• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1714-1716
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• 2000

We fabricated the optical system of merocyanine dye using Langmuir-Blodgett(LB) technique because quite uniform orientation could be obtained, which is one of the most important factors to affect to its optical characteristics. The resonance frequency and other electrical parameters at the parallel resonance state were measured using the impedance analyser(HP 4294 A). Also the morphological changes of dye molecules after UV irradiation were observed using AFM. The parallel resonance frequency and resistance by electrical equivalent circuit were decreased with the UV irradiation and these aspects are different from general mass adsorption process. Therefore the structural changes of dye molecules are being considered, that is, the aggregated molecules become dissociated. It indicates that the shifts of the resonance frequency and the others occurred without mass absorption.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.517-520
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• 2001

The optical properties of TiO$_2$ thin films dispersed in epoxy film, which were prepared with bits-(4,4'-P-toluenesulfonylacidic isoproplyidene) cycolhexadiol(BTSPC) and UVI 6990 in dry sol-gel process, were investigated. In the case of irradiating UV light on TiO$_2$ thin films, how many nanoparticles of TiO$_2$ are dispersed in epoxy film was investigated by AFM. The absorption peak of the films was showed at 360nm. Squarylium dye was dispersed in TiO$_2$-epoxy film. Photodegration concerned with amount of dye and time of UV light irradiation was investigated. UV light irradiation on the film occurred dramatical photodegration.

• 한국염색가공학회지
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• 제25권3호
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• pp.165-171
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• 2013

A new monoazo violet dye optimized for polyolefin fibers such as polypropylene and ultra high molecular weight polyethylene fibers was synthesized and its dyeability was investigated. Two hexyl groups were introduced to coupler, 2,5-dimethoxyaniline, in order to increase hydrophobicity of the dye. The maximum absorption wavelength was appeared at 580nm, which meant that the dye showed violet color. From the dyeing results at various conditions, the optimum dyeing was determined as $130^{\circ}C$ for 1 hour with 5% owf of dyes. The good fastness ratings to washing, rubbing were obtained showing at least 4 for both fibers. Light fastness was acceptable for polypropylene fibers giving ratings 3~4. However, relatively poor light fastness was obtained in case of ultra high molecular weight polyethylene fibers showing ratings 2.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1569-1571
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• 1996

The role of ESR spectroscopy in the characterization of functional LB films is discussed. Optical absorption were performed on LB films of binary mixtures of three kinds of merocyanine dyes where DS and 6Me-DS form J-like aggregates but not DO in single component films. The observed optical absorption spectra of mixed films were markedly dependant on the combination of dyes. We found the formation of J-aggregates in a mixed merocyanine dyes containing a non J-aggregate forming dye DO, in a single component case. In structural studios, ESR is of particular important in the analysis of molecular orientation of LB films. Development of new functional LB films may provide more cases where ESR spectroscopy will clarify the nature of such films.

• 한국염색가공학회지
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• 제28권3호
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• pp.156-163
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• 2016

The 6 novel super hydrophobic bluish-green dyes, showing the maximum absorption at 600~650nm, were synthesized to dye polyolefin fibers such as polypropylene and high strength polyethylene fibers. Their absorption spectra appeared almost the same at visible range, which meant the length of alkyl substituents did not affect on color appearance of the dyes. The optimum length of alkyl group was determined as hexyl substituents from the practical point of view. From the dyeing results, the optimum dyeing condition was $130^{\circ}C$ for 1 hour. The good fastness ratings to washing, rubbing were obtained showing 4-5 for both fibers. Light fastness was obtained also good rating 4 for both fibers.

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.610-616
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• 2014

The influence of solvent polarity on the absorption spectra of some synthesized azo dye with heterocyclic moieties and ${\beta}$-naphthol (1-3) have been investigated using a UV-Visible spectrophotometer. The spectral characteristics of the azo dyes (1-3) in different solvents at room temperature were analyzed. The solvatochromic empirical variables like ${\pi}^*$, ${\alpha}$, and ${\beta}$ have been used to discuss the solvatochromic behaviour of the dyes and to evaluate their contributions to the solute-solvent interactions. A multi-parameter regression model for quantitative assessment of the solute/solvent interaction and the absorption has been used to explain the solvent effect on azo dyes (1-3).

