Delignified Juncus Effusus Fibers Obtained From Various Pre-treatments and Their Applications

Juncus effusus fibers (JEFs) are considered “natural aerogel materials,” which have been used in the textile field in China for > 2700 years. However, the brittle fracture of JEFs limits their wide application. Herein, the influences of different delignification pretreatments, including NaOH aq., NaClO 2 aq., H 2 O 2 aq., and deep eutectic solvents (DES), on the structure, morphology, and physical and chemical properties of JEFs have been investigated. The modified JEFs treated with NaOH aq. exhibited the most significant weight loss (30%), and their three-dimensional (3D) cylindrical shape was torn apart because of the strong delignification effect. However, the other three methods exhibit delignification processes for structural retention. Particularly, NaClO 2 aq. could selectively remove the majority of lignin/hemicelluloses, resulting in modified JEFs whose tensile strength and specific surface area increased by 62.7% and 481.3%, respectively. On this basis, high efficiency oil-absorbing fiber and strain/humidity monitoring sensor were prepared by dip coating-drying method. The understanding of modified fibers gained in this study enables us to easily improve the JEFs properties of a given application.