• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.492-498
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• 2012

A hyper branched 10-butylphenothiazine with in-situ thermally curable methacrylate (1,3,5-tris-[$\{$10-Butyl-3-(4-(2-methyl-acryloyloxy)-phenyl)-7-yl-10H-phenothiazine$\}$]-benzene, (tris-PTMA)) was synthesized successfully. From the TGA thermogram of tris-PTMA was thermally stable up to $336^{\circ}C$. In the first heating scan of DSC thermogram, tris-PTMA showed glass transition temperature (Tg) at $140^{\circ}C$ and broad endothermic process in the region of $144-179^{\circ}C$, which is thermally curing temperature. In the second heating process, $T_g$ exhibited at $158.7^{\circ}C$ and endothermic process was not observed. Thermally cured tris-PTMA showed no big change in the UV-visible spectrum after washing with organic solvent such as methylene chloride, chloroform, toluene, indicating that thermally cured film was very good solvent resistance. Thermally cured tris-PTMA was electrochemically stable and the HOMO energy level of tris-PTMA was -5.54 eV. The maximum luminance efficiency of double layer structured polymer light-emitting diode based on in-situ thermally cured tris-PTMA was 0.685 cd/A at 16.0 V, which was higher than that of the device without thermally cured tris-PTMA (0.348 cd/A at 15.0 V).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.127-127
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• 2009

The most important part of the fabrication solar cells is the anti-reflection coating when excludes the kinds of silicon substrates (crystalline, polycrystalline, or amorphous), patterns and materials of electrodes. Anti-reflection coatings reduce the reflection of sunlight and at last increase the intensity of radiation to inside of solar cells. So, we can obtain increase of solar cell efficiency about 10% using anti-reflection coating. There are many kinds of anti-reflection film for solar cell, such as SiN, $SiO_2$, a-Si, and so on. And, they have two functions, anti-reflection and passivation. However such materials could not perfectly prevent reflection. So, in this work, we investigated the anti-reflection coating with the columnar structure ZnO thin film. We synthesized columnar structure ZnO film on glass substrates. The ZnO films were synthesized using a RF magnetron sputtering system with a pure (99.95%) ZnO target at room temperature. The anti-reflection coating layer was sputtered by argon and oxygen gases. The angle of target and substrate measures 0, 20, 40, 60 degrees, the working pressure 10 mtorr and the 250 W of RF power during 40 minutes. The confirm the growth mechanism of ZnO on columnar structure, the anti-reflection coating layer was observed by field emission scanning electron microscopy (FE-SEM). The optical trends were observed by UV-vis and Elleso meter.

• 한국진공학회지
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• 제10권1호
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• pp.104-111
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• 2001

$SiH_4$, $CH_4$, $B_2H_6$ 혼합기체를 이용하여 플라즈마 화학증착법으로 비정질 탄화실리콘(a-SiC:H) 박막을 증착하였다. 기상 doping 농도를 0에서 $2.5\times10^{-2}$ 범위에서 변화시켜 얻은 박막의 물성을 SEM, XRD, Raman 분광법, FTIR, SIMS, 광흡수도와 전기전도도 분석을 통하여 살펴보았다. $B_2H_6$/($CH_4+SiH_4$) 기체유량비가 증가할수록 붕소의 도핑효율와 미세결정성은 감소하였다. 증착 중 $B_2H_6$ 기체가 첨가됨에 따라 비정질 탄화실리콘 박막의 Si-C-H 결합기의 강도는 감소하였으며, 이의 영향으로 박막내의 수소함량은 $B_2H_6/(SiH_4+CH_4$) 기체 유량비가 증가함에 따라 16.5%에서 7.5%로 단조감소하였다. $B_2H_6(CH_4+SiH_4$) 기체유량비가 증가할수록 a-SiC:H 박막의 광학적 밴드갭과 전기활성화 에너지는 감소하였고, 전기전도도는 증가하였다.