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2276-2280
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• 2013

The accurate prediction of vertical excitation energies is very important for the development of new materials in the dye and pigment industry. A time-dependent density functional theory (TD-DFT) approach coupled with 22 different exchange-correlation functionals was used for the prediction of vertical excitation energies in the halogenated copper phthalocyanine molecules in order to find the most appropriate functional and to determine the accuracy of the prediction of the absorption wavelength and observed spectral shifts. Among the tested functional, B3LYP functional provides much more accurate vertical excitation energies and UV-vis spectra. Our results clearly provide a benchmark calibration of the TD-DFT method for phthalocyanine based dyes and pigments used in industry.

• 한국의류산업학회지
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• 제14권3호
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• pp.478-485
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• 2012

The dying properties of fabrics with Chaenomelis Fructus extract were studied through an investigation of the characteristic of Chaenomelis Fructus colorants, the effect of dyeing conditions (dye temperature, dyeing concentration, and times on dye uptakes), effect of mordant, effect of UV irradiation, and color change in addition, antimicrobial ability and deodorant ability were estimated. In the UV-Visible spectrum, the wavelength of maximum absorption of Chaenomelis Fructus extract was 280 nm and showed that tannin is the major pigment component. From the increase of absorbance by UV irradiation, it was assumed that catechol tannin color was developed through UV irradiation. An increased dyeing concentration resulted in a larger dye uptake. Dye uptake increased as the dyeing time and temperature increased. Chaenomelis Fructus extract showed relatively good affinity to silk than cotton. Mordant, Fe and Cu were effective to increase the dye uptake of cotton fabric in addition, the dye uptake of silk fabric mordanted with Fe and K improved. UV irradiation let the color of dyed fabrics develop regardless of the UV irradiation stage however, UV irradiation on the dyed fabric was more effective than on the extract for the color development. Dyed silk fabric showed very good antimicrobial abilities of 99.9% in addition, deodorant ability improved in the fabric dyed with Chaenomelis Fructus extract.

• 한국분말재료학회지
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• 제24권6호
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• pp.483-488
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• 2017

Transition-metal oxide semiconductors have various band gaps. Therefore, many studies have been conducted in various application fields. Among these, methods for the adsorption of organic dyes and utilization of photocatalytic properties have been developed using various metal oxides. In this study, the adsorption and photocatalytic effects of $WO_3$ nanomaterials prepared by hydrothermal synthesis are investigated, with citric acid added in the hydrothermal process as a structure-directing agent. The nanostructures of $WO_3$ are studied using transmission electron microscopy and scanning electron microscopy images. The crystal structure is investigated using X-ray diffraction patterns, and the changes in the dye concentrations adsorbed on $WO_3$ nanorods are measured with a UV-visible absorption spectrophotometer based on Beer-Lambert's law. The methylene blue (MB) dye solution is subjected to acid or base conditions to monitor the change in the maximum adsorption amount in relation to the pH. The maximum adsorption capacity is observed at pH 3. In addition to the dye adsorption, UV irradiation is carried out to investigate the decomposition of the MB dye as a result of photocatalytic effects. Significant photocatalytic properties are observed and compared with the adsorption effects for dye removal.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2265-2268
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• 2012

Aqueous solution of oxygenated Direct yellow 12 dye has been evaluated spectrophotometrically as a possible gamma rays dosimeter. The neutral (pH-7), alkaline (pH-12.5) and acidic (pH-5.5) aqueous solution of the dye were prepared and exposed to various gamma doses. Absorption spectra of unirradiated and irradiated solutions were recorded at 400 nm peak. The increase in absorbance with the increase in irradiation dose was observed from 1 to 6 kGy. The stability response of the dye solution for different environmental conditions such as temperature (low & high), light and darkness were investigated during post irradiation storage for ten days. The dye solution showed high stability in darkness for the studied period. The optical density of the dye solution was found to be decreased at high temperature storage.