졸-겔법으로 제조된 비정질의 텅스텐 산화물 박막과 황산 전해질 계면에서 일어나는 수소의 층간 반응에 대한 전기화학적 특성

강태혁,민병철,주재백,손태원,조원일,Kang, Tae-Hyuk,Min, Byoung-Chul,Ju, Jeh-Beck,Sohn, Tae-Won,Cho, Won-Il 한국공업화학회 1996 공업화학 Vol.7 No.6

본 연구에서는 W-IPA(peroxo-polytungstic acid)를 출발 물질로 하는 졸 용액을 ITO(indium tin oxide)가 입혀진 유리판 위에 침적 도포(dip-coating) 방법으로 침적시키고, 이것을 겔화시킨 후에 열처리하여 전기 발색 소자 (electrochromic device, ECD)의 텅스텐 산화물 박막 전극을 만들어 이의 전기화학적인 특성을 고찰하였다. 가장 좋은 전기 화학적 특성을 나타내는 조건은 $2g/10mL(W-IPA/H_2O)$졸 용액에 15회 침적 도포하여 $230{\sim}240^{\circ}C$의 온도로 최종 열처리 한 텅스텐 산화물 박막 전극이었으며, 침적 횟수의 증가에 따라 산화 텅스텐 박막의 두께는 비례하여 증가하였고, 5회 침적 도포 이후에는 1회 침적 도포시 약 $60{\AA}$ 두께로 막이 생성됨을 알 수 있었다. 졸-겔법으로 제조된 텅스텐 산화물 박막 전극은 X-선 회절 분석에 의하여 비정질 구조, 주사 전자 현미경에 의하여 박막 표면은 균일한 것으로 조사되었다. 다중 순환 전류-전위 주사법에 의하여 작성된 전류-전위 곡선에 의하면 순환 횟수가 수백회 이상임에도 불구하고 소 발색은 뚜렷하게 나타났으나, 더욱 많은 순환 횟수에서는 전해질인 황산 수용액 중에서 텅스텐 산화물 박막의 박리 현상이 일어나 소 발색의 전류 밀도는 차츰 감소하였다. 전위 주사 속도를 변화시키면서 순환 전류-전위 주사법에 의하여 작성된 전류-전위 곡선으로부터 구한 전기화학적 특성 값을 이용하여 반응에 참여하는 수소 이온의 확산 계수를 구할 수 있었다. The peroxo-polytungstic acid was formed by the direct reaction of tungsten powder with the hydrogen peroxide solution. Peroxo-polytungstic powder were prepared by rotary evaporator using the fabricated on to ITO coated glass as substrate by dip-coating method using $2g/10mL(W-IPA/H_2O)$ sol solution. A substrate was dipped into the sol solution and after a meniscus had settled, the substrate was withdrawn at a constant rate of the 3mm/sec. Thicker layer could be built up by repeated dipping/post-treatment 15 times cycles. The layers dried at the temperature of $65{\sim}70^{\circ}C$ during the withdrawn process, and then tungsten oxides thin film was formed by final heating treatment at the temperature of $230{\sim}240^{\circ}C$ for 30min. A linear rotation between the thickness of thin film and the number of dipping/post-treatment cycles for tungsten oxides thin films made by dip-coating was found. The thickness of thin film had $60{\AA}$ after one dipping. From the patterns of XRD, the structure of tungsten oxides thin film identified as amorphous one and from the photographs of SEM, the defects and the moderate cracks were observed on the tungsten oxides thin film, but the homogeneous surface of thin films were mostly appeared. The electrochemical characteristic of the $ITO/WO_3$ thin film electrode were confirmed by the cyclic voltammetry and the cathodic Tafel polaization method. The coloring bleaching processes were clearly repeated up to several hundreds cycles by multiple cyclic voltammetry, but the dissolved phenomenon of thin film revealed in $H_2SO_4$ solution was observed due to the decrease of the current densities. The diffusion coefficient was calculated from irreversible Randles-Sevick equation from the data obtained by the cyclic voltammetry with various scan rates.

전기화학적 임피던스법에 의한 철근콘크리트의 부식연구 -

강태혁,조원일,조병원,주재백,윤경석 ( Tae Hyuk Kang,Won Il Cho,Byung Won Cho,Jeh Beck Ju,Kyung Suk Yun ) 한국공업화학회 1998 공업화학 Vol.9 No.6

졸 - 겔법으로 제조된 비정질의 텅스텐 산화물을 박막과 황산 전해질 계면에서 일어나는 수소의 층간 반응에 대한 전기화학적 특성

강태혁,민병철,주재백,손태원,조원일 ( Tae Hyuk Kang,Byoung Chul Min,Jeh Beck Ju,Tae Won Sohn,Won Il Cho ) 한국공업화학회 1996 공업화학 Vol.7 No.6

