연료전지차용 전해질막의 동력학적 강도 측정을 위한 압력인가 블리스터 하이브리드 시스템

임윤재,김우영,이한종,라일채,이창현 한국막학회 2017 한국막학회 총회 및 학술발표회 Vol.2017 No.11

Polymer electrolyte membrane (PEM) is one of key elements to determine both electrochemical performances and lifetimes of fuel cell electric vehicles (FCEVs). PEM is exposed to a variety of dynamic stimuli (e.g., temperature, humidity, pressure, fuel gases and so on) under their operation conditions and meets unavoidable mechanical damages derived from unequal pressure difference between anode and cathode feed gases. Even though there have been approaches to evaluate the mechanical strength of PEM materials, most of the trials could provide static information on their mechanical strength. In this study, a pressure-loaded blister hybrid system connected with gas chromatography was developed to disclose the efficacy of the system as an evaluation tool of dynamic PEM strength under realistic FCEV operation conditions.

연료전지용 고분자전해질막의 실시간 수소 투과도 측정법 연구

임윤재,이창현 한국막학회 2016 멤브레인 Vol.26 No.2

고분자전해질막은 전극 이외에 전기 화학 연료전지의 성능을 결정하는 중요한 요소이다. 고분자전해질막은 가스나 양성자 등의 작은 분자를 선택적으로 수송해야 한다. 고분자전해질막을 투과한 가스는 급속히 전기 화학적 환원을 발생시켜 음극 촉매의 열화를 유발하기 때문에 수소 장벽으로 작동해야 하며 가능한 한 빨리 양성자를 이동시켜야 한다. 지금까지고분자전해질막의 수소 기체 투과도를 측정하는데 한정된 방법(예 : Constant volume/variable pressure (Time-lag)법)을 사용했다. 그러나 측정의 대부분은 고분자전해질막은 건조된 진공 하에서 이루어진다. 그렇지 않으면 얻어진 수소 투과도는 측정오차가 커지는 원인이 되기 쉽다. 이 연구에서는 일반적으로 고분자전해질막으로 사용되는 Nafion212의 수소 가스 투과 특성을 온도와 습도가 동시에 제어되는 in-situ 측정 시스템을 이용하여 평가하였다. Polymer electrolyte membranes (PEMs) are key components to determine electrochemical fuel cell performances, in addition to electrode materials. The PEMs need to satisfy selective transport behaviors to small molecules including gases and protons; the PEMs have to transport protons as fast as possible, while they should act as hydrogen barriers, since the permeated gas induces the thermal degradation of cathode catalyst, resulting in rapid electrochemical reduction. To date, limited tools have been used to measure how fast hydrogen gas permeates through PEMs (e.g., Constant volume/variable Pressure (time-lag) method). However, most of the measurements are conducted under vacuum where PEMs are fully dried. Otherwise, the obtained hydrogen permeance is easily changeable, which causes the measurement errors to be large. In this study, hydrogen permeation properties through Nafion212 used as a standard PEM are evaluated using an in-situ measurement system in which both temperature and humidity are controlled at the same time.

수전해 용 촉매 바인더 소재의 화학적 구조에 대한 효과

임윤재,이창현 한국막학회 2018 한국막학회 총회 및 학술발표회 Vol.2018 No.11

Water electrolysis is a representative electrochemical process to generate hydrogen gas together with oxygen gas by applying electric power. Perfluorinated sulfonic acid (PFSA) ionomers have been widely used as electrode binder materials, in addition to polymer electrolyte membrane materials for water electrolysis to generate hydrogen and oxygen gases with a high purity simultaneously. PFSA binder materials act as physical supports for inorganic catalyst materials in both electrodes. The binder materials play role in transporting protons for hydrogen gas and oxygen gas evolution reaction in the cathode and the anode, respectively. In this study, PFSA ionomers with different chemical architectures and equivalent weights were used as binder materials for water electrolysis. The structure property performance relationship was disclosed.

수전해용 과불소계 이오노머 막의 화학적 구조에 대한 효과

임윤재,이창현 한국막학회 2018 한국막학회 총회 및 학술발표회 Vol.2018 No.05

Perfluorinated sulfonic acid (PFSA) ionomers have been widely used as representative polymer electrolyte membrane (PEM) materials for water electrolysis to generate hydrogen and oxygen gases with a high purity (e.g., 99.999%) simultaneously. PEM should satisfy high selectivity of proton to water and act as gas barrier to hydrogen and oxygen in order to improve current efficiency which is a barometer to determine how effectively the electric energy is used for water electrolysis. In this study, PFSA ionomers with different chemical architectures and equivalent weights were used to make PEM materials for water electrolysis. The structure-property-performance relationship was systematically investigated.

