Dual-scale encapsulation via Pickering emulsion microencapsulation in nanocellulose aerogel for thermal energy storage

This study reports a dual-scale encapsulation strategy using nanocellulose (CNF) to create high-performance, leakage-proof composite phase change materials. Bio-derived palmitic acid (PA) and lauric acid (LA) serve as the phase change materials and CNF acts as a green emulsifier. Pickering emulsion technology is employed to encapsulate them into microcapsules. These microcapsules are further embedded into an CNF aerogel skeleton via directional freeze-drying, resulting in a composite phase change material (PA/CNF) with a dual microcapsule-aerogel coating structure. Even with a high PA loading of 88.9% ( w ), the composite exhibits excellent shape stability and leakage resistance. After heating at 80 °C for 120 min, its leakage rate is only 0.03%. Its latent heat reaches 183 J/g, along with good thermal cycling stability and reversibility. Moreover, the material demonstrates remarkable thermal buffering and regulation capabilities, indicating great potential for thermal management applications. This work provides a novel and scalable green approach for developing high-performance composite phase change materials.