• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.88.2-88.2
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• 2010

Dye-sensitized solar cells (DSSCs) have attracted considerable attention on account of their high solar energy-to-conversion efficiencies and low cost processes compared to conventional p-n junction solar cells. The mechanism of DSSC is based on the injection of electrons from the photo excited dyes into the conduction band of the semiconductor electrode. The oxidized dye is reduced by the hole injection into either the hole conductor or the electrolyte. Thus, the light harvesting effect of dye plays an important role in capturing the photons and generating the electron/hole pair, as well as transferring them to the interface of the semiconductor and the electrolyte, respectively. We used the organic fluorescence materials which can absorb short wavelength light and emit longer wavelength region where dye sensitize effectively. In this work, the DSSCs were fabricated with fluorescence materials added $TiO_2$ photo-electrode which were sensitized with metal-free organic dyes. The photovoltaic performances of fluorescence aided DSSCs were compared, and the recombination dark current curves and the incident photon-to-current (IPCE) efficiencies were measured in order to characterize the effects of the additional light harvesting effect in DSSC. Electro-optical measurements were also used to optimize the fluorescence material contents on TiO2 photo-electrode surface for higher conversion efficiency (${\eta}$), fill factor (FF), open-circuit voltage (VOC) and short-circuit current (ISC). The enhanced light harvesting effect by the judicious choice/design of the fluorescence materials and sensitizing dyes permits the enhancement of photovoltaic performance of DSSC.

• 폴리머
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• 제29권2호
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• pp.107-121
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• 2005

전기인광소자(electrophosphorescent light emitting diodes)의 경우 인광염료내에 있는 중금속에 의해 효과적인 전자 스핀-궤도 결합(spin-orbit coupling)이 가능하며, 이로 인해 일중항 여기자뿐만 아니라 삼중항 여기자로부터 발광이 가능하므로 이론적으로 $100\%$ 내부발광효율을 얻을 수 있다. 본 논문에서는 지난 몇 년 동안 본 연구실에서 진행한 고분자 호스트를 사용한 고분자 전기인광소자의 특성 및 에너지 전이 메커니즘에 대하여 기술하였다. 또한 고분자 전기인광소자에서의 상분리 및 응집현상이 고분자 호스트와 게스트인 인광염료간의 에너지 전이와 소자 특성에 미치는 영향을 규명하였다. 마지막으로 인광염료의 리간드에 치환체 도입 및 리간드 변화에 따른 전이금속화합물의 광학적, 전기적 특성 변화에 대하여 연구하였다.

• 한국환경보건학회지
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• 제42권1호
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• pp.61-70
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• 2016

Objectives: The purpose of this study is to determine the exposure risk to tattoo components by analyzing skin absorption using the in vitro method. Tattoos are commonly used for cosmetic purposes, and the skin of not only the operator but of the people who are undergoing the cosmetic procedure is continuously exposed to hazardous chemicals. Methods: Skin permeation risk determination was conducted by the in vitro Franz diffusion cell method according to the ingredient types of tattoo dyes, such as volatile organic compounds (VOCs), non-volatile organic compounds and heavy metals, using hairless mouse full skin and human cadaver epidermis. Results: The major components with good skin penetration for each type of tattoo dye ingredient were clarified. Among the tatto dye ingredients, 1,2-Dichlorobenzene, Zn, Al, Pb and Ti showed good skin penetration. Most of the skin transmission rates were higher in hairless mouse full skin than in human cadaver epidermis. Conclusion: A possible exposure risk to hazardous substances in tattoo dyes was confirmed from this study. These results are expected to provide a positive contribution to the establishment of management regulations for tattoo dyes.

• Elastomers and Composites
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• 제50권1호
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• pp.7-12
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• 2015

The $BaCrO_4$ nanoparticles were synthesized from a 0.1 M $K_2CrO_4$ and 0.1 M $BaCO_3$ solution with stirring for 10 h. The product was washed several times with acetone and heated to $700^{\circ}C$ for 6 h. At that time, the color of mixture was a greenish yellow. The graphene/$BaCrO_4$ nanocomposites were prepared with graphene and $BaCrO_4$ nanoparticles by stirring in tetrahydrofuran and heated in an electric furnace at $700^{\circ}C$ for 2 h. The $BaCrO_4$ nanoparticles, graphene/$BaCrO_4$ and heated graphene/$BaCrO_4$ nanocomposites were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The graphene/$BaCrO_4$ nanocomposites and heated graphene/$BaCrO_4$ nanocomposites were evaluated as a photocatalyst and discussed about kinetics study for the degradation of organic dyes, such as methylene blue and rhodamine B under ultraviolet light irradiation at 254 nm.

• Elastomers and Composites
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• 제51권3호
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• pp.240-249
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• 2016

$BiVO_4$ nanomaterial was synthesized from bismuth (III) nitrate pentahydrate [$Bi(NO_3)_3{\cdot}5H_2O$] and ammonium vanadate (V) [$NH_4VO_3$]. The $BiVO_4$-graphene nanocomposite was fabricated by calcining the $BiVO_4$ nanomaterial and graphene under an oxygen-free atmosphere at $700^{\circ}C$. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to characterize structural and morphological properties of samples. The catalytic activity of the $BiVO_4$-graphene nanocomposite was studied for the reduction of 4-nitrophenol, 3-nitrophenol and 2-nitrophenol by sodium borohydride [$NaBH_4$]. The photocatalytic activity of the $BiVO_4$-graphene nanocomposite was demonstrated by the degradation of organic dyes like BG, MB, MO and RhB under irradiation at 365 nm. The catalytic and photocatalytic activity were studied by UV-vis spectrophotometry.

