• 분석과학
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• 제8권4호
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• pp.881-886
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• 1995

Several forms of gangliosides have been separated from various types of biological matrices using cyclodextrin-modified capillary zone electrophoresis (CZE). Quantitative analysis of phospholipids from biological fluids was achieved by micellar electrokinetic capillary chromatography (MECC) using 35mM sodium dodecyl sulfate. Phosphorylation, one of the most important post-translational modifications of proteins at serine, threonine and tyrosine residues in small peptides were identified and quantitative analyses of phosphopeptides were performed. Seven different neuropeptides which are relative the pain reachanism in the vertebrate central nervons system were also separated by CZE.

• 대한전자공학회논문지SD
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• 제37권4호
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• pp.25-30
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• 2000

금속 유도 측면 결정화에 의한 다결정 실리콘 박막 트랜지스터의 제작에서 이온 질량 주입이 MILC 속도 및 거동에 미치는 영향을 분석하였다. 비정질 실리콘에 도펀트를 주입하거나 이온충돌을 가하면 MILC의 속도가 50% 이상 감소하고 MILC선단이 불균일 해졌다. IMD에 따른 비정질 실리콘 박막의 성질 변화를 분석하기 위하여 자외선 반사도 및 표면 거칠기를 관찰하였고, 이온 충돌에 의한 표면 거칠기의 증가가 MILC 속도 감소와 균일도에 영향을 주는 것으로 나타났다.

• Advances in concrete construction
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• 제15권3호
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• pp.149-159
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• 2023

Water glass (WG) and sodium sulfate (SS) were used to prepare polymeric aluminum chloride residue cement mortar (PACRM) by single and compound blending with polymeric aluminum chloride waste residue, respectively. The structural strength and textural characteristics examinations showed that PACRM consistency increased by incorporating WG, but decreased by incorporating SS. When WG and SS were compounded, the mortar consistency initially rose before falling. The compressive strength of PACRM increased and then decreased as WG was increased. The mechanical properties of PACRM were better enhanced by SS than WG, showing no strength deterioration. The main reason for the improved mechanical properties of polymeric aluminum chloride waste residue in the presence of activators is the increased precipitation of reactive substances, such as C-S-H gels, calcium silica, and Ca(OH)₂. The density of the specimens with PACRM and the degree of aggregation of hydration products were significantly enhanced by generating more hydration products in the mortar. Further, the cracks and pores were significantly reduced, and the matrix structure was continuous and dense at 5% SS doping and 3% compound doping.

• 한국초전도ㆍ저온공학회논문지
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• 제20권3호
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• pp.1-4
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• 2018

The effect of sulfate substitution on the formation of (Pb,S)-1201 type phase was investigated. Polycrystalline samples with nominal compositions of $(Pb_{0.5}B_{0.5-x}S_x)(Sr_{2-y}La_y)CuO_z$, (x = 0 - 0.5, y = 0.7 - 1.0) and $(Pb_{0.5}S_{0.5})(Sr_{2-y}La_y)CuO_z$ (y = 0.5 - 1.0) were prepared by using a solid-state reaction method. The samples were characterized by powder X-ray diffraction (XRD) and resistivity measurements. XRD data revealed that almost-single (Pb,S)-1201 phase samples could be obtained for x = 0.5 and y = 0.9-1.0, judging from the similar results of the XRD patterns between the (Pb,S)-1201 and (Pb,B)-1201 phases. Each of the samples has a crystal structure with tetragonal symmetry. The sample with x = 0.5 and y = 0.9 is found to show an onset of resistivity dropping at over 23 K and zero resistivity at 12 K.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.65-65
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• 2011

Single-well carbon nanotubes (SWNT) have been proposed as a promising candidate for various applications owing to their excellent properties. In particular, their fascinating electrical and mechanical properties could provide a new area for the development of advanced engineering materials. A transparent conductive thin film (TCF) has increased for applications such as liquid crystal displays, touch panels, and flexible displays. Indium tin oxide (ITO) thin films, which have been traditionally used as the TCFs, have a serious obstacle in TCFs applications. SWNTs are the most appropriate materials for conductive films for displays due to their excellent high mechanical strength and electrical conductivity. But, a bundle of CNTs has different electrical properties than their individual counterparts. In this work, the fabrication by the spraying process of transparent SWNT films and reduction of its sheet resistance on PET substrates is researched. Arc-discharge SWNTs were dispersed in deionized water by adding sodum dodecyl sulfate (SDS) as surfactant and sonicated, followed by the centrifugation. The dispersed SWNT was spray-coated on PET substrate and dried on a hotplate at $100^{\circ}C$. When the spray process was terminated, the TCF was immersed into deionized water to remove the surfactant and then it was dried on hotplate. The TCF film was then treated with ionic doping treatment, rinsed with deionized water and dried. The surface morphology of TCF was characterized by field emission scanning electron microscopy. The sheet resistance and optical transmission properties of the TCF were measured with a four-point probe method and a UV-visible spectrometry, respectively. Results, we show that 97 ${\Omega}$/> sheet resistance can be achieved with 81% transmittance at the wavelength of 550 nm. The changes in electrical and optical conductivity of SWNT film before and after ionic doping treatments were discussed.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.111.1-111.1
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• 2012

