아토피 화장품 시장동향

박세규 ( Sehkyu Park ),이봉진 ( Bongjin Lee ) 한국공업화학회 2019 공업화학전망 Vol.22 No.1

최근 화장품 산업은 제약사들을 중심으로 기업들이 보유한 바이오 및 의약 기술을 접목하여 기능성 화장품 개발에 주목하고 있다. 화장품과 의약품의 경계가 무너지고 코스메슈티컬이 화장품 산업의 블루오션 시장으로 각광받고 있다. 특히 현대병으로 알려진 고질적 피부질환 아토피성 피부 인구가 늘면서 아토피 기능성 스킨케어 시장이 급부상하고 있다. 98년부터 시작된 아토피 관련 시장은 국내 약국 아토피성 화장품 시장 100억 원을 포함해 현재 700억원대로 급성장하고 있어 앞으로 확고한 수익 시장으로 자리잡을 것이라 전망되고 있다. 현 사회에서 심각한 문제로 인식되는 아토피 피부를 치료할 수 있는 다양한 화장품 제품들이 급증하고 있으므로, 본 기획에서는 아토피 화장품시장의 현황, 동향 및 전망을 분석하여 살펴보고자 한다.

Enzyme Electrode Platform Using Methyl Viologen Electrochemically Immobilized on Carbon Materials

Lee, Donghee,Kim, Yong Hwan,Park, Sehkyu The Electrochemical Society 2016 Journal of the Electrochemical Society Vol.163 No.8

<P>This paper presents the electrochemical stabilization of methyl viologen cations on a variety of carbon materials using a glassy carbon electrode. Three different types of voltammetry (potential hold, triangular wave, and square wave voltammetry) were used to stabilize the methyl viologen cation. Methyl viologen cation-modified multi-walled carbon nanotubes (MWCNTs) of different diameters and with various functional groups were examined to observe the effects of carbon particle size and surface modification. Various carbon materials containing MWCNTs, acetylene black, Super P, Vulcan XC-72, and Ketjenblack were modified by methyl viologen and then electrochemically characterized. Their electrochemical behaviors are discussed in terms of carbon properties, such as pore structure and electrical conductivity. Carbon with immobilized the methyl viologen cation and glucose oxidase was assessed to confirm its feasibility for enzyme electrode applications. (C) 2016 The Electrochemical Society. All rights reserved.</P>

분무열분해로 합성한 수전해용 Co₃O₄의 입자형태에 따른 산소발생 활성에 관한 연구

김인겸 ( Ingyeom Kim ),나인욱 ( In Wook Nah ),박세규 ( Sehkyu Park ) 한국화학공학회 2016 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.54 No.6

