• 한국전기전자재료학회논문지
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• 제24권5호
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• pp.398-403
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• 2011

Recently, Near-infrared (NIR)colorant is intriguing and attractive but full of challenges. Although some cyanine colorant have been commercialized, near-infrared colorant with intensive NIR absorption, good chemical and photo-stability, and high solubility still remain as target compound. Certain polycyclic aromatic compounds such as quaterrylene represent a key class of NIR colorant and also give rise to outstanding physical and chemical properties after appropriate chemical modification. In this study, We have tried to introduceimide functional group to quaterrylene in order to give chemical and thermal stability. Finally, N,N'-bis (2,6-diisopropylphenyl)-quarterrylene-3,4:13,14-tetracarboximide was synthesized and evaluated its properties using $^1H$ NMR, Maldi-tof, TGA, and UV/VIS/NIR spectroscopy as NIR colorant. The quaterrylene bisimide compound exhibit a excellent thermal stability and chemical stability.

• Current Photovoltaic Research
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• 제6권4호
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• pp.91-93
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• 2018

Polythiophene-$TiO_2$ composite was synthesized with different molar ratios of thiophene and titaniumisopropoxide ($Ti(OPr)_4$) for flexible solar cell application as a flexible electrode or an active material. The $Ti(OPr)_4$ was stabilized by thiophene. The thiophene was polymerized by ferric chloride catalyst. The synthesized polythiophene exhibited strong UV-visible absorption in the range of the wavelength shorter than 500 nm. Field emission scanning electron microscope (FESEM) image of low concentration of $TiO_2$ film showed smooth surface. However, FESEM image of high concentration of $TiO_2$ film exhibited relatively rough surface. Polythiophene concentration dependent strong photoluminescence quenching of surfrhodamine-B was observed.

• 폴리머
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• 제26권3호
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• pp.326-334
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• 2002

본 실험에서는 PCL 마이크로캡슐을 제조하여 형태적 분석 및 제조 조건에 따른 특성을 살펴보고 약물방출거동을 통하여 약물전달체계로서의 가능성을 고찰하였으며 액중건조법을 사용하여 약물을 함유한 마이크로캡슐을 제조하였다. 마이크로캡슐 입경과 형태는 교반속도, 교반시간 그리고 유화제의 농도에 따라 어떠한 영향을 받는가에 대하여 관찰하였다. 마이크로캡슐의 모양과 표면을 image analyzer와 SEM으로 관찰한 결과 제조된 마이크로캡슐은 평균 입경이 40~400$\pm$20 $mu extrm{m}$로 주름이 발달된 구형의 형태였다. 제조된 PCL 마이크로캡슐의 약물함유 여부는 FT-IR을 사용하여 확인하였고 접촉각 측정을 통해 PCL과 약물간의 계면에서의 부착일을 살펴보았다. 또한 방출거동을 살펴보기 위해 UV/vis. 흡광광도법으로 흡광도를 측정하여 용출된 약물비 양을 정량 하였으며, 그 결과, 유화제의 농도를 높게 하여 제조한 마이크로캡슐의 약물 방출이 상당히 빠름을 알 수 있었다.

• 한국인쇄학회지
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• 제31권1호
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• pp.15-37
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• 2013

Split digital printing into interior and outdoors on present advertisement. When is printing machine for interior mainly, use ink of water-based type. Equipment of this type embodies high resolution, but ink special quality light stability is weak. Also, when is printing machine for outdoors, printing machines of solvent or UV type are used because of water resistance and light stability. This printing machines hard to embody ink special quality high resolution mainly. And because outside is far visibility range, is uncommon in case high resolution requires embodiment. Therefore, high resolution of inside is water-based type considering this item and outside printing machine of low resolution solvent type mainly announce. Also, divide into eco-friendly latex ink type that is announced to water-based, solvent, UV according to ink type and the latest market using in occasion of digital printing machine used as advertisement industry. Color management that is been consistent of original image has a lot of difficulties by using substrate that is also various to digital printing machine for such various advertisement. But, consumers is rising realization about color or desire about quality improvement of color gradually in interior outside advertisement market. So, require solution method. Therefore, in this paper, eco-friendly ink use applied device calibration through linearization in done latex digital printing machine to basis. And studied right color management plan of digital printing for interior outside advertisement through three steps such as G7 calibration application and ICC profile application.

• 대한화장품학회지
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• 제23권3호
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• pp.48-74
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• 1997

Retinlyl Palmitate, the skin normalizerm is useful to promote greater skin elasticity, to diminish lipid peroxidation and skin roughness following UV exposure, and promote a youthfulgeneral skin appearance. In manufacturing creams, Retinyl Palmitate, which is a derivative of retinol, is used since reionol is easily oxidized by heat and light. However, only a small mount of retinol, is used since using a large amount of it may be harmful to its stability. In this study, thermal stability and UV stability of W/O-, W/S-, O/W-, and MLV-type creams containing 5% of retinyl palmitate and 10% of tocopheryl acetate are measured by Chroma Meters, and the content of RP is quantitatively analyzed by HPLC at 25 $^{\circ}C$ and 45 $^{\circ}C$. Also, how RP has been changed by heat, light, etc. is measured by HPLC, and toxicity of the changed substance is studied. Particle size of each type of the cream if measured, cellular renewal is measured by using DHP and Chroma Meters in order to study their efficacy and effect, moisture content is measured by using Corneometer and Tewameter, and how much wrinkles are improved is studied by using Image Analyzer. Development of MLV-type cream containing 5% of RP and 10% of TA, and satisfying conditions for better creams has been successful.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.51.1-51.1
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• 2010

