• Title/Summary/Keyword: oxide salt

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Improvement of Binding Property of the Alg-Na/PEO Blends (PEO를 이용한 Alg-Na 바인더의 물성향상)

  • Park, Yong Wan;Kim, Eui Hwa;Cho, Ho Hyun
    • Textile Coloration and Finishing
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    • v.26 no.1
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    • pp.32-38
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    • 2014
  • There has been increasing demand to the eco-friendly materials such as phytoncide which is extracted to plants in the textile industry, recently. It is interesting that alginic acid sodium salt(Alg-Na) is used to eco-friendly binder for the functional capsule finishing. In this study, we made PEO/Alg-Na blend solutions of various ratio and observed the changing binding property of the blend solutions according to PEO contents through FT-IR, DSC, contact angle, peel strength, etc. The viscosity of Alg-Na/PEO blend solutions increased with increase of contents and the viscosity quickly increased with increase of PEO content in Alg-Na 5% content, specially. It is shown that the hydrogen bond peak by blend of Alg-Na and PEO found through FT-IR analysis but the peak decreased in PEO above 60% content. And the peel strength was predominant in PEO 50% ratio.

Lithium Ion Concentration Dependant Ionic Conductivity and Thermal Properties in Solid Poly(PEGMA-co-acrylonitrile) Electrolytes

  • Kim, Kyung-Chan;Roh, Sae-Weon;Ryu, Sang-Woog
    • Journal of Electrochemical Science and Technology
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    • v.1 no.1
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    • pp.57-62
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    • 2010
  • The lithium ion concentration dependant ionic conductivity and thermal properties of poly(ethylene glycol) methyl ether methacrylate (PEGMA)/acrylonitrile-based copolymer electrolytes with $LiClO_4$ have been studied by differential scanning calorimetry (DSC), linear sweep voltammetry (LSV) and AC complex impedance measurements. In systems with 11 wt% of acrylonitrile all liquid electrolytes were obtained regardless of lithium ion concentration. Complex impedance measurements with stainless steel electrodes give ambient ionic conductivities $8.1\times10^{-6}\sim1.4\times10^{-4}S cm^{-1}$. On the other hand, a hard and soft films at ambient temperature were obtained in copolymer electrolyte system consists of 15 wt% acrylonitrile with 6 : 1 and 3 : 1 of [EO] : [Li] ratio, respectively. DSC measurements indicate the crystalline melting temperature of poly(PEGMA) disappeared completely after addition of $LiClO_4$ in this system due to the complex formation between ethylene oxide (EO) unit and lithium salt. As a result, free standing film with room temperature ionic conductivity of $1.7\times10^{-4}S cm^{-1}$ and high electrochemical stability up to 5.5V was obtained by controlling of acrylonitrile and lithium salt concentration.

Effect of the Anode-to-Cathode Distance on the Electrochemical Reduction in a LiCl-Li2O Molten Salt

  • Choi, Eun-Young;Im, Hun-Sook;Hur, Jin-Mok
    • Journal of the Korean Electrochemical Society
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    • v.16 no.3
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    • pp.138-144
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    • 2013
  • Electrochemical reductions of $UO_2$ at various anode-to-cathode distances (1.3, 2.3, 3.2, 3.7 and 5.8 cm) were carried out to investigate the effect of the anode-to-cathode distance on the electrochemical reduction rate. The geometry of the electrolysis cell in this study, apart from the anode-to-cathode distance, was identical for all of the electrolysis runs. Porous $UO_2$ pellets were electrolyzed by controlling a constant cell voltage in molten $Li_2O-LiCl$ at $650^{\circ}C$. A steel basket containing the porous $UO_2$ pellets and a platinum plate were used as the cathode and anode, respectively. The metallic products were characterized by means of a thermogravimetric analyzer, an X-ray diffractometer and a scanning electron microscope. The electrolysis runs conducted during this study revealed that a short anode-to-cathode distance is advantageous to achieve a high current density and accelerate the electrochemical reduction process.

Electrochemical Characteristics and Physical Properties of Poly(ethylene oxide)-Li based Polymer Electrolyte (Poly(ethylene oxide)-Li계 고분자 전해질의 전기화학적 특성 및 물리적 성질)

  • Kim, Hyung-Sun;Cho, Byung-Won;Yun, Kyung-Suk;Chun, Hai-Soo
    • Applied Chemistry for Engineering
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    • v.7 no.3
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    • pp.433-442
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    • 1996
  • Electrochemical characteristics and physical properties of polymer electrolyte which immobilized lithium salts such as $LiClO_4$ and $LiCF_3SO_3$ and plasticizers such as ethylene carbonate(EC) and propylene carbonate(PC) in high molecular weight poly(ethylene oxide)[PEO] polymer was investigated. PEO-Li based polymer electrolyte with plasticizers showed ionic conductivity of $10^{-4}S/cm$ at room temperature and high electrochemical stability up to 4.5 V(vs. $Li^+/Li$), so it can be applied to lithium secondary battery. The crystallinity of PEO decreased with the addition of lithium salts and plasticizers, especially $LiClO_4$ and PC showed more effective than and $LiCF_3SO_3$ and EC. Glass transition temperature($T_g$) of polymer electrolyte increased with increasing lithium salt concentration whereas melting temperature ($T_m$) decreased. Polymer electrolyte with plasticizers crystallized at $6^{\circ}C$.

