• Title/Summary/Keyword: ionic liquids

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Promoting Effect of AlCl_3 on the Fe-catalyzed Dimerization of Bicyclo[2.2.1]hepta-2,5-diene

  • Nguyen, Mai Dao;Nguyen, Ly Vinh;Lee, Je-Seung;Han, Jeong-Sik;Jeong, Byung-Hun;Cheong, Min-Serk;Kim, Hoon-Sik;Kang, Ho-Jung
    • Bulletin of the Korean Chemical Society
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    • v.29 no.7
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    • pp.1364-1368
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    • 2008
  • The activity of the catalytic system composed of Fe$(acetylacetonate)_3$ (Fe$(acac)_3$), triphenylphosphine, and diethylaluminum chloride for the dimerization of bicyclo[2.2.1]hepta-2,5-diene (2,5-norbornadiene, NBD) to produce hexacyclic endo-endo dimer (hexacyclo[$7.2.1.0^{2,8}.1^{3,7}.1^{5,13}.0^{4,6}$]tetradec-10-ene, Hnn) was significantly enhanced by the presence of $AlCl_3$, especially at the molar ratios of NBD/Fe$(acac)_3$ of 500. XPS analysis of the catalytic systems clearly demonstrates that $AlCl_3$ facilitates the reduction of Fe$(acac)_3$ to form active species, Fe(II) and Fe(0) species. The layer separation was observed when [BMIm]Cl was used along with $AlCl_3$, but catalyst recycle was not very successful.

Equimolar Carbon Dioxide Absorption by Ether Functionalized Imidazolium Ionic Liquids

  • Sharma, Pankaj;Park, Sang-Do;Park, Ki-Tae;Jeong, Soon-Kwan;Nam, Sung-Chan;Baek, Il-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.7
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    • pp.2325-2332
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    • 2012
  • A series $[C_3Omim]$[X] of imidazolium cation-based ILs, with ether functional group on the alkyl side-chain have been synthesized and structure of the materials were confirmed by various techniques like $^1H$, $^{13}C$ NMR spectroscopy, MS-ESI, FTIR spectroscopy and EA. More specifically, the influence of changing the anion with same cation is carried out. The absorption capacity of $CO_2$ for ILs were evaluated at 30 and $50^{\circ}C$ at ambient pressure (0-1.6 bar). Ether functionalized ILs shows significantly high absorption capacity for $CO_2$. In general, the $CO_2$ absorption capacity of ILs increased with a rise in pressure and decreased when temperature was raised. The obtained results showed that absorption capacity reached about 0.9 mol $CO_2$ per mol of IL at $30^{\circ}C$. The most probable mechanism of interaction of $CO_2$ with ILs were investigated using FTIR spectroscopy, $^{13}C$ NMR spectroscopy and result shows that the absorption of $CO_2$ in ether functionalized ILs is a chemical process. The $CO_2$ absorption results and detailed study indicates the predominance of 1:1 mechanism, where the $CO_2$ reacts with one IL to form a carbamic acid. The $CO_2$ absorption capacity of ILs for different anions follows the trend: $BF_4$ < DCA < $PF_6$ < TfO < $Tf_2N$. Moreover, the as-synthesized ILs is selective, thermally stable, long life operational and can be recycled at a temperature of $70^{\circ}C$ or under vacuum and can be used repeatedly.

Review on Polymer Electrolyte Membranes for Dye-sensitized Solar Cells (염료감응 태양전지용 고분자 전해질막의 총설)

  • Lee, Jae Hun;Park, Cheol Hun;Lee, Chang Soo;Kim, Jong Hak
    • Membrane Journal
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    • v.29 no.2
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    • pp.80-87
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    • 2019
  • Dye-sensitized solar cells (DSSCs) have attracted great attention as sustainable energy devices. The efficiency and long-term stability of DSSCs are greatly influenced by electrode materials and electrolytes. In this review, we focused on the electrolytes of DSSCs. Polymer electrolyte membranes have been proposed as an alternative to conventional liquid electrolytes in DSSCs. Conventional liquid electrolytes can exhibit a high efficiency, but due to some problems such as poor long-term stability of device and leakage of liquid, much interest in polymer electrolyte membranes continues to rise and the papers on polymer electrolytes membranes have been extensively reported recently. This review covers the concept and development of polymer electrolyte membranes for DSSCs, and discusses the efficiency and electrochemical properties of DSSCs, highlighting the modification of polymer matrix, the introduction of additives such as organic-inorganic plasticizers and ionic liquids.

Design of Polymer Composites for Effective Shockwave Attenuation (충격파 완화 복합재의 설계)

  • Gyeongmin Park;Seungrae Cho;Hyejin Kim;Jaejun Lee
    • Composites Research
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    • v.37 no.1
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    • pp.21-31
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    • 2024
  • This review paper investigates the use of shockwave attenuating materials within composite structures to enhance personnel protection against blast-induced traumatic brain injury (bTBI). This paper also introduces experimental methodologies exploited in the generation and measurement of shockwaves to evaluate the performance of the shock dissipating composites. The generation of shockwaves is elucidated through diverse approaches such as high-energy explosives, shock tubes, lasers, and laser-flyer techniques. Evaluation of shockwave propagation and attenuation involves the utilization of cutting-edge techniques, including piezoelectric, interferometer, electromagnetic induction, and streak camera methods. This paper investigates phase-separated materials, including polyurea and ionic liquids, and provides insight into composite structures in the quest for shockwave pressure attenuation. By synthesizing and analyzing the findings from these experimental approaches, this review aims to contribute valuable insights to the advancement of protective measures against blast-induced traumatic brain injuries.