• Korean Chemical Engineering Research
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• 제57권3호
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• pp.408-412
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• 2019

본 연구에서는 urea를 이용해 질소 도핑된 카본 펠트 전극을 제조하고 이를 바나듐 레독스 흐름 전지용 전극으로 적용하였다. Urea는 암모니아 보다 취급이 용이할 뿐 아니라 고온 열분해를 통해 $NH_2$ 라디칼이 발생하여 탄소 표면에 질소 작용기를 만들고 이는 바나듐 이온의 산화/환원 반응을 향상시키는 활성점(active site)로 작용한다. Urea로 활성화된 카본 펠트 전극은 $150mA/cm^2$의 전류 밀도에서 14.9 Ah/L의 방전 용량을 보였으며 이는 산소작용기로 활성화된 카본 펠트(OGF) 및 비활성화 카본 펠트(GF)보다 각각 23% 및 187% 더 높았다. 이러한 결과는 urea로 활성화된 카본 펠트 전극이 레독스 흐름 전지용 전극 소재로 사용될 수 있는 가능성을 보여준다.

• 멤브레인
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• 제28권2호
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• pp.96-104
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• 2018

해수담수화의 빠른 증가와 함께 붕소 제거에 대한 중요성이 상승하고 있다. 본 연구는 표면개질 시 친수성 화합물을 이용하여 수투과량을 최대한 막고 붕소 제거율을 높이기 위한 연구를 진행하였다. 첫째로, Control polyamide 역삼투막을 얻기 위해 M-phenylenediamine (MPD)와 trimesoyl chloride (TMC)를 Polysulfone 한외여과막에 계면중합을 시켜 polyamide 활성층을 제조하였다. 다음으로, Control polyamide 역삼투막에 표면개질을 진행시켜 D-gluconic acid (DGCA)와 D-gluconic acid sodium salt (DGCA-Na)를 glutaraldehyde (GA)와 hydrochloric acid (HCl)을 이용하여 합성시켰다. 합성된 역삼투막의 표면 분석을 위해 XPS 분석을 진행하였으며, DGCA 및 DGCA-Na 화합물과의 반응이 되었음을 확인하였다. 또한, morphology 측정을 위해 FE-SEM과 AFM 분석을 진행하였으며, polyamide 활성층 형성 및 표면 거칠기를 확인할 수 있었다. 수투과량의 경우, 표면개질을 진행한 역삼투막은 10 GFD 수준이거나 그 이하의 값을 가졌다. 하지만, DGCA 및 DGCA-Na 화합물과 표면개질을 진행한 역삼투막의 붕소 제거율은 94.38, 94.64%로, Control polyamide 역삼투막보다 각각 12.03, 12.29 %p만큼 큰 값을 가지는 것을 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1195-1198
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• 2013

Nickel hexacyanoferrate supported palladium nanoparticles (Pd-NiHCF NPs) were synthesized and studied for oxygen reduction reactions in direct methanol fuel cell. The NiHCF support was readily synthesized by a comixing of $Ni(OCOCH_3)_2$ and equimolar $K_3[Fe(CN)_6]$ solution into DI water under rigorous stirring. After the preparation of NiHCF support, Pd NPs were loaded on NiHCF via L-ascorbic acid reduction method at $80^{\circ}C$. Pd-NiHCF NPs were electrochemically active for oxygen reduction reaction in 0.1 M $HClO_4$ solution. X-ray absorption near edge structure analysis was conducted to measure the white line intensity of Pd-NiHCF to verify the OH adsorption. As a comparison, carbon supported Pd NPs exhibited same white line intensity. This study provides a general synthetic approach to easily load Pd NPs on porous coordination polymers such as NiHCF and can provide further light to load Pd based alloy NPs on NiHCF framework.

• 전기학회논문지
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• 제59권11호
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• pp.2016-2020
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• 2010

Indium-zinc-oxide (IZO) films were deposited at room temperature via RF sputtering with varying the flow rate of additive nitrogen gas ($N_2$). Thin film transistors (TFTs) with an inverted staggered configuration were fabricated by employing the various IZO films, such as $N_2$-added and pure (i.e., w/o $N_2$-added), as active channel layers. For all the deposited IZO films, effects of additive $N_2$ gas on their deposition rates, electrical resistivities, optical transmittances and bandgaps, and chemical structures were extensively investigated. Transfer characteristics of the IZO-based TFTs were measured and characterized in terms of the flow rate of additive $N_2$ gas. The experimental results indicated that the transistor action occurred when the $N_2$-added (with $N_2$ flow rate of 0.4-1.0 sccm) IZO films were used as the active layer, in contrast to the case of using the pure IZO film.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.222-222
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• 2010