본 연구에서는 W-IPA(peroxo-polytungstic acid)를 출발 물질로 하는 졸 용액을 ITO(indium tin oxide)가 입혀진 유리판 위에 침적 도포(dip-coating) 방법으로 침적시키고, 이것을 겔화시킨 후에 열처리하여 전기 발색 소자(electrochromic device, ECD)의 텅스텐 산화물 박막 전극을 만들어 이의 전기화학적인 특성을 고찰하였다. 가장 좋은 전기 화학적 특성을 나타내는 조건은 29/10mL(W-IPA/H₂O)졸 용액에 15회 침적 도포하여 230∼240℃의 온도로 최종 열처리 한 텅스텐 산화물 박막 전극이었으며, 침적 횟수의 증가에 따라 산화 텅스텐 박막의 두께는 비례하여 증가하였고, 5회 침적 도포 이후에는 1회 침적 도포시 약 60 두께로 막이 생성됨을 알 수 있었다. 졸-겔법으로 제조된 텅스텐 산화물 박막 전극은X-선 회절 분석에 의하여 비정질 구조, 주사 전자 현미경에 의하여 박막 표면은 균일한 로조사되었다. 다중 순환 전류-전위 주사법에 의하여 작성된 전류-전위 곡선에 의하면 순환 횟수가 수백회 이상임에도 불구하고 소·발색은 뚜렷하게 나타났으나, 더욱 많은 순환 횟수에서는 전해질인 황산 수용액 중에서 텅스텐 산화물 박막의 박리 현상이 일어나 소·발색의 전류 밀도는 차츰 감소하였다. 전위 주사 속도를 변화시키면서 순환 전류-전위 주사법에 의하여 작성된 전류-전위 곡선으로부터 구한 전기화학적 특성 값을 이용하여 반응에 참여하는 수소 이온의 확산 계수를 구할 수 있었다. The peroxo-polytungstic acid was formed by the direct reaction of tungsten powder with the hydrogen peroxide solution. Peroxo-polytungstic powder were prepared by rotary evaporator using the fabricated on to ITO coated glass as substrate by dip-coating method using 2g/10mL(W-IPA/H₂O) sol solution. A substrate was dipped into the sol solution and after a meniscus had settled, the substrate was withdrawn at a constant rate of the 3mm/sec. Thicker layer could be built up by repeated dipping/post-treatment 15 times cycles. The layer dried at the temperature of 65∼70℃ during the withdrawn process, and then tungsten oxides thin film was formed by final heating treatment at the temperature of 230∼240℃ for 30min. A linear relation between the thickness of thin film and the number of dipping/post-treatment cycles for tungsten oxides thin films made by dip-coating was found. The thickness of thin film had 60 after one dipping. From the patterns of XRD, the structure of tungsten oxides thin film identified as amorphous one and from the photographs of SEM, the defects and the moderate cracks were observed on the tungsten oxides thin film, but the homogeneous surface of thin films were mostly appeared. The electrochemical charateristic of the ITO/WO₃ thin film electrode were conformed by the cyclic voltammetry and the cathodic Tafel polarization method. The colaring-bleaching processes were clearly repeated up to several hundreds cycles by multiple cyclic voltammetry, but the dissolved phenomenon of thin film revealed in H₂SO₄ solution was observed due to the decrease of the current densities. The diffusion coefficient was calculated from irreversible Randles-Sevick equation from the data obtained by the cyclic voltammetry with various scan rates.

리튬이온전지용 주석산화물이 도포된 흑연전극의 싸이클 성능

강태혁,김형선,조원일,조병원,주재백,Kang, Tae-Hyuk,Kim, Hyung-Sun,Cho, Won-Il,Cho, Byung-Won,Ju, Jeh-Beck 한국전기화학회 2002 한국전기화학회지 Vol.5 No.2

졸-겔법을 이용하여 주석산화물을 흑연입자 표면에 도포하고 $400-600^{\circ}C$에서 열처리하여 미세결정구조를 갖는 리튬이온 전지용 주석산화물 전극을 제조하였다. 도포 된 주석산화물의 양은 $2.25 wt\%\~11.1 wt\%$로 조절하여 실험한 결과 주석산 화물의 함량에 따라 방전용량이 증가하고 또한 초기의 비가역 용랑도 증가함을 알 수 있었다. 싸이클에 따른 주석 산화물 전극의 방전용량은 propylene carbonate(PC) 계 전해액에서도 초기 싸이클에서 350mAh/g 이상, 30 싸이클 후 에서는 300mAh/g을 나타낸 반면, 표면개질이 되지 않은 흑연전극의 경우에는 140mAh/g의 방전용량을 나타내었다. 충방전 속도를 C/5에서 C/2로 빠르게 했을 때 주석산화물 전극과 흑연전극의 방전용량은 초기 용량의 $92\%,\;77\%$로 각각 나타났다. 이러한 전극 특성의 향상은 주석산화물이 리튬이온과 반응하여 형성된 리튬 옥사이드$(Li_2O)$부동태 피막이 흑연전극의 탈리 현상을 막고 또한 환원된 주석이 흑연입자간의 전기전도를 원활하게 하여 전극의 전류분포를 향상시키기 때문인 것으로 해석되었다. Tin oxide was coated on graphite particle by sol-gel method and an electrode with this material having microcrystalline structure for lithium ion battery was obtained by heat treatment in the range $400-600^{\circ}C$. The content of tin oxide was controlled within the range of $2.25wt\%\~11.1wt\%$. The discharge capacity increased with the content of tin oxide and also initial irreversible capacity increased. The discharge capacity of tin oxide electrode showed more than 350 mAh/g at the initial cycle and 300 mAh/g after the 30th cycle in propylene carbonate(PC) based electrolyte whereas graphite electrode without surface modification showed 140 mAh/g. When the charge and discharge rate was changed from C/5 to C/2, The discharge capacity of tin oxide and graphite electrode showed $92\%\;and\;77\%$ of initial capacity, respectively. It has been considered that such an enhancement of electrode characteristics was caused because lithium $oxide(Li_2O)$ passive film formed from the reaction between tin oxide and lithium ion prevented the exfoliation of graphite electrode and also reduced tin enhanced the electrical conduction between graphite particles to improve the current distribution of electrode.