이번 연구에서는 저온 용액공정을 이용하여p-type 반도체로 많이 사용되고 있는 $Cu_xS$를 기판 위에 증착하여 그 특성을 분석하였다. $Cu_xS$는 x의 값에 따라 다섯가지의 결정구조를 가지는데 CuS, $Cu_{1.75}S$, $Cu_{1.8}S$, $Cu_{1.95}S$, $Cu_2S$ 들이 그것이다. 태양전지에서 p형 반도체로 중요한 역할을 담당하고 있는 $Cu_xS$는 cell에서 사용되었을 때 energy bandgap이 1.2-2.5eV일 때 가장 좋은 특성을 나타낸다. 이번 연구에서는 특히 조성에 따라서 물리적, 광학적으로 어떤 특성을 나타내는지에 대하여 XRD, SEM, Uv-vis 등의 분석을 해보았다. XRD의 경우 농도가 높아질수록 peak의 intensity는 커지지만 어느 농도 이상부터는 Cu가 Oxide화 되는 것을 관찰할 수 있었다. SEM image의 경우에는 조성에 따른 포면의 상태를 분석해보았다. 조성에 따른energy bandgap을 알아보기 위해서는 Uv-vis을 측정하였으며 이를 이용하여 증착된 박막의 투과도 역시 함께 분석해보았다.

• 한국정밀공학회지
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• 제23권11호
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• pp.116-125
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• 2006

MEMS and LIGA technologies have been used for fabricating microstructures, but their shape is not 3D because of difficulty for preparation of many masks. To fabricate 3D microstructures, microstereolithography technology based on Digital Micromirror Device($DMD^{TM}$) was introduced. It has no need of masks and is capable of fabricating high aspect ratio microstructures. In this technology, STL file is the standard format as the same of conventional rapid prototyping system, and 3D parts are fabricated by layer-by-layer according to 2D section sliced from STL file. The UV light source is illuminated to DMD which makes bitmap images of 2D section, and they are transferred and focused on resin surface. In this paper, we addressed optical design of microstereolithography system in consideration of light path according to DMD operation and image-forming on the resin surface using optical design program. To verify the performance of implemented microstereolithography system, 3D microstructures with complexity and high aspect ratio were fabricated.

• Macromolecular Research
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• 제15권1호
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• pp.74-81
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• 2007

A series of photoreactive mesogens based on chalcone were prepared and their morphological behavior and reactivity were studied according to a variable number of alkyloxy tail carbons. The linear ester compounds 3a-h comprised two chalcone units connected to a benzene ring through ester linkages. All linear ester compounds showed enantiotropic liquid crystalline phases. The X-ray diffractograms for the mesophases of compounds 3a-h showed a set of reflections in the small-angle region which consisted of more than three sharp diffraction peaks with d spacings in the ratio of 1:1/2:1/3, confirming the well defined smectic A structures of the compounds. Compounds 3a-h were considered to be bifunctional monomers due to the presence of two photoreactive chalcone groups. Upon UV irradiation, its polymerization proceeded through the [2+2] addition reaction between chalcone units in a stepwise manner. An image pattern was obtained by the photopolymerization of the liquid crystal of the compound (3h) with decyloxy tails through a photomask. The irradiated part became dark while the masked part remained birefringent under polarized optical microscopy, which was ascribed to the production via the UV irradiation of a polymer or a dimer having cyclobutane rings by [2+2] addition, which thereby disrupted the alignment of the molecules.

• 조명전기설비학회논문지
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• 제21권9호
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• pp.57-63
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• 2007

The occurrence of a corona is that electrical discharge due to the heterogeneity that occurs when an electrical field is concentrated in an electrode due to a cusp formed on said electrode. Wire treatment at the end of a 154[kV] dead end clamp for end users accelerates the occurrence of corona, which in turn leads to power loss and noise. In this study, the characteristics of the corona which occurs between porcelain insulators and support clamps of overhead lines used in 154[kV] power receiving facilities for end users were investigated. The corona, which cannot be identified by one common method, was measured utilizing a UV image camera. A risk assessment for fire damage and its status was suggested. The stress distribution of the electrical field by length of bare wire was suggested by means of the finite element method(FEMLAB). As a result, it was found to affect a porcelain insulators. These results can be utilized for the enhancement of clamp installation and safety in power facilities.

• Current Photovoltaic Research
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• 제3권3호
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• pp.71-74
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• 2015

Soluble polyaniline was synthesized by attaching titanium isoproxide ($Ti(OPr)_4$) to the amine group of the aniline. Approximately 1 to 1 molar ratio of aniline and $Ti(OPr)_4$ was mixed and polymerized with ammonium persulfate. The FTIR result showed clear difference between $TiO_2$-aniline composite ($TiO_2An$) and $TiO_2$-polyaniline composite ($TiO_2PAn$). Although the $TiO_2An$ had negligible UV-visible absorption, the $TiO_2PAn$ showed strong absorption in the UV-visible region. Photoluminescence (PL) peaks of $TiO_2An$ were shifted toward red with the reduction of the excitation energy, which could be due to the multiple emission centers. The luminescence peak shift stopped at 501 nm. The PL spectra of $TiO_2PAn$ exhibited three emission peaks at 2.88 eV (430 nm), 2.48 eV (501 nm) and 2.22 eV (558 nm). The new emission center (2.22 eV) was observed after polymerization. Field emission scanning electron microscope image showed crack-free composite film.