Degradable cellulose nanofiber/MXene composite films with low thermal conductivity for infrared stealth and...

Advances in modern infrared (IR) detection technology have created a pressing need for intelligent multifunctional shielding materials based on sustainable biological macromolecules. Cellulose, as the most abundant renewable biopolymer on Earth, offers an excellent platform for developing eco-friendly functional materials. However, simplifying the preparation of cellulose-based composites while ensuring multifunctionality remains challenging. Herein, we report a flexible cellulose nanofiber (CNF)/MXene/poly(vinyl alcohol) composite film with a nacre-like structure, fabricated via water-evaporation-induced self-assembly. The optimized CMP-3 film (the mass ratio of CNF, MXene, and PVA was 18:12:70) exhibits outstanding comprehensive performance: excellent mechanical properties (tensile strength of 23.72 MPa), low thermal conductivity (0.0913 W·m^-1·K^-1), low IR emissivity (0.51 at 8-14 μm) for effective IR stealth, and superior photothermal conversion (70.8 °C within 120 s under 100 mW·cm^-2). Notably, the film demonstrates complete oxidative degradability in 3% H₂O₂ within 24 h, highlighting its chemical degradability under oxidative conditions. This study provides a facile fabrication strategy for multifunctional cellulose-based composites in adaptive IR camouflage and thermal management.