최근 화석연료를 대체할 친환경 신재생에너지에 대한 요구가 증가하면서 수소에너지가 미래 대체에너지원으로서 주목받고 있다. 수소를 생산하는 방법 중 수전해 기술은 에너지효율과 안정성이 뛰어난 장점이 있지만, 산소발생반응시 발생하는 높은 과전압은 여전히 단점으로 지적되고 있다. 본 연구에서는 분무열분해 공정을 통하여 Co 전구체로부터 Co₃O₄ 를 제조하였다. 또한, urea, sucrose, citric acid의 유기물첨가제를 사용하여 다양한 입자 크기와 표면형상을 가지는 Co₃O₄를 제조하였고, 필요에 따라 추가로 열처리를 실시하였다. 합성한 Co₃O₄ 의 물리적 특성을 분석하기 위해 X-선 회절 분석(XRD)으로 결정성을 조사하였고, 주사전자현미경(SEM)과 투과전자현미경(TEM)으로 입자형상 및 표면을 분석하였다. 질소 흡·탈착 시험을 통해 촉매의 비표면적 및 기공부피를 측정하였고, 질소도핑을 확인하기 위해 X-선 광전자 분광법(XPS)을 사용하였다. 촉매의 산소발생반응 활성을 알아보기 위해 3전극 셀에서 선형주사전위법(LSV)으로 전기화학적 거동을 분석하였다. 첨가제를 사용하지 않은 Co₃O₄ 가 가장 우수한 활성을 보였고, 이는 분무열분해법을 통하여 상대적으로 작은 입자형성과 높은 비표면적의 영향인 것으로 판단된다. As the demand for a clean energy to replace fossil fuel being depleted increases, hydrogen energy is considered as a promising candidate for future energy source. Water electrolysis which produces hydrogen has high energy efficiency and stability but still has a large overpotential for oxygen evolution reaction (OER). In this study, Co₃O₄ cat-alysts with different morphology were prepared by spray pyrolysis from solutions which contain Co precursor and var-ious organic additives (urea, sucrose, and citric acid), followed by post heat treatment. For the catalysts synthesized, X-ray diffraction (XRD) measurements were performed to identify their crystal structure. Morphology and surface shape of the catalysts were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Sur-face area and pore volume were examined by nitrogen adsortpion & desorption tests and X-ray photoelectron spectros-copy (XPS) was conducted to confirm nitrogen doping. Linear sweep voltammetry (LSV) was carried out to investigate OER activity of Co₃O₄ catalysts. As a result, bare-Co₃O₄ which has high surface area and small particle size determined by spray pyrolysis showed high activity toward OER.

In situ electrochemical and mechanical accelerated stress tests of a gas diffusion layer for proton exchange membrane fuel cells

Joo, Dongguk,Han, Kookil,Jang, Jong Hyun,Park, Sehkyu Springer-Verlag 2019 Korean Journal of Chemical Engineering Vol.36 No.2

Crumpled rGO-supported Pt-Ir bifunctional catalyst prepared by spray pyrolysis for unitized regenerative fuel cells

Kim, In Gyeom,Nah, In Wook,Oh, In-Hwan,Park, Sehkyu Elsevier Sequoia 2017 Journal of Power Sources Vol. No.

<P><B>Abstract</B></P> <P>Three-dimensional (3D) crumpled reduced graphene oxide supported Pt-Ir alloys that served as bifunctional oxygen catalysts for use in untized regenerative fuel cells were synthesized by a facile spray pyrolysis method. Pt-Ir catalysts supported on rGO (Pt-Ir/rGOs) were physically characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) to observe change in composition by heat treatment, alloying, and morphological transition of the catalysts. Their catalytic activities and stabilities for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) conditions were electrochemically investigated using cyclic voltammetry (CV), linear sweep voltammetry (LSV), potential cycling and hold tests on the rotating disk electrode (RDE). Pt-Ir/rGO with no post heat-treatment (Pt-Ir/rGO_NP) showed a lower activity for ORR and OER although metal nanoparticles decorated on the support are relatively small. However, Pt-Ir/rGO showed remarkably enhanced activity following heat treatment, depending on temperature. Pt-Ir/rGO heat-treated at 600 °C after spray pyrolysis (Pt-Ir/rGO_P600) exhibited a higher activity and stability than a commercially available Pt/C catalyst kept under the ORR condition, and it also revealed a comparable OER activity and durability versus the commercial unsupported Ir catalyst.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Pt-Ir/rGO was synthesized by a facile spray pyrolysis and following heat-treatment. </LI> <LI> ORR and OER catalytic activities of Pt-Ir/rGO were enhanced by post heat treatment. </LI> <LI> Pt-Ir/rGO_P600 exhibited higher catalytic activities than commercial catalysts. </LI> <LI> Pt-Ir/rGO_P600 showed superior stabilities under reducing and oxidizing conditions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Thermally Robust Porous Bimetallic (Ni_<i>x</i>Pt_1-<i>x</i>) Alloy Mesocrystals within Carbon Framework: High-Performance Catalysts for Oxygen Reduction and Hydrogenation Reactions

