• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1485-1488
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• 2010

Novel photoluminescent graphene, graphene/europium/picolinate, was made from the reaction of the graphene carboxylate, europium(III) and $\alpha$-pyridoin anion in methanol solution. There was evidence on IR spectroscopic data that europium metal was coordinated by graphene carboxylate. The graphene/europium/picolinate materials emitted the red luminescence with main peaks at 609 and 695 nm, when solid sample was excited by an UV light at the wavelength of 254 nm. The surface morphology and physical properties of the graphene/europium/picolinate product have been investigated by IR, PL, SEM, TEM and TGA measurements.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.973-976
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• 2011

The addition of organic ligand (${\beta}$-diketone or heterocyclic compound) to the europium (III)-containing ionic liquid resulted in bright luminescent soft materials with the molar ratio of europium/ionic liquid (IL)/ligand being 1:3:1 that exhibit bright red light under UV lamp. The luminescent properties such as emission features and lifetime of $^5D_0$ $Eu^{3+}$ excited level are dependent on the organic ligands. The materials were characterized by FT-IR and luminescence spectroscopy. The data shows that at least parts of the ILs (carboxylic acid) are replaced with ${\beta}$-diketone ligand rather than the formation of europium complex with the molar ratio of $Eu^{3+}$:IL: ligand being 1:3:1, while no ILs could be replaced by the heterocyclic ligand such as Bpy and Phen.

• 분석과학
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• 제11권5호
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• pp.409-412
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• 1998

수용액 중의 europium(III) 이온을 europium(III) 이온의 농도에 따른 calmodulin의 형태변화 때문에 나타나는 형광세기를 측정함으로써 정량하는 방법에 대하여 조사하였다. 광섬유센서는 광섬유의 끝 부분에 투석막을 이용하여 지시용액을 담을 공간을 만들고, 여기에 fluorescein으로 표지된 calmodulin, EGTA 및 완충용액을 넣는 방법으로 제작하였다. 지시용액으로 $5.0{\times}10^{-5}M$ calmodulin, 0.5 mM, EGTA, 5.0 mM Tris-HCl 완충용액을 사용하고, 용액의 pH, 들뜸파장 및 형광 측정파장을 각각 7.0, 495 nm와 520 nm로 고정하였을 때의 europium(III) 이온에 대한 검정곡선을 작성하였다. 검출 한계는 $1.0{\times}10^{-11}M$ 이었고, 직선감응범위는 $1.0{\times}10^{-11}M{\sim}1.0{\times}10^{-9}M$ 이었다. 광섬유센서의 감응 시간은 15분 이었다. Europium(III) 이온을 본 방법으로 정량할 때, $Na^+$ 이온과 $K^+$ 이온은 전혀 방해를 하지 않았으나 $Ca^{2+}$ 이온은 심하게 방해하였다.

• 한국재료학회지
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• 제32권4호
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• pp.193-199
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• 2022

In this study, lenses are fabricated using various nanomaterials as additives to a silicone polymer made with an optimum mixing ratio and short polymerization time. In addition, PVP is added at a ratio of 1 % to investigate the physical properties according to the degree of dispersion, and the compatibility with hydrophobic silicone and the possibility of application as a functional lens material are confirmed. The main materials are SIU as a silicone monomer, DMA, a hydrophilic copolymer, EGDMA as a crosslinking agent, and 2H2M as a photoinitiator. Holmium (III) oxide, Europium (III) oxide, aluminum oxide, and PVP are used. When Holmium (III) oxide and Europium (III) oxide are added based on the Ref sample, the characteristics of the lens tend to be similar overall, and the aluminum oxide shows a tendency slightly different from the previous two oxides. This material can be used as a silicone lens material with various nano oxides and polyvinylpyrrolidone (PVP) acting as a dispersant.

