• Title/Summary/Keyword: Ammonium bromide

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A Calix[4]pyrrole Bearing a Quaternary Ammonium Group: A Fluoride-Selective Anion Receptor

  • Oh, Ju Hyun;Lee, Joon Hwa;Kim, Sung Kuk
    • Journal of the Korean Magnetic Resonance Society
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    • v.25 no.4
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    • pp.45-50
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    • 2021
  • A calix[4]pyrrole (1) bearing a quaternary ammonium pendant via its meso phenoxy linker has been synthesized as the bromide salt form. It was revealed by 1H NMR spectroscopic analyses performed in DMSO-d6 that receptor 1 binds F- with high affinity and selectivity over other halide anions. The binding of receptor 1•Br- with F- and Cltakes place by anion metathesis with the anions including F- and Cl-.

An Expeditious Oxidative Aromatization of Hantzsch 1,4-Dihydropyridines to Pyridines Using Cetyltrimethylammonium Peroxodisulfate: A Phase Transferring Oxidant

  • Kumar, Parvin;Kumar, Ashwani
    • Bulletin of the Korean Chemical Society
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    • v.31 no.8
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    • pp.2299-2303
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    • 2010
  • A new approach to the use of potassium peroxodisulphate as an oxidizing reagent is proposed and applied to the case of oxidative aromatization of 1, 4-dihydropyridines with cetyltrimethylammonium peroxodisulfate, a phase transfer oxidant. We demonstrate how it is possible to increase the reactivity of potassium peroxodisulphate in the presence of phase transfer catalyst. Dealkylation in case of 4-n-alkyl/n-alkenyl was not obtained.

막을 이용한 상이동 촉매 반응기의 성능해석

  • 송철환;홍창식;최창균
    • Proceedings of the Membrane Society of Korea Conference
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    • 1994.04a
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    • pp.49-50
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    • 1994
  • 상호 불용성인 용매에 녹아있는 반응물들 간의 반응은 각 물질이 상 경계면을 뛰어 넘기가 어려워 매우 느린 속도로 진행된다. 그러나 상호 불용성인 비균질계에 상이동 촉매라는 제 3의 물질을 첨가하면 반응은 급격히 향상된다[1, 2]. 따라서 본 연구에서는 클로로벤젠 상의 브로모 옥탄이 TBABr(Tetra Butyl Ammonium Bromide) 이온 촉매의 존재 하에 수용액상의 요오드 이온과 반응하는 평판형 막반응기를 대상으로 수치모사를 수행하여 그 결과를 Stanley와 Quinn[3]의 실험값 및 수치모사치와 비교하였으며, 막 반응기의 모듈 선택, 설계 및 운영, scale-up시 고려되어야 할 사항들을 탐색연구하여 보았다.

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A Study on Polyester Fabric treated with Quarternary Ammonium Salt and Alkali (사급암모늄염/수산화나트륨용액에서 폴리에스테르 직물의 알칼리처리에 관한 연구)

  • 류효선
    • Journal of the Korean Home Economics Association
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    • v.25 no.4
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    • pp.9-18
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    • 1987
  • This study is conducted to investigate the influence of addition of quarternary ammonium salt(cetyl trimethyl ammonium bromide: CTAB) when polyester(PET) fabric is treated with sodium hydroxide(NaOH), depending on experimental variables such as CTAB concentration, NaOH concentration, time & temperature, and the change in physical & chemical properties of alkaline-hydrolyzed PET fabrics depending on their weight loss. The results are as follows: 1. By adding CTAB in aqueous NaOH, the weight loss of PET fabric is increased remarkably and until the concentration of CTAB is reached at its cmc, and the higher the concentration of CTAB are, the more weight loss on PET fibrics are. 2. The addition of CTAB in aqueous NaOH is most effective at lower NaON concentration(2%) among various NaOH concentration, on increasing the amount of weight loss, while there are almost similar results through various treatment time and temperature. 3. As the amount of weight of weight loss on PET fabric is increased, the increase of void space in the PET yarn, of softness & dyeability of PET fabric and the decrease of tensile strength are found. On the other hand, the moisture regain shows a little increase by alkaline-hydrolysis on PET fabric while vertical absorption test & water retention value are not sufficiently sensitive to distinguish between the hydrophillicity of untreated and treated PET fabric. The shrinkage of PET fabric is induced by swelling in hot aqueous NaOH regardless of NaOH concentration & addition of CTAB.