• 한국재료학회지
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• 제27권5호
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• pp.255-262
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• 2017

Reactive oxygen species (ROS) can be produced by interactions between sunlight and light-absorbing substances in natural water environments and can completely destroy various organic pollutants in waste water. In this study, we used graphene oxide modified $Ag_2Se$ nanoparticles to enhance photochemically generated oxygen (PGO) species activity. Surface area and pore volumes of the $Ag_2Se-graphene$ ($Ag_2Se-G$) samples showed catastrophic decrease due to deposition of $Ag_2Se$. The generation of reactive oxygen species was detected through the oxidation reaction of DPCI to DPCO. The photocurrent density and the PGO effect increase in the case of the use of modified graphene. The PGO effect of the graphene modified with $Ag_2Se$ composites increased significantly due to a synergetic effect between graphene and the $Ag_2Se$ nanoparticles. The photocatalytic activity of sample was evaluated by measuring the degradation of organic pollutants such as methylene blue (MB) and industrial dyes such as Texbrite BA-L (TBA) under visible light.

• Advances in Energy Research
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• 제1권2호
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• pp.117-126
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• 2013

In this paper, core-shell semiconductor quantum dots (QDs) CdSeS/ZnS with emission at 490 nm and 450 nm were investigated for their use in luminescent down-shifting (LDS) layers. Luminescent quantum yield (LQY) of the QDs measurements in solution proposed that they were suitable candidates for inclusion in LDS layers. QDs were encapsulated in poly(methyl,methacrylate) (PMMA) polymer matrix and films were fabricated of $134{\pm}0.05$ microns. Selections of organic dyes from BASF Lumogen F range were also investigated for their use as LDS layers; Violet 570 and Yellow 083. The addition of LDS layers containing Violet 570 dye demonstrated a unity LQY when encapsulated within a PMMA matrix. A PV device of an LDS layer of Lumogen Violet 570 deposited on top of a crystalline silicon cell was fabricated where it was demonstrated to increase the efficiency of the cell by 34.5% relative.

• 공업화학
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• 제31권6호
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• pp.607-611
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• 2020

본 연구에서는 그래파이트로부터 직접적으로 그래핀 복합체를 합성하는 방법을 이용하여 Au/TiO2/그래핀 복합체를 합성하였다. 계면활성제를 이용하여 박리된 그래파이트로부터 합성된 그래핀 복합체에서 TiO2는 아주 얇은 시트 형태로 그래핀 표면에 분포되어있고 10 nm 미만의 Au 나노입자들이 TiO2 시트 표면 위에 골고루 분포되어 있다. 이렇게 만들어진 그래핀 복합체를 이용하여 다양한 염료의 광분해 반응에 적용하였다. 이들 중 가장 광분해 활성에 뛰어난 것으로 나타난 염료는 메틸렌블루(91.6%)였으며 로다민 B(31.0%)에서는 광분해 특성이 뛰어나지 않는 것으로 나타났다.

• 청정기술
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• 제20권2호
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• pp.141-145
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• 2014

본 연구에서는 자기조립다층박막을 활용하여 금 나노막대와 유기염료로 이루어진 복합체의 형성과 나노막대-염료간의 광학적 특성에 관한 연구를 진행하였다. 이를 위해 이온성 고분자로는 폴리아릴아민 하이드로클로라이드와 폴리스티렌 술폰산염을 선택하였으며, 나노막대와의 스펙트럼 중첩을 고려하여 유기염료는 로다민 비 이소디오시아네이트를 사용하였다. 자기조립적인 관점에서는 수용액상에서 이들 화합물을 순차적으로 금 나노막대 표면에 코팅시킴으로써 표면 플라즈몬 특성과 형광특성을 동시에 갖는 조립체를 형성하였으며, 그 후 금 나노막대를 화학적으로 제거 해나가면서 나노막대-염료간의 상호의존 특성을 연구하였다.

• 대한가정학회지
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• 제41권8호
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• pp.55-62
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• 2003

Natural dyes generally fan into two categories; organic dyes coming from animals and plants and inorganic dyes obtained from various minerals such as bengala, loess, ultramarine, prussian blue and etc. The main components of volcanic ash is clay mineral such as kaolinite, illite, quartz. Clay minerals Composing volcanic ash are kaolinite［$Al_4Si_4O_{10}{(OH)_{8}}$］, illite［$K_{X}Al_2(Si,\;Al)_4O_{10}{(OH)}_2$］, quartz［$SiO_2$］, homblende［$Na_{0-1}\;Ca_2{(Mg,\;Fe,\;Al)}_5{(Si,\;Al)}_{8}O_{22}{(OH)}_2$］and etc. And the redish color mainly comes from iron oxide. In this paper, two different classes of dyeing process were tested; dyeing with volcanic ash only and cationic agent pre-treatment followed by dyeing with volcanic ash. The compositions of the volcanic ash powder and the volcanic ash deposited on the cotton knitted fabrics identified by energy dispersive spectrometer and XRD analysis. The major chemical components of volcanic ash deposited on the cotton knitted fabrics were confirmed to be the saicon oxide, iron oxide, and aluminum oxide and etc. According to the analysis by XRD and EDS-SEM, kaolinite, illite and quartz were also identified.