• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.955-956
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• 2006

Fe-doped $TiO_2$ nanopowders were prepared by mechanical alloying (MA) varying Fe contents up to 8.0 wt.%. The UV-vis absorption showed that the UV absorption for the Fe-doped powder shifted to a longer wavelength (red shift). The absorption threshold depends on the concentration of nano-size Fe dopant. As the Fe concentration increased up to 4 wt.%, the UV-vis absorption and the magnetization were increased. The benefical effect of Fe doping for photocatalysis and ferromagnetism had the critical dopant concentration of 4 wt.%. Based on the UV absorption and magnetization, the dopant level is localized to the valence band of $TiO_2$.

• 분석과학
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• 제12권3호
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• pp.243-247
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• 1999

HCl 산성에서 aconitine류 알칼로이드는 Reineke 시액으로 백색의 침전을, 그리고 TCR 시액으로 청색의 침전을 형성하였다. 백색의 침전은 $NH_4OH$ 알칼리성의 물에 녹아 aconitine류 알칼로이드를 유리시키며, 유리된 aconitine류 알칼로이드는 DCE층으로 쉽게 전용되었다. 전용된 DCE층을 분취하여 UV흡광파장을 측정하고 TLC로 분리하였다. 청색의 침전은 DCE층에 전용되므로 전용된 DCE층을 분취하여 UV/Vis.흡광파장을 측정하였다. 이상의 방법으로 aconitine류 알칼로이드를 검출하여 생약이나 제제에서 aconitine류 알칼로이드를 함유한 부자류 생약을 확인할 수 있었다.

• 한국결정성장학회지
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• 제16권1호
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• pp.25-31
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• 2006

남미, 아프리카, 아시아 대륙의 자수정을 대상으로 하였다 ICP-AES 분석에서 나타난 발색원소는 Fe, Cr, Cu, Co이며 대체적으로 남미 지역에서 발색원소의 함유량이 높게 나타났다. UV-VIS 분석결과 천연자수정과 합성자수정은 350nm 영역과 550nm 영역에서 흡수가 일어나는 특성을 나타냈고 투과율은 합성에 비해 천연이 낮게 나타났다. FT-IR분석결과 천연자수정과 합성자수정의 구분은 합성자수정의 특징인 $3543cm^{-1}$ 흡수밴드의 유무에 의해 알 수 있었다 남미 지역은 $3584cm^{-1},\;3435cm^{-1}$ 흡수밴드가 강하게 나타나며, 아프리카 지역은 $3299cm^{-1},\;3196cm^{-1}$ 흡수밴드가 나타났다. 아시아 지역은 $3381cm^{-1}$ 흡수밴드가 특징적으로 관찰되었다.

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.392-396
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• 2014

New organic-inorganic composite of 2,4-dihydroxybenzophenone (BP-1) encapsulation into dodecylbenzenesulfonate (DBS) modified layered double hydroxide (LDH) was successfully prepared. The surface, structural, thermal and absorption properties of the BP-1/DBS-LDH nanohybrid was characterized by BET analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG) and diffuse reflectance UV-Vis absorbance spectra (DRUV-vis). The interlayer configuration of composite and the adsorption mechanism of BP-1 on MgAl-DBS-LDH were discussed. It was suspected that DBS anions located in the form of monolayer arrangement with a $75^{\circ}$ anti parallel angle between dodecylbenzenesulfonate chain axis. The diffuse reflectance UV-Vis absorbance results revealed that the UV absorbing wavelength of BP-1/DBS-LDH evidently extends to about 400 nm, which shows that the BP-1/DBS-LDH has the potential application as a UV absorber.

• 한국전기전자재료학회논문지
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• 제29권1호
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• pp.35-39
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• 2016

In this research, we focused on the improvement of cy3 dye's characteristics for LCD color filter. Solubility and thermal stability are main characteristics of dyes for LCD color filter. We performed experiment to change counter cation of cy3 dyes with alkoxy substituent for these purposes. These cy3 dyes (1b~5b) were prepared through the synthetic procedure of three steps. The synthesized new cy3 dyes were charaterized by using NMR, FT-IR, UV/Vis spectroscopy, and TGA. These cy3 dyes showed purple color and maximum absorption wavelength (${\lambda}_{max}$) in the range of 578~590 nm in UV/Vis spectrum. We confirmed that solubility and thermal stability of cy3 dyes were dependent on the structure of counter cation. Cy3 dyes with alkoxy substituent have good solubility in organic solvents such as dichloromethane, methanol, and acetone. Especially, Cy3 dye with 4-nitrobenzyl counter cation (5b) gave excellent solubility characteristics.

