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Huang C.-H.,Material and Chemical Research Laboratories | Huang C.-H.,National Chiao Tung University | Wang D.-Y.,National Chiao Tung University | Chiu Y.-C.,Material and Chemical Research Laboratories | And 2 more authors.
RSC Advances | Year: 2012

The yellow-emitting phosphor Sr8MgGd(PO4) 7:xEu2+ (SMGP:xEu2+) was successfully synthesized by a solid-state reaction and used for the first time to fabricate white light-emitting diodes (LEDs) with excellent color rendering index (CRI). Furthermore, the luminescence properties" reflectance spectra and fabricated LEDs were firstly investigated. The excitation and reflectance spectra of this phosphor show broad band excitation and absorption in the 240-470 nm near ultraviolet (NUV) region, indicating its potential application in NUV diode based white-light LEDs. Upon excitation at 385 nm, the Eu 2+ doped SMGP phosphors showed strong yellow emission centered at 512 and 606 nm, which could be ascribed to the 4f65d1 → 4f7 transitions of Eu2+. The optimal doping concentration of Eu2+ in SMGP was determined to be 0.01 mol. Non-radiative transitions between the Eu2+ ions in the SMGP host were demonstrated to be attributable to dipole-dipole interactions. A white-light NUV LED was fabricated using a phosphor blend of SMGP:0.01Eu2+ and BAM:Eu 2+ pumped by a 385 nm NUV chip, driven by a 350 mA current. The color, chromaticity coordinates (x, y), correlated color temperature (CCT) and Commission Internationale de l'Eclairage (CIE) coordinates can be tuned from yellow ((0.442, 0.481), 3456 K, 75.4) through warm white-light ((0.350, 0.348), 4804 K, 95.6) and eventually to white-light ((0.331, 0.321), 5592 K, 94.1) by weight ratio tuning of the SMGP:0.01Eu2+ and BAM:Eu2+ phosphors, and the luminous efficacy between 9.6 to 7.6 lm W-1. We are currently evaluating the potential applications of SMGP:xEu2+ as a yellow-emitting near-ultraviolet (NUV) convertible phosphor in fabricating warm white-light LEDs with excellent CRI. © 2012 The Royal Society of Chemistry.


Huang C.-H.,National Chiao Tung University | Liu W.-R.,Material and Chemical Research Laboratories | Chen T.-M.,National Chiao Tung University
Journal of Physical Chemistry C | Year: 2010

Single-phased white-light-emitting phosphors Ca9Gd(PO 4)7:Eu2+, Mn2+ were synthesized by solid state reactions. Tuning the Eu2+/Mn2+ ratio via the energy transfer varied the emission hue of Ca9Gd(PO4) 7:0.007Eu2+, Mn2+ from blue-greenish (0.219, 0.371) to white-light (0.326, 0.328) and eventually to red (0.625, 0.307). The mechanism of transferring energy from a sensitizer Eu2+ to an activator Mn2+ in Ca9Gd(PO4) 7:Eu2+, Mn2+ phosphors was demonstrated to be an electric dipole-quadrupole interaction. Combining a near-UV 380 nm chip and a white-emitting Ca9Gd(PO4)7:0.007Eu 2+, 0.02 Mn2+ phosphor produced a white-light near-UV LED, demonstrating CIE chromaticity coordinates of (0.312, 0.327) and a color temperature of 6569 K. © 2010 American Chemical Society.


Wang Y.-C.,National Chung Hsing University | Chen M.-Y.,National Chung Hsing University | Wu H.-Y.,National Chung Hsing University | Chen J.-H.,National Chung Hsing University | And 2 more authors.
Polyhedron | Year: 2014

The crystal structures of (2-aza-2-benzyloxycarbonylmethyl-5,10,15,20- tetraphenyl-21-carbaporphyrinato-N,N′,N″)platinum(II) [Pt(2-NCH 2COOCH2C6H5NCTPP); 4], (2-aza-2-p-cyanobenzyl-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N′, N″)platinum(II) [Pt(2-NCH2-p-C6H4- CNNCTPP); 5] and (2-aza-2-p-trifluoromethylbenzyl-5,10,15,20-tetraphenyl-21- carbaporphyrinato-N,N′,N″)platinum(II) [Pt(2-NCH2-p- C6H4-CF3NCTPP); 6] have been established. The coordination sphere around Pt2+ ion in 4-6 is distorted square planar (DSP). The Pt-C(17) bonds are 1.947(5) Å (4), 1.965(6) Å (5) and 1.958(5) Å (6) and the corresponding one-bond coupling constants 1J[Pt-C(17)] are 990 Hz (4), 980 Hz (5) and 980 Hz (6). The shape of 195Pt satellite lines in 1H spectra of H(19) vary with the magnetic field owing to CSA relaxation of the 195Pt in 4-6. The 13C [C(19)] and 1H [H(19)] chemical shifts of N +CH(Ar) fragment at 20 C in CDCl3 are separately located at 156.2 ± 0.7 ppm and 8.01 ± 0.08 ppm for the iminium ion of dipolar form in complexes 4-6. The X-ray diffraction data of N(4)-C(19) = 1.320 ± 0.015 Å indicate the existence of dipolar form for 4-6. © 2013 Elsevier Ltd. All rights reserved.


