions between CNCs and PUPCMs, in-situ crystallization and assembly of PUPCMs proceed on CNC-directed three-dimensional scaffolds via ice templating, generating flower-like crystal clusters with hierarchical porosity. This unique structure offers dual benefits: 1) Robust anchoring of shape stabilized PUPCM to prevent leakage; 2) Excellent properties of high phase change enthalpy (115.6 J/g) and porosity (69.35%), ultralow thermal conductivity (0.076 W·m −1 ·K −1 ), and superior thermal stability (91.35% enthalpy retention after 600 cycles). The as-woven C f PCF fabric demonstrates exceptional thermal buffering performance, achieving a temperature lag of up to 750 s at 80 °C. This effect stabilizes the temperature through phase-change endothermy and reduces infrared-detected temperatures by 51 °C. This work presents a new pathway for developing next-generation intelligent fibrous materials with integrated functionality.