Interest in flexible transparent conducting films (TCFs) has been growing recently mainly due to the demand for electrodes incorporated in flexible or wearable displays in the future. Indium tin oxide (ITO) thin films, which have been traditionally used as the TCFs, have a serious obstacle in TCFs applications. SWNTs are the most appropriate materials for conductive films for displays due to their excellent high mechanical strength and electrical conductivity. In this work, the fabrication by the spraying process of transparent SWNT films and reduction of its sheet resistance on PET substrates is researched Arc-discharge SWNTs were dispersed in deionized water by adding sodium dodecyl sulfate (SDS) as surfactant and sonicated, followed by the centrifugation. The dispersed SWNT was spray-coated on PET substrate and dried on a hotplate. When the spray process was terminated, the TCF was immersed into deionized water to remove the surfactant and then it was dried on hotplate. The TCF film was then was doped with Au-ionic doping treatment, rinsed with deionized water and dried. The surface morphology of TCF was characterized by field emission scanning electron microscopy. The sheet resistance and optical transmission properties of the TCF were measured with a four-point probe method and a UV-visible spectrometry, respectively. This was confirmed and discussed on the XPS and UPS studies. We show that 87 ${\Omega}/{\Box}$ sheet resistances with 81% transmittance at the wavelength of 550nm. The changes in electrical and optical conductivity of SWNT film before and after Au-ionic doping treatments were discussed. The effect of Au-ion treatment on the electronic structure change of SWNT films was investigated by Raman and XPS.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.434-434
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• 2012

Despite recent efforts for fabricating flexible transparent conducting films (TCFs) with low resistance and high transmittance, several obstacles to meet the requirement of flexible displays still remain. Indium tin oxide (ITO) thin films, which have been traditionally used as the TCFs, have a serious obstacle in TCFs applications. SWNTs are the most appropriate materials for conductive films for displays due to their excellent high mechanical strength and electrical conductivity. Recently, it has been demonstrated that acid treatment is an efficient method for surfactant removal. However, the treatment has been reported to destroy most SWNT. In this work, the fabrication by the spraying process of transparent SWNT films and reduction of its sheet resistance by Au-ionic doping treatment on PET substrates is researched. Arc-discharge SWNTs were dispersed in deionized water by adding sodium dodecyl sulfate (SDS) as surfactant and sonicated, followed by the centrifugation. The dispersed SWNT was spray-coated on PET substrate and dried on a hotplate. When the spray process was terminated, the TCF was immersed into deionized water to remove the surfactant and then it was dried on hotplate. The TCF film was then was doped with Au-ionic doping treatment, rinsed with deionized water and dried. The surface morphology of TCF was characterized by field emission scanning electron microscopy. The sheet resistance and optical transmission properties of the TCF were measured with a four-point probe method and a UV-visible spectrometry, respectively. This was confirmed and discussed on the XPS and UPS studies. We show that 87 ${\Omega}/{\Box}$ sheet resistances with 81% transmittance at the wavelength of 550 nm. The changes in electrical and optical conductivity of SWNT film before and after Au-ionic doping treatments were discussed. The effects of hole transport interface layer using Au-ionic doping SWNT on the performance of organic solar cells were investigated.

