• Title, Summary, Keyword: $AgBF_4$

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Poly(ethylene oxide)/AgBF4/Al(NO3)3/Ag2O Composite Membrane for Olefin/Paraffin Separation (올레핀/파라핀 분리를 위한 poly(ethylene oxide)/AgBF4/Al(NO3)3/Ag2O 복합체 분리막)

  • Jeong, Sooyoung;Kang, Sang Wook
    • Membrane Journal
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    • v.27 no.4
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    • pp.313-318
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    • 2017
  • For the separation of olefins/paraffins, $Poly(ethylene oxide)(PEO)/AgBF_4/Al(NO_3)_3/Ag_2O$ composite membranes were prepared. When $Ag_2O$ was introduced, the initial selectivity and permeance of composite membranes were observed to be 13.7 and 21.7 GPU, respectively. The increase in performance compared to the initial performance of $PEO/AgBF_4/Al(NO_3)_3$ membrane (selectivity 13 and permeance 7.5 GPU) was thought to be due to the increase of Ag ion activity due to the addition of $Ag_2O$. However, performance degradation over time was observed, which was thought to be due to the polymer matrix PEO. Since the PEO polymer could not stabilize the $Ag_2O$ particles, the $Ag_2O$ particles becmae aggregated together as the solvent evaporates, and $Ag_2O$ acts as a barrier. As a result, the permeance decreases over time.

Fabrication of Poly(ethylene oxide)/Ag Nanoparticles/p-benzoquinone Composite Membrane Using AgNO3 Precursor for Olefin/Paraffin Separation (올레핀/파라핀 분리용 AgNO3 전구체를 활용한 poly(ethylene oxide)/Ag nanoparticles/p-benzoquinone 복합체 분리막 제조)

  • kim, Minsu;Kang, Sang Wook
    • Membrane Journal
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    • v.28 no.4
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    • pp.260-264
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    • 2018
  • Poly (ethylene oxide) (PEO)/Ag nanoparticles (AgNPs)(precursor : $AgBF_4$)/p-benzoquinone (p-BQ) composite membrane was prepared for olefin/paraffin separation. As a result, the performance of composite membrane was observed to be maintained at selectivity of 10 and permeance of 15 GPU up to 100 hours. The performance of the membrane was maintained for 100 hours was attributable to that Ag ions could be converted into stable Ag NPs by addition of p-BQ. Furthermore, the surface was partially polarized by the electron acceptor p-BQ, resulting in the formation of olefin carrier. In this study, since the cost of $AgBF_4$ used as a precursor of Ag NPs was relatively higher, $AgNO_3$ was utilized. As a result, it was confirmed that $AgNO_3$ couldn't show the stable formation of nanoparticle, resulting in the poor separation performance.

Preparation of PEBAX-5513/Ag Nanoparticles/7,7,8,8-tetracyanoquinodimethane Composites for Olefin Separation and Analysis of Anions (올레핀 분리용 PEBAX-5513/Ag Nanoparticles/7,7,8,8-tetracyanoquinodimethane 복합체 제조 및 음이온 효과 분석)

  • Kim, Soyoung;Kang, Sang Wook
    • Membrane Journal
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    • v.29 no.5
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    • pp.246-251
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    • 2019
  • Facilitated transport membranes using silver nanoparticles as carriers for olefin/paraffin separation have been interested. $AgBF_4$ has been used as a precursor of silver nanoparticles in previous studies. However, relatively expensive $AgBF_4$ is not suitable for commercialization, and thus, PEBAX-5513/AgNPs (precursor: $AgClO_4$)/7,7,8,8-tetracyanoquinodimethane (TCNQ) composite membranes were prepared using silver nanopaticles with relatively inexpensive $AgClO_4$ precursors. Composite membranes of various compositions were prepared for PEBAX-5513/AgNPs/TCNQ composites, but no separation performance was observed. As a result of FT-IR analysis, it was confirmed that silver nanoparticles were formed in the PEBAX-5513 polymer and the surface of Ag nanoparticles was polarized by TCNQ, but the formed silver nanoparticles were not stabilized. From these results, it was concluded that the anion of the precursor plays an important role in the olefin/paraffin separation.