• 통합자연과학논문집
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• 제2권3호
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• pp.215-218
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• 2009

A silaspirotropylidene has been obtained from the reaction of the lithium salt of tetraphenylsilole dianion with 2 equiv of diphenylcyclopropene, followed by quenching with Me3SiCl. Silaspirotropylidene exhibits an unusual optical property its optical property was characterized by UV-vis and fluorescence spectroscopy. Absorption wavelength maxima of silaspirotropylidene was 420 nm. silaspirotropylidene displayed an emission band at 550 nm with excitation wavelength of 420 nm.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
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• pp.137-140
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• 2006

This paper describes a technique combining chemometrics with UV spectroscopy for the determination of the concentra tions of two tissue additives (i.e., wet strength and softening agents) in a cellulose fiber containing solution. In single as ent solutions, the concentration of the additive can be measured by UV spectroscopy at the wavelength where the species having absorption. For a binary (i.e., containing two additives) solution system, the spectral characterization is very complicated. However, if aided by a chemometrical calibration technique, each additive in the binary solution can be quantified simultaneously. The present method is very rapid and simple, it can easily perform a continuous measurement in the changes in the additives' concentration after fiber addition, and therefore this becomes a valuable tool for the adsorption kinetics study of chemical additives onto the cellulose fibers. The time-dependent adsorption behaviors of the wet-strength, softening agent, and their both on fiber were also presented.

• 한국분말재료학회지
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• 제27권3호
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• pp.233-240
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• 2020

Nano-sized ZnSe particles are successfully synthesized in an aqueous solution at room temperature using sodium borohydride (NaBH₄) and thioglycolic acid (TGA) as the reducing agent and stabilizer, respectively. The effects of the mass ratio of the reducing agent to Se, stabilizer concentration, and stirring time on the synthesis of the ZnSe nanoparticles are evaluated. The light absorption/emission properties of the synthesized nanoparticles are characterized using ultraviolet-visible (UV-vis) spectroscopy, photoluminescence (PL) spectroscopy, and particle size analyzer (PSA) techniques. At least one mass ratio (NaBH4/Se) of the reducing agent should be added to produce ZnSe nanoparticles finer than 10 nm and to absorb UV-vis light shorter than the ZnSe bulk absorption wavelength of 460 nm. As the ratio of the reducing agent increases, the absorption wavelengths in the UV-vis curves are blue-shifted. Stirring in the atmosphere acts as a deterrent to the reduction reaction and formation of nanoparticles, but if not stirred in the atmosphere, the result is on par with synthesis in a nitrogen atmosphere. The stabilizer, TGA, has an impact on the Zn precursor synthesis. The fabricated nanoparticles exhibit excellent photo-absorption/discharge characteristics, suggesting that ZnSe nanoparticles can be alloyed without the need for organic solutions or high-temperature environments.

• 한국세라믹학회지
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• 제34권9호
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• pp.993-1001
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• 1997

The (0.8PPV+0.2DMPPV) copolymer and silica/borosilicate composites were synthesized by sol-gel process. The organic-inorganic hybrid solution was prepared by using of (0.8PPV+0.2DMPPV) copolymer precursor solution as a raw material for organic components and TEOS and TMB for glass components. Then by drying the solution in vacuum at 5$0^{\circ}C$ for 7days and subsequent heat treatment in vacuum at 15$0^{\circ}C$~30$0^{\circ}C$ for 2h~72h with heating rate of 0.2$^{\circ}C$/min and 1.8$^{\circ}C$/min, the organic-inorganic composites were synthesized. Microstructural evolution of the composites was characterized by DSC, IR spectrocopy, UV/VIS spectroscopy, and TEM. Elimination of the polymer precursor and degradation of the polymer were observed by DSC and Si-O and trans C=C absorption peaks were identified by IR spectra. The polymer was found to be successfully incorporated into the glass matrix and it was confirmed by the absorption peaks from the polymer in the UV/VIS spectra and the TEM results. The absorption peak of the composites was found to shift toward short wavelength side compared to that of the pure polymer and the amount of the blue shift increased with increasing the heat treatment temperature and heat treatment time and with decreasing the heating rate.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.925-928
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• 2010

Nitrogen-doped $TiO_2$ ($TiO_2$:N) nano-particles with a pure anatase crystalline structure were successfully synthesized through the hydrolysis of $TiCl_4$ in an ammonia aqueous solution. The samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), $N_2$-sorption, and UV-vis diffuse reflectance spectra (UV-vis DRS) techniques. The absorption edge of nitrogen-doped $TiO_2$ shifted into the visible wavelength region. The photoelectrochemical (PEC) performances were investigated for the $TiO_2$ mesoporous electrodes doped with different nitrogen concentrations. The $TiO_2$:N electrodes exhibited much higher PEC responses compared to the pure $TiO_2$ electrode because of the significantly enhanced visible-photoresponsibility of the $TiO_2$:N electrodes.