• Journal of Conservation Science
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• v.36 no.6
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• pp.519-532
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• 2020

This study aimed to interpret the coloring materials recorded in the ceremonial writing with the scientific investigation results of the Hanging Painting of the Chiljangsa Temple (Five Buddhas). The results confirm that the Jinboon, Joohong, Hwangdan, Hwanggeum and Seokjahwang are clearly connected to lead white, cinnabar, minium, gold, and orpiment, respectively. Danghayeop and samrok are related to Copper trihydroxychloride, while Daecheong and Joongcheong are azurite, and they seems to be classified by the particle size. Yeonji and Chunghwa are organic dyes in red and blue, respectively, with blue confirming the existence of the side, but Yeonji differs from the names of the ancient texts and Chinese characters; it is unclear whether it is a commonly used Yeonji because of differences in the names of the ancient texts. The presence of Sootohwang has not been confirmed in the gwaebultaeng, but it can be extracted from the soil as a yellow-colored material but the possibility of Deunghwang cannot be ruled out.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.4
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• pp.392-397
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• 2022

We present the structural and optical properties of Au@TiO₂ core-shell microsphere structure prepared by a hydrothermal synthesis method. As a way to improve the efficiency of organic solar cells, the Au@TiO₂ core-shell microsphere was synthesized to use the local surface plasmon resonance (LSPR) phenomenon. The synthesized results were confirmed to have the Au@TiO₂ core-shell structure using a high-resolution transmission electron microscopy. An absorption was observed to occur at 527 nm belonging to the visible light region using a visible light spectroscopy, which supports the LSPR phenomenon. We suggest that the Au@TiO₂ core-shell microsphere is highly likely to be applied to organic solar cells including dye-sensitized solar cells. In addition, we expect it to be widely used not only in the energy but also in the bio as well as in the environmental fields.

• Applied Chemistry for Engineering
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• v.34 no.1
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• pp.51-56
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• 2023

Composite membranes consisting of TiO₂ nanoparticles (NPs) and porous polymers have been widely utilized in photocatalytic water treatment because the composite membranes can allow an easy recovery of NPs after the photocatalytic reaction as well as the reduction of fouling in the membrane. However, the photocatalytic efficiency of the immobilized TiO₂ NPs in the composite membranes has been discussed to a limited degree. In this study, we prepared polyethersulfone (PES)/TiO₂ composite membranes to study the photocatalytic decomposition of organic dyes under light illumination. The decomposition kinetics of dye molecules by the PES/TiO₂ composite membranes and colloidal TiO₂ NPs have been compared to discuss the photocatalytic efficiency of NPs before and after their immobilization on the polymer membrane.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.396-396
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• 2012

$TiO_2$ anatase nanotube arrays (NTAs) were grown by electrochemical anodization and followed annealing of Ti foil. Ethylene glycol/$NH_4F$-based organic electrolyte was used for electrolyte solution and using second anodization process to obtain free-standing NTAs. After obtaining NTAs, ITO film was deposited by sputtering process on bottom of NTAs. UV-curable NOA was used for attach free-standing NTAs on flexible plastic substrate (PEN). Solid state electrolyte (spiro-OMeTAD) was coated via spin-coating method on top of attached NTAs. Ag was deposited as a counter electrode. Under AM 1.5 simulated sunlight, optical characteristics of devices were investigated. In order to use flexible polymer substrate, processes have to be conducted at low temperature. In case of $TiO_2$ nano particles (NPs), however, crystallization of NPs at high temperature above $450^{\circ}C$ is required. Because NTAs were conducted high temperature annealing process before NTAs transfer to PEN, it is favorable for using PEN as flexible substrate. Fabricated flexible solid-state DSSCs make possible the preventing of liquid electrolyte corrosion and leakage, various application.

• Journal of Photoscience
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• v.12 no.2
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• pp.87-93
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• 2005

A new assay technique to distinguish between pure compounds and the isomeric mixtures has been suggested using single molecule (SM) fluorescence detection technique. Since the number of emission spots in a fluorophorespread film prepared from a genuine dye solution was determined by experimental condition, the deviation of spot numbers from the expected values could be considered to be an indication of lower purity of the sample solution. The lower limit of sample concentration for this assay was determined to be $5{\times}10^{-10}$ M to show uniform number of expected spots within 10% uncertainties in our experimental condition. An individual fluorescence intensity distribution for a mixture of isomers having doubly different emissivities was simulated by adding distributions obtained from Cy3 and nile red (NR) independently. The result indicated that the mixture could be identified from the pure compounds through the difference in the number of Gaussian functions to fit the distribution. This new assay technique can be applied to the purity test for synthetic biofluorophores which are usually prepared in small quantities not enough for classical ensemble assays.

