Synthesis and luminescence properties of mesophase silica thin films doped with in-situ formed europium complex (original) (raw)
Related papers
Microporous and Mesoporous Materials, 2008
A novel periodic mesoporous organosilica (PMO) covalently grafting with phen (phen-PMO, phen = 1, 10phenanthroline) was synthesized via a co-condensation of 1,2-bis(triethoxysilyl)ethane (BTESE) and 5, 6bis(N-3-(triethoxysilyl)propyl)ureyl-1, 10-phenanthroline (phen-Si) using supramolecular polyoxyethylene (10) stearyl ether (Brij 76) surfactant as template (under acidic conditions). Accordingly, a series of PMO materials (PMOs) containing Eu(tta) 3 phen (denoted as Eu(tta) 3 phen-PMO, tta = 2-thenoyltrifluoroacetone) were synthesized by impregnation of Eu(tta) 3 Á 2H 2 O into phen-PMO through a ligand exchange reaction. For comparison, Euphen-PMO was also prepared using the same approach except EuCl 3 Á 6H 2 O instead of Eu(tta) 3 Á 2H 2 O. The mesostructures of the PMO materials were characterized by XRD, N 2 adsorption-desorption and TEM measurements. The results showed that during the surfactant extraction process, the chelating organic ligand structure was preserved, which was confirmed by Fourier transform infrared (FTIR) and 29 Si CP-MAS NMR spectroscopies. Under UV irradiation, Eu(tta) 3 phen-PMO exhibited the characteristic emission of Eu 3+ ions. Based on the emission spectra, the experiment intensity parameters for Eu(tta) 3 phen, Euphen-PMO and Eu(tta) 3 phen-PMO were calculated according to Judd-Ofelt theory. Compared to the pure complex, the resulting hybrid material exhibited better thermal stability and similar emission quantum efficiency, demonstrated by thermogravimetric analysis and luminescence characterization, respectively. The hybrid material Eu(tta) 3 phen-PMO showed higher emission quantum efficiency than that of Euphen-PMO, indicating that tta is an efficient sensitizer for the luminescence of central Eu 3+ ions.
Luminescent mesoporous films containing europium III complex
Microporous and Mesoporous Materials, 2018
Mesoporous materials have large specific area and pore volume, low density, and high mechanical and thermal stability. These materials can be applied as catalysts, shape-selective adsorbents, chemical sensors, and capsules for controlled release of therapeutic agents; they can also be employed in microelectronics, electro-optics, and other emerging nanotechnologies. In this study, we used the sol-gel process to obtain mesoporous silica films by dip coating. A trispyrazolyl borate, or scorpionate (Tp), complex containing europium III was incorporated into a mesoporous silica film via wet impregnation. The silica precursor solution was prepared by homogenizing tetraethylorthosilicate, deionized water, ethanol, and cetyltrimethylammonium bromide. The films were obtained by the dip-coating technique (between one and two depositions) at a deposition rate of 300 mm/min; borosilicate glasses were used as substrates. The films were characterized by X-ray diffraction, infrared spectroscopy, transmittance, and europium III photoluminescence analyses. X-ray diffraction showed that mesoporous silica was present in the substrate. Silica without thermal treatment and silica treated at 200°C presented pore diameters of 3.75 and 3.45 nm, respectively. Thermal treatment eliminated the surfactant. The excitation and emission spectra confirmed that the luminescent europium III complex was incorporated into the mesoporous silica film, which can be employed as sensor.
Chemistry of Materials, 2012
Europium(III) ions containing mesoporous silica coatings have been prepared via a solvent evaporationinduced self-assembly (EISA) approach of different singlesource precursors (SSPs) in the presence of Pluronic P123 as a structure-directing agent, using the spin-coating process. A deliberate tailoring of the chemical composition of the porous coatings with various Si:Eu ratios was achieved by processing mixtures of tetraethylorthosilicate (TEOS) and Eu 3+-coordinated SSPs. Small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) analyses demonstrate that the thin metal oxide-doped silica coatings consist of a porous network with a short-range order of the pore structure, even at high europium(III) loadings. Furthermore, luminescence properties were investigated at different temperatures and different degrees of Eu 3+ contents. The photoluminescence spectra clearly show characteristic emission peaks corresponding to the 5 D 0 → 7 F J (J = 0−5) transitions resulting in a red luminescence visible by the eyes, although the films have a very low thickness (150−200 nm).
