• Title/Summary/Keyword: non-chemical

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Analysis of Surface Properties of PVC Thin Film according to Addition of Non-solvent to PVC-THF Solution (PVC-THF 용액에 비용매 첨가에 따른 PVC 박막의 표면 특성 분석)

  • Lee, Seung Gyu;Moon, Je Cheol;Lee, Won Gyu
    • Applied Chemistry for Engineering
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    • v.33 no.4
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    • pp.367-372
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    • 2022

  • The effect of the addition of a polyvinylchloride (PVC) non-solvent to a PVC-tetrahydrofuran (THF) solution on the surface properties of the PVC thin film was analyzed. The non-solvents used were composed of alcohol-based and non-alcoholic ones. Surface morphologies of PVC thin films according to the addition of the non-solvent were compared. In addition, the hydrophobic properties relying on the surface characteristics were compared. The micro-bubbles generated in the preparation of PVC-THF solution affected the surface morphology of the thin film. In order to implement the normal surface physical properties of the coating thin film at the relatively high concentration of PVC-THF solution, the selection of appropriate drying method was required. When an alcohol-based non-solvent was added, a PVC thin film having a granular porous surface was obtained and exhibited super hydrophobic properties. The volume ratio of the PVC-THF solution to the non-solvent affects the surface shape of the coating thin film. The larger the amount of non-solvent was added, the more advantageous it was to form a super hydrophobic PVC thin film.

  • https://doi.org/10.14478/ace.2022.1033 인용 PDF KSCI

Prediction of a Strong Effect of a Wek Magnetic Field on Diffusion Assisted Reactions in Non Equilibrium Conditions

  • Kipriyanov, Alexey A. Jr.;Purtov, Peter A.
    • Bulletin of the Korean Chemical Society
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    • v.33 no.3
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    • pp.1009-1014
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    • 2012

  • The influence of magnetic fields on chemical processes has long been the subject of interest to researchers. For this time numerous investigations show that commonly the effect of a magnetic field on chemical reactions is insignificant with impact less than 10 percent. However, there are some papers that point to the observation of external magnetic field effect on chemical and biochemical systems actually having a significant impact on the reactions. Thus, of great interest is an active search for rather simple but realistic models, that are based on physically explicit assumptions and able to account for a strong effect of low magnetic fields. The present work theoretically deals with two models explaining how an applied weak magnetic field might influence the steady state of a non-equilibrium chemical system. It is assumed that external magnetic field can have effect on the rates of radical reactions occurring in a system. This, in turn, leads to bifurcation of the nonequilibrium stationary state and, thus, to a drastic change in the properties of chemical systems (temperature and reagent concentration).

  • https://doi.org/10.5012/bkcs.2012.33.3.1009 인용 PDF KSCI

Synthesis of binary Cu-Se and In-Se nanoparticle inks using cherry blossom gum for CuInSe2 thin film solar cell applications

  • Pejjai, Babu;Reddy, Vasudeva Reddy Minnam;Seku, Kondaiah;Cho, Haeyun;Pallavolu, Mohan Reddy;Le, Trang Thi Thuy;Jeong, Dong-seob;Kotte, Tulasi Ramakrishna Reddy;Park, Chinho
    • Korean Journal of Chemical Engineering
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    • v.35 no.12
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    • pp.2430-2441
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    • 2018

  • Selenium (Se)-rich binary Cu-Se and In-Se nanoparticles (NPs) were synthesized by a modified heat-up method at low temperature ($110^{\circ}C$) using the gum exudates from a cherry blossom tree. Coating of CISe absorber layer was carried out using Se-rich binary Cu-Se and In-Se NPs ink without the use of any external binder. Our results indicated that the gum used in the synthesis played beneficial roles such as reducing and capping agent. In addition, the gum also served as a natural binder in the coating of CISe absorber layer. The CISe absorber layer was integrated into the solar cell, which showed a power conversion efficiency (PCE) of 0.37%. The possible reasons for low PCE of the present solar cells and the steps needed for further improvement of PCE were discussed. Although the obtained PCE is low, the present strategy opens a new path for the fabrication of eco-friendly CISe NPs solar cell by a relatively chief non-vacuum method.

  • https://doi.org/10.1007/s11814-018-0155-0 인용 KSCI

Synthesis of New Bimetallic Chiral Salen Catalyst Bearing Co(BF4)2 Salt and Its Application in Asymmetric Ring Opening of Epoxide

  • Kim, Yong-Suk;Lee, Choong-Young;Kim, Geon-Joong
    • Bulletin of the Korean Chemical Society
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    • v.31 no.10
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    • pp.2973-2979
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    • 2010

  • The newly synthesized homogeneous chiral Co(III) salen complexes were anchored non-covalently on the acidic sites of mesoporous Al-SBA-15. The Bronsted and Lewis acidic sites are attributed to the immobilization of fluorine functionalized chiral salen complexes on the supports. XRD, BET, TEM, FT-IR and ESCA (XPS) analyses were performed to characterize the property of support, and the structure of new homogeneous and heterogeneous chiral Co salen catalyst. The homogeneous and heterogeneous catalysts could be applied in asymmetric ring opening of epichlorohydrine (ECH) by water. They showed very high enantioselectivity and a good yield up to 99% in the catalytic synthesis of optically active products.

  • https://doi.org/10.5012/bkcs.2010.31.10.2973 인용 PDF KSCI