Novel photo-responsive composite fibers fabricated by facile wet-spinning process for UV detection and high-level encryption

Fibers with reversible optical properties under light irradiation are highly demanded in diverse applications such as information storage, wearable camouflage and multicolor displays. However, conventional photo-responsive fibers are not able to be detected in both daylight and darkness limiting their application as smart materials in intelligent systems. Herein, the photo-responsive fibers detectable in both daylight and darkness are fabricated by a facile wet-spinning process. By employing spiropyran dyes and two types of rare-earth phosphors (SrAl 2 O 4 :Eu 2+, Dy 3+, Sr 2 MgSi 2 O 7 : Eu 2+, Dy 3+ ), the prepared fibers exhibit excellent and swift reversible photochromic properties. Furthermore, the fibers emit greenish-blue light with long afterglow for a broad range of excitation wavelengths from visible light to ultraviolet (UV) light. Capitalizing the intriguing photo-responsive features, the developed fibers offer applications in wearable and visualized UV detectors as well as high-level information encryption.