Synthesis, characterization and luminescence of europium perchlorate with MABA-Si complex and coating structure SiO sub(2)Eu(MABA-Si) luminescence nanoparticles

• Published in: Luminescence (Chichester, England) England), 2017-05, Vol.32 (3), p.327-333
• Main Authors: Fu, Zhi-Fang, Li, Wen-Xian, Bai, Juan, Bao, Jin-Rong, Cao, Xiao-fang, Zheng, Yu-Shan
• Format: Article
• Language: English
• Subjects: Coating; Fluorescence; Luminescence; Nanoparticles; Scanning electron microscopy; Silicon dioxide; Spectra; Transmission electron microscopy
• ISSN: 1522-7235; 1522-7243
• DOI: 10.1002/bio.3182

This article reports a novel category of coating structure SiO sub(2)Eu(MABA-Si) luminescence nanoparticles (NPs) consisting of a unique organic shell, composed of perchlorate europium(III) complex, and an inorganic core, composed of silica. The binary complex Eu(MABA-Si) sub(3).(ClO sub(4)) sub(3).5H sub(2)O was synthesized using HOOCC sub(6)H sub(4)N(CONH(CH sub(2)) sub(3)Si(OCH sub(2)CH sub(3)) sub(3)) sub(2) (MABA-Si) and was used as a ligand. Furthermore, the as-prepared silica NPs were successfully coated with the -Si(OCH sub(2)CH sub(3)) sub(3) group of MABA-Si to form Si-O-Si chemical bonds by means of the hydrolyzation of MABA-Si. The binary complexes were characterized by elemental analysis, molar conductivity and coordination titration analysis. The results indicated that the composition of the binary complex was Eu(MABA-Si) sub(3).(ClO sub(4)) sub(3).5H sub(2)O. Coating structure SiO sub(2)Eu(MABA-Si) NPs were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and infrared (IR) spectra. Based on the SEM and TEM measurements, the diameter of core-SiO sub(2) particles was ~400 and 600 nm, and the thickness of the cladding layer Eu(MABA-Si) was ~20 nm. In the binary complex Eu(MABA-Si) sub(3).(ClO sub(4)) sub(3).5H sub(2)O, the fluorescence spectra illustrated that the energy of the ligand MABA-Si transferred to the energy level for the excitation state of europium(III) ion. Coating structure SiO sub(2)Eu(MABA-Si) NPs exhibited intense red luminescence compared with the binary complex. The fluorescence lifetime and fluorescence quantum efficiency of the binary complex and of the coating structure NPs were also calculated. The way in which the size of core-SiO sub(2) spheres influences the luminescence was also studied. Moreover, the luminescent mechanisms of the complex were studied and explained.