• 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.

• 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.

• 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.

• 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).

• 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.

• 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.

• 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.

• 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.

• Membrane Journal
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• v.31 no.1
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• pp.61-66
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• 2021

This study was a study on an facilitated transport membrane to replace the cryogenic separation method currently used in olefin/paraffin separation. Cost reduction is also a very important factor to commercialize facilitated transport membranes. However, AgBF4, which has been studied a lot, is a relatively expensive silver salt. To replace this, a PEBAX-2533/ AgCF3SO3/Al(NO3)3 composite film was prepared using relatively inexpensive AgCF3SO3. It was analyzed through SEM, FT-IR, and RAMAN. Through this study, it was confirmed that the polymer matrix affects the long-term stability.

• 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.