• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.36-36
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• 2011

고분자 전해질 연료전지용 분리판은 가격비와 중량비가 높아 부품 가격 및 중량을 낮출 경우 파급 효과가 높을 것으로 예상된다. 일반적인 금속판들은 연료전지 스택 내의 산성 분위기에서 존재하므로 표면 부식이 쉽게 발행한다. 본 연구에서는 연료전지의 사용환경을 고려하여 금속판의 부식방지 및 표면특성 향상을 위해 그라핀을 코팅하였으며, 연료전지 스택 내부와 유사한 산화성 분위기를 모사하여 전기화학적 특성을 분석하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.311-312
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• 2012

PEO(Plasma Electrolytic Oxidation) 방법으로 인한 마그네슘 합금의 산화막 코팅시 Sodium Aluminate의 역할을 알아보았다. 전해액 내에 Sodium Aluminate 의 농도가 증가할수록 Plasma arc 발생에 필요한 전압의 상승이 빨라졌으며 그 산화막이 치밀해짐을 알 수 있었다. 또한 치밀한 산화막의 기공률은 분석하여 이를 내식성 결과와 비교함으로써 산화막의 기공률이 내식성에 미치는 영향을 고찰해보았다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.296-296
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• 1994

수술시 근육 이완제로 사용되고 있는 metocurine iodide는 항생물질 투여환자, 중증 근무력중, 전해질 평형실조, 중증 신질환이 있는 환자 등에서는 작용이 증가되어서 상용량에서도 약화사고의 우려가 있어 규제가 필요한 약물이다. Metocurine iodide를 생체 시료중에서 분석하기 위해 rosebengal과 착제를 형성시켜 유기용매로 이온쌍 추출을 한 후, HPLC를 이용하여 rose bengal율 분석함으로써 metocurine iodide를 간접 정량하는 방법을 확립하였다. 이 방법은 뇨와 혈액증에 함유된 metocurine iodide를 0.09 - 9.10$\mu\textrm{g}$/m1농도에서 분석할 수 있었으며, 상관계수는 0.994 - 0.999로 양호한 직선성을 나타내었고, 동시 처방 약물의 영향은 거의 없었다. 뇨 및 혈액중 metocurine iodide의 검출 한계는 각각 0.8ng. 1.2ng (S =3)이었다.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.6
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• pp.180-189
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• 2012

This study was carried out to suggest an experiment based for selecting Sedum, which can adapt well with heat tolerance in extensive green roof system. The heat tolerance of Sedum subject to laboratory high temperature treatment and heat processing time were evaluated using electrolyte leakage, chlorophyll content and regrowth test, and the relation between soil water content and heat tolerance were researched. Logistic model of nonlinear regression analysis was used to evaluate the lethal temperatures that were predicted with the range of $45.0{\sim}48.1^{\circ}C$(soil water content 5%), $47.5{\sim}49.3^{\circ}C$(10%), $48.6{\sim}52.8^{\circ}C$(15%) in 6-hours high-temperature treatment. The higher the soil water content, the stronger the heat resistance property of Sedum. there is. The higher the treatment temperature, the lower the chlorophyll content, and the less the soil water content, the faster the chlorophyll decomposition. The order of hot-temperature resistance was S. reflexum>S. takevimense>S. middendorffianum>S. album>S. sieboldii>S. spurium when soil water content was 5%. The order of hot-temperature resistance was S. album>S. reflexum>S. spurium>S. takevimense>S. middendorffianum>S. sieboldii when soil water content was 15%. The more of soil water content, S. album, S. reflexum, S. spurium had stronger tolerant of hot temperature. These results were consistent with those from the regrowth test and the heat tolerance tested by electrolyte leakage evaluation.

• Journal of Energy Engineering
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• v.25 no.3
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• pp.66-72
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• 2016

In this study, a sulfonated poly(arylene ether ketone) block copolymer was prepared from hydrophilic oligomer and hydrophobic oligomer. The structure of the prepared membrane was characterized by $^1H$-NMR, FT-IR and GPC. The $M_w$(weight-average molecular weights) of the polymer was $209,700g\;mol^{-1}$ and the molecular weight distribution($M_w/M_n$) of 1.25 was obtained. The prepared membrane showed excellent thermal stability with gradual weight loss up to $200^{\circ}C$. The proton conductivity of SPAEK block copolymer reached the maximum of $9.0mS\;cm^{-1}$ at $90^{\circ}C$ under 100% relative humidity (RH). From the observed results, it is necessary to do more aggressive attempt to study the possibility of application as an ion-conductive composite electrolyte.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.291-298
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• 2019

