High Energy-Capacity and Multiresponsive Phase Change Fibers Via in Situ Polymer Composition with Expanded Carbon Nanotube Networks

Phase change fibers with abilities to storage/release thermal energy and response to multiple stimuli are of high interest for wearable thermal management textiles. However, there are long-term challenges for carbon nanotube (CNT) network-directed phase change composites, such as the limited polymer loading, nonuniform composite structure, and weak connectivity between CNTs. Herein, an expansion-based in situ composition strategy is proposed to impregnate polyethylene glycol (PEG) into CNT network, leading to a high and homogeneous PEG loading (96 wt%) and robust PEG confinement inside the expanded CNT network. As the expansion induced CNT separation from aggregation, leading to the full utilization of CNT surfaces, the CNT/PEG composite fibers at the highest PEG loading exhibited superior high latent heat of 195-205 J g-1, and were electrically and thermally conductive. More importantly, owing to the confinement, these fibers showed remarkable cyclic thermal sta-bility, without any liquid leakage. The composite fibers were also embroidered and woven into various fabrics, which showed excellent thermal managing capacity and rapid responses to electrical and optical stimuli.