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Spectrophotometric Determination of Lanthanide Ions by Flow Injection Analysis (Flow Injection Analysis에 의한 란탄족 이온들의 흡광광도 정량)

  • Kang, Sam-Woo;Cho, Kwang-Hee
    • Analytical Science and Technology
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    • v.9 no.3
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    • pp.244-252
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    • 1996
  • Spectrophotometric properties of lanthanide complexes with methylthymol blue(MTB) and cetyltrimethylammonium bromide(CTAB) were studied and also lanthanide(III) ions were determined by flow injection analysis on the base of the above results. The absorption maxima of lanthanide(III)-MTB complexes in the presence of CTAB are 635nm with molar absorptivity of $4.51{\sim}6.11{\times}10^4Lmol^{-1}cm^{-l}$ at pH 5.8. The mole ratio of lanthanide(III) complexes with MTB is 1:2 in the presence of CTAB. The calibration curves of lanthanide(III) ions obey the Beer's law in the range of 0.1 to 0.4ppm under the optimum condition. The samples throughput was ca. $60hr^{-1}$. The interfering effect of some cations and anions was investigated. The ligand anions such as tartrate and citrate, many transition and rare earth elements interfered severely and must be removed before the determination of lanthanide(III) ions.

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Study on Poly(triazine bissulfide)s Derivatives being the Synthesized Optical Plastic Material (합성한 광학플라스틱 재료인 Poly(triazine bissulfide)s 유도체에 대한 연구)

  • Lee, Y.H.;Lee, D.H.;Kim, J.J.;Ha, T.W.;Cha, J.W.
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.481-489
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    • 2004
  • Poly(triazine bissulfide)s were synthesized from 6-dibutylamino-1,3,5-triazine-2,4-dithiol with bis(4-chloro-3-nitrophenyl)sulfone in the presence of the phase transfer catalyst, and from m-dibromide xylene and p-dibromide xylene with 6-dibutylamino-1,3,5-triazine-2,4-dithiol in the presence of cetyltrimethyl ammonium bromide at $70^{\circ}C$ for 24h. We could acquire the good results about solubility, thermal property, and molecular weight to make cast film. These results are important as base for the synthesis of functionalization polymer material being optical plastic material. The maximum algebra viscosity was 0.57~1.40dl/g at the temperature more than $50{\sim}60^{\circ}C$.

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A Study on Alumina Nanoparticle Dispersion for Improving Injectivity and Storativity of CO2 in Depleted Gas Reservoirs (고갈 가스전에서 CO2 주입성 및 저장성 향상을 위한 알루미나 나노입자의 분산 특성 연구)

  • Seonghak Cho;Chayoung Song;Jeonghwan Lee
    • Journal of the Korean Institute of Gas
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    • v.27 no.1
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    • pp.23-32
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    • 2023
  • In this study, the Al2O3 nanofluid was synthesized as an additive for improving the injection efficiency and storage capacity of carbon dioxide (CO2) in a depleted sandstone reservoir or deep saline aquifer. As the base fluid, deionized water (DIW) and saline prepared by referring to the composition of API Brine were used, and the fluid was synthesized by using Al2O3 nanofluid with CTAB (cetyltrimethyl-ammonium bromide), a cationic surfactant. After that, the dispersion stability was evaluated by using visual observation, dynamic light scattering (DLS), transmission electron microscope (TEM), and miscibility test. As a result, it was presented that stable nanofluid without agglomeration and precipitation after reaction with 70,000 ppm of brine could be synthesized when the nanoparticle concentration was 0.05 wt% or less.