• 한국응용과학기술학회지
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• 제18권1호
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• pp.12-19
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• 2001

Eu(III) exhibits one electron-transfer reduction at $E_{1/2}$ = -0.564 V(vs. Ag/AgCl) and the hypersensitive peak at 615 ㎚ corresponding to $^{5}D_{0}{\rightarrow}^{7}F_{2}$ transition in 0.1 M $LiClO_{4}$ aqueous solution. Upon the addition of 2,6-pyridine dicarboxylic acid(PDA) to the Eu(III) aqueous soultion, the reduction potential shifts negatively and the PDA, and the Eu(III)-PDA complex emits great fluorescence than free-Eu(III) ion at 615 nm. The results are interpreted in term of the electrochemical and spectrofluorometric studies.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2549-2551
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• 2007

• 분석과학
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• 제28권3호
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• pp.204-211
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• 2015

란탄족 착물은 독특한 발광 특성으로 인하여 많은 연구가 되고 있는 물질이다. 유로피움(III) β-디케토네이트 착물에 아민계열 또는 포스핀옥사이드계열 리간드를 추가로 배위 결합시켜 발광 효율을 비교하였으며, 아민계열 배위보다는 발광 효율 증진에는 포스핀옥사이드 계열이 더 좋은 추가 리간드임을 확인하였다. 그 중에서도 트리옥틸포스핀 옥사이드를 배위시켰을 때 가장 높은 발광효율이 관찰되었다. 추가로 배위될 수 있는 트리옥틸포스핀 옥사이드의 당량을 확인하기 위해서 ³¹P-NMR과 photoluminescence를 분석하였다. 유로피움(III) β-디케토네이트 화합물은 리간드의 입체장애에 따라 트리옥틸포스핀 옥사이드의 배위 당량은 1 개 또는 2 개가 가능함을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4145-4149
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• 2012

A novel and simple method of luminescence enhancement effect for the determination of trace amounts of bile acid was proposed. The procedure was based on the luminescence intensity of the balofloxacin-europium(III) complex that could be strongly enhanced by bile acid in the presence of sodium dodecyl benzene sulfonate (SDBS). Under the optimum conditions, the enhanced luminescence intensity of the system exhibited a good linear relationship with the bile acid concentration in the range $5.0{\times}10^{-9}-7.0{\times}10^{-7}\;mol\;L^{-1}$ with a detection limit of $1.3{\times}10^{-9}\;mol\;L^{-1}$ ($3{\sigma}$). The relative standard deviation (RSD) was 1.7% (n = 11) for $5.0{\times}10^{-8}\;mol\;L^{-1}$ bile acid. The applicability of the method to the determination of bile acid was demonstrated by investigating the effect of potential interferences and by analyzing human serum and urine samples. The possible enhancement mechanism of luminescence intensity in balofloxacin-europium(III)-bile acid-SDBS system was also discussed briefly.

• 응용화학
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• 제15권1호
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• pp.29-32
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• 2011

Surfactant enhanced fluorescence (FL) of europium-salicylic acid (SA) complex has been studied. It was observed that weak FL of Eu(III) at the wavelength of 589 nm and 612 nm was found to be enhanced after addition of salicylic acid and cetyltrimethylammonium bromide (CTAB) surfactant upon excitation at 395 nm. Under optimized condition, FL intensity of Eu(III) at 612 nm responded linearly with the concentration of SA in the range of 5.5×10^-9 to 1.5×10^-6 M of SA. The detection limit was calculated from the calibration curve(3Sb/m) as 9.27×10^-9 M.

• Nuclear Engineering and Technology
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• 제56권5호
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• pp.1738-1746
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• 2024

The effect of europium-driven corrosion behavior of Alloy 709 in FLiNaK molten salt was investigated by static immersion tests at 700 ℃. It was found that the corrosion of Alloy 709 increased after the addition of EuF₃, even though the standard reduction potential of Eu(III)/Eu(II) was negative than those of Fe(II)/Fe, Ni(II)/Ni and Cr (II)/Cr. The presence of Eu(III) led to deeper corrosion attack layers and more pits on the steel surface in comparison with corrosion in blank FLiNaK. However, the addition of Eu(III) seemed to have a role in reducing surface cracking that was explored in corrosion by blank FLiNaK, which depended on Eu(III) concentration.