• 한국환경과학회지
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• 제17권11호
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• pp.1195-1201
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• 2008

Enhancing with non-metallic elemental nitrogen(N) is one of several methods that have been proposed to modify the electronic properties of bulk titanium dioxide($TiO_2$), in order to make $TiO_2$ effective under visible-light irradiation. Accordingly, current study evaluated the feasibility of applying visible-light-induced $TiO_2$ enhanced with N element to cleanse aromatic compounds, focusing on xylene isomers at indoor air quality(IAQ) levels. The N-enhanced $TiO_2$ was prepared by applying two popular processes, and they were coated by applying two well-known methods. For three o-, m-, and p-xylene, the two coating methods exhibited different photocatalytic oxidation(PCO) efficiencies. Similarly, the two N-doping processes showed different PCO efficiencies. For all three stream flow rates(SFRs), the degradation efficiencies were similar between o-xylene and m,p-xylene. The degradation efficiencies of all target compounds increased as the SFR decreased. The degradation efficiencies determined via a PCO system with N-enhanced visible-light induced $TiO_2$ was somewhat lower than that with ultraviolet(UV)-light induced unmodified $TiO_2$, which was reported by previous studies. Nevertheless, it is noteworthy that PCO efficiencies increased up to 94% for o-xylene and 97% for the m,p-xylene under lower SFR(0.5 L $min^{-1}$). Consequently, it is suggested that with appropriate SFR conditions, the visible-light-assisted photocatalytic systems could also become important tools for improving IAQ.

• 대한환경공학회지
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• 제22권11호
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• pp.2077-2083
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• 2000

산업 현장에서 많이 사용되고 있는 반응성 염료인 remazol $black_5$를 연구 대상물로 선택하여 촉매습식 산화공법으로 처리하였다. 이때 반응성 염료성분의 분해효율, 촉매 첨가량 및 반응온도와 상호 관련하여 검토한 결과를 정리하였다. 이산화티탄 담체에 백금을 5.0wt% 담지한 촉매 1.5g/L, 6기압, $200^{\circ}C$ 이상에서 remazol $black_5$는 약 95% 이상 분해되었다. 반응온도 $250^{\circ}C$에서 240분 촉매산화를 하였을 때 uv 흡광 잔존율은 4%이고 반응온도가 $250^{\circ}C$, 120분 경과 후 색도 제거율은 약 95% 이상이었다.

• Environmental Engineering Research
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• 제21권4호
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• pp.384-392
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• 2016

The aim of this study was to investigate the removal efficiency of $17{\alpha}$-methyltestosterone (MT) from aqueous solution by Salvinia cucullata Roxb. ex Bory in an active plant-based reactor with a specific focus on linear regression analysis for the sorption phenomena of MT onto the plant roots. A high performance liquid chromatographic method using UV detection (245 nm) was used to analyse the samples. The batch experiments of the active plant reactor (APR) were established to investigate the ability of Salvinia cucullata to remove MT from the liquid phase. The results revealed that 40% and 60% removal of MT from the liquid phase was observed at 5 min. and at 4 h, respectively. Salvinia cucullata can effectively remove MT from the aqueous solution in APRs. Kinetic studies revealed that the sorption phenomena of MT by Salvinia is best described using a linearized pseudo - second order model. Based on the kinetic parameters, it is likely that during the first 4 h of the contact (t = 0 to t = 4 h) sorption is the major driving mechanism of the disappearance of MT from aqueous solutions. However, at higher MT concentrations, diffusivity of MT has a significant effect on the migration of MT from the bulk stream to the root surface. The isotherm analysis revealed that the sorption kinetics favourably followed pseudo second-order. The results of isotherm analysis have indicated that the sorption of MT onto the root surfaces of Salvinia cucullata was favourable and almost irreversible.

• 환경위생공학
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• 제16권3호
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• pp.96-103
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• 2001

This study was carried out to investigate the major factors for the removal of NOMs (Natural Organic Matters) by alum ferric chloride and blended coagulants that consisted of alum and ferric chloride. Investigated factors were pH, the dosage of coagulant, alkalinity, hardness and bloc strength. The particle size contained in the test water came from the Han River was also measured. DOC(Dissolved Organic Carbon) removal at pH 6 was two to three times higher than at pH 8.5. The blended coagulant showed 9 to 10 percent higher DOC removal efficiency and 2 to 4 percent higher turbidity under the same condition. Alkalinity consumption of alum, ferric chloride and blended coagulant was 81%, 90% and 86% of theoretical value, respectively. The limit concentration of alkalinity to avoid pin floe was 10 mg $CaCO_3/L$ when alum was used. Hardness had no apparent effect on coagulation. The residual turbidity and $UV_{254}$ showed a tendency of increasing with floc strength($sec^{-1}$) increase. The order of floe strength was the following; alum >blended coagulant > ferric chloride. The particle counter test showed 89 percent of the small particle size(SPS, $1~5{\;}{\mu}textrm{m}$) and 11 percent of the medium to large particle size(M.LPS, $5~125{\;}{\mu}textrm{m}$). At PH7.85, the particle removal efficiencies of SPS($1~5{\;}{\mu}textrm{m}$) and M.LPS($5~125{\;}{\mu}textrm{m}$) in the coagulation process were 81% and 95%, respectively.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.11.2-11.2
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• 2011

