Independent dual-responsive luminous composite fibers with controllable full-color emissions

Abstract

Accumulated ultraviolet (UV) under high temperature is prone to cause photoaging, skin burns, and even induce skin cancers during outdoor activities. Fiber-based wearable sensors with color-tunable luminescent ability are urgently demanded for real-time monitoring of human health conditions to enhance personal awareness of these hazards. To achieve tunable full-color emission, a set of three primary colors (red, green, and blue) of rare-earth doped persistent luminescent phosphors are successfully synthesized. After simply mixing them with particular ratios, a tunable full-color emission system can be realized. Herein, by integrating the thermochromic dyes, photochromic dyes, and luminescent phosphors directly into polyacrylonitrile (PAN) matrix, novel thermo-UV-sensing composite fibers with color-tunable luminescent ability are prepared via the facile wet-spinning process. The obtained fibers can be switched among four different colors with brilliant reversible color changes in response to temperature and UV irradiation both independently and in combination. Besides, the fibers can emit tunable emissions under in full spectral range 365 nm excitation. This work paves the way for as-prepared fibers for diverse applications including energy-free, wearable real-time monitors of the temperature/UV, and high-level information encryption.