Study of Polytriazine Derivatives having High Refrative Index (높은 굴절률을 가지는 Polytriazine 유도체에 대한 연구)

  • Lee, Y.H.;Kim, J.J.;Ha, T.W.;Cha, J.W.
    • Journal of Korean Ophthalmic Optics Society
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    • v.8 no.2
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    • pp.31-35
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    • 2003
  • Several poly(6-dialkylamino-1,3,5-triazine-2,4-dithioxylene) derivatives were synthesized by the polycondensation of 6-dialkylamino-1,3,5-triazine-2.4-dithiol with m- and p-dibromide xylene in a cetyltrimethyl ammonium bromide at $70^{\circ}C$ for 24h. The synthesized derivatives had refractive Indexes of 1.580~1.697 and had molar absorptivity of 97~196.6. In these derivatives, we knew that they are a polymer having high refraction indexes without double refraction because they contain triazine rings and sulfur atoms with high electron density.

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Stereoselective Solvolyses of Activated Esters in the Aggregate System of Imidazole-Containing Copolymeric Surfactants

  • Cho, I-Whan;Lee, Burm-Jong
    • Bulletin of the Korean Chemical Society
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    • v.10 no.2
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    • pp.172-177
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    • 1989
  • Stereoselective solvolyses of optically active activated esters in the aggregate system of optically active polymeric surfactants containing imidazole and benzene moieties were performed. The catalyst polymers employed were copolymers of N-methacryloyl-L-histidine methyl ester (MHis) with N,N-dimethyl-N-hexadecyl-N-[10-(p-methacryloylo xyphenoxycarbonyl)-decyl]ammonium bromide(DEMAB). In the solvolyses of N-carbobenzoxy-D- and L-phenylalanine p-nitrophenyl esters (D-NBP and L-NBP) by polymeric catalysts, copoly(MHis-DEMAB) exhibited not only increased catalytic activity but also enhanced enantioselectivity as the mole ${\%}$ of surfactant monomers in the copolymers increased. The polymeric catalysts showed noticeable enantioselective solvolyses toward D- and L-NBP of the substrates employed. As the reaction temperature was lowered for the solvolyses of D- and L-NBP with the catalyst polymer containing 3.5 mole ${\%}$ of MHis, the increased reaction rate and enhanced enantioselectivity were observed. The coaggregative systems of the polymer and monomeric surfactants were also investigated. In the case of coaggregate system consisted of 70 mole ${\%}$ of cetyldimethylethylammonium bromide with polymeric catalyst showed maximum enantioselective catalysis, viz., $k_{cat}(L)/k_{cat}(D)$ = 2.85. The catalyst polymers in the sonicated solvolytic solutions were confirmed to form large aggregate structure by electron microscopic observation.

Preparation, Physical Characteristics and Antibacterial Finishing of PCM/Nylon Fibers having Sheath/Core Structure (상전이물질(PCM)과 Nylon 6를 이용한 Sheath/Core 형태의 복합섬유 제조, 물리적 특성 및 항균가공특성 연구)

  • Kim, Hak-Soo;Hwang, Ji-Yong;Lim, Sang-Hyun;Lim, Jeong-Nam;Son, Young-A
    • Textile Coloration and Finishing
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    • v.26 no.4
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    • pp.311-321
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    • 2014
  • In this study, Aftertreatment properties of PCM/Nylon sheath/core fabrics have been determined. Especially, the relationship between finishing property and content including of PCM ratio. Samples of PCM/Nylon fabrics were monitored, separately, with 2% o.w.f solutions of each of the berberine chloride, cetylpyridinium chloride(CPC), benzyldimethylhexadecyl ammonium chloride(BDHAC) and dodecyltrimetyl ammonium bromide(DTAB). Various temperatures and liquor ratio and pH conditions were also studied to optimize aftertreatment properties. Berberine chloride finished sample showed the good color fastness. Cetylpyridinium chloride(CPC) finished sample showed very effective antibacterial properties against Staphylococcus aureus and Klebsiella pneumoniae.