• 한국재료학회지
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• 제20권9호
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• pp.483-487
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• 2010

To fabricate $TiO_2$ nanoparticle-based dye sensitized solar cells (DSSCs) at a low-temperature, DSSCs were fabricated using hydropolymer and ZnO nanoparticles composites for the electron transport layer around a low-temperature ($200^{\circ}C$). ZnO nanoparticle with 20 nm and 60 nm diameter were used and Pt was deposited as a counter electrode on ITO/glass using an RF magnetron sputtering. We investigate the effect of ZnO nanoparticle concentration in hydropolymer and ZnO nanoparticle solution on the photoconversion performance of the low temperature fabricated ($200^{\circ}C$) DSSCs. Using cis-bis(isothiocyanato)bis(2,20 bipyridy1-4,40 dicarboxylato) ruthenium (II) bis-tetrabutylammonium (N719) dye as a sensitizer, the corresponding device performance and photo-physical characteristics are investigated through conventional physical characterization techniques. The effect of thickness of the ZnO photoelectrode and the morphology of the ZnO nanoparticles with the variations of hydropolymer to ZnO ratio on the photoconversion performance are also investigated. The morphology of the ZnO layer after sintering was examined using a field emission scanning electron microscope (FE-SEM). 60 nm ZnO nanoparticle DSSCs showed an incident photon-to-current conversion efficiency (IPCE) value of about 7% higher than that of 20 nm ZnO nanoparticle DSSCs. The maximum parameters of the short circuit current density ($J_{sc}$), the open circuit potential ($V_{oc}$), fill factor (ff), and efficiency ($\eta$) in the 60 nm ZnO nanoparticle-based DSSC devices were 4.93 mA/$cm^2$, 0.56V, 0.40, and 1.12%, respectively.

• Composites Research
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• 제17권4호
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• pp.40-46
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• 2004

본 연구에서는 single lap 전단시험을 통해 자가치료제와 촉매의 혼합비율 및 경화온도가 자가치료용 폴리머 복합재에 적용되는 자가치료제의 접착성능에 미치는 영향을 조사하였다. 자가치료세로는 DCPD (dicyclopentadiene), ENB(5-ethylidene-2-norbornene), DCPD와 ENB가 혼합된 경우를 고려하였으며 촉매로는 bis(riclohexylphosphine) benzyllidine rethenium (IV) dichloride Grubbs' catalyst를 사용하였다. 이때 DCPD에 대한 촉매의 혼합비율은 1.0wt%와 0.5wt%, ENB에 대한 촉매의 혼합비율은 0.lwt%, DCPD와 ENB의 혼합액에 대한 촉매의 혼합비율은 0.5wt%를 적용하였으며 경화온도는 $25^{\circ}C$, $60{\circ}C$, $80^{\circ}C$를 고려하였다. 연구결과에 따르면 DCPD의 경우 안정화된 접착강도를 얻기 위해서는 많은 양의 촉매와 긴 경화시간이 요구되었다 ENB의 경우는 DCPD의 경우에 비해 촉매의 혼합비율이 낮아도 빠른 경화반응을 얻을 수 있었지만 경화시간이 증가함에 따라 접착전단강도는 DCPD와는 달리 최대 값에 도달하였다가 점차 감소하면서 안정화되는 양상을 나타내었다. DCPD와 ENB의 혼합액 경우도 ENB와 유사한 경화거동을 나타내며 DCPD에 대한 ENB의 혼합비율이 높을 수록 경화반응이 빨라지는 양상을 얻을 수 있었다. 아울러 경화온도가 높을수록 집착전단강도는 증가되며 안정화된 평탄부에 도달하는 경화시간은 짧아짐을 알 수 있었다

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1659-1663
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• 2012