Wang Y.-C.,National Chung Hsing University | Chen J.-H.,National Chung Hsing University | Wang S.-S.,Material and Chemical Research Laboratories | Tung J.-Y.,Tainan University of Technology
Polyhedron | Year: 2014

The crystal structures of (2-aza-2-benzyloxycarbonylmethyl-5,10,15,20- tetraphenyl-21-carbaporphyrinato-N,N', N'')nickel(II) [Ni(2-NCH 2COOCH2C6H5NCTPP); 5], (2-aza-2-benzyloxycarbonylmethyl-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N, N',N'')palladium(II) toluene solvate [Pd(2-NCH2COOCH 2C6H5NCTPP)·C6H 5CH3; 6·C6H5CH3] and bromo(2-aza-2-benzyloxycarbonylmethyl-5,10,15,20-tetraphenyl-21- carbaporphyrinato-N,N',N'')manganese(III) ethyl acetate solvate [Mn(2-NCH 2COOCH2C6H5NCTPP)Br·EtOAc; 7·EtOAc] have been established. The coordination sphere around the Ni2+ ion in 5 (or Pd2+ ion in 6·C6H 5CH3) is distorted square planar (DSP), whereas for Mn3+ in 7·EtOAc, it is square-based pyramidal with the Br atom lying in the axial site. The g value of 10.98 measured from the parallel polarization of the X-band ESR spectrum at 4 K is consistent with a high spin mononuclear manganese(III) centre (S = 2) in 7. The magnitude of the axial (D) zero-field splitting (ZFS) for the mononuclear Mn(III) centre in 7 was determined to be approximately 0.52 cm-1 by paramagnetic susceptibility measurements. The 13C [C(19)] and 1H [H(19)] chemical shifts of the N+CH(Ar) fragment at 20°C in CDCl3 are located at δ 152.5 ± 0.5 and 8.21 ± 0.04 ppm respectively for the iminium ion of the dipolar form in complexes 5-7. From the X-ray diffraction data, the N(4)-C(19) bond length of 1.312 ± 0.013 Å indicates the existence of the dipolar form for 5-7. © 2013 Elsevier Ltd. All rights reserved.


Wang Y.-C.,National Chung Hsing University | Chen J.-H.,National Chung Hsing University | Wang S.-S.,Material and Chemical Research Laboratories | Tung J.-Y.,Tainan University of Technology
Inorganic Chemistry | Year: 2013

The inner C-benzyl- and C-p-xylyl-substituted cobalt(II) complexes of a 2-N-substituted N-confused porphyrin were synthesized from the reaction of 2-NCH2COOCH2C6H5NCTPPH (1) and CoCl2·6H2O in toluene (or p-xylene), and the structures were revealed by single-crystal X-ray analysis. © 2013 American Chemical Society.


Hsaio D.-Z.,National Chung Hsing University | Chen J.-H.,National Chung Hsing University | Wang S.-S.,Material and Chemical Research Laboratories | Tung J.-Y.,Tainan University of Technology
Polyhedron | Year: 2012

The crystal structures of (2-aza-2-benzyl-5,10,15,20-tetraphenyl-21- carbaporphyrinato-N,N′,N″) nickel(II) methylene chloride solvate [Ni(2-NCH2C6H5NCTPP); 4], (2-aza-2-benzyl-5,10, 15,20-tetraphenyl-21-carbaporphyrinato-N,N′,N″) palladium(II) [Pd(2-NCH2C6H5NCTPP); 5] and bromo(2-aza-2-benzyl-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N′, N″) manganese(III) toluene solvate [Mn(2-NCH2C 6H5NCTPP)Br·C6H5CH 3; 3·C6H5CH3] have been established. The coordination sphere around the Ni2+ ion in 4 (or Pd2+ ion in 5) is distorted square planar (DSP), whereas for Mn 3+ in 3·C6H5CH3, it is a square-based pyramid with the Br atom lying in the axial site. The g value of 11.34, measured from parallel polarization of the X-band EPR spectra at 4 K, is consistent with a high spin mononuclear manganese(III) centre (S = 2) in 3. The magnitude of the axial (D) zero-field splitting (ZFS) for the mononuclear Mn(III) centre in 3 was determined approximately to be 1.4 cm-1 by paramagnetic susceptibility measurements and conventional EPR spectroscopy. © 2011 Elsevier Ltd. All rights reserved.


