Preparation And Research Of Polymer/LaF₃:Ln³⁺ Composite Nanofibers With Upconversion Luminescence Property

Due to the great specific surface area, the surface energy and activity of nanoparticles increase.Therefore,the nanoparticles show many special chemical and physical (light, electricity, magnetism, heat, etc.) properties and a lot of scientists have been attracted by these characteristic. Because rare earth materials, especially their fluoride, have excellent luminescent properties and potential application in new photosource, bio-sensor, chemistry sensor, infrared quantum counter and so on, they have become a hot research field recently.In this paper, composite nanofibers with high upconversion properties were successfully prepared by electrospinning method, such as PVP (polyvinylpyrrolidone)/LaF3:Er3+ and PPV (poly p-phenylene vinylene)/LaF3:Er3+,Yb3+ composite nanofibers. The manufacture steps were to blend the nanoparticles in polymer solution, then the mixed solution was stirred (the speed was about 50rpm) for 48h, finally electrospinning.By using the transmission electron microscope (TEM) and the scanning electron microscope (SEM), we characterized the morphology of nanofibers and distribution of nanoparticle in polymer/LaF3:Ln3+ composite nanofibers. And by using fourier transform infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRD) etc., we characterized chemical and crystal structure of polymer/LaF3:Ln3+ composite nanofibers. The upconversion (UC) properties of the polymer/LaF3:Ln3+ composite nanofibers were characterized and discussed.The results showed that the average diameter of composite nanofibers was 200-400nm and the average diameter of LaF3:Ln3+ nanoparticles was about 40 nm. The nanoparticles were uniformly dispersed in the composite nanofibers. Under the excitation of a 980 nm laser, the polymer/LaF3:Ln3+ composite nanofibers had emitted a high upconversion luminescence, and the upconversion luminescence intensity was stronger than that of LaF3:Ln3+ nanoparticles. Up to now, we have not seen the report about the above results, and the paper is being written now.