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1.
The europium complex, Eu(BA)3Phen was introduced to the methylsilicone resin film, the investigation showed that the variation of the morphology and surface components of the film was not obvious comparing to methylsilicone resin film, and the superhydrophobicity of the as-prepared film was still retained. Furthermore, the film showed excellent luminescent property, the red light can be observed. 相似文献
2.
Guo-Lun Zhong Yong-Hong WangCun-Kuan Wang Bing-Yin PuYu Feng Kong-Zhang YangJung-Il Jin 《Journal of luminescence》2002,99(3):213-222
Langmuir-Blodgett (LB) films of different molar percentages of Eu(TTA)3Phen (TTA=2-thenoyltrifluoroacetone; Phen=1,10-phenanthroline) with Gd(TTA)3Phen coexisting with arachidic acid (AA) (complexes:AA=1:l, in molar ratio) were fabricated and the luminescence enhancement of Eu(III) in the films was studied in this investigation. The monolayers and LB films were characterized by π-A isotherms, fluorescence microscopy, UV-vis spectroscopy and low-angle X-ray diffraction. High-quality LB films and strongly luminescent films were obtained. It was learned from the present study that an efficient intermolecular energy transfer occurred from Gd(TTA)3Phen to Eu(TTA)3Phen in the films, which resulted in the luminescence enhancement effect. According to the proposed model of the “active enhancement circle” the distance of energy transfer from Gd-, Tb-, La-, and Y-complex to Eu-complex were calculated to be 1.2, 1.2, 0.7 and 1.0 nm, respectively. 相似文献
3.
Meso-structured silica monoliths using PEG (PEG=polyethylene glycol) as a low-cost template and synthesized via sol-gel methods were used as host materials for incorporation of europium complexes Eu(BA)3Phen (BA=benzoic acid and Phen=1,10-phenanthroline). The meso-structured silica was silylated by 3-aminopropyltriethoxysilane (APTES) or 3-glycidoxypropyltrimethoxysilane (GPTMS) before wet impregnation. Samples were characterized by BET, diffuse reflectance (DR) spectroscopy, infrared spectroscopy and fluorescence measurements. The results showed that the emission quantum efficiency of GPTMS silylated meso-structured silica with larger pore size was up to 44.6%. Also, the lifetime measurement showed the complex encapsulated in this rigid matrix had longer lifetime than the pure complex in solid or liquid. 相似文献
4.
G. Reiter G. Castelein P. Hoerner G. Riess J.-U. Sommer G. Floudas 《The European physical journal. E, Soft matter》2000,2(4):319-334
Spin-coated thin films of about 100nm of low-molecular-weight hydrogenated poly(butadiene-b- ethyleneoxide) (PBh-PEO) diblock copolymers have been crystallized at various constant temperatures. Crystallization has been observed in real
time by light microscopy. Detailed structural information was obtained by atomic force microscopy, mainly enabled by the large
viscoelastic contrast between amorphous and crystalline regions. The behavior in thin films is compared to the bulk properties
of the polymer. Crystallization started from an annealed microphase separated melt where optical microscopy indicated a lamellar
orientation parallel to the substrate. A small difference in the length of the crystallizable block produced significantly
different crystallization behavior, both in the bulk and in thin films. For thin films of the shortest diblock copolymer (45%
PEO content) and for an undercooling larger than about 10 degrees, crystallization created vertically oriented lamellae. These
vertical lamellae could be preferentially aligned over several micrometers when crystallization occurred close to a three-phase
contact line. Annealing at temperatures closer to the melting point or keeping the sample at room temperature for several
months allowed the formation of a lamellar structure parallel to the substrate. A tentative interpretation based on kinetically
caused chain folding and relaxation within the crystalline state, with implications on general aspects of polymer crystallization,
is presented.
Received 19 March 1999 and Received in final form 14 December 1999 相似文献
5.
6.
Asymmetric PS-b-PEO block copolymer exhibits well-ordered cylindrical morphology with nanoscale domain sizes due to microphase separation. Since the PS and PEO blocks have large stiffness difference, this polymer system represents an ideal candidate for studies of the phase contrast behavior in atomic force microscopy (AFM). In this paper, PS-b-PEO films are investigated under different scanning conditions using two different atomic force microscopes. It is found that the phase contrast of the film can be well described in terms of energy dissipation, though the exact phase image may also depend on the scanning parameters (e.g., the repulsive versus attractive regimes) as well as the settings of the microscope. Height variation on sample surface does not have significant effect on phase contrast. However, in order to obtain true topography of the polymer film, care has to be taken to avoid damage to the sample by AFM. Under certain conditions, true topography can be obtained during the first scan in spite of the surface-damaging forces are used. 相似文献
7.