Hydroacylation of 1,5-Hexadiene through C-H Bond Activation (탄소-수소 결합 활성을 이용한 1,5-헥사디엔의 하이드로아실화반응 연구)

  • Jeon, Cheol Ho;Han, Jong Su;Kim, Seon Il
    • Journal of the Korean Chemical Society
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    • v.38 no.11
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    • pp.833-840
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    • 1994
  • 8-Quinolinecarboxaldehyde (1) reacted with 1,5-hexadiene (2) in THF under Wilkinson's catalyst(3) and $AgBF_4(8)$ to give a mixture of 8-quinolinyl 5-hexenyl ketone (4) and 8-quinolinyl 5-hexen-2-yl ketone (9) at initial reaction stage. The reason for the formation of the branched alkenyl ketone 9 is supposed to be that the vacant coordination site, generated from Wilkinson's catalyst and $AgBF_4(8)$, makes it possible to form the 5.5 membered ring metallacycle intermediate. The higher the concentration of $AgBF_4(8)$ was used, the greater the ratio of 9 to 4 was observed. Longer reaction time and high temperature induced isomerization of 9 and 4 to 10 and 5. Especially the high reaction temperature increased the possibility of cyclization of the 5-hexenyl metal intermediate to give 8-quinolinyl cyclopentylmethyl ketone (11).

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AgBF4/[Bmim]BF4-Catalyzed [3+2] Cycloaddition of Cyclic Diazodicarbonyl Compounds: Efficient Synthesis of 2,3-Dihydrofurans and Conversion to 3-Acylfurans

  • Xia, Likai;Lee, Yong-Rok;Kim, Sung-Hong;Lyoo, Won-Seok
    • Bulletin of the Korean Chemical Society
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    • v.32 no.5
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    • pp.1554-1558
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    • 2011
  • A novel and efficient method for the synthesis of 2,3-dihydrofurans bearing a variety of substituents on the dihydrofuran ring was achieved by the reaction of cyclic diazodicarbonyl compounds with styrene and vinyl acetate. The key strategy was AgBF$_4$/[Bmim]BF$_4$-catalyzed [3+2] cycloaddition. The synthesized dihydrofurans with an acetate group were further converted to the corresponding 3-acylfurans.

Preparation of Polyvinylpyrrolidone/AgBF4/Al(NO3)3 Electrolyte Membranes for Facilitated Gas Transport (기체 촉진수송을 위한 polyvinylpyrrolidone/AgBF4/Al(NO3)3 전해질 분리막 제조)

  • Yoon, Ki Wan;Kang, Sang Wook
    • Membrane Journal
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    • v.26 no.1
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    • pp.38-42
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    • 2016
  • Polyvinylpyrrolidone (PVP), which is glassy polymer to have amide functional group, was induced to fabricate the facilitated olefin transport membranes for olefin/paraffin separation. Separation performance for the mixed gas consisting of propylene and propane (50 : 50 vol%) was measured by gas chromatography and bubble flow meter. The properties of membranes were confirmed by scanning electron microscope and FT-IR. The results of long-term separation tests showed the selectivity of 15 and permeance of 1.3 GPU. The membranes was compared with poly(2-ethyl-2-oxazoline) $(POZ)/AgBF_4/Al(NO_3)_3$ membranes and the characteristics were confirmed as polymer matrix for facilitated transport membranes.

Preparation of Silver Nanoparticles Using AgNO3 Precursor as Carrier for Olefin/Paraffin Separation and the Effect Analysis of NO3- (올레핀/파라핀 분리용 운반체로서 AgNO3 전구체를 활용한 은 나노입자 제조 및 NO3-의 효과 분석)

  • kim, Minsu;Kang, Sang Wook
    • Membrane Journal
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    • v.28 no.4
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    • pp.265-270
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    • 2018
  • In previous studies, a poly(ethylene oxide)(PEO)/Ag nanoparicles (AgNPs)(precursor $AgBF_4$)/p-benzoquinone (p-BQ) composite membrane was prepared for olefin/paraffin separation and the performance of this composite membrane was maintained at a selectivity of 10 and a permeability of 15 GPU. However, since the price of $AgBF_4$ precursor is high, this study used $AgNO_3$ as a precursor of Ag nanoparticles which is competitive in terms of price. As a result, it was observed that the separation performance was not obtained because the existing $NO_3{^-}$ could surround AgNPs. In this study, we fabricated PEO, poly(vinyl alcohol)(PVA), and polyether block amide-1657 (PEBAX-1657) polymer composite membrane using electron acceptor 7,7,8,8-tetracyanoquinodimethane (TCNQ) for separation performance even when $AgNO_3$ was used as a precursor of Ag nanoparticles. As a result, it was analyzed that the performance was not observed regardless of the influence of the polymer and the electron acceptor, indicating that the anion of the precursor plays a crucial role in the separation performance.

