• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1034-1037
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• 2002

In this study, we fabricated red organic electrolu-minescent device with a doping material (DCJTB), and The cell structure used ITO:indium tin oxide $[20{\Omega}]$/CuPc:Hole injection layer 20nm/NPB: Hole transfer layer 40nm/$Alq_3$ (host) + DCJTB(1% or 3%) (guest) Emitting layer 40nm/$Alq_3$ : Electron transfer layer 30nm/Al :Cathode layer 150nm. the luminescent layer consisted of a host material. 8-hydrozyquinoline aluminum $(Alq_3)$, and DCJTB dye as the dopant. a stable red emission (chromaticity coordinates : x=0.64, y=0.36) was obtained in this cell with the luminance range of $100-600cd/m^2$. we study the electrical and optical properties of devices.

• Electrical & Electronic Materials
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• v.10 no.10
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• pp.989-994
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• 1997

In a Guest-Host cell the orientational ordering of dyes doped into liquid crystals has been investigated. To evaluate the influence of the host liquid crystals on the ordering of the dyes we have measured precisely the ordering parameters of the liquid crystals by using the dichroic ratio of the absorbances for infrared light polarized parallel and perpendicular to the diector. Our experimental results show that the ordering of the dyes can be expressed as a function of not only the molecular structure of the dyes but also the order parameter of the liquid crystals. These functions are dependent on the kinds of the liquid crystals and the dyes. Particularly the combination such as anthraquinone dyes doped into cyanobiphenyl liquid crystals show a very high ordering parameter. This is considered due to a strong intermolecular interaction between the dipoles of both liquid crystals and dyes.

• Bulletin of the Korean Chemical Society
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• v.23 no.6
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• pp.891-896
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• 2002

The structures and energies of p-tert-butylcalix[4]crown-6-ether(1) in various conformers and their alkyl ammonium complexes have been calculated by ab initio HF/6-31G quantum mechanics method. We have tried to obtain the relative affinity of partial-cone and 1,3-alternate conformers of 1 for alkyl ammonium guests by comparison with its cone-shaped analogue. We have also calculated the relative complexation efficiency of these host-guest complexes focusing on the binding sites of $crown-\sigma-enther$ moiety or benzene-rings pocket of the host molecule 1. These calculations revealed that the crown moiey has better complexation efficiency than upper rim part of calyx[4]arene that is in similar trend to the cone-shaped complexes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.6
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• pp.512-515
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• 2009

We have fabricated blue phosphorescent organic light emitting diodes (PHOLEDs) using a 3,5'-N,N'-dicarbazole-benzene (mCP) host and iridium (III) bis[(4,6-difluorophenyl)-pyridinato-N,$C^{2'}$] picolinate (Flrpic) guest materials, The Flrpic was partially doped into the mCP host layer, for investigating recombination zone, current efficiency, and emission characteristics of the blue PHOLEDs. The recombination of electrons and holes takes place inside the mCP layer adjacent to the mCP/hole blocking layer interface. The best current efficiency was obtained in a device with an emission layer structure of mCP (10 nm)/mCP:Flrpic (20 nm, 10%). The high current efficiency in this device was attributed to the confinement of Ffrpic triplet excitons by the undoped mCP layer with high triplet energy, which blocks diffusion of Ffrpic excitons to the adjacent hole transport layer with a lower triplet energy.

• Polymer(Korea)
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• v.26 no.5
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• pp.568-574
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• 2002

Inclusion compounds using cyclic poly(oxyethylene)s as host molecules have been used to polymerize pyrrole chemically in aqueous medium. This general synthetic strategy makes it possible to grow rigid aromatic polymers in aqueous medium by chemical oxidation method. It is an easy method to obtain rigid polymers in a very mild manner. Some threaded and water-soluble polypyrroles are obtained, and their characterization is performed by NMR, IR, UV, and MALDI-TOF MS measurements.

• Asia-Pacific Journal of Business
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• v.9 no.3
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• pp.1-9
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• 2018

Despite a wide practice of e-market sellers communicating with their consumers, little attention is given to how the practice affects consumers' purchase decision process. Based on the text analysis of 10,479 accommodation cases obtained from Airbnb, we empirically examine the relationship between the sellers' communication efforts and the wish-listing behaviors of guests. We find that the wish-listing is positively associated with the communication efforts of a host, such as (1) the feedback volume, (2) tailored messages and personalized contents, and (3) contingent responses to guest reviews. We discuss the theoretical and practical implications of the study.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.542-545
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• 2002

High performance organic electroluminescnet(EL) devices which are composed of organic thin multilayer films are fabricated. The basic structure is ITO/Emitting layer/LiF/Al in which have a blended emitting layer. The emitting layer is consisted of a host material(N,N' diphenyl-N,N' (3-methyl phenyl)-l,l'-biphenyl-4,4'diamine)(TPD)) and a guest emitting material(poly(3-hexylthiophehe)(P3HT)). We think that the energy transfer in blending layer occurred from TPD to P3HT. Red emitting multilayer EL devices were fabricated using tris(8-hydroxyqunolinate) aluminum$(Alq_3)$ as electron transport material. The device structure of ITO/blending layer(TPD+P3HT)$/Alq_3$/LiF/Al was employed. In the Voltage-current-luminance characteristics of multilayer device, the device tum on at the 2V and the luminance of $10{\mu}W/cm^2$ obtain at l0V. Red emission peak at 640nm was observed with this device structure. We have presented evidence that the excitation energy migration between a polymeric host and guest has to be explained. And by using multilayer, the red light emitting EL device enhances not only Voltage-current-luminance characteristic but also stability of device.