Uninuclear europium (Eu), as well as binuclear Eu and terbium (Tb), complexes were synthesized using acrylic acid (AA) as the first ligand and 1,10-phenanthroline (Phen) as the second ligand. The relative weight ratio of the europium (III) (Eu3+) to terbium (III) (Tb3+) ions of the binuclear complex was 1:1 as determined via energy dispersive X-ray analysis. The structures of the Eu(AA)3Phen and Eu0.5Tb0.5(AA)3Phen complexes were characterized by Fourier transform infrared spectroscopy. A series of tri-cellulose acetate (TCA)/ the Eu(AA)3Phen and TCA/Eu0.5Tb0.5(AA)3Phen composites were prepared by solution blending, and their luminescent properties were investigated by fluorescence spectrophotometry. The excitation spectra of all composites indicated that the TCA matrix probably affected the energy absorption and transfer of organic ligands. In TCA/Eu0.5Tb0.5(AA)3Phen composites the introduced Tb3+ ions had some influence on energy absorption and transfer of organic ligands; the energy transfer process of the complex is suggested to be as follows: Phen→AA→Tb3+ion→Eu3+ion. The emission spectra indicated that the luminescent intensity of the TCA/Eu0.5Tb0.5(AA)3Phen composites was noticeably stronger than that of the TCA/Eu(AA)3Phen composites, suggesting that the comparatively stable and high-efficiency energy transfer process was only slightly influenced by the TCA matrix. In summary, the TCA/Eu0.5Tb0.5(AA)3Phen (90/10) composite possesses fine luminescent properties for potential usage as red fluorescent materials. 相似文献
8.
X.H. Zhao K.L. Huang F.P. Jiao Z.G. Liu 《Journal of Physics and Chemistry of Solids》2007,68(9):1674-1680
This work reports the synthesis and luminescent properties of complexes of europium(III) with 2-thienyltrifluoroacetonate (HTTA), terephthalic acid (TPA) and phenanthroline (Phen), in the solid state. The new complexes were characterized by elemental analysis, infrared (IR) spectroscopy, scanning electronic microscopy (SEM) and thermal stability analysis. Both binuclear complex Eu2(TPA)(TTA)4Phen2 and polynuclear complex Eu(TPA)(TTA)Phen present better thermal stability than the mononuclear complex Eu(TTA)3Phen does. The formation of the binuclear/polynuclear structure of the complexes appears to be responsible for the enhancement of the thermal stability. The emission spectra show narrow emission bands that arise from the 5D0→7FJ (J=0-4) transition of the Eu3+ ion. The spectral data of the complexes Eu(TPA)(TTA)Phen and Eu2(TPA)(TTA)4Phen2 present only one sharp peak in the region of the 5D0→7F0 transition indicating that only one Eu3+ ion species is present in each sample. In addition, the luminescence decay curves of the complexes Eu(TPA)(TTA)Phen and Eu2(TPA)(TTA)4Phen2 fit a single-exponential decay law. The values of quantum efficiencies of the emitting 5D0 level for the complexes Eu(TPA)(TTA)Phen and Eu2(TPA)(TTA)4Phen2 are 29% and 28%, respectively. 相似文献
9.
Xiao Zhang 《Journal of luminescence》2010,130(6):1060-127
In this paper, ligand effect of several bi-dental oxygen (O) and nitrogen (N) ligands on the red luminescence properties of europium ion (Eu3+) was studied comprehensively. Absorption, emission, and excitation spectral properties of ternary europium complexes with different combinations of ligands including thenoyl trifluoroacetone (TTA), naphthyl trifluoroacetone (NTA), 2,2′-bipyridyl (bpy) and phenanthroline (Phen) were investigated. Efficient Eu3+ red emission was observed with all the combinations of the above mentioned ligands. The most intense emission was found with the all nitrogen coordinated complex Eu(bpy)2(Phen)2 while the longest wavelength excitation band was recorded with oxygen-nitrogen mixed NTA-bpy complex Eu(NTA)1(bpy)3. With change of the ligands combination and ratio, the Eu3+ emission peak changes slightly from 612 to 618 nm. The absorption and excitation spectra of the europium complexes were compared and analyzed referring to the individual absorption spectral properties of the ligands. The relation between ligand-to-metal charge transfer states and luminescence intensities for different complexes was studied. 相似文献
10.
Shichun Jiang Chaoliang He Yongfeng Men Xuesi Chen Lijia An Sérgio S. Funari Chi-Ming Chan 《The European physical journal. E, Soft matter》2008,27(4):357-364
The reversible transitions of the lamellae of a crystalline-crystalline diblock copolymer from the melt to crystallites were
studied using simultaneous small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) measurements with synchrotron
radiation. A symmetric poly(ethylene oxide)-poly( -caprolactone) diblock copolymer was chosen for this study. We showed in the course of the block copolymer crystallisation
that the time-resolved integrated intensity I
int was proportional to the product of the volume fractions of the PEO and PCL phases and the scattering contrast due to the
electron density difference. These results demonstrated that simultaneous SAXS/WAXS measurements could be used to monitor
the crystallisation process in two domains of different sizes at the same time. 相似文献