Liu W.-R.,Chung Yuan Christian University | Huang C.-H.,Material and Chemical Research Laboratories | Yeh C.-W.,National Taiwan University | Chiu Y.-C.,Material and Chemical Research Laboratories | And 2 more authors.
RSC Advances | Year: 2013

Single-phased white light-emitting KCaGd(PO4) 2:Eu2+,Tb3+,Mn2+ phosphors were synthesized by a solid state reaction. By changing the doping contents of Eu2+, Tb3+ and Mn2+, the emission hue could be precisely controlled via the energy transfer mechanism. The structure refinement, luminescence properties as well as their thermal quenching and energy transfer mechanism were firstly investigated. The mechanism of transferring energy between Eu2+, Mn2+ and Tb3+ ions was also discussed in this study. The optimal-composition for white-light is K(Ca0.89Eu0.01Mn0.1)(Gd0.9Tb 0.1)(PO4)2, which gives the CIE coordinates of (0.2984, 0.3171). These results indicate that the KCaGd(PO4) 2:Eu2+,Mn2+,Tb3+ phosphor could be a promising single-composition phosphor for applications involving white-light NUV LEDs. © The Royal Society of Chemistry 2013.


Chung Y.-C.,Material and Chemical Research Laboratories
7th Asian-Australasian Conference on Composite Materials 2010, ACCM 2010 | Year: 2010

Injection molding is one of the most important processing techniques by which blends are fabricated into plastic parts; the morphological anisotropy characteristic of injection-molded blends is primarily the result of orientation of phases along the complex melt flow lines during mold filling, which include the 'fountain flow' pattern at the melt front. In this case, PLA (poly(lactic acid)) and PC (polycarbonate) blend is highly immiscible and phase separated during injection molding procedure. The morphology of injection-molded blends of PC/PLA has been examined across different composition range. A very thin region of material at the mould surface experiences elongational flow at the front of the fountain flow pattern and creates an oriented surface skin. A transition occurred between PC/PLA=75/25 and 50/50 wt% compositions from the bead-and-string structure with some interconnections to a coalesced, stratified morphology near the edge; while in the centre, the morphology changed from a dispersion of PLA particles to thick coalesced PC matrix that created regions where PC was co-continuous with PC. The PC-rich blends had a conventional blend morphology with PC domains dispersed in PC. The structure-properties relationship is discussed on the basis of transmission electron microscopy, scanning electron microscopy and UV-Vis analysis.


Hwang C.-L.,National Tsing Hua University | Hwang C.-L.,Material and Chemical Research Laboratories | Tai N.-H.,National Tsing Hua University
Applied Catalysis B: Environmental | Year: 2010

Removal of low-concentration sulfide in clean rooms is important in the semiconductor industry. In dry conditions, silver-manganese exchanged Y zeolite (Ag-Mn/Na-Y) has high removal efficiency and high saturation adsorption capacity towards dimethylsulfide (DMS). However, the removal efficiency of DMS on Ag-Mn/Na-Y decreases with increasing water concentration in inlet gas at room temperature and normal pressure. In high humidity conditions, the removal efficiency and saturation adsorption capacity of DMS is high for silver-manganese exchanged ZSM zeolite (Ag-Mn/ZSM-5). In this paper, the influence of water concentration on the removal efficiency of DMS on Ag-Mn/zeolites was examined. The variations of functional group detected in FT-IR spectroscopy and temperature programmed desorption (TPD) confirm that water molecules influence the ability of DMS adsorption by Ag-Mn/zeolites. Crown Copyright © 2009.


Hwang C.-L.,National Tsing Hua University | Hwang C.-L.,Material and Chemical Research Laboratories | Tai N.-H.,National Tsing Hua University
Applied Catalysis A: General | Year: 2011

This work studied the catalyst activity and stability of ion-exchanged zeolites during the oxidation of dimethyl sulfide (DMS) in the presence of ozone. Ozone was used as an oxidant to assess the oxidation capability of Ag/ZSM-5, Mn/ZSM-5 and Ag-Mn/ZSM-5 of DMS at both room temperature and 130 °C. Ion-exchange with silver ions (Ag+) strengthened the adsorption of DMS, resulting in an increased oxidation capacity for DMS. Furthermore, the introduction of manganese ions (Mn2+) strengthened the oxidation capability of DMS, thus enhancing the selectivity of SO 2 obtained from the oxidation and reducing the degradation of activity because the pores of the catalyst were blocked by the oxidation products, such as dimethyl sulfoxide (DMSO) and dimethyl sulfone (DMSO 2). Ag-Mn/ZSM-5 demonstrated a 100% conversion of DMS; not only SO2 but also H2SO3 and H2SO 4 were detected at a high GHSV (90,000 h-1) and low reaction temperature (130 °C). The SO2 adsorption curve and temperature-programmed desorption (TPD) showed that the single metal ion-exchanged zeolite had a weak adsorption capability for SO2 at room temperature, whereas the bi-metal ion-exchanged zeolite had an excellent adsorption capability towards SO2; it could convert SO2 into H2SO3 and could convert oxidized SO2 into H2SO4 in gas phase at room temperature. © 2010 Published by Elsevier B.V. All rights reserved.

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