• Title/Summary/Keyword: 화학공학

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Characteristics of Silver Electrode Formed from Nano-Sized Silver and Glass Powders (나노 크기의 실버 및 글래스 분말로부터 형성된 실버 전극의 특성)

  • Koo, Hye Young;Kim, Jung Hyun;Yi, Jang Heui;Ko, You Na;Kang, Yun Chan
    • Korean Journal of Metals and Materials
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    • v.48 no.6
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    • pp.570-574
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    • 2010
  • Silver conducting films were formed from nano-sized silver powders and glass frits prepared by flame spray pyrolysis. The mean sizes of the silver powders and glass frits were 73 and 63 nm, respectively. Nano-sized glass frits improved the adhesion strength of the silver conducting film to the glass substrate. The densities of the silver conducting films increased by increasing the glass contents of the films at firing temperatures of 400 and $500{^{\circ}C}$. The specific resistances of the silver conducting films with 5 wt.% glass of silver component were 7.8, 4.2 and 2.4 cm at firing temperatures of 400, 450 and $500{^{\circ}C}$.

Experimental resarch for sensor-based chemical identification (센서기반 화학물질 식별을 위한 실험적 연구)

  • Nam, Su Han;Ku, Tae Geom;Park, Ye Lim;Lee, Jeong Min;Kwon, Jae Hyun;Kim, Young Do
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.142-142
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    • 2020
  • 하천에서의 화학사고는 자연적 및 인위적인 원인으로 인해 발생할 수 있으며, 대량의 화학물질이 하천으로 유입되는 것을 말한다. 이러한 화학사고는 수환경의 변화를 야기해 생태계나 인간에게 악영향을 초래하여 심각한 문제가 발생 될 수 있다. 하천으로 유입된 화학물질의 정량적 평가에 대한 연구는 활발하게 진행되고 있지만, 화학사고 초기 대응을 위한 하천에서의 화학물질 감지에 대한 연구는 미비한 실정이다. 한국 하천의 주요 지점에는 pH 및 EC 등을 실시간으로 측정하는 자동측정망을 운영하고 있기 때문에 이러한 측정항목들을 활용하여 화학물질을 감지하거나 식별 가능성에 대한 평가 연구는 하천 화학사고 대응을 위한 중요한 기초자료로 활용될 수 있다. 또한 분석된 결과를 바탕으로 미지의 화학물질을 다른 용매에 적용 시켰을 때 변화되는 pH 및 EC 결과와 통계적 수치비교를 통해 미지의 화학물질 식별 가능성을 평가하였다. 이를 통해 본 연구에서 선정한 pH 및 EC 항목이 화학물질 감지 및 식별을 위한 대체지표로써의 활용 가능성을 실험적 연구를 통해 평가하고자 하였다. 본 연구의 결과는 현장에서 쉽고, 신속하게 화학물질 감지 및 식별을 위한 정보를 제공할 수 있다는데 의미가 있으며, 화학사고의 신속한 대응을 위한 기초자료로 활용될 수 있을 것으로 판단된다.

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New Yellow Quinoline Derivatives Including Dione Moiety for Image Sensor Color Filters (이미지 센서 컬러 필터용 다이온 성분을 포함하는 신규 황색 퀴놀린 유도체)

  • Sunwoo, Park;Seyoung, Oh;Yuna, Kang;Hyukmin, Kwon;Sunwoo, Dae;Changyu, Lee;Dae Won, Kim;Min-Sik, Jang;Jongwook, Park
    • Applied Chemistry for Engineering
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    • v.34 no.1
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    • pp.80-85
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    • 2023
  • New yellow quinoline-dione dye derivatives were designed and synthesized for use in image sensor color filters. The synthesized compounds have a basic chemical structure composed of quinoline and dione groups. New materials were evaluated on the basis of their optical and thermal properties under conditions mimicking those of a commercial device fabrication process. A comparison of their related performances revealed that, between the two prepared compounds, 2-(3-hydroxyquinolin-2(1H)-ylidene)-1H-indene-1,3(2H)-dione (HQIDO) exhibited the superior performance as an image sensor color filter material, including a solubility greater than 0.5 wt% in propylene glycol monomethyl ether acetate solvent and a high decomposition temperature of 298 ℃, respectively. The results suggest that HQIDO can be used as a yellow dye additive in an image sensor colorant.

