• YAKHAK HOEJI
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• v.38 no.4
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• pp.366-371
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• 1994

To improve the identification power of TLC/HPTLC the in situ reflectance spectra obtained directly from plates with commercial scanner are used. The spectrum normalization should be carried out prior to comparing and searching the spectra from library for the identification of compounds. Because the reflectance does not obey the Lambert-Beer's law, there arise some problems in normalization. These problems could be solved to some extent by normalizing the spectra with regression methods. The spectra are manipulated with the regression function of a curve obtained from the correlation plot. When the parabola was used as the manipulating function, the spectra were identified with the accuracy of 97% and this result was better than that of conventionally used the point and area normalization method.

• Journal of the Korean Applied Science and Technology
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• v.14 no.2
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• pp.71-79
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• 1997

Ultra-thin films of poly[2-[4-(9-(10-phenyl)anthracenyl)phenoxy)hexyloxy]]-1,4-phenylenevinyleylene(PAHPV) were prepare-d on the hydrophilic ITO substrate by Langmuir-Blodgett(LB) technique. ${\lambda}_{max}$ in the photoluminescence spectrum of these films was 458nm at the excitation wavelength of 365nm before thermal treatment, which comes from diphenylanthracene side chain of PAHPV. It was also confirmed with UV-Vis spectrometer that ultra-thin LB films of PAHPV precursor polymer were prepared well. After thermal treatment for conjugation of PAHPV precursor polymer, ${\lambda}_{max}$ in the photoluminescence spectrum of these films changed to 365nm, which means that the conjugation of these PAHPV films was completed.

• Journal of Integrative Natural Science
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• v.3 no.1
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• pp.24-27
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• 2010

Multi-functionalized rugate porous silicon (PSi) for biosensor was developed by hydrosilylation with silole and its further reaction with biotin groups. PSi was generated by an electrochemical etching of silicon wafer in aqueous ethanolic HF solution PSi prepared by using etching conditions showed that many sharp spectral lines can be obtained in the optical reflectivity spectrum. 1,1-hydrovinyl-2,3,4,5-tetraphenylsilole was obtained from the reaction of 1,1-dilithio-2,3,4,5-tetraphenyl-1,3-butadiene with dichlorovinylsilane. Multi-functionalized PSi with silole and biotin groups was characterized by UV-vis absorption spectroscopy, Ocean optics 2000 spectrometer, and fluorescence spectroscopy. Optical characteristics such as reflectivity and photoluminescence (PL) were observed. An increase of the reflection wavelength in the reflectivity spectrum by 20 nm was observed, indicative of a change in refractive indices induced by hydrosilylation of the silole and biotin groups to the rugate PSi. This red-shift was attributed to the replacement of some of the Si-H group of fresh rugate PSi with silole and biotin group.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.525-528
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• 1997

In this study, Eu(TTA)$_3$(phen) was synthesized and its films were prepared by vapor deposition method. Its films were characterized by UV-Vis absorption spectroscopy, Atomic Force Microscopy(AFM) and Photoluminescence(PL) measurements. Their electroluminescent(EL) characteristics were investigated by PL measurements, where a cell structure of glass substrate/ITO/Eu(TTA)$_3$(phen)/Al was employed. It was found that its films were well prepared without any decomposition and the film thickness could be controlled by adjusting the amount of Eu(TTA)$_3$(phen) in a boat. The EL spectrum of these films was almost the same as that of PL spectrum of these films.

• Journal of the Korean Physical Society
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• v.73 no.11
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• pp.1729-1734
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• 2018

Organic-inorganic halide perovskite single crystals undergo phase transition of being cubic, tetragonal, or orthorhombic depending on the temperature. We investigated the $CH_3NH_3PbBr_{3-x}I_x$ single crystals grown by the inverse temperature crystallization method with temperature-dependent UV-Vis absorption and photoluminescence. From the temperature-dependent absorption measurement, the optical band gap is extracted by derivation of absorption spectrum fitting and Tauc plot. In our results, $CH_3NH_3PbBr_{3-x}I_x$ single crystals show that an abrupt change in optical band gap, PL peak position and intensity appears around 120 K - 170 K regions, indicating the phase transition temperature.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1491-1504
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• 2012

InP quantum dot (QD)-organosilicon nanocomposites were synthesized and their photoluminescence quenching was mainly investigated because of their applicability to white LEDs (light emitting diodes). The as-synthesized InP QDs are capped with myristic acid (MA), which are incompatible with typical silicone encapsulants. We have introduced a new ligand, 3-aminopropyldimethylsilane (APDMS), which enables embedding the QDs into vinyl-functionalized silicones through direct chemical bonding. The exchange of ligand from MA to APDMS does not significantly affect the UV absorbance of the InP QDs, but quenches the PL to about 10% of its original value with the relative increase in surface related emission intensities, which is explained by stronger coordination of the APDMS ligands to the surface indium atoms. InP QD-organosilicon nanocomposites were synthesized by connecting the QDs using a short cross-linker such as 1,4-divinyltetramethylsilylethane (DVMSE) by the hydrosilylation reaction. The formation and changes in the optical properties of the InP QD-organosilicon nanocomposite were monitored by ultraviolet visible (UV-vis) absorbance and steady state photoluminescence (PL) spectroscopies. As the hydrosilylation reaction proceeds, the QD-organosilicon nanocomposite is formed and grows in size, causing an increase in the UV-vis absorbance due to the scattering effect. At the same time, the PL spectrum is red-shifted and, very interestingly, the PL is quenched gradually. Three PL quenching mechanisms are regarded as strong candidates for the PL quenching of the QD nanocomposites, namely the scattering effect, F$\ddot{o}$rster resonance energy transfer (FRET) and cross-linker tension preventing the QD's surface relaxation.

