• Title/Summary/Keyword: 수소 이온 전도도

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Preparation and Characterization of Jochung, a Grain Syrup, with Onion (옥총(玉葱) 첨가 조청의 제조 및 특성)

  • Kim, D.H.;Kim, Y.B.;Koo, H.J.;Baek, H.J.;Chang, K.J.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.22 no.1
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    • pp.145-152
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    • 2020

  • Onion is a perennial herb of the lily family that has a long history and has long been widely used throughout the world as it is one of the most important condiments in our diet, along with chili peppers and garlic. It has been used for cooking and processing food with its unique flavor and aroma. Because of the nature of onions, long-term storage can lead to spoilage. Research was done to increase profits through processing and expand various onion products. A low temperature extraction method was used to study the physiological activation effect and onion processing method of flavonoid component weak to heat.

  • https://doi.org/10.23097/JPAF.2020.22(1):145 인용 PDF

Role of Electrode Reaction of Electrolyte in Electrokinetic-Fenton Process for Phenanthrene Removal (동전기-펜턴 공정에서 전해질의 전극반응이 처리효율에 미치는 영향)

  • Park Ji-Yeon;Kim Sang-Joon;Lee You-Jin;Yang Ji-Won
    • Journal of Soil and Groundwater Environment
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    • v.11 no.1
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    • pp.7-13
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    • 2006

  • The effects of electrolytes were investigated on the removal efficiency when several different electrolytes were used to change the electrode reaction in an electrokinetic (EK)-Fenton process to remediate phenanthrene-contaminated soil. Electrical potential gradient decreased initially due to the ion entrance into soil and then increased due to the ion extraction from soil under the electric field. Accumulated electroosmotic flow was $NaCl>KH_2PO_4>MgSO_4$ at the same concentration because the ionic strength of $MgSO_4$ was the highest and $Mg(OH)_2$ formed near the cathode reservoir plugged up soil pore to inhibit water flow. When hydrogen peroxide was contained in electrolyte solution, removal efficiency increased by Fenton reaction. When NaCl was used as an electrolyte compound, chlorine ($Cl_2$) was generated at the anode and dissolved to form hypochlorous acid (HClO), which increased phenanthrene removal. Therefore, the electrode reaction of electrolyte in the anode reservoir as well as its transport into soil should be considered to improve removal efficiency of EK-Fenton process.

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A Review on Development of PPO-based Anion Exchange Membranes (PPO 기반 음이온 교환막 소재 개발 동향)

  • An, Seong Jin;Kim, Ki Jung;Yu, Somi;Ryu, Gun Young;Chi, Won Seok
    • Membrane Journal
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    • v.31 no.6
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    • pp.371-383
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    • 2021

  • Anion exchange membranes have been used for water electrolysis, which can produce hydrogen, and fuel cells, which can generate electrical energy using hydrogen fuel. Anion exchange membranes operate based on hydroxide ion (OH-) conduction under alkaline conditions. However, since the anion exchange membrane shows relatively low ion conductivity and alkaline stability, there is still a limit to its commercialization in water electrolysis and fuel cells. To address these issues, it is important to develop novel anion exchange membrane materials by rationally designing a polymer structure. In particular, the polymer structure and synthetic method need to be controlled. By doing so, for polymers, the physical properties, ionic conductivity, and alkaline stability can be maintained. Among many anion exchange membranes, poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) is commercially available and easily accessible. In addition, the PPO has relatively high mechanical and chemical stability compared to other polymers. In this review, we introduce the recent development strategy and characteristics of PPO-based polymer materials used in anion exchange membranes.

  • https://doi.org/10.14579/MEMBRANE_JOURNAL.2021.31.6.371 인용 PDF KSCI

Research Trends on Developments of High-performance Perfluorinated Sulfonic Acid-based Polymer Electrolyte Membranes for Polymer Electrolyte Membrane Fuel Cell Applications (고분자 전해질 막 연료전지 응용을 위한 고성능 과불소화계 전해질 막 개발 연구 동향)

  • Choi, Chanhee;Hwang, Seansoo;Kim, Kihyun
    • Membrane Journal
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    • v.32 no.5
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    • pp.292-303
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    • 2022

  • An eco-friendly energy conversion device without the emission of pollutants has gained much attention due to the rapid use of fossil fuels inducing carbon dioxide emissions ever since the first industrial revolution in the 18th century. Polymer electrolyte membrane fuel cells (PEMFCs) that can produce water during the reaction without the emission of carbon dioxide are promising devices for automotive and residential applications. As a key component of PEMFCs, polymer electrolyte membranes (PEMs) need to have high proton conductivity and physicochemical stability during the operation. Currently, perfluorinated sulfonic acid-based PEMs (PFSA-PEMs) have been commercialized and utilized in PEMFC systems. Although the PFSA-PEMs are found to meet these criteria, there is an ongoing need to improve these further, to be useful in practical PEMFC operation. In addition, the well-known drawbacks of PFSA-PEMs including low glass transition temperature and high gas crossover need to be improved. Therefore, this review focused on recent trends in the development of high-performance PFSA-PEMs in three different ways. First, control of the side chain of PFSA copolymers can effectively improve the proton conductivity and thermal stability by increasing the ion exchange capacity and polymer crystallinity. Second, the development of composite-type PFSA-PEMs is an effective way to improve proton conductivity and physical stability by incorporating organic/inorganic additives. Finally, the incorporation of porous substrates is also a promising way to develop a thin pore-filling membrane showing low membrane resistance and outstanding durability.

  • https://doi.org/10.14579/MEMBRANE_JOURNAL.2022.32.5.292 인용 PDF KSCI