Organic dye fluorescent fibers for wearable devices

Organic fluorescent dyes are gradually gaining wide application in the fields of sensors, displays, and lighting. However, the use of organic fluorescent dyes for White light-emitting diodes (WLEDs) is still not sufficiently studied to be applied to the market. In this study, FR and FG with red and green fluorescence emission, respectively, were designed and synthesized, and two fluorescent dyes FB and FBP with aggregation-induced luminescence (AIE) properties were selected and dissolved in polyacrylonitrile (PAN) solution (in the ratio of 0.15 wt%, 2 wt%, 2 wt%, 1 wt%, respectively) to make flexible fiber films with fluorescence emission by electrostatic spinning. These fluorescent fiber films still have 78% of luminescence intensity after five days of immersion in water. The fluorescence quantum yields of the four fiber membranes were 12.89% (FR/PAN), 6.23% (FG/PAN), 39.85% (FB/PAN), 11.51% (FBP/PAN), respectively. Then 460 nm light-emitting diode (LED) chips and 365 nm LED chips were used to make WLEDs respectively with their color product coordinates (CIEs) of (0.3176,0.3256) and (0.3144,0.3158). Based on the good flexibility and mechanical strength of the fiber films, we used them to fabricate the wearable bracelet. The results indicate that the organic dye-based fluorescent fiber film has good potential for application in the field of WLED and wearable devices.