• Title/Summary/Keyword: Chemical energy

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Electrocatalytic Activity of Sulfamic Acid Doped Polyaniline Nanofiber Counter Electrode for Dye Sensitized Solar Cell

  • Jo, Chul-Gi;Ameen, Sadia;Akhtar, M.Shaheer;Kim, Young-Soon;Yang, O-Bong;Shin, Hyung-Shik
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.385-385
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    • 2009
  • Uniform polyaniline nanofibers (PANI NFs), and chemically doped sulfamic acid(SFA) PANI NFs, synthesized via template free interfacial polymerization process, were used as new counter electrodes materials for the fabrication of the highly-efficient dyesensitized solar cells (DSSCs). The PANI NFs based fabricated DSSCs exhibited a solarto-electricity conversion efficiency of ~ 4.02% while, the SFA doped PANI NFs based DSSC demonstrated ~ 27% improvement in the solar-to-electricity conversion efficiency. The obtained solar-to-electricity conversion efficiency for SFA doped PANI NFs based DSSC was 5.47% under 100mW/$cm^2$(AM1.5). The enhancement in the conversion efficiency was due to the incorporation of SFA into the PANI NFs which resulted to the higher electrocatalytic activity for the $I^{3-}/I^-$ redox reaction.

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Equilibrium Thermodynamics of Chemical Reaction Coupled with Other Interfacial Reactions Such as Charge Transfer by Electron, Colligative Dissolution and Fine Dispersion: A Focus on Distinction between Chemical and Electrochemical Equilibria

  • Pyun, Su-Il;Lee, Sung-Jai;Kim, Ju-Sik
    • Journal of the Korean Electrochemical Society
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    • v.11 no.4
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    • pp.227-241
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    • 2008
  • This article involves a unified treatment of equilibrium thermodynamics of the chemical reaction coupled with other interfacial (phase boundary) reactions. The modified (restrictive) chemical potential ${\mu}_k^+$, such as electrochemical potential, hydrostatic-chemical (mechanochemical) potential (exceptionally in the presence of the pressure difference) and surface-chemical potential, was first introduced under the isothermal and isobaric conditions. This article then enlightened the equilibrium conditions in case where the release of chemical energy is counterbalanced by the supply of electrical energy, by the supply of hydrostatic work (exceptionally in the presence of ${\Delta}p$), and finally by the release of surface energy, respectively, at constant temperature T and pressure p in terms of the modified chemical potential ${\mu}_k^+$. Finally, this paper focussed on the difference between chemical and electrochemical equilibria based upon the fundamentals of the isothermal and isobaric equilibrium conditions described above.

Continuous methanol synthesis directly from methane and steam over Cu(II)-exchanged mordenite

  • Lee, Sae Ha;Kang, Jong Kyu;Park, Eun Duck
    • Korean Journal of Chemical Engineering
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    • v.35 no.11
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    • pp.2145-2149
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    • 2018
  • The formation of methanol directly from methane and steam was observed over Cu ion-exchanged mordenite. Furthermore, the continuous production of methanol was achieved by co-feeding methane and steam over Cumordenite. The methanol production rate was comparable to that reported in the stepwise process in which activation, methane reaction, and extraction of methanol were carried out separately.

Study on the Properties of UV Curing Thermal Conductive and Pressure Sensitive Adhesive Using Inorganic Fillers

  • Oh, Ji-Hwan;Choi, Jin-Yeong;Kim, Su-Hwan;Jang, Se-Hoon;Shin, Yoo-Jin;Kim, Dae-Hyun;Yoo, Hwan-Kyu;Cho, Ur Ryong
    • Elastomers and Composites
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    • v.52 no.1
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    • pp.22-26
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    • 2017
  • The thermal conductivity and the adhesive properties were measured, after synthesis of thermal conductive composite which was obtained as a result of mixing alumina or graphite with acrylic adhesive synthesized by UV polymerization. The adhesive properties of the composite were evaluated measuring the peel strength at 180 degrees, the retention, and the initial tack;the thermal conductivity was estimated using laser flash analysis. As the filler contents increased, a decrease in peel strength and initial tack and an increase in retention and thermal conductivity were observed. When compared to alumina, the adhesion of graphite showed a dramatic decrease, whereas the thermal conductivity was further enhanced. It was found out that the small size of graphite increased the mechanical interlocking between the polymer and the filler, and it was easier for graphite to come into contact with other graphite in the matrix.

Initial Reaction of Hexachlorodisilane on Amorphous Silica Surface for Atomic Layer Deposition Using Density Functional Theory

  • Kim, Ki-Young;Yang, Jin-Hoon;Shin, Dong-Gung;Kim, Yeong-Cheol
    • Journal of the Korean Ceramic Society
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    • v.54 no.5
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    • pp.443-447
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    • 2017
  • The initial reaction of hexachlorodisilane ($Si_2Cl_6$, HCDS) on amorphous silica ($SiO_2$) surface for atomic layer deposition was investigated using density functional theory. Two representative reaction sites on the amorphous $SiO_2$ surface for HCDS reaction, a surface hydroxyl and a two-membered ring, were considered. The reaction energy barrier for HCDS on both sites was higher than its adsorption energy, indicating that it would desorb from the surface rather than react with the surface. At high temperature range, some HCDSs can have kinetic energy high enough to overcome the reaction energy barrier. The HCDS reaction on top of the reacted HCDS was investigated to confirm its self-limiting characteristics.