The Journal of Physical Chemistry C, 2012
A new betadiketonate ligand displaying a trimethoxysilyl group as grafting function and a diketone moiety as complexing site propyl)-1-3-butanedione (C 4 H 3 S)COCH[(CH 2 ) 3 Si(OCH 3 ) 3 ]COCF 3 ) and its highly luminescent europium(III) complex [Eu(TTA-Si) 3 ] have been synthesized and fully characterized. Luminescent silica-based hybrids have been prepared as well with this new complex grafted on the surface of dense silica nanoparticles (28 ( 3 nm) or on mesoporous silica particles. The covalent bonding of Eu(TTA-Si) 3 inside the core of uniform silica nanoparticles (40 ( 5 nm) was also achieved. Luminescence properties are discussed in relation to the europium chemical environment involved in each of the three hybrids. The general methodology proposed allowed high grafting ratios and overcame chelate release and tendency to agglomeration, and it could be applied to any silica matrix (in the core or at the surface, nanosized or not, dense or mesoporous) and therefore numerous applications such as luminescent markers and luminophors could be foreseen.
Organic complexes of Eu3+ supported in functionalized silica gel: highly luminescent material
Journal of Alloys and Compounds, 1994
Eu III ion and its chelates of 1,10-phenantroline (phen), 2,2-bipyridine (bpy), benzoyltrifluoroacetone (bfa) and acetylacetone (acac) were supported on silica gel (SG) and silica gel functionalyzed with propyl imidazole (IPG). The luminescence studies of Eu III showed an increase in the intensity and lifetime of the Eu IIII 5Do--* 7F2 transition in the presense of IPG, when compared with SG. The energy transfer from bfa and phen to the Eu III ion was also detected. In these cases, an increase in the intensity and lifetime of Eu III related to the direct excitation at the metallic ion was observed.
Luminescent Properties of Eu3+-Doped Hybrid SiO2-PMMA Material for Photonic Applications
Micromachines
Hybrid organic-inorganic materials are of great interest for various applications. Here, we report on the synthesis and optical characterization of silica-PMMA samples with different Eu3+ molar concentrations. The optical properties of this material make it suitable for photonic applications. The samples were prepared using the sol-gel method, mixing tetraethyl orthosilicate (TEOS) as a silica glass precursor and methyl methacrylate (PMMA) as a polymer component. Europium nitrate pentahydrate was then added in six different molar concentrations (0.0, 0.1, 0.25, 0.5, 0.75, and 1%) to obtain as many different samples of the material. The absorption spectra were obtained applying the Kubelka–Munk formula to the diffuse reflectance spectra of the samples, all in the wavelength range between 240 and 2500 nm. The emission and excitation measurements were made in the visible range. Five bands could be identified in the emission spectra, related to electronic transitions of the ion Eu3+ (4D...
J. Mater. Chem., 2010
A novel class of efficient visible light sensitized antenna complexes of Eu 3+ based on the use of a highly conjugated b-diketonate, namely, 1-(4-biphenoyl)-3-(2-fluoroyl)propanedione (HBFPD) and 1,10phenanthroline as an ancillary ligand has been designed, synthesized, characterized and their photophysical properties (PL) investigated. PL measurement results indicated that suitably expanded p-conjugation in the complex molecules makes the excitation band red shift to the visible region and hence the Eu 3+ complexes exhibit intense red emission under blue light excitation (440 nm) with a solidstate quantum yield of 32 AE 3%, which is the highest so far reported in the literature. Further, in the present work, the visible sensitized Eu 3+ complex has been covalently anchored to the ordered mesoporous MCM-41 via the modified HBFPD ligand for the first time to the best of our knowledge. b-Diketonate grafted to the coupling agent 3-(triethoxysilyl)propylisocyanate was used as the precursor for the preparation of mesoporous nanomaterials. MCM-41 consisting of ternary complex Eu(SiBFPD) 3 (phen) covalently bonded to the silica-based network, which was designated as Eu(SiBFPD) 3 (Phen)/MCM-41 (3), was obtained by interacting europium nitrate, SiBFPD-Na and 1,10-phenanthroline into the hybrid material via a ligand-exchange reaction. The designed material was further characterized by powder X-ray diffraction, dynamic light scattering (DLS) technique, thermogravimetric analysis, N 2 adsorption-desorption, SEM, TEM, FT-IR, FT-Raman, 13 C and 29 Si CPMAS NMR and photoluminescence spectroscopic techniques. The hybrid material covalently bonded to MCM-41 exhibits an efficient intramolecular energy transfer process from the silylated bdiketonate to the central Eu 3+ , namely, the ''antenna effect'', which favored a stronger red/orange intensity ratio, longer lifetime, and high thermal stability than the precursor complex.
