• 폴리머
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• 제30권5호
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• pp.367-372
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• 2006

전도성 고분자에 곁가지로 chromophore를 결합시켜 만든 다양한 전기 변색 물질과 그 특성을 소개하였다. 전도성 고분자로는 Polypyrrole, Polythiophene, Poly(3,4-ethylenedioxythiophene), Poly(cyclopen-tadithiophene), 및 poly (1,4-bis [2- (3,4-ethylenedioxy)thienyl] benzene)를 사용하고, chromophore로는 viologen과 perylenetetracarboxylic diimide를 사용한 경우에 대하여 설명하였다. 전도성 고분자와 thromophore의 변색 파장 범위가 다른 경우에는 변색의 다양성을 성취할 수 있었으며, 변색 파장 범위가 비슷한 경우에는 색대비를 높일 수 있다. 최대 색대비를 나타내는 필름의 두께를 쉽게 예측할 수 있는 방법도 설명하였다.

• 대한원격탐사학회지
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• 제38권2호
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• pp.215-222
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• 2022

본 연구에서는 pandora 직달광 원시자료로부터 차등흡수분광법(DOAS, Differential Optical Absorption Spectroscopy)을 이용하여 이산화질소 연직칼럼농도(VCD, Vertical column density) 산출 시 파장구간과 흡수단 면적이 미치는 영향을 비교 분석하였다. GEMS Map of the Air Pollution (GMAP) 2020 캠페인 기간 동안 서산에서 Pandora 장비로 관측된 자료를 사용하였으며, 차등흡수분광법을 이용하여 CINDI-2 캠페인과 PGN의 산출 방법에 따라 4가지 조건으로 이산화질소 연직칼럼농도를 산출하였다. 4가지 조건으로 산출된 이산화질소 평균 연직칼럼농도는 1.22×10¹⁶~1.38×10¹⁶ molec. cm^-2으로, 각 조건 간 최대 0.16×10¹⁶ molec. cm^-2의 차이를 보였다. 피팅 에러는 평균 3.19~9.59%로 모든 조건에서 10% 이내였으며, RMS는 5.11×10^-3~7.16×10^-3 molec. cm^-2으로 나타났다. 4가지 방법으로 산출된 이산화질소 연직칼럼농도와 Pandonia Global Network (PGN)에서 제공하는 이산화질소 연직칼럼농도와 기울기는 0.98~1.09이었으며, 0.96~0.98의 상관관계를 보여주었다.

• 대한화학회지
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• 제44권1호
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• pp.60-67
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• 2000

표면공명흡수는 매질의 유전상수값에 의존한다. 금 나노미립자가 함침된 $TiO_2/SiO_2$ 복합산화물 박막을 $Ti(OPr^i)_4$과 $Si(OEt)_4$, 그리고 $HAuCl_4{\cdot}7H_2O$를 사용하여 졸-겔 방법으로 제조하였다. $TiO_2/SiO_2$ 박막에 함침된 금 나노미립자의 최대 표면 공명 흡수는 $TiO_2/SiO_2$의 몰비에 따라 540 nm에서 615 nm 까지 선형적으로 변하였다. 이러한 박막에 함침된 금 나노미립자의 크기와 구조를 TEM과 XRD로 측정하였다. 그리고 $TiO_2/SiO_2$ 박막의 유전상수값을 실험 data로부터 이론적으로 계산하였다

• 한국광학회지
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• 제15권1호
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• pp.1-5
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• 2004

분리막을 이용한 산소-18 분리실험에서 분리된 시료의 동위원소 성분비 분석을 위해 다이오드 레이저 흡수분광장치를 구성하였다. 흡수신호의 신호 대 잡음비를 높이기 위해 lock-in증폭기를 사용한 파장변조 분광법을 채택하였다. 레이저의 주파수 변조폭 최적화와 FFT 저역통과 필터링을 통해 다중반사흡수셀에서 발생하는 간섭무늬 잡음을 줄였다. 산소-18에 대한 흡수분광장치의 최대편차는 $\pm$4$\textperthousand$로 측정되었다.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.393-397
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• 2012

We report a new route to synthesize high quality zinc blende CdS and ZnS nanocrystals in noncoordinating solvent 1-octadecene, using dodecanethiol (DDT) molecules as both the sulfur source and surface capping ligands. Different reaction temperatures and Cd(Zn)/DDT molar ratios were tested to optimize the synthesis conditions. Absorption photoluminescence (PL) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) pattern, and transmission electron microscopy (TEM) were used to characterize assynthesized nanocrystals. The narrow half width at the half-maximum on the long wavelength side of the firstexcitonic absorption peak and TEM images demonstrated nearly monodisperse size distributions of asprepared CdS, ZnS, and CdS/ZnS core/shell nanocrystals. Only trap emissions of the nanocrystals were detected when the amount of DDT was excessive, this came from the strong quenching effect of thiol groups on the nanocrystal surfaces. After overcoating with ZnS shells, band-gap emissions of CdS nanocrystals were partially recovered.