Sohn, Hiesang,Xiao, Qiangfeng,Seubsai, Anusorn,Ye, Youngjin,Lee, Jinwoo,Han, Hyokyung,Park, Sehkyu,Chen, Gen,Lu, Yunfeng American Chemical Society 2019 ACS APPLIED MATERIALS & INTERFACES Vol.11 No.24

<P>Thermally stable porous bimetallic (Ni<SUB><I>x</I></SUB>Pt<SUB>1-<I>x</I></SUB>) alloy mesocrystals within a carbon framework are produced via an aerosol-assisted process for high-performance catalysts for the oxygen reduction reaction (ORR) and hydrogenation. The porous Ni<SUB><I>x</I></SUB>Pt<SUB>1-<I>x</I></SUB> alloy has a robust composite of alloy nanoparticles with an adjustable composition and a porous carbon skeleton. Porous Ni<SUB><I>x</I></SUB>Pt<SUB>1-<I>x</I></SUB> alloys exhibit high thermal stability, retaining their crystalline structure and morphology at 550 °C for 6 h, as observed in thermal treatment tests under various conditions (time, temperature, and atmosphere). The porous Ni<SUB><I>x</I></SUB>Pt<SUB>1-<I>x</I></SUB> alloy as a catalyst for the hydrogenation of propylene has high conversion efficiency (>80%) and low activation energy (<I>E</I><SUB>a</SUB> < 20 kJ/mol) at ≥80 °C through the suitable control of the element composition and a pore structure. As a catalyst for the ORR, the catalytic activity of the porous Ni<SUB><I>x</I></SUB>Pt<SUB>1-<I>x</I></SUB> alloy is superior to that of conventional Pt/C (0.115 mA) (0.853 mA/cm<SUB>Pt</SUB><SUP>2</SUP> at 0.9 V/cm<SUB>Pt</SUB><SUP>2</SUP>). This is attributed to the homogeneous alloying of the metal components (Ni and Pt) and the increased accessibility of the reactants to the catalyst, resulting from the unique morphology of the porous Ni<SUB><I>x</I></SUB>Pt<SUB>1-<I>x</I></SUB> alloy, i.e., hierarchical structure with high porosity.</P> [FIG OMISSION]</BR>

Text Mining과 네트워크 분석을 활용한 교육훈련용 모의사격 시뮬레이션 경험지식 분석

김성규,손창호,김종만,정세교,박재현,전정환,Kim, Sungkyu,Son, Changho,Kim, Jongman,Chung, Sehkyu,Park, Jaehyun,Jeon, Jeonghwan 한국군사과학기술학회 2017 한국군사과학기술학회지 Vol.20 No.5

Recently, the military need more various education and training because of the increasing necessity of various operation. But the education and training of the military has the various difficulties such as the limitations of time, space and finance etc. In order to overcome the difficulties, the military use Defense Modeling and Simulation(DM&S). Although the participants in training has the empirical knowledge from education and training based on the simulation, the empirical knowledge is not shared because of particular characteristics of military such as security and the change of official. This situation obstructs the improving effectiveness of education and training. The purpose of this research is the systematizing and analysing the empirical knowledge using text mining and network analysis to assist the sharing of empirical knowledge. For analysing texts or documents as the empirical knowledge, we select the text mining and network analysis. We expect our research will improve the effectiveness of education and training based on simulation of DM&S.

Polarization characteristics of a low catalyst loading PEM water electrolyzer operating at elevated temperature

Lee, Byung-Seok,Park, Hee-Young,Choi, Insoo,Cho, Min Kyung,Kim, Hyoung-Juhn,Yoo, Sung Jong,Henkensmeier, Dirk,Kim, Jin Young,Nam, Suk Woo,Park, Sehkyu,Lee, Kwan-Young,Jang, Jong Hyun Elsevier Sequoia 2016 Journal of Power Sources Vol. No.