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Polymers and Inorganics: A Happy Marriage?

  • Wegner Gerhard;Demir Mustafa M.;Faatz Michael;Gorna Katazyrna;Munoz-Espi Rafael;Guillemet Baptiste;Grohn Franziska
    • Macromolecular Research
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    • v.15 no.2
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    • pp.95-99
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    • 2007
  • The most recent developments in two areas: (a) synthesis of inorganic particles with control over size and shape by polymer additives, and (b) synthesis of inorganic-polymer hybrid materials by bulk polymerization of blends of monomers with nanosized crystals are reviewed. The precipitations of inorganics, such as zinc oxide or calcium carbonate, in presence and under the control of bishydrophilic block or comb copolymers, are relevant to the field of Biomineralization. The application of surface modified latex particles, used as controlling agents, and the formation of hybrid crystals in which the latex is embedded in otherwise perfect crystals, are discussed. The formation of nano sized spheres of amorphous calcium carbonate, stabilized by surfactant-like polymers, is also discussed. Another method for the preparation of nanosized inorganic functional particles is the controlled pyrolysis of metal salt complexes of poly(acrylic acid), as demonstrated by the syntheses of lithium cobalt oxide and zinc/magnesium oxide. Bulk polymerization of methyl methacrylate blends, with for example, nanosized zinc oxide, revealed that the mechanisms of tree radical polymerization respond to the presence of these particles. The termination by radical-radical interaction and the gel effect are suppressed in favor of degenerative transfer, resulting in a polymer with enhanced thermal stability. The optical properties of the resulting polymer-particle blends are addressed based on the basic discussion of the miscibility of polymers and nanosized particles.

Recent Progress in Waste Treatment Technology for Pyroprocessing at KAERI (파이로 공정폐기물 처리기술의 최근 KAERI 연구동향)

  • Park, Geun-Il;Jeon, Min Ku;Choi, Jung-Hoon;Lee, Ki-Rak;Han, Seung Youb;Kim, In Tae;Cho, Yung-Zun;Park, Hwan-Seo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.3
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    • pp.279-298
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    • 2019
  • This study comprehensively addresses recent progress at KAERI in waste treatment technology to cope with waste produced by pyroprocessing, which is used to effectively manage spent fuel. The goal of pyroprocessing waste treatment is to reduce final waste volume, fabricate durable waste forms suitable for disposal, and ensure safe packaging and storage. KAERI employs grouping of fission products recovered from process streams and immobilizes them in separate waste forms, resulting in product recycling and waste volume minimization. Novel aspects of KAERI approach include high temperature treatment of spent oxide fuel for the fabrication of feed materials for the oxide reduction process, and fission product concentration or separation from LiCl or LiCl-KCl salt streams for salt recycling and higher fission-product loading in the final waste form. Based on laboratory-scale tests, an engineering-scale process test is in progress to obtain information on the performance of scale-up processes at KAERI.

Synthesis of Mesoporous Titanium Dioxide Nanoparticles and Their Application into Dye Sensitized Solar Cells (다공성 산화타이타늄 나노입자 합성과 염료감응형 태양전지 응용)

  • Kim, Whidong;Ahn, Jiyoung;Kim, Soohyung
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.64.2-64.2
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    • 2010
  • In order to improve the overall power conversion efficiency in dye-sensitized solar cells (DSSCs), it is very important to secure the sufficient surface area of photocatalytic nanoparticles layer for absorbing dye molecules. It is because increasing the amount of dye absorbed generally results in increasing the amount of light harvesting. In this work, we proposed a new method for increasing the specific surface area of photocatalytic titanium oxide ($TiO_2$) nanoparticles by using an inorganic templating method. Salt-$TiO_2$ composite nanoparticles were synthesized in this approach by spray pyrolyzing both the titanium butoxide and sodium chloride solution. After aqueous removal of salt from salt-$TiO_2$ composite nanoparticles, mesoporous $TiO_2$ nanoparticles with pore size of 2~50 nm were formed and then the specific surface area of resulting porous $TiO_2$ nanoparticle was measured by Brunauer-Emmett-Teller (BET) method. Generally, commercially available P-25 with the average primary size of ~25 nm $TiO_2$ nanoparticles was used as an active layer for dye-sensitized solarcells, and the specific surface area of P-25 was found to be ~50 $m^2/g$. On the other hand, the specific surface area of mesoporous $TiO_2$ nanoparticles prepared in this approach was found to be ~286 $m^2/g$, which is 5 times higher than that of P-25. The increased specific surface area of $TiO_2$ nanoparticles will absorb relatively more dye molecules, which can increase the short curcuit current (Jsc) in DSSCs. The influence of nanoporous structures of $TiO_2$ on the performance of DSSCs will be discussed in terms of the amount of dye molecules absorbed, the fill factor, the short circuit current, and the power conversion efficiency.