New semiconducting polymer, poly[1,4-bis(($E$)-2-(5-bromo-3-dodecylthiophen-2-yl)vinyl)benzene], was designed, synthesized and characterized. The structure of polymer was confirmed by $^1H$-NMR, IR and elemental analysis. The polymer was soluble in specific organic solvent. The weight-average molecular weights (MW) of polymer was found to be 11,000 with polydispersity of 1.82. UV-Visible absorption spectrum showed the maximum absorption at 428 nm (in solution) and 438 nm (in film). The highest occupied molecular orbital (HOMO) energy of the polymer is -5.36 eV by measuring cyclic voltammetry (CV). A solutionprocessed polymer thin film transistor device shows a mobility of $8.59{\pm}10^{-4}\;cm^2\;V^{-1}\;s^{-1}$, an on/off current ratio of $2.0{\times}10^4$.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.529-534
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• 2012

The fluorescence of 4',6-diamidino-2-phenylindole (DAPI) bound to DNA at a [DAPI]/[DNA base] ratio of 0.005 was quenched by meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (TMPyP) or cis-bis(N-methylpyridinium-4-yl)porphyrin (BMPyP) when both DAPI and either porphyrin spontaneously bound to the same DNA strand. The quenching was investigated using the "one-dimensional inner sphere" and the "F$\ddot{o}$rster resonance energy transfer" (FRET) models. Total quenching occurred when DAPI and TMPyP were up to 19.3 base pairs or $66\AA$ apart. BMPyP could quench the fluorescence up to 13.9 base pairs or $47\AA$. TMPyP, which intercalated between the DNA base-pairs, appeared to be a better acceptor than BMPyP, which stacked along the DNA stem. The higher quenching and higher resonance energy transfer efficiency of TMPyP was due to the larger overlap integral between its absorption spectrum and the emission spectrum of DNA-bound DAPI.

• 환경위생공학
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• 제16권4호
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• pp.69-76
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• 2001

The catalytic oxidation of volatile organic compounds (VOCs), which were benzene and toluene, was studied in the supercritical carbon dioxide($SC-CO_2$) media. In $SC-CO_2$ media, the deep oxidation conversion of VOCs was increased with the temperature and pressure. The deep oxidation conversion in SC -$CO_2$ media is better than that in air media at same pressure condition. This can be explained by the solubility of VOCs in $SC-CO_2$. The many intermediates produced by the partial oxidation of VOCs were detected from off-line samples. The intermediates were Identified as benzene, toluene, benzaldehyde, phenol, naphthalene, 1,1`-biphenyl, benzoic acid, 3-methylphenol, 1,1'-(1,2-ethanediyl)bis- benzene, 1,1'-(1,2-ethene- diyl)bis-benzene, anthracene, and so on. The amount of intermediates was decreased as the molar radio of oxygen to carbon dioxide was decreased. When the molar ratio of oxygen to carbon dioxide was 1 : 16, the deep conversion was kept constant. Thus, the catalytic oxidation process in $SC-CO_2$ media can be combined on-line with supercritical fluid extraction of environmental matrices and supercritical regeneration of used adsorbent. Thus, the nontoxic $SC-CO_2$ media process was suggested as the new VOCs control technology.

• KSBB Journal
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• 제32권2호
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• pp.103-107
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• 2017

The effect of the trehalose incorporation on the biological membranes was investigated with respect to the phase of the membranes using the fluorescence intensity change. Spherical phospholipid bilayers, vesicles, were prepared only with the variation in the phase of each layer via a double emulsion technique. In the aqueous inside of the vesicles, 8-Aminonaphthalene-1,3,6-trisulfonic acid disodium salt(ANTS) was encapsulated. As a quencher, p-Xylene-bis(N-pyridinium bromide)(DPX) was included in the buffer where the vesicles were dispersed. The fluorescence scale was calibrated with the fluorescence of ANTS vesicles in p-Xylene-bis(N-pyridinium bromide)(DPX)-included-buffer taken as 100% fluorescence and the mixture of ANTS and DPX in the buffer as 0% fluorescence. Trehalose injection into the vesicle solution led the distortion of the membrane. It was found that the distortion was related to the phase of each layer the vesicle up on the ratio of trehalose to lipid. In the identical measurements at glucose, the behavior of the distortion was completely different from that of trehalose. These results seem to depend on the stability of the vesicles, due to the osmotic and volumetric effects on the headgroup packing disruption.