<P><B>Abstract</B></P> <P>The effect of temperature and pressure, and diffusion layer thickness is assessed on performance of a proton exchange membrane water electrolyzers (PEMWEs) with an ultralow iridium oxide (IrO<SUB>2</SUB>) loading (0.1 mg cm<SUP>−2</SUP>) anode prepared by electrodeposition and a Pt/C catalyzed cathode with a Pt loading of 0.4 mg cm<SUP>−2</SUP>. Increasing pressure to 2.5 bar at 120 °C enhances the water electrolysis current, so the anode electrodeposited with 0.1 mg cm<SUP>−2</SUP> IrO<SUB>2</SUB> gives a current density of 1.79 A cm<SUP>−2</SUP> at 1.6 V, which is comparable to the conventional powder-type IrO<SUB>2</SUB> electrode with 2.0 mg cm<SUP>−2</SUP> at a temperature of 120 °C and pressure of 2.5 bar. The major factors for cell performances are rationalized in terms of overpotentials, water flow rates and thickness of diffusion layers, based on polarization behavior and ac-impedance response.</P> <P><B>Highlights</B></P> <P> <UL> <LI> IrO<SUB>2</SUB> anodes with ultralow loading (0.1 mg cm<SUP>−2</SUP>) were fabricated by electrodeposition. </LI> <LI> The effect of operating conditions on PEMWE performance was studied at 120 °C. </LI> <LI> The current density at 1.6 V was as high as 1.79 A cm<SUP>−</SUP> <SUP>2</SUP> at 120 °C and 2.5 bar. </LI> <LI> Water transport characteristics in a PEMWE were experimentally examined. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Systematic Analysis for the Effects of Atmospheric Pollutants in Cathode Feed on the Performance of Proton Exchange Membrane Fuel Cells

Yoon, Young-Gon,Choi, Insoo,Lee, Chang-Ha,Han, Jonghee,Kim, Hyoung-Juhn,Cho, EunAe,Yoo, Sung Jong,Nam, Suk Woo,Lim, Tae-Hoon,Yoon, Jong Jin,Park, Sehkyu,Jang, Jong Hyun Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.12

This paper describes how primary contaminants in ambient air affect the performance of the cathode in fuel cell electric vehicle applications. The effect of four atmospheric pollutants ($SO_2$, $NH_3$, $NO_2$, and CO) on cathode performance was investigated by air impurity injection and recovery test under load. Electrochemical analysis via polarization and electrochemical impedance spectroscopy was performed for various concentrations of contaminants during the impurity test in order to determine the origins of performance decay. The variation in cell voltage derived empirically in this study and data reported in the literature were normalized and juxtaposed to elucidate the relationship between impurity concentration and performance. Mechanisms of cathode degradation by air impurities were discussed in light of the findings.

Catalytic decomposition of hydrogen peroxide aerosols using granular activated carbon coated with manganese oxides

Kwon, Ki Min,Kim, In Gyeom,Nam, Yun-Sik,Choi, Jaeyoung,Cho, Won Il,Oh, In Hwan,Lee, Kang-Bong,Jang, Min,Park, Sehkyu,Nah, In Wook THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2018 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.62 No.-

<P><B>Abstract</B></P> <P>Granular activated carbon (GAC) was coated by a uniform nanosized MnO<SUB>2</SUB> layer with a thickness of 0.5μm using a redox process in order to enhance its ability to decompose the H<SUB>2</SUB>O<SUB>2</SUB> aerosols formed from decontamination applications. The surface characteristics of the resulting MnO<SUB>2</SUB>/GAC indicated that it possessed an amorphous structure with manganese of the oxidation state +4, as confirmed by SEM, EDS, XPS, SAED and BET analyses. The H<SUB>2</SUB>O<SUB>2</SUB> aerosols decomposition activity of the new catalyst was found to be more than 20–30% higher than that of bare GAC.</P>