Propylene/Nitrogen Separation Membranes Based on Amphiphilic Copolymer Grafted from Poly(1-trimethylsilyl-1-propyne) (양친성 고분자가 그래프팅된 Poly(1-trimethylsilyl-1-propyne) 기반의 프로필렌/질소 분리막)

  • Park, Cheol Hun;Lee, Jae Hun;Park, Min Su;Kim, Jong Hak
    • Membrane Journal
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    • v.29 no.2
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    • pp.88-95
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    • 2019
  • Hydrocarbons containing carbon double bonds are generally called olefins and it is extensively used in petro-chemical industry as essential base material. Especially, olefins are essential in polymer synthesis and thus the effective separation and purification of olefins from gas mixture are very important and it gives significant positive effect on the future industrial development. In this study, we fabricated polymeric composite membrane based on poly(1-trimethylsilyl-1-propyne) (PTMSP) for propylene/nitrogen separation and enhancement of its separation performance by grafting amphiphilic copolymer. Furthermore, to accelerate facilitated transport for propylene molecules, Ag salt ($AgBF_4$) and ionic liquid ($EMIM-BF_4$) was incorporated to polymer composite membranes. The neat PTMSP membrane exhibited extremely high gas permeance and low gas selectivity due to its high free volume. To address this issue, PTMSP was grafted with poly(oxyethylene glycol methacrylate) (POEM) and poly(ethylene glycol) behenyl ether methacrylate (PEGBEM). Additionally, the additives such as $AgBF_4$ and $EMIM-BF_4$ further increased the propylene permeance, resulting in increment of propylene/nitrogen selectivity.

Effect of Salt on Facilitated Propylene Transport through Crosslinked PVA/Silver Salt Complex Membranes

  • Kim, Jong-Hak;Min, Byoung-Ryul;Lee, Ki-Bong;Kang, Yong-Soo
    • Korean Membrane Journal
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    • v.8 no.1
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    • pp.43-49
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    • 2006
  • Complex membranes consisting of silver salt ($AgBF_4,\;AgCF_3SO_3,\;AgSbF_6,\;AgNO_3$) and poly(vinyl alcohol) (PVA) or crosslinked PVA (CPVA) were prepared and tested for the separation of propylene/propane mixtures. For the tested membranes, the complex membranes containing $AgBF_4$ exhibited the highest separation properties, i.e., approximately 20 GPU ($1 GPU=10^{-6}cm^3 (STP)/(cm^2 sec cmHg)$) and 100 of selectivity at 0.2 of silver mole fraction. The CPVA membranes containing silver salt always showed higher selectivity than PVA membranes, presenting silver ions coordinated to -CHO are more effective than those to -OH groups. The threshold silver concentration of CPVA membranes was lower than that of PVA membranes, which might be due to stronger interaction of silver ions with -CHO than that with -OH. The composition at which the selectivity is the highest did not significantly depend on the crosslinking, but did on the kind of silver salt.

FT-Raman Studies on Ionic Interactions in ${\pi}$-Complexes of Poly(hexamethylenevinylene) with Silver Salts

  • Kim Jong-Hak;Min Byoung-Ryul;Won Jong-Ok;Kang Yong-Soo
    • Macromolecular research
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    • v.14 no.2
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    • pp.199-204
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    • 2006
  • Remarkably high and stable separation performance for olefin/paraffin mixtures was previously reported by facilitated olefin transport through ${\pi}$-complex membranes consisting of silver ions dissolved in poly(hexamethylenevinylene) (PHMV). In this study, the ${\pi}$-complex formation of $AgBF_4,\;AgClO_4\;and\;AgCF_{3}SO_3$ with PHMV and their ionic interactions were investigated. FT-Raman spectroscopy showed that the C=C stretching bands of PHMV shifted to a lower frequency upon incorporation of silver salt, but the degree of peak shift depended on the counter-anions of salt due to different complexation strengths. The symmetric stretching modes of anions indicated the presence of only free ions up to [C=C]:[Ag]=1:1, demonstrating the unusually high solubility of silver salt in PHMV. Above the solubility limit, the ion pairs and higher-order ionic aggregates started to form. The coordination number of silver ion for C=C of PHMV was in the order $AgBF_4$ > $AgClO_4$ > $AgCF_{3}SO_3$, but became similar at [C=C]:[Ag]=1:1. The different coordination number was interpreted in terms of the different transient crosslinks of silver cations in the complex, which may be related to both the interaction strength of the polymer/silver ion and the bulkiness of the counteranion.