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Screening of Peroxynitrite and DPPH Raoical Scavenging Activities from Salt Marsh Plants (염생식물로부터 Peroxynitrite와 DPPH 라디칼 소거 활성 검색)

  • 서영완;이희정;김유아;안종웅;이범종;문성기
    • KSBB Journal
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    • v.19 no.1
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    • pp.57-61
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    • 2004
  • A peroxynitrite is formed when superoxide and nitric oxide exist at near eqimolar ratio in biological systems. Although not a free radical by chemical nature, peroxynitrite is a powerful oxidant having a wide array of tissue damaging effects ranging from lipid oxidation and inactivation of enzymes and ion channels through protein oxidation and nitration to inhibition of mitochondrial respiration. During our search for new antioxidizing components from natural resources, twenty salt marsh plants were screened for their ONOO and DPPH radical scavenging activities. Among them, methanol extract of Rosa rugosa, lxeris tamagawaensis, Erigeron annus, Tetragonia tetragonoides, Imperata cylindrica, and Suaeda japonica inhibited more than 85% of peroxynitrite produced by 3-morpholinsydnonimine (SIN-1) at a concentration of 5 $\mu\textrm{g}$/$m\ell$. In addition, Rosa rugosa, Artemisia capillaris, Erigeron annus and Ixeris tamagawaensis showed significant scavenging effect against DPPH (1,1-diphenyl-2-picrylhydrazyl radical).

Study on the NiAl Coating for Corrosion Resistance of Stainless Steel in Molten Carbonate Salt (용융탄산염에 대한 스테인레스강의 내식성 향상을 위한 NiAl 피복에 관한 연구)

  • Hwang, Eung-Rim;Gang, Seong-Gun
    • Korean Journal of Materials Research
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    • v.7 no.1
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    • pp.76-80
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    • 1997
  • '4 NiAl coating process was applied on 316 stainless steel to retard the corrosion of the wet- seal area of separator for the molten carbonate fuel cell. The Nit11 phasc on the stainless steel substrate could be formed by pre-coating with Ni, plated with A1 and ther, heat treated at $800^{\circ}C$ for 3 hr in $H_2/N_2$ gas atmosphere. The corrosion protection behavior of YiAl coating layer was stuilied under immersion condition in molten cxhonate salt($62^{m}/_{o}Li_2CO_3-38^{m}/_{o}/K_{2}CO_{3}$) at $650^{\circ}C$. The NiAl coating layer ticposited on the AiSi 316 stainless steel had high corrosion resistance in molten carbor. dte salt. The corrosion resistance of XiAl (~~jpoared to be associated with the .A1 oxide formed on the surface of coating layer.

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Nitric oxide-Releasing Chitosan Nanoparticles; A Potential Impeding Strategy Against Salinity Stress in Arabidopsis thaliana

  • Waqas Rahim;Anjali Pande;Nusrat Jahan Methela;Da-Sol Lee;Bong-Gyu Mun;Hak-Yoon Kim;Byung-Wook Yun
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.157-157
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    • 2022
  • Plants being sessile are prone to various abiotic challenges, including salinity. Plants generally cope with salt stress by regulating their endogenous NO levels. NO exogenously applied in various forms also successfully impedes the salt stress, but its small size, short half life, and high volatility rate hamper its application in agriculture. NO application via CS as a nanocarrier is an alternate option to ensure the optimal kinetic release of NO for a long period compared to the free NO form. Herein, we synthesized and characterized GSNO-CS NP by ionic gelation of TPP with CS and then reacting with GSH, followed by reaction with NaNO2 suspension. The synthesized NPs were characterized using non-destructive analytical techniques such as DLS, FTIR, and SEM to ensure their synthesis and surface morphology. NO-release profile confirmed optimal kinetic NO release for 24 h from NO-CS NP as compared to free NO form. The efficiency of NO-CS NP was checked on Arabidopsis plants under salinity stress by gauging the morphological, physiological, and enzymatic antioxidant system and SOS pathway gene expression levels. Overall, the results revealed that NO-CS NP successfully mitigates salinity stress compared to free GSNO. Concluding, the findings provide sufficient experimental evidence for the application of nanotechnology to enhance NO delivery, thus inducing more benefits for the plants under stress conditions by mitigating the deleterious impacts of salt stress on the morphological and physiological status of the plants, and regulating the ions exchange by overexpression of SOS pathway candidate genes.

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