졸겔법에 의한 W - IPA 박막제조 및 특성

강태혁,민병철,주재백,손태원 ( Tae Hyuk Kang,Byung Chul Min,Jeh Beck Ju,Tae Won Sohn ) 한국화학공학회 1995 화학공학의이론과응용 Vol.1 No.2

FB-ESS 기술 및 발전 방안

강태혁(Tae Hyuk Kang) 한국신재생에너지학회 2015 한국신재생에너지학회 학술대회논문집 Vol.2015 No.6

대용량 ESS용 Flow Battery의 현황 및 기술 전망

강태혁(Tae-Hyuk Kang) 한국신재생에너지학회 2017 한국신재생에너지학회 학술대회논문집 Vol.2017 No.5

고층 주거건물의 악취의 거동 분석

강태혁(Tae-Hyuk Kang),김재헌(Kim Jae-Hun),김주영(Joo-Young Kim),서정민(Jung-Min Seo),이중훈(Jung-Hoon Lee),송두삼(Doosam Song) 대한설비공학회 2012 대한설비공학회 학술발표대회논문집 Vol.2012 No.11

Researchs for residence environment make our life more comfort and keep us convenient life. Especially a lot of effort is invested for better Indoor Air Quality. However despite of the effort for IAQ, the indoor air quality in high-rise building is still poor. This comes from the vertical air flow in high-rise building caused by stack effect. Stack effect arouses a lot of related problems such as noise, draft, contaminant dispersion in high-rise buildings. among these problems the most important thing is fragrance from drain. Fragrance makes Residents feel uncomfort and get down residence quality. A lot of claims of residential buildings are about fragrance. In this study, the behaviors of the fragrance spilled from the floor trap in bathroom will be analyzed. Also, the correlation between the air flow and the spread of the fragrance will be analyzed.

겨울철 고층 주거건물의 공기유동에 따른 악취확산에 관한 연구

강태혁(Kang, Tae-Hyuk),김재헌(Kim, Jae-Hun),김주영(Kim, Joo-Young),서정민(Seo, Jung-Min),이중훈(Lee, Jung-Hoon),송두삼(Song, Doosam) 한국태양에너지학회 2012 한국태양에너지학회 학술대회논문집 Vol.2012 No.11

With the quality of residence is getting better, the time that people stay in indoor is getting longer. Therefore dwelling performance of buildings is more and more important. Especially, indoor air quality(IAQ) is emphasized in residential buildings. Despite of the effort for IAQ, the indoor air quality in high-rise building is still poor. This comes from the vertical air flow in high-rise building caused by stack effect in winter. It arouse a lot of related problems such as noise, draft, contaminant dispersion in high-rise buildings. As a stack effect related problem, the characteristics of the fragrance spilled from the floor trap in bathroom will be analyzed in this study. The correlation between the weather condition and the spread of the fragrance lead from a septic tank will be analyzed. Also, the effect of the exhaust fan in bathroom on fragrance spread will be discussed in this paper.

설문조사를 통한 설계 및 시공 기술자의 연돌현상과 연돌저감방안에 대한 인식 분석

강태혁(Kang, Tae-Hyuk),김주영(Kim, Joo-Young),송두삼(Song, Doo-Sam) 대한건축학회 2013 대한건축학회논문집 Vol.29 No.10

The purpose of this study is to analyze the understanding of the building designers and construction engineers about stack effect. Even though lots of studies about the problems caused by stack effect have been reported, the stack effect problems are still reported. The countermeasures for stack effect are determined by the building designer and construction engineer in the planning phase and construction phase. However, there are still differences over the selection of the countermeasures between the design team and construction team, which can result in an incomplete countermeasures for stack effect. In this study, the recognitions of the designer and construction engineer for stack effect were analyzed by the questionnaire survey. The differences of recognition for stack effect between the two were analyzed in this paper. This result can be used for determining the countermeasures for stack effect in effect.