• 멤브레인
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• 제19권2호
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• pp.104-112
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• 2009

본 연구에서는 용매로 N-methyl-2-pyrrollidone을 사용하여, 상전환 방법으로 carboxylic acid를 함유한 음이온성 한외여과막을 제조하였다. 첨가제, 제막조건 및 운전조건에 따른 투과 특성을 알아보았다. Bovin serum albumin (BSA) 수용액의 pH에 따른 상대투과유속을 측정하여 fouling형성에 따른 투과 특성의 변화를 살펴보았다. 투과 특성은 막 제조환경과 투과 공정에 영향을 받았다. 이온교환용량과 측정 온도가 증가할수록, 그리고 BSA의 등전점으로부터 수용액의 pH값이 멀어질수록 상대투과유속이 증가하였다.

• Environmental Engineering Research
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• 제11권4호
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• pp.208-216
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• 2006

In order to create a single flocculant/dual flocculation system, polyacrylamide-co-trimethyl ammonium ethyl acrylate chloride (TAEAC) polymers with varying molecular weights and structures were prepared for use of flocculants. The higher the cationic density of the polymer is higher, the higher was the conversion rate and the ratio of monomer. An acrylamide as nonionic monomer was less reactive than a TAEAC as cationic monomer. The branched polymer which was polymerized with a cross-linking agent, N, N-methylene bis-acrylamide had a higher stability and higher viscosity than a linear polymer but its dewatering efficiency was poor in a single flocculation system. In the case of single flocculant/dual flocculation, the branched polymer has better flocculation efficiency and the water content of the dewatered cakes was lower than the others, as the result of a re-flocculation effect. The optimum conditions for dual flocculation are a sequence in which the $1^{st}$ and $2^{nd}$ dosage are 75% and 25%/total dosage of a single flocculation system. The dewatering efficiency of a dual flocculation system is improved considerably from 10 to 25% under the experimental conditions used herein.

• Bulletin of the Korean Chemical Society
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• 제30권4호
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• pp.853-856
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• 2009

Highly polycrystalline copper indium diselenide (CuInSe2, CIS) thin films were deposited on glass or ITO glass substrates by two-stage metal organic chemical vapor deposition (MOCVD) at relatively mild conditions, using Cuand In/Se-containing precursors. First, pure Cu thin film was prepared on glass or ITO glass substrates by using a single-source precursor, bis(ethylbutyrylacetate)copper(II) or bis(ethylisobutyrylacetato)copper(II). Second, on the resulting Cu films, tris(N,N-ethylbutyldiselenocarbamato)indium(III) was treated to produce CuInSe2 films by MOCVD method at 400 ${^{\circ}C}$. These precursors are very stable in ambient conditions. In our process, it was quite easy to obtain high quality CIS thin films with less impurities and uniform thickness. Also, it was found that it is easy to control the stoichiometric ratio of relevant elements on demands, leading to Cu or In rich CIS thin films. These CIS films were analyzed by XRD, SEM, EDX, and Near-IR spectroscopy. The optical band gap of the stoichiometric CIS films was about 1.06 eV, which is within an optimal range for harvesting solar radiation energy.

• 대한화학회지
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• 제18권4호
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• pp.267-271
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• 1974

네자리 schiff base 리간드로서 N,N-비스(살리실알데히드)에틸렌디이민과 Mo(IV), Mo(V), Mo(VI) 및 Mo(III)의 각 산화상태인 몰리브덴이온들과의 반응으로서 새로운 착물$[MoO_2(C_{16}H_{14}O_2-N_2)], [MoO(C_{16}H_{14}O_2N_2)]_2O, (Mo(SCN)(C_{16}H_{14}O_2N_2)]_2O$들을 합성하였다. 이들 착물들은 리간드와 몰리브덴의 몰비가 1:1이며, 6배위의 가상적인 구조로 주어짐을 원소 분석치와 가시부 및 적외선 흡수스펙트럼, T.G.A., D.T.A. 및 X-ray 회절의 고찰로서 알아보았다.