Oxygen Control in CdS Thin Film by UV Illumination in Chemical Bath Deposition (용액성장법에서 자외선 조사를 이용한 CdS의 산소함량 제어)

  • Baek, Hyeon-ji;Oh, Ji-A;Seo, Young-Eun;Shin, Hye-Jin;Cho, Sung-Wook;Jeon, Chan-Wook
    • Current Photovoltaic Research
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    • v.7 no.2
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    • pp.33-37
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    • 2019
  • In this paper, we compared the performance of $Cu(In,Ga)(S,Se)_2$ (CIGSSe) thin film solar cell with CdS buffer layer deposited by irradiating 365 nm UV light with 8 W power in Chemcial Bath Deposition (CBD) process. The effects of UV light irradiation on the thin film deposition mechanism during CBD-CdS thin film deposition were investigated through chemical and electro-optical studies. If the UV light is irradiated during the solution process, the hydrolysis of Thiourea is promoted even during the same time, thereby inhibiting the formation of the intermediate products developed in the reaction pathway and decreasing the pH of the solution. As a result, it is suggested that the efficiency of the CdS/CIGSSe solar cell is increased because the ratio of the S element in the CdS thin film increases and the proportion of the O element decreases. This is a very simple and effective approach to control the S/O ratio of the CdS thin film by the CBD process without artificially controlling the process temperature, solution pH or concentration.

A Study on Activity Testing of Various Catalysts for Hydrogen Production from Ammonia (암모니아로부터 수소 제조를 위한 다양한 촉매 활성 테스트에 관한 연구)

  • JAE-HYEOK LEE;KYOUNG-HA SHIN;JINSIL KANG;HYEONHUI SHIN;SEYEON PARK;YUJIN CHOI;WANGYU SONG;HO-GEUN AHN
    • Journal of Hydrogen and New Energy
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    • v.34 no.6
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    • pp.587-593
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    • 2023
  • This research project focused on the production of hydrogen through ammonia decomposition reactions while investigating how the reactivity of this process varies when employing different catalysts. Several metal oxide supports (Al2O3, La2O3, CeO2) were utilized as catalysts, with active metals from both the transition metal group (Co, Ni, Fe, Cr, Cu) and the noble metal group (Ru, Rh, Pd, Pt) impregnated onto these supports. Furthermore, the study examined how the reactivity evolves with changes in reaction temperature when employing the prepared catalysts. Additionally, the research delved into the distinctive activation energies associated with each of the catalysts. In this research, In the noble metal catalyst system, the order of high activity for ammonia decomposition reaction to produce hydrogen is Ru > Rh > Pt ≈ Pd. In the transition metal catalyst system, the order of high activity is Co > Ni > Fe > Cr > Cu.

차세대 태양전지 동향

  • Kim, Byeong-Man;Im, Seong-Jun;Lee, Jeong-Gyeong;Son, Jung-Geon;Jang, Hyeong-Su;Kim, Gi-Hwan;Sim, Jae-Won;Gi, Hyeon-Cheol;U, Han-Yeong;Kim, Jin-Yeong;Gwon, Tae-Hyeok
    • Bulletin of the Korea Photovoltaic Society
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    • v.7 no.1
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    • pp.33-49
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    • 2021

Study on the Fabrication of Various AAO Membranes for the Application of Li-ion Battery Separator (다양한 형태의 AAO membrane 제조 및 리튬이온 전지의 분리막 응용 연구)