• Textile Coloration and Finishing
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• v.14 no.4
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• pp.229-239
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• 2002

Colorants were extracted from the heartwood of sappan lin. with MeOH under reflux, and the concentrate or the powder of dye was prepared by low pressure concentration method using suitable organic solvent. Various components were isolated from sappan wood, and the chemical structure and mechanism of compound having the excellent antibacterial and deodorization properties were analyzed. The results obtained are as follows ; The seventeen components of sappan wood were seperated by HPLC chromatography, and the five components among them were existed more than 6% and the other components were existed lower than 0.6%. The resolving powers of the non-polar solvent and polar solvent systems were evaluated by their ability to resolve the samples. It showed that chloroform-methanol-water(800:150:10) system has the best resolving power. Although the seperation rate is very slow, polyamide C-100 column chromatography gives a clear seperation of sappan wood. On the basis of the spectrometric data such as IR, UV, $GC-Mass,\;^1H-NMR,\;^{13}C-NMR\;and\;^1H-^{ 13}C-NMR$, the chemical structure of compound haying the excellent antibacterial and deodorization properties was established as brazilin containing the functional groups such as two quaternary carbon, one benzyl carbon, methylene contiguous to oxygen and methylene caused by oxygen atom.

• Journal of Energy Engineering
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• v.13 no.2
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• pp.112-117
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• 2004

Volatile organic compounds (VOCs) are low calorific value gases (LCVG) emitted from chemical processes such as painting booth, dye works and drying processes etc. Characteristics of VOCs are low calorific values less than 150kcal/㎥, high activation energy for ignition and low energy output. These characteristics usually make combustion unstable and its treatment processes needs high-energy consumption. The cyclone combustion system is suitable for LCVG burning because it can recirculate energy through a high swirling flow to supply the activation energy for ignition, increases energy density In make a combustion temperature higher than usual swirl combustor and also increases mixing intensity. This research was conducted to develop optimized cyclone combustion system for thermal oxidation of VOCs. This research was executed to establish the effect of swirl number with respect to the combustion temperature and composition of exhausted gas in the specific combustor design.

• Journal of Environmental Science International
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• v.29 no.4
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• pp.383-393
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• 2020

To increase electrolysis performance, the applicability of seawater to the iron-fed electro-Fenton process was considered. Three kinds of graphite electrodes (activated carbon fiber-ACF, carbon felt, graphite) and dimensionally stable anode (DSA) electrode were used to select a cathode having excellent hydrogen peroxide generation and organic decomposition ability. The concentration of hydrogen peroxide produced by ACF was 11.2 mg/L and those of DSA, graphite, and carbon felt cathodes were 12.9 ~ 13.9 mg/L. In consideration of durability, the DSA electrode was selected as the cathode. The optimum current density was found to be 0.11 A/㎠, the optimal Fe²⁺ dose was 10 mg/L, and the optimal ratio of Fe²⁺ dose and hydrogen peroxide was determined to be 1:1. The optimum air supply for hydrogen peroxide production and Rhodamine B (RhB) degradation was determined to be 1 L/min. The electro-Fenton process of adding iron salt to the electrolysis reaction may be shown to be more advantageous for RhB degradation than when using iron electrode to produce hydrogen peroxide and iron ion, or electro-Fenton reaction with DSA electrode after generating iron ions using an iron electrode.

• Textile Coloration and Finishing
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• v.31 no.4
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• pp.233-240
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• 2019

Dyeing is an essential process for improving the value of textile products, but it is considered as one of industries causing pollution because of producing wastewater containing hazardous chemicals as well as using a large amount of water and energy. Global demand for greener technologies in textile field is getting much more attention and accordingly, the use of eco-friendly natural dyes is growing much larger. In textile printing, both dyes and pigments can be used. Pigment printing is more simple process and requires less water and less energy, compared to dye printing. In this study, the organic pigment was prepared from the marigold colorant. Samples were stencil printed, pressed(70℃, 3min) and then heat treated(150℃, 5min). The uptake of polyacrylic acid as a chemical binder was the lowest. In particular, marigold pigments were excellent in color and texture when Guar Gum and Sodium Alginate were used as binders. In addition, the light and washing fastness was rated very high as 4, 4/5 grades, and the rubbing fastness was also excellent as 3 and 4 grades.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1437-1439
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• 2007

We fabricated white organic light emitting device (WOLED) with the layered fluorescent blue material and phosphorescent green/red dye-doped materials. Addition of the non-doped phosphorescent host material between the fluorescent and phosphorescent light emitting layers provided the result of broadband white spectrum, with improved balance, higher efficiency, and lower power consumption. In our devices, there was no need of exciton-blocking layer between the each emission layer for the further confinement of the diffusion of excitons.