Transparent semiconductor oxide thin films have been attracting considerable attention as potential channel layers in thin film transistors (TFTs) owing to their several advantageous electrical and optical characteristics such as high mobility, high stability, and transparency. TFTs with ZnO or similar metal oxide semiconductor thin films as the active layer have already been developed for use in active matrix organic light emitting diode (AMOLED). Of late, there have been several reports on TFTs fabricated with InZnO, AlZnSnO, InGaZnO, or other metal oxide semiconductor thin films as the active channel layer. These newly developed TFTs were expected to have better electrical characteristics than ZnO TFTs. In fact, results of these investigations have shown that TFTs with the new multi-component material have excellent electrical properties. In this work, we present TFTs with inverted coplanar geometry and with a novel HfInZnO active layer co-sputtered at room temperature. These TFTs are meant for use in low voltage, battery-operated mobile and flexible devices. Overall, the TFTs showed good performance: the low sub-threshold swing was low and the $I_{on/off}$ ratio was high.

• Carbon letters
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• 제22권
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• pp.110-114
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• 2017

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.348-351
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• 2007

A pure polyimide substrate and polyimide substrate with nano-silica additive have been formed on glass by coating. The a-Si:H TFT arrays have been formed on such polyimide substrate for driving TNLCD.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2017년도 추계학술논문요약집
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• pp.177-178
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• 2017

• Advances in nano research
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• 제13권5호
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• pp.417-426
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• 2022

Bisphenol A (BPA) is one of the chemicals used in monomer epoxy resins and polycarbonate plastics. The surface-enhanced Raman spectroscopy (SERS) method is precise for identifying biological materials and chemicals at considerably low concentrations. In the present article, the substrates coated with gold nanoparticles have been studied to identify BPA and control the diseases caused by this chemical. Gold nanoparticles were made by a simple chemical method and by applying gold salt and trisodium citrate dihydrate reductant and were coated on glass substrates by a spin-coat approach. Finally, using these SERS substrates as plasmonic sensors and Raman spectroscopy, the Raman signal enhancement of molecular vibrations of BPA was investigated. Then, the molecular vibrations of BPA in some consumer goods were identified by applying SERS substrates as plasmonic sensors and Raman spectroscopy. The fabricated gold nanoparticles are spherical and quasi-spherical nanoparticles that confirm the formation of gold nanoparticles by observing the plasmon resonance peak at 517 nm. Active SERS substrates have been coated with nanoparticles, which improve the Raman signal. The enhancement of the Raman signal is due to the resonance of the surface plasmons of the nanoparticles. Active SERS substrates, gold nanoparticles deposited on a glass substrate, were fabricated for the detection of BPA; a detection limit of 10-9 M and a relative standard deviation (RSD) equal to 4.17% were obtained for ten repeated measurements in the concentration of 10-9 M. Hence, the Raman results indicate that the active SERS substrates, gold nanoparticles for the detection of BPA along with the developed methods, show promising results for SERS-based studies and can lead to the development of microsensors. In Raman spectroscopy, SERS active substrate coated with gold nanoparticles are of interest, which is larger than gold particles due to the resonance of the surface plasmons of gold nanoparticles and the scattering of light from gold particles since the Raman signal amplifies the molecular vibrations of BPA. By decreasing the concentration of BPA deposited on the active SERS substrates, the Raman signal is also weakened due to the reduction of molecular vibrations. By increasing the surface roughness of the active SERS substrates, the Raman signal can be enhanced due to increased light scattering from rough centers, which are the same as the larger particles created throughout the deposition by the spin-coat method, and as a result, they enhance the signal by increasing the scattering of light. Then, the molecular vibrations of BPA were identified in some consumer goods by SERS substrates as plasmonic sensors and Raman spectroscopy.

• The Plant Pathology Journal
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• 제18권2호
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• pp.102-105
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• 2002

A strain of Acremonium strictum, the mycoparasite of Botrytis cinerea, showed strong antifungal activities both in vitro and in vivo against several phytopathogenic fungi. An antifungal substance was purified from the liquid cultures of A. strictum and identified as verlamelin by instrumental analyses. Verlamelin exhibited in vitro antifungal activity against some phytopathogenic fungi such as Magnaporthe grisea, Bipolaris maydis, and Botrytis cinerea, while it was net active against all the bacteria tested. In viva, verlamelin exhibited strong protective and curative activities, particularly against barley powdery mildew. At 100 μg/ml, it inhibited the development of barley powdery mildew with control values of more than 90% in 7-day protective and 2-day curative applications. This is the first report on the production of verlamelin by Acremonium species.