  • Kim, Moonsu;Lim, Kyungmin;Ha, Jaeyun;Kim, Yong-Tae;Choi, Jinsub
    • Journal of the Korean institute of surface engineering
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    • v.54 no.5
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    • pp.213-221
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    • 2021
  • In order to improve the energy density and safety of Li-ion batteries, the development of a separator with high thermal stability and electrolyte wettability is an important desire. Thus, the ceramic separator to replace the polymer type is one of the most promising materials that can prevent short-circuit caused by the formation of dendrite and thermal deformation. In this study, we introduce the fabrication of various anodic aluminum oxide membranes for the application of Li-ion battery separators with the advantages of improved mechanical/thermal stability, wettability, and a high rate of Li+ migration through the membrane. Two different types of through-holes and branched anodic aluminum oxide membranes are well used in lithium-ion battery separators, however, branched anodic aluminum oxide membranes exhibit the most improved performance with capacity (126.0 mAh g-1 @ 0.3C), capacity drop at the high C-rate (30.6 %), and low internal resistance (8.2 Ω).

Study on the preparation of electrochemical exfoliated graphene/Fe oxide compound according to synthetic conditions (합성 조건 변화에 따른 전기화학적 박리 그래핀/철 산화물 복합체 제조 연구)

  • Park, Eunjin;Kim, Yong-Tae;Choi, Jinsub
    • Journal of the Korean institute of surface engineering
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    • v.55 no.2
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    • pp.84-90
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    • 2022
  • With the growing interest in energy storage and conversion systems including secondary batteries, capacitors, and water electrolysis, various electrode materials are being developed to improve the energy efficiency. Among them, graphene is regarded as one of the promising candidates owing to its exceptional properties - large surface area, and excellent electrical conductivity. Herein, we report a facile one-step electrochemical approach to synthesize exfoliated graphene/Fe oxide compound. The effect of experimental conditions - the types of applied voltage, kinds of counter electrodes, acidity of electrolyte on the synthesis of graphene/Fe oxide compound is investigated.

Recent Research Trends in Eco-Friendly Materials for Solving Environmental Microplastic Problems (미세플라스틱 문제 해결을 위한 친환경소재 연구동향)

  • Moon, Sung Min;Jeon, So Hui;Eom, Taesik;Shim, Bong Sup
    • Prospectives of Industrial Chemistry
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    • v.22 no.2
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    • pp.25-43
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    • 2019
  • 미세플라스틱으로 인한 환경생태오염이 심화함에 따라, 기존 난분해성 플라스틱을 대체할 수 있는 친환경 소재에 관심이 높아지고 있다. 또한 석유 기반 자원의 고갈 및 이산화탄소 배출로 인한 온난화 환경문제 등으로 기존 석유계 플라스틱 소재를 대체 보완하는 친환경 천연소재 개발의 사회적 요구는 더욱 커지고 있다. 이에, 생분해가 가능한 천연자원으로부터 다양한 물리 화학적 엔지니어링 기능성을 추가하여 플라스틱의 환경문제를 극복하려는 시도들이 활발히 진행되고 있다. 본 기고에서는 나노셀룰로오스, 생분해성 고분자, 멜라닌 소재를 중심으로 친환경 기능성 천연소재의 최신 연구 동향을 소개하고, 이의 기존 합성 플라스틱 대체응용 방안의 가능성을 탐색한다.

Biomimetic Nano Delivery Carrier and Surface Chemistry (생체모사 나노전달체 연구와 계면화학)

  • Oh, Seung-joo;Kim, Hee-Jin;Han, Sara;Jeong, Jae Hyun
    • Prospectives of Industrial Chemistry
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    • v.20 no.6
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    • pp.40-53
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    • 2017
  • 나노전달체 관련 기술은 다양한 질병 치료에 사용되어 단위세포 수준의 치료를 가능하게 할 뿐 아니라 영상 진단과 접목되어 질병의 진단 및 치료가 동시에 가능한 기술로 진화하고 있다. 본지에서는 이러한 연구 중 하나로 생체모사 나노전달체에 대해 다룬다. 다양한 면역세포 및 백혈구, 적혈구 등의 살아있는 세포의 기능을 나노전달체에 부여하여 전달효율 및 치료효과를 높이고자 하는 기술이다. 지금까지의 나노전달체 연구 및 개발 동향에 대하여 간략하게 살펴보고 특별히 최근 주목 받고 있는 생체모사 나노전달체의 개념, 제조 방법, 응용 및 앞으로의 전망에 대하여 논하였다.