Preparation And Properties Of Fluorescent PS Microspheres And Its Ordered Self - Assembled Materials

The preparation of fluorescent microspheres published was usually through the fluorescence dyeing of the polymer microspheres with organic dyes and quantum dots. But the product got both showed short fluorescence lifetimes and easily interfered by the background fluorescence and stray light. So, some researchers are turning to the study of the rare earth material, which has long luminescence lifetime, large Stokes shift and sharp line-like atomic emission, helping eliminate the interference of the background fluorescence and the stray light, improve the detection sensitivity and resolution. Currently, the rare earth polymer microspheres could be got by embedding and binding. The key point is the control of monodisperse property. In order to get high quality rare earth fluorescence microspheres with good disperse, the copolymerization of rare earth complex with Styrene (St) is introduced in this article. The main contents are as following:1. The preparation of monodisperse nano polystyrene microspheres by improved dispersion polymerizationThe nano polystyrene microspheres have been synthesized by the improved dispersion polymerization with styrene (St) as the monomer, azodiisobutyronitrile (AIBN) as the initiator, poly (vinyl pyrrolidone) (PVP) as the dispersant, sodium dodecylsulphate (SDS) as the stabilizer, the mixture of absolute ethyl alcohol and deionized water as the dispersing medium. The composition and particle size as well as their particle distribution of the polystyrene microspheres obtained were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and dynamic light scattering (DLS), and etc. The results showed that by the ad of SDS, microspheres with well disperse and fine sphericities could be got in the range of 120 to 300 nm. The particle size increased as the content of AIBN and St increased while the particle size decreased with the content of PVP increased.2. The preparation of Eu3+-PS copolymerization fluorescence microspheres by improved dispersion polymerizationThe Eu3+-PS copolymerization fluorescent microspheres have been synthesized by the improved dispersion polymerization with styrene (St) as the monomer, azodiisobutyronitrile (AIBN) as the initiator, poly (vinyl pyrrolidone) (PVP) as the dispersant, sodium dodecylsulphate (SDS) as the stabilizer, the mixture of the absolute ethyl alcohol and deionized water as the dispersing medium and the rare earth complex Eu(MAA)3phen as the fluorescent substance. By the methods of flourier transform infrared spectroscopy (FT-IR) and the simult-aneous thermal analysis (STA), the combination between St and Eu (MAA)3phen was indirectly proved to be through copolymerization key. The results of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and dynamic light scat-tering (DLS) indicated that the Eu3+-PS fluorescent microspheres were well disperse and fine sphericities. Through the analysis of ultraviolet and fluorescence, the product showed good rare earth characteristic fluorescence property and the fluorescent intensity was increased with the content of Eu(MAA)3phen was increased without the "quenching" phenomenon of the concentration.3. The preparation of Eu3+-PS colloidal crystal microspheres by microfluidic methodColloidal crystal microspheres with purple, green and red structural color were got by the new droplet emulsion method of micro fluid pump from the solution of Eu3+-PS fluorescence microspheres respectively. The results of scanning electron microscopy (SEM) indicated that the colloidal crystal microspheres had a structure of hexagonal close packed. And the analysis of fiber spectrometer showed that the reflected wavelength were 426 nm,523 nm and 655 nm, belonged to purple light, green light and red light respectively, which meets the requirements of CIE 1931 for display lighting materials.