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Liu L.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | Liu L.,University of Chinese Academy of Sciences | Li B.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | Qin R.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | And 4 more authors.
Solid State Sciences | Year: 2010

Novel upconversion nanocomposites with nanoporous structure were presented in this paper. Silica-coated cubic NaYF4:Yb3+, Tm3+ nanoparticles were first prepared. After annealing, monodisperse cubic/hexagonal mixed phases NaYF4:Yb3+, Tm3+@SiO2 nanoparticles were obtained, and the NaYF4:Yb3+, Tm3+ cores became nanoporous. To the best of our knowledge, the nanoporous structure in NaYF4:Yb3+, Tm3+@SiO2 nanocomposites was observed for the first time. They demonstrate increased upconversion emission compared with unannealed dense NaYF4:Yb3+, Tm3+ nanoparticles due to the appearance of the hexagonal NaYF4:Yb3+, Tm3+. The silica shell not only makes the nanocomposites possess bio-affinity but also protects the NaYF4:Yb3+, Tm3+ cores from aggregating and growing up. Thus the upconversion, nanoporous and bio-affinity properties were combined into one single nanoparticle. The nanocomposites have been characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), small angle X-ray diffraction (SAXRD) and emission spectroscopy. These multifunctional nanocomposites are expected to find applications in biological fields, such as biolabels, drug storage and delivery. © 2009 Elsevier Masson SAS. All rights reserved. Source


Wu X.,Polyoxometalate Science Key Laboratory | Song L.,Polyoxometalate Science Key Laboratory | Li B.,Polyoxometalate Science Key Laboratory | Li B.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | Liu Y.,CAS Changchun Institute of Optics and Fine Mechanics and Physics
Journal of Luminescence | Year: 2010

Novel oxygen sensing materials consisting of [Ru(Bphen)2bpy]2+ (Bphen=4,7-diphenyl-1,10-phenanthroline, bpy=2,2′-bipyridyl) portion covalently grafted to the backbones of the ordered functionalized mesoporous MCM-41 are synthesized by co-condensation of tetraethoxysilane (TEOS) and the functionalized Ru(II) complex [Ru(Bphen)2Bpy-Si]2+ using surfactant cetyltrimethylammoniumbromide (CTAB) as template. The Bpy-Si was used as not only one of the precursors of the sol-gel process but also the second ligand of Ru(Bphen)2Cl2·2H2O complex to prepare the functionalized mesoporous materials for oxygen sensors. Dye leaching shortcoming is overcome due to the Si-C bonds. The derivative mesoporous oxygen sensing materials are characterized by Fourier transform infrared (FT-IR), small angle X-ray diffraction (SAXRD), luminescence intensity quenching Stern-Volmer plots, and excited-state decay analysis. The mesoporous materials show higher sensitivity to the O2 concentration in N2 (I0/I100=23.2) and shorter response time (1.2 s) in comparison with those based on sol-gel method. When the concentration of oxygen is 10%, the luminescence intensity of the oxygen sensor can be quenched by 89.9%, suggesting that it is highly sensing at low concentration of oxygen. © 2009 Elsevier B.V. All rights reserved. Source


Wang D.,Polyoxometalate Science Key Laboratory | Li B.,Polyoxometalate Science Key Laboratory | Li B.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | Zhang L.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | And 2 more authors.
Journal of Luminescence | Year: 2010

In this paper, a novel luminescent organic-inorganic hybrid material containing covalently bonded ternary europium complex in mesoporous silica MCM-41 has been successfully prepared by co-condensation of tetrethoxysilane (TEOS) and the modified ligand 2-phenyl-1H-imidazo[4,5-f][1,10]phen-3-(triethoxysilyl)propylcarbamate (PIP-Si) in the presence of cetyltrimethylammonium bromide (CTAB) surfactant as template. PIP-Si containing 1,10-phenanthroline covalently grafted to 3-(triethoxysilyl)propyl isocyanate is used not only as a precursor but also as the second ligand for Eu(TTA)3·2H2O (TTA: 2-thenoyltrifluoroacetate) complex to prepare a novel functionalized mesoporous material. The resulted mesoporous composite materials, which demonstrate strong characteristic emission lines of Eu3+5D0-7FJ (J=0, 1, 2, 3, 4), were characterized by Fourier transform infrared (FT-IR), small-angle X-ray diffraction, excited-state decay analysis. Emission intensity of the Eu(III) complex covalently linked to MCM-41 (Eu-MCM-41) increases with the increasing irradiation time, demonstrating better photostability compared with both pure Eu(III) complex and physically incorporated sample. © 2009. Source


Zuo Q.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | Zuo Q.,University of Chinese Academy of Sciences | Li B.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | Zhang L.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | And 8 more authors.
Journal of Solid State Chemistry | Year: 2010

A novel Eu3+ complex of Eu(DPIQ)(TTA)3 (DPIQ=10H-dipyrido [f,h] indolo [3,2-b] quinoxaline, TTA=2-thenoyltrifluoroacetonate) was synthesized and encapsulated in the mesoporous MCM-41, hoping to explore an oxygen-sensing system based on the long-lived Eu3+ emitter. The Eu(DPIQ)(TTA)3/MCM-41 composites were characterized by infrared spectra (IR), ultraviolet-visible (UV-vis) absorption spectra, small-angle X-ray diffraction (SAXRD), luminescence intensity quenching upon various oxygen concentrations, and fluorescence decay analysis. The results indicated that the composites exhibited the characteristic emission of the Eu3+ ion and the fluorescence intensity of 5D0-7F2 obviously decreased with increasing oxygen concentrations. The oxygen sensing properties of the composites with different loading levels of Eu(DPIQ)(TTA)3 complex were investigated. A sensitivity of 3.04, a short response time of 7 s, and good linearity were obtained for the composites with a loading level of 20 mg/g. These results are the best reported values for optical oxygen-sensing materials based on Eu3+ complexes so far. © 2010 Elsevier Inc. All rights reserved. Source

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