(Sr,Ca)₂MgSi₂O₇:Eu²⁺,Dy³⁺ Long-persistent Luminescence Materials And Their Applications In Electrospinning

(Sr, Ca)2MgSi2O7:Eu2+,Dy3+are two afterglow performance outstanding silicate long persistence luminescence materials, which have incomparable advantages of chemical stability compare with other long persistence luminescence materials. With the development of nanotechnology and biomedical, rare earth metals doped alkaline-earth metal silicate long persistence luminescence materials represents a rapidly expanding field such as biological probe, cell targeted tag and medical imaging. In this paper, for the first time, we have tried to mix the(Sr, Ca)2MgSi2O7:Eu2+,Dy3+long persistent luminescence particles with polymer, and fabricate them into a new superfine composite fierbs by electrospinning. Also, properties of that have been characterized.Firstly,(Sr,Ca)2MgSi2O7:Eu2+,Dy3+particles were synthesized by sol-gel method.Then, the results of characterization show that two kinds of crystal respectively can be indexed to PDF card no.75-1736(Sr2MgSi2O7) and no.35-0592(Ca2MgSi2O7). Two samples were respectively detected emission peak at 468 nm and 452 nm/537 nm. They rapidly decay in 200 s and 100 s after removing excitation and slowly decay in 400 s and200s, respectively. For Sr2MgSi2O7:Eu2+,Dy3+particles, we have analyzed some factors which may affect the performance of their fluorescence and long afterglow, such as different synthesis methods, different Eu2+and Dy3+doping amount, different Eu2+/Dy3+doping ratio and immersion environment. Results showed that the fluorescent performance and afterglow synthesized by sol-gel are better than that synthesized by solid phase method.Fluorescence emission intensity mainly depends on the content of Eu2+. Afterglow initial brightness and decay trend mainly depends on the content of Dy3+. The optimal doping ratio of Eu2+/Dy3+is 1:2, also we verified the luminescence performance of that is very stable in water.Subsequently, the two synthesized particles have been dispersed into poly lactic acid solution respectively and synthesize them into uniform stability of solid/liquid mixture respectively. Finally, fabricated the mixtures into two new compositer fibers of PLA/(Sr,Ca)2MgSi2O7:Eu2+,Dy3+. The results of characterization show that the twocompositer fibers are composited by semitransparent polymer fibers matrix and long persistent luminescence particles which dispersed in polymer fibers randomly and uniformly. Two kinds of fiber diameter size distribute in 1~3μm which are randomly dispersed particles of long afterglow particles sizes ranging from dozens to hundreds nanometers. After being excitated, two products are presented as a continuous uniform light line observed by the fluorescence microscope. Two kinds of composite fibers are respectively presented the same emission spectrum and similar afterglow decay trend as long-peresistent luminescence powder, which show that luminescent performance of particles were not be affected after being fabricated into compositer fibers.