Journal of materials science, 2000
Microporous silica gel has been prepared by the sol-gel method utilizing the hydrolysis and polycondensation of tetraethylorthosilicate (TEOS). The gel has been doped with the luminescent ternary europium complex Eu(TTA) 3 ·phen: where HTTA = 1-(2-thenoyl)-3,3,3-trifluoracetone and phen = 1,10-phenanthroline. By contrast to the weak f-f electron absorption bands of Eu 3+ , the complex organic ligand exhibits intense near ultraviolet absorption. Energy transfer from the ligand to Eu 3+ enables the production of efficient, sharp visible luminescence from this material. Utilizing the polymerization of methyl methacrylate or ethyl methacrylate, the inorganic/polymer hybrid materials containing Eu(TTA) 3 ·phen have also been obtained. SEM micrographs show uniformly dispersed particles in the nanometre range. The characteristic luminescence spectral features of europium ions are present in the emission spectra of the hybrid material doped with Eu(TTA) 3 ·phen. C 2000 Kluwer Academic Publishers
Highly efficient visible light sensitized red emission from europium tris1-(4-biphenoyl)-3-(2-fluoroyl)propanedione complex grafted on silica nanoparticles
Journal of Materials Chemistry, 2010
A novel class of efficient visible light sensitized antenna complexes of Eu 3+ based on the use of a highly conjugated b-diketonate, namely, 1-(4-biphenoyl)-3-(2-fluoroyl)propanedione (HBFPD) and 1,10phenanthroline as an ancillary ligand has been designed, synthesized, characterized and their photophysical properties (PL) investigated. PL measurement results indicated that suitably expanded p-conjugation in the complex molecules makes the excitation band red shift to the visible region and hence the Eu 3+ complexes exhibit intense red emission under blue light excitation (440 nm) with a solidstate quantum yield of 32 AE 3%, which is the highest so far reported in the literature. Further, in the present work, the visible sensitized Eu 3+ complex has been covalently anchored to the ordered mesoporous MCM-41 via the modified HBFPD ligand for the first time to the best of our knowledge. b-Diketonate grafted to the coupling agent 3-(triethoxysilyl)propylisocyanate was used as the precursor for the preparation of mesoporous nanomaterials. MCM-41 consisting of ternary complex Eu(SiBFPD) 3 (phen) covalently bonded to the silica-based network, which was designated as Eu(SiBFPD) 3 (Phen)/MCM-41 (3), was obtained by interacting europium nitrate, SiBFPD-Na and 1,10-phenanthroline into the hybrid material via a ligand-exchange reaction. The designed material was further characterized by powder X-ray diffraction, dynamic light scattering (DLS) technique, thermogravimetric analysis, N 2 adsorption-desorption, SEM, TEM, FT-IR, FT-Raman, 13 C and 29 Si CPMAS NMR and photoluminescence spectroscopic techniques. The hybrid material covalently bonded to MCM-41 exhibits an efficient intramolecular energy transfer process from the silylated bdiketonate to the central Eu 3+ , namely, the ''antenna effect'', which favored a stronger red/orange intensity ratio, longer lifetime, and high thermal stability than the precursor complex.