• Journal of Photoscience
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• 제8권3_4호
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• pp.113-117
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• 2001

Several styrylquinolium salts were synthesized to investigate their absorption and thermal properties, which had five different p-aminobenzene units and three different counter ions (iodide, perchlorate, and hexafluorophosphorate anion), respectively. Hydroxy, methoxy, and methyl group in the meta position to the amino group led to bathochromic shift, while Ν-ethyl-Ν-chloroethylamino unit instead of Ν,Ν-diethylamino unit resulted in hypsochromic shift. A dye having a methoxy group in the meta position to the amino group had the highest molar extinction coefficient ($\xi$), while a dye carrying chloro group in Ν-alkyl chains had the lowest $\xi$. The type of counter ions had no effect on spectral properties like the maximum absorption wavelength and $\xi$. All styryl dyes had exothermic peaks at decomposition in DSC curves. Among these styryl dyes, S2 series with perchlorate anions showed the strongest exothermic decomposition. From TGA spectra, S3 series with hexafluorophosphorate anions had the best thermal stability and the sharpest threshold at thermal decomposition.

• 한국생활과학회지
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• 제21권5호
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• pp.989-1004
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• 2012

The purpose of this study was to investigate the characteristics of the pigment and the dyeability of juniperus chinensis needles, berry, bark and heartwood extracts using distilled water, methanol, normal butanol and ethyl acetate as a solvent. Ultraviolet-visible absorption spectrum bands of the extracts were measured at around 280nm to 320nm in all the solvent extracts. The maximum absorption wavelength was able to determine tannin. All the solvent extracts except for distilled water extracts were able to confirm the presence of chlorophyll. Infrared absorption spectra (FT-IR) of all parts of the extracts showed broad absorption bands of OH due to phenolic-OH, benzene CH peak of phenol chemical structure, ether-based stretching vibration peak and the peak of flavonoid compounds that appeared in all the solvent extracts. The yield of juniper needles and heartwood in distilled water and methanol extraction were effective. Extraction of berry yields in distilled water was also effective. The yield of ethanol extraction from the bark showed better efficiency. As a result of using distilled water for the dye solution, the color of the fabrics dyed with all extracts of the needles and Y series berries generally showed light Y progression with a strong red tinge. By using a mixture of 20% ethanol and 80% distilled water for the dye solution, the color of the fabrics dyed with needles and berry extracts showed Y series dominantly. The color of the fabrics dyed with Bark and heartwood extracts were dominantly R series.

• Fibers and Polymers
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• 제2권3호
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• pp.159-163
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• 2001

Five yellow disperse dyes were synthesized and their dyeing, fastness and photodegradation behaviors were investigated. It was found that dyes derived from phenylindole and N-alkylaminobenzene showed dye uptake directly proportional to the dye concentration, but the build-up of dyes derived from carbazole and pyridone were not good. The wavelength at maximum absorption. molar extinction coefficient. and the tendency to the photodegradation were strongly dependent on the electron donating ability of the coupling component. The dye, whose coupling component was phenylindole, possessed the excellent dyeing properties and the high degree of lightfastness. UVA had an effect on the inhibition of the photodegradation especially for the easily photodegradabte dyes.

• 세라미스트
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• 제10권3호
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• pp.7-14
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• 2007

PbS QDs in glasses have attracted much attention due to the potentials for near-infrared applications. Growth of PbS QDs in the glass is discussed and size of PbS QDs formed in the glass can be tuned by varying the thermal treatment conditions. Hyperbolic-band approximation and four-band envelope function provide good simulation of the exciton energies of PbS QDs. Absorption and photoluminescence of PbS QDs was tuned into $1{\sim}2{\mu}m$ wave-length regime with large full width at half maximum photoluminescence intensity (>160 nm). Photoluminescence intensity of PbS QDs in the glasses was closely related to size of quantum dots, temperature, excitation and defects. Decrease in temperature shifted the photoluminescence bands to shorter wavelength and switched the photoluminescence from darkened state and brightened state.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.582-584
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• 2004

The light-emitting properties of poly(2-triethylgermyl-1,4-phenylenevinylene) (TEG-PPV) are compared with those of the silyl-substituted PPV homologue, poly(2-trimethylsilyl-1,4phenylenevinylene) (TMS-PPV). The precursor polymer is solution-processable. After carrying out thermal elimination on the precursor polymer film, the resulting fully conjugated polymer film was found to exhibit high thermal stability in air, and absorption that is shifted to the longer wavelength region owing to the extension of the n-conjugated system. TEG-PPV exhibits efficient green light emission; the maximum PL emission of a TEG-PPV thin film was found to be at 515 nm. The HOMO and LUMO energy levels were also determined using photo-emission spectroscopy. The performance of the TEG-PPV EL device was found to be comparable to that of the TMS-PPV device.