We describe the improvement of insulation performance and the prevention of electrolyte leakage in a single cell in order to prevent the fuming phenomenon caused by leakage of electrolyte in a lithium secondary battery in a submerged weapon (torpedo) operated in Korea. A torpedo using lithium secondary battery as a main power source (propulsion battery) can induce the heat and fuming phenomenon, which makes it inconvenient for naval equipment operation in Korea. In the simulation test, the electrolyte of some battery cells leaked in the battery pack unit, leading to a short circuit between the main power circuit and the terminal tab of the high voltage part. We analyzed the characteristics and mechanism of the lithium secondary battery during this heat generation and fuming phenomenon. In order to prevent leakage of the electrolyte in the lithium secondary battery, the design was improved via fundamental (terminal tap enhancement) and complementary (insulation block selection and installation) measures. Comparison of the performance test before and after the improvement showed that the tensile strength of the tap terminal was improved about 2 times and the withstand voltage characteristic was improved. The application of quality improvement measures resulted in no fuming even after more than 3 years of field operation. This result is expected to improve the operation and storage stability of the torpedo propulsion cell.

• Journal of the Korean Chemical Society
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• v.56 no.6
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• pp.731-738
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• 2012

The purpose of this study is to analyze the understandings of science high school students on the conception of chemical cell in relation to chemical equilibrium from the microscopic viewpoint at molecular level through questionnaires and follow-up interviews. The results show that they have high understandings on the chemical equilibrium states in the electrochemical cell and on the redox reaction taking place simultaneously when a metal electrode is immersed in the metal ion solution. However, they do not fully comprehend the development of electrical potential difference, electron movement, electrode potential measurement in the half-cells, and calculation of the net cell voltage between anode and cathode in the chemical cell because of difficulties in the microscopic understanding the interaction on the interface at the electrode and the electrolyte solution.

• Korean Chemical Engineering Research
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• v.47 no.4
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• pp.476-480
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• 2009

A polymer composite electrolyte of a blend of poly(methyl methacrylate)(PMMA) and poly(ethylene oxide) (PEO) as a host polymer, the ethylene carbonate as a solvent, and $LiClO_4$ as a salt was studied. The crystallinity of the polymer electrolytes was evaluated using differential scanning calorimeter(DSC). The ionic conductivity of the polymer electrolytes was measured by frequency response analyzer(FRA) method. The effect of PEO/PMMA blend ratios on the ionic conduction in these electrolytes was investigated. The electrolyte films showed a phase separation due to immiscibility of the PMMA with the PEO. The PMMA-rich phase and the PEO-rich phase were produced during a film casting. The ionic conductivity of blend electrolyte was dependent on the content of PMMA and showed the highest value at 20 wt.%. However, when PMMA content exceeds 20 wt.%, the ionic conductivity was decreased due to the slow ionic transport through the PMMA-rich phase.

• Journal of the Korean Applied Science and Technology
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• v.37 no.5
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• pp.1200-1207
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• 2020

We have fabricated the supercapacitor composed of porous activated carbon, metal-organic framework (MOF) with polymer based solid state electrolyte as a "ion gel" and characterized its electrochemical behaviour as a function of the MOF contents. The electrochemical properties of the supercapacitor were analyzed via cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS) and galvanostatic charge/discharge test. As a results, the supercapacitor based on porous activated carbon/MOF composite showed the highest capacitance value at 0.5 wt% of MOF contents and decreased capacitance with increase MOF contents over the 0.5 wt%. Consequently, the porous activated carbon/MOF composite based supercapacitor is applicable to various aspect for energy storage device.

• Polymer(Korea)
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• v.29 no.4
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• pp.392-398
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• 2005

Self-assembled multilayer thin films of poly(ethylene-alt-maleic anhydride) (PEMAh) and poly(4-vinyl pyridine) (P4VP) were fabricated by layer-by-layer (LbL) sequential adsorption. Fourier transform infrared (FT-IR) spectroscopic analysis of the self-assembled PEMAh/P4VP multilayer films confirms that the driving forces for the multilayer buildup are the intermolecular hydrogen bonding and electrostatic interactions. The linear increase of absorption peak of P4VP at 256 nm with increasing number of PEMAh/P4VP bilayers indicates that the multilayer buildup is an uniform assembling process. We also investigate the effects of polyelectrolyte concenhation variation of the dipping solution and pH variation of the PEMAh solution on the multilayer film formation. Thickness. adsorbed polyelectrolyte mass and surface roughness of the multilayer films were measured by UV-visible spectroscopy, quartz crystal microbalance (QCM), and atomic force microscopy (AFM), respectively.