• 한국환경과학회지
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• 제18권11호
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• pp.1215-1224
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• 2009

This study evaluated the applicability of visible-light-driven N- and S-doped titanium dioxide($TiO_2$) for the control of low-level dimethyl sulfide(DMS) and dimethyl disulfide(DMDS). In addition, a photocatalytic unit(PU)-adsorption hybrid was evaluated in order to examine the removal of DMS and DMDS which exited the PU and a gaseous photocatalytic byproduct($SO_2$) which was generated during the photocatalytic processes. Fourier-Tranform-Infrared(FTIR) spectrum exhibited different surface characteristics among the three-types of catalysts. For the N- and S-doped $TiO_2$ powders, a shift of the absorbance spectrum towards the visible-light region was observed. The absorption edge for both the N- and S-doped $TiO_2$ was shifted to $\lambda$ 720 nm. The N-doped $TiO_2$ was superior to the S-doped $TiO_2$ in regards to DMS degradation. Under low input concentration(IC) conditions(0.039 and 0.027 ppm for DMS and DMDS, respectively), the N-doped $TiO_2$ revealed a high DMS removal efficiency(above 95%), but a gradual decreasing removal efficiency under high IC conditions(7.8 and 5.4 ppm for DMS and DMDS, respectively). Although the hybrid system exhibited a superior characteristic to PU alone regarding the removal efficiencies of both DMS and DMDS, this capability decreased during the course of a photocatalytic process under the high IC conditions. The present study identified the generation of sulfate ion on the catalyst surface and sulfur dioxide(maximum concentrations of 0.0019 and 0.0074 ppm for the photocatalytic processes of DMS and DMDS, respectively) in effluent gas of PU. However, this generation of $TiO_2$ would be an insignificant addition to indoor air quality levels.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2010년도 춘계학술발표대회
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• pp.57.2-57.2
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• 2010

대표적인 투명 전극 재료indium tin oxide(ITO)의 경우, 우수한 투과성과 낮은 면저항을 기반으로 차세대 디스플레이용 전극으로 각광 받고 있다. 하지만 제조 단가가 높으며 brittle 하여 유연 디스플레이에 적용이 어려우며 대면적 제조가 어렵다는 단점이 있어 이를 대체할 수 있는 새로운 물질이 필요한 실정이다. 대표적인 후보 물질로는 탄소 육각형이 서로 연결된 관 형태인 탄소나노튜브가 있으며 뛰어난 전기 전도도와 물리적 특성을 투명 전극에 적용하기 위한 연구가 활발히 진행 중이다. 본 연구에서는 탄소나노튜브 투명 전극 제조 시 잔여 분산제 제거 및 doping의 효과를 위해 수행되는 산처리 공정을 하지 않고 투명 전극의 특성을 향상 시키는 연구를 진행하였다. 제작된 박막에 압력을 인가하여 탄소나노튜브 네트워킹의 향상과 두께의 감소를 얻을 수 있었다. 실험에 사용된 탄소나노튜브는 아크 방전 공정으로 합성된 2nm의 single wall 탄소나노튜브이며 이를 분산제인 sodium dodecyl sulfate(SDS)에 분산하여 용액형태로 제작하여 사용하였다. 분산제를 제거하기 위해 탈이온수를 사용하였으며 고분자 mold를 사용하여 압력을 인가하여 그에 따른 전기적, 광학적 변화를 관찰하였다. 제조된SWCNT 박막은 four point probe measurement를 이용하여 sheet resistance를 측정하였고 UV-vis를 이용하여 투과도와 반사도 등의 광학적 특성을 측정하였다. 박막의 표면은 field emission scanning electron microscope (FESEM)과 Atomic force microscope(AFM)를 이용하여 관찰하였다.

• Journal of Electrochemical Science and Technology
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• 제10권2호
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• pp.159-169
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• 2019

The activated carbon materials were prepared from waste biomass by ultrasonic assisted chemical activation method (UCA), ultrasonic assisted physical activation method (UPA) and Manganese nitrogen doped carbon (Mn/N-C). The XRD result shows the turbostatic (fully disordered) structure. The cyclic voltammetry test was done at 50 mV/s using 1M sodium sulfate and the values of specific capacitance were found to be 93, 100 and 115 F/g for UCA, UPA and Mn/N-C respectively. The power density values for the samples UCA, UPA and Mn/N-C were found to be 46.04, 87.97 and 131.42 W/kg respectively. The electrochemical impedance spectroscopy was done at low frequency between 1 to 10 kHz. The Nyquist plot gives the resistant characteristics of the materials due to diffusional resistance at the electrode-electrolyte interface. The Energy Dispersive X-Ray Spectroscopyanalysis (EDAX) analysis showed that the percentage doping of nitrogen and manganese were 3.53 wt% and 9.44 wt% respectively. It is observed from the experiment Mn/N-C doped carbon show good physical and electrochemical properties.