• Bulletin of the Korean Chemical Society
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• v.30 no.2
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• pp.348-354
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• 2009

Copper(II) complexes with tetraoxo dithia tetraaza macrocyclic ligands; [18]ane$N_4S_2$: 1,4,10,13-tetraaza-5,9,14,18-tetraoxo-7,16-dithia-cyclooctadecane, [20]ane$N_4S_2$: 1,5,11,15-tetraaza-6,10,16,20-tetraoxo-8,18-dithia-cyclocosane,Bzo2[18]ane$N_4S_2$: dibenzo-1,4,10,13-tetraaza-5,9,14,18-tetraoxo-7,16-dithia-cyclooctadecane, Bzo2[20]ane$N_4S_2$: dibenzo-1,5,11,15-tetraaza-6,10,16,20-tetraoxo-8,18-dithia-cyclocosane; were entrapped in the nanopores of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of [bis(diamine)copper(II)] (diamine = 1,2-diaminoethane, 1,3-diaminopropane, 1,2-diaminobenzene, 1,3-diaminobenzene); $[Cu(N-N)_2]^{2+}$-NaY; in the nanopores of the zeolite, and (ii) in situ template condensation of the copper(II) precursor complex with thiodiglycolic acid. The obtained complexes and new host-guest nanocomposite materials; $[Cu([18]aneN_4S_2)]^{2+}-NaY,\;[Cu([20]aneN_4S_2)]^{2+}-NaY,\;[Cu(Bzo_2[18]aneN_4S_2)]^{2+}-NaY,\;[Cu(Bzo_2[20]aneN_4S_2)]^{2+}$-NaY; have been characterized by elemental analysis FT-IR, DRS and UV-Vis spectroscopic techniques, molar conductance and magnetic moment data, XRD and, as well as nitrogen adsorption. Analysis of data indicates all of the complexes have been encapsulated within nanopore of zeolite Y without affecting the zeolite framework structure.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.232-243
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• 2010

Gas hydrates are crystalline solids composed of water and gas molecules. Water molecules are linked through hydrogen bonding and create cavities(host lattice) that can capture a large variety of guest molecules under appropriate conditions, generally high pressure and low temperature. Recently, many researchers try to apply gas hydrates to industrial processes to capture greenhouse gases due to the facts that the process is eco-friendly and target gas molecules can be preferentially captured. In this paper, we introduced recent studies on $CO_2$ and $CO_2-N_2$ mixture hydrates to evaluate the feasibility of industrial application of gas hydrate technology to $CO_2$ capture process. Specifically, we put emphasis on the technical feasibility of $CO_2$ separation in steel industry using gas hydrate formation principles.

• Bulletin of the Korean Chemical Society
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• v.11 no.6
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• pp.521-527
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• 1990

The binding characteristics and analytical applications of anilinium ion complexes with 18-crown-6 were studied by polarography and NMR. First, the electrochemical reduction of the 10 species of mono and dimethylsubstituted anilinium ion complexes with 18-crown-6 as host in methanol are examined. The addition of 18-crown-6 to anilinium guest solution the polarographic waves remain well defined but shifted toward more negative potentials, indicating the complex formation. The values of formation constants, log Κ for 10 species of methylsubstituted anilinium ion complexes with 18-crown-6 varies from 2.7 to 4.8 in methanol at $25^{\circ}C$. The stability order of complexes for 18-crown-6 is anilinilum > 4-methyl > 3,4-dimethyl > 3-methyl > 3,5-dimethyl > 2,4-dimethyl > 2,5-dimethyl > 2,3-dimethyl > 2-methyl > 2,6-dimethylanilinium ion. The steric hindrance shows significant effect. Second, Proton NMR was used to elucidate their interaction characteristics. From the results of so called NMR titration techniques, the behaviors of binding sites on complexation, and the stoichiometry and stability order of complex were obtained. And the later results show the satisfactory agreement with the quantitative values obtained by polarography. Finally, the individual determinations of anilinium ion mixtures were also accomplished by addition of 18-crown-6. In some mixtures of methyl or dimethylanilinium ions the reduction peaks of differential pulse method appeared into one unresolved wave attributed to the small difference of half-wave potential, ${\Delta}E_{1/2}$. In the presence of 18-crown-6, the polarographic waves were resolved into individual maxima because of the shift toward more negative direction by the difference of selectivity of anilinium ions with 18-crown-6. It may be concluded that quantitative analysis of methylanilinium ion mixture make possible because the half-wave potential shift by the selectivity difference due to the steric hindrance between methyl group and 18-crown-6 on complexation.