CO2 포집용 정 삼투 올리고머계 유도용액

임윤재,이창현 한국막학회 2015 한국막학회 총회 및 학술발표회 Vol.2015 No.05

Forward osmosis (FO) is an emerging technology to produce clean water with low energy consumption. The key elements in FO are a water-permeable membrane, and a draw solution inducing an osmotic pressure difference across the membrane. A desirable draw solution should result in a high osmotic pressure difference,together with an internal concentration polarization as low as possible.The draw solution should also have a very low toxicity,particularlywhen usedin drinking water purification. Furthermore, it is important to be easily recovered from a feed solution after FO operation for a certain period time. The multiple requirements make it difficult to develop an effective draw solution. In the present study, thermally and pH-sensitive oligomeric mixtures are used as potential draw solutions for FO system.

수전해용 과불소계 술폰산 이오노머 막의 화학적 구조 효과

임윤재,이창현 한국막학회 2019 한국막학회 총회 및 학술발표회 Vol.2019 No.11

수전해 효율 향상을 위한 PFSA 이오노머 막 소재의 중요성

임윤재,이창현 한국막학회 2019 한국막학회 총회 및 학술발표회 Vol.2019 No.05

기존 공정과 차별화 된 과불소계 이오노머 막의 투과거동

임윤재,이창현 한국막학회 2015 한국막학회 총회 및 학술발표회 Vol.2015 No.11

Perfluorinated sulfonic acid (PFSA) ionomers have been widely used as representative polymer electrolyte membrane materials for fuel cells and water/salined water electrolyses. The PFSA ionomers membranes need to satisfy complicated transport behaviors to small molecules including gases and ionic species. That is, the PFSA ionomers membranes have to transport protons as fast as possible, while the membranes should act as hydrogen barriers, since the permeated gas induces thermal degradation of cathode catalyst resulting in rapid reduction in fuel cell performances. In this study, it is disclosed that these permeation behaviors can be easily tunable by controlling membrane processing histories even though the ionomers have the same chemical architecture and equivalent weight.

과불소계 이오노머 막의 실시간 기체투과거동

임윤재,이창현 한국막학회 2016 한국막학회 총회 및 학술발표회 Vol.2016 No.11

Perfluorinated sulfonic acid (PFSA) ionomers have been widely used as representative polymer electrolyte membrane (PEM) materials for fuel cells and water/salined water electrolysis. The PFSA membranes need to satisfy selective transport behaviors to small molecules including gases and ionic species; the PFSA membranes have to transport protons as fast as possible, while they should act as hydrogen barriers, since the permeated gas induces the thermal degradation of cathode catalyst, resulting in rapid electrochemical reduction. In this study, hydrogen permeation properties of PFSA membranes are evaluated using a handmade measurement system, which is designed for measuring gas transport properties through PEM materials or membrane-electrode assembly under actual fuel cell operation conditions.

휴대폰을 위한 임베디드 리눅스 경량화 기법

임윤재(Yunjae Lim),남영진(Youngjin Nam),김성률(Sungryul Kim),서대화(Daewha Seo) 한국정보과학회 2006 한국정보과학회 학술발표논문집 Vol.33 No.1

임베디드 리눅스 운영체제는 전형적인 임베디드 시스템 중의 하나인 휴대폰 환경에도 적용될 수 있다. 실제로 최근 휴대폰 제조사들이 휴대폰에 리눅스를 채택하기 시작하면서 리눅스 기반의 운영체제를 탑재한 휴대폰이 다수 개발되어 휴대폰 시장에서 꾸준한 성장 추세를 이어가고 있다. 임베디드 리눅스를 휴대폰 환경에 적용하기 위해서는 몇 가지 기술적인 요구사항들이 고려되어야 하며, 대표적으로 리눅스 시스템 크기에 대한 경량화가 필요하다. 본 논문에서는 임베디드 리눅스를 휴대폰 환경에 적용하기 위한 구체적인 경량화 기법들을 제시하고 각 기법을 휴대폰 리눅스 플랫폼 환경에 적용하여 커널과 루트 파일 시스템 각각의 ROM, RAM 사용량 측면에서 그 효과를 검증해 본다.