• Journal of the Korean Society of Clothing and Textiles
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• v.43 no.2
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• pp.288-296
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• 2019

This study examined the proper dyeing conditions, color fastness and functionality for wool fabrics dyed with Chamaecyparis obtusa leaf extract. FT-IR and UV-Vis spectrum analysis showed that tannin and flavonoids were contained in the extracted colorant. The dyeing of wool fabrics using Chamaecyparis obtusa leaf was good without pretreatment or mordant treatment. Optimal dyeing conditions for wool fabrics were a colorant concentration of 70%(v/v), dyeing temperature of $100^{\circ}C$, dyeing time of 100 minutes and dyebath pH of 5.8. Color fastness of dyed wool fabrics to washing, rubbing, perspiration was good, whereas light was grade 3. The UV protection rate and deodorization rate of wool fabrics dyed with Chamaecyparis obtusa leaf improved. Reduction rate of Staphylococcus aureus/Klebsiella pneumoniae were excellent at 99.9%. Therefore, it was confirmed that Chamaecyparis obtusa leaf can be used as environ-mentally friendly natural dye.

• Journal of Biomedical Engineering Research
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• v.20 no.6
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• pp.547-553
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• 1999

생체재료로 사용되는 polyurethane(PU) 표면에 항혈전성 lumbrokinase(LK)를 고정함으로써 생체적합성을 향상시키고자하였다. 먼저 LK를 PU 표면에 고정하기 위한 가교제로서 4-azidoaniline hydrochloride와 poly(acrylic acid)를 이용하여 4-azidophenyl 작용기가 amido 결합으로 치환된 수용성, 광반응성 poly(acrylic acid)(PPa-II)를 합성하였다. H-nuclear magnetic reasonance spectrum(500MHz H-NMR)의 6-7 peak와 infrared spectrum (FT-IR) 의 2125.48 cm peak으로부터 PPA-II의 합성을 지원하였다. EH한 4-azidophenyl 작용기가 poly(acrylid acid) 잔기에 치환된 정도는 UV/VIS adpectrophotometric spectrum을 확인한 결과 11~14%임을 알 수있었다. 0.5 1및 5% PPA-II를 각각 광반응하여 얻은 PU는 39.5, 161.8 및 181.5 nmole/$\textrm{cm}^2$의 농도로 표면에 carvoxyl 작용기가 유도되었음을 알 수있었다. 0.05M KH2PO4 (pH 4.5) 용액에서 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide(EDC)를 촉매로 사용하여 LK를 PU표면에 amido 공유결합으로 고정하였으며, 이것은 지속적인 fibrinolytic 활성도를 보였다. PPA-II를 이용한 표면 개질 방법은 수용성 반응조건에서 이루어진다는 점과 광반응을 이용함으로써 특정부위에서의 표면개질이 가능하다는 점에서 그 응용가치가 크며 아울러 PU의 생체적합성을 향상시킬 수 있는 방법으로서 판단된다.

• Fashion & Textile Research Journal
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• v.18 no.6
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• pp.869-877
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• 2016

This study looks into the dyeing properties and functionality of cotton fabrics dyed in both the Spirodela polyrhiza extract and the extract resulting from the mixture of Salvia plebeia R. Br. and Spirodela polyrhiza. Since the UV-Vis Spectrum of the methanol extract of Spirodela polyrhiza shows absorption peaks at 256, 268nm, and 345nm, it can be inferred that the compound that Spirodela polyrhiza contains is a flavonoid. In addition, it can also be presumed that, by analyzing the infrared absorption spectrum of Spirodela polyrhiza, the plant contains flavonoid compounds, just like Salvia plebeia R. Br.. The UV protection factors of the cotton fabrics dyed in both the Spirodela polyrhiza extract and the extract from the mixture of Salvia plebeia R. Br. and Spirodela polyrhiza were 50+, presenting outstanding UV protection factors. The deodorization rate of the cotton dyed in the Spirodela polyrhiza extract was between 30 and 120 minutes, and the rate rose from 92% to 97% as time passed. The deodorization rate of the cotton dyed in the extract from the mixture of Salvia plebeia R. Br. and Spirodela polyrhiza increased from 88% to more than 91%. The result also revealed that overall the fastness of color, including color fastness to washing related to change in color, as well as the color fastness to light of the fabric dyed in the extract from the mixture of the two plants improved, compared to the cloth dyed only in Spirodela polyrhiza extract. Furthermore, the antibacterial activity was also strengthened.

• Conservation Science in Museum
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• v.11
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• pp.61-72
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• 2010

This is the analysis of material dyed with Korean yellow dyes such as tumeric, amur cork tree, goldthread, gardenia, and the flowers of sophora japonica using nondestructive ultraviolet-visible and fluorescence spectrophotometry. In order to find out whether type of fabric or mordant influences analysis results, test fabrics were made using two types of fabric(silk and cotton) and dyed using three different mordants(no mordant, alum, iron). After analysis with UV-Vis reflectance spectrum on the dyed fabric, when the fabric was dyed with tumeric, amur cork tree and goldthread, the results were similar with no mordant and alum mordant, whereas there was a difference with an iron mordant. Also when the fabric was dyed using gardenia, different fabrics brought different results but there was no difference in results with mordants. On the other hand, when the fabric was dyed using the flowers of sophora japonica, there was no difference with fabrics but with mordants. After analysis with 3D-fluorescence spectrum, fabrics dyed with tumeric, amur cork tree and goldthread showed their own fluorescent spectrum with no regard to fabric and mordant; but with gardenia, there were differences with different fabrics whereas with the flowers of sophora japonica, there were differences with mordants.