Polymer based organic photovoltaics have attracted a great deal of attention due to the potential cost-effectiveness of light-weight and flexible solar cells. However, most BHJ polymer solar cells are not thermally stable as subsequent exposure to heat drives further development of the morphology towards a state of macrophase separation in the micrometer scale. Here we would like to show three different approaches for developing new electroactive polymers to improve the thermal stability of the BHJ solar cells, which is a critical problem for the commercialization of these solar cells. For one of the examples, we report a new series of functionalized polythiophene (PT-x) copolymers for use in solution processed organic photovoltaics (OPVs). PT-x copolymers were synthesized from two different monomers, where the ratio of the monomers was carefully controlled to achieve a UV photo-crosslinkable layer while leaving the ${\pi}-{\pi}$ stacking feature of conjugated polymers unchanged. The crosslinking stabilizes PT-x/PCBM blend morphology preventing the macro phase separation between two components, which lead to OPVs with remarkably enhanced thermal stability. The drastic improvement in thermal stabilities is further characterized by microscopy as well as grazing incidence X-ray scattering (GIXS). In the second part of talk, we will discuss the use of block copolymers as active materials for WOLEDs in which phosphorescent emitter isolation can be achieved. We have exploited the use of triarylamine (TPA) oxadiazole (OXA) diblock copolymers (TPA-b-OXA), which have been used as host materials due to their high triplet energy and charge-transport properties enabling a balance of holes and electrons. Organization of phosphorescent domains in TPA-b-OXA block copolymers is demonstrated to yield dual emission for white electroluminescence. Our approach minimizes energy transfer between two colored species by site isolation through morphology control, allowing higher loading concentration of red emitters with improved device performance. Furthermore, by varying the molecular weight of TPA-b-OXA and the ratio of blue to red emitters, we have investigated the effect of domain spacing on the electroluminescence spectrum and device performance.

• 펄프종이기술
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• 제31권4호
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• pp.76-83
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• 1999

This study was carried to investigate optimum conditions of charcoal added paper in making cigarette filter for the removal of smoke contents of cigarettes. We investigated the physical properties of charcoal added paper according to the ratio of pulps, the amounts of characoal , the weight of sheets and crimping conditions in dry method, and then analyzed the smoke contents of cigarettes. The results obtained were as follows. 1. Sw-BKP was higher than Hw-BKP in methylene blue absorption by UV test. 2. Charcoal had an effect on stiffness for decreasing factor greatly , while the addition amounts of Sw-BKP and high weigth of sheets increased it, and the interaction of weight of sheets and charcoal was higher than other factors. 3. Tear index decreased by charcoal addition greatly, on the other hand high weight of sheets and Sw-BKP/Hw-BKP ratio increased ter, and the interaction of pulps and chacoal acted on major factors. 4. We estimated crimp index with sensory evaluation , and charcoal hand an effect on decreasing factor in crimping greatly, while the interaction of weight of sheets and pulp ratio was higher than others. 5. In the case of charcoal added paper filter, tar removal efficiency of smoke contents was higher but about 6% than cigarette filter. Especially vapour phase(aldehyde) in smoke contents was removed greatly.

• 한국진공학회지
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• 제21권1호
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• pp.55-61
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• 2012

본 연구에서는 주기적인 3차원 패턴이 형성된 유리기판을 사용하여 비정질 실리콘 박막 태양전지를 제작하였다. 주기적인 패턴은 일반적인 전도성 투명 산화막(TCO: Trasparent Conductive Oxide) 표면의 불규칙 패턴과 비교하여 더 효율적인 광포획을 가능하게 한다. 태양전지 제작 전 광특성 전산모사를 통하여 주기적인 패턴 유리 기판의 광학적 특성을 알아보았다. 비정질 실리콘 박막 태양전지의 제작은 PECVD를 이용하여 구면 패턴이 형성된 유리기판을 이용하여 제작되었으며, 인공 태양광 조사장치를 이용하여 제작된 태양전지의 성능 평가를 진행하였다. 태양전지 전산모사 결과와 실험 결과들을 비교 분석하여 주기적인 패턴 유리 기판을 이용한 비정질 실리콘 박막 태양전지의 효율향상 가능성을 확인하였다.