Waste-Derived High-Strength Cellulosic Fibers with Reversible Thermal Energy Storage Properties

This study presents a sustainable strategy for upcycling textile waste into high-tenacity cellulosic fibers, addressing critical environmental challenges in the textile industry. A selective dissolution process efficiently separates cellulose from difficult-to-recycle cotton-polyester blends, enabling its recovery and reuse. The extracted cellulose is regenerated via an eco-friendly wet-spinning process, yielding high-strength fibers with a tenacity of 49.8 ± 1.4 cN/Tex. To improve functionality, phase change material (PCM) microcapsules are embedded within the cellulose matrix, enabling reversible thermal energy storage. At the highest PCM loading of 40%, the fibers exhibit a reversible energy storage capacity of 66.6 J/g alongside excellent washing fastness for durable applications. By integrating green chemistry principles with advanced fiber engineering, this approach offers a scalable, circular solution for textile waste valorization, enabling the development of high-performance, thermoregulatory materials for sustainable applications.