• 제목/요약/키워드: oligo (ethylene glycol)

검색결과 7건 처리시간 0.02초

Characterization of a Cross-linked Polymer Electrolyte Prepared from Oligo(ethylene glycol) methacrylates-Acrylonitrile

  • Lee, Chang-Ryoul;Hyun, Seok-Hee;Lee, Suk-Kee;Kim, Woo-Sik;Moon, Seong-In;Jin, Bong-Soo
    • Macromolecular Research
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    • 제9권5호
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    • pp.292-295
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    • 2001
  • A cross-linked solid polymer electrolyte was prepared by copolymerizing photochemically acrylonitrile (AN), oligo(ethylene glycol ethyl ether) methacrylate, oligo(ethylene glycol) dimethacrylate in the presence of lithium perchlorate as a lithium salt, ethylene carbonate-propylene carbonate as a mixed plasticizer, and poly(ethylene oxide) as a polymer matrix. The maximum ionic conductivity of the polymer electrolyte was 2.35$\times$10$\^$-3/ S/cm. The interface resistance of the polymer electrolyte was very low compared to that of the polymer electrolyte without AN. The former electrolyte was stable up to 4.3 V and the Ah efficiency was nearly 100% during the charge-discharge cycle.

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Effect of Poly(ethylene glycol) dimethyl ether Plasticizer on Ionic Conductivity of Cross-Linked Poly[siloxane-g-oligo(ethylene oxide)] Solid Polymer Electrolytes

  • Kang, Yongku;Seo, Yeon-Ho;Kim, Dong-Wook;Lee, Chang-Jin
    • Macromolecular Research
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    • 제12권5호
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    • pp.431-436
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    • 2004
  • Cross-linked network solid polymer electrolytes were prepared by means of in situ hydrosilylation between poly[hydromethylslioxane-g-oligo(ethylene oxide)] and diallyl or triallyl group-containing poly(ethylene glycols). The conductivities of the resulting polymer electrolytes were greatly enhanced upon the addition of poly(ethylene glycol) dimethyl ether (PEGDME) as an ion-conducting plasticizer. Conductivities of the cross-linked polymer electrolytes were more dependent on the molecular weight of PEGDME than on the cross-linkers. The maximum conductivity was found to be 5.6${\times}$10$\^$-4/ S/cm at 30$^{\circ}C$ for the sample containing 75 wt% of PEGDME (M$\_$n/ =400). These electrolytes exhibited electrochemical stability up to 4.5 V against the lithium reference electrode. We observed reversible electrochemical plating/stripping of lithium on the nickel electrode.

초임계 이산화탄소 유체를 이용한 결정성/무정형 폴리에테르 전해질의 이온전도특성 연구 (Characterization of ion-conductive Behaviors for Crystalline/Amorphous Solid Polyether Electrolytes Using Supercritical $CO_2$ Fluid)

  • 곽근호;;;;홍성권
    • 폴리머
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    • 제26권6호
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    • pp.785-791
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    • 2002
  • 결정성 및 무정형 고분자 전해질의 이온전도 거동에 미치는 초임계 이산화탄소 (sc$CO_2$) 유체의 영향에 대해 조사하였다. 본 연구는 폴리에테르 전해질의 이온전도도 향상에 관한 새로운 개념의 접근 방법이다. sc$CO_2$ 처리결과, 결정성 PEO 전해질의 경우 실온에서 100배 이상의, 무정형 PMEO 전해질은 9$0^{\circ}C$에서 30배 가까운 이온전도도의 상승을 나타내었다. 이는 고분자 매트릭스 내부로 $CO_2$ 분자가 침투함으로써 이온 분산효과로 캐리어 이온의 수를 증가시키고 가소화 효과로 인해 유리전이온도를 저하시켜 이온이동도를 향상시킨 결과이다.

Double-Enhancement Strategy: A Practical Approach to a Femto-Molar Level Detection of Prostate Specific $Antigen-{\alpha}_1-Antichymotrypsin$ (PSA/ACT Complex) for SPR Immunosensing

  • Cao, Cuong;Sim, Sang-Jun
    • Journal of Microbiology and Biotechnology
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    • 제17권6호
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    • pp.1031-1035
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    • 2007
  • Prostate specific $antigen-{\alpha}_1-antichymotrypsin$ was detected by a double-enhancement strategy involving the exploitation of both colloidal gold nanoparticles (AuNPs) and precipitation of an insoluble product formed by HRP-biocatalyzed oxidation. The AuNPs were synthesized and conjugated with horse-radish peroxidase-PSA polyclonal antibody by physisorption. Using the protein-colloid for SPR-based detection of the PSPJACT complex showed their enhancement as being consistent with other previous studies with regard to AuNPs enhancement, while the enzyme precipitation using DAB substrate was applied for the first time and greatly amplified the signal. The limit of detection was found at as low as 0.027 ng/ml of the PSA/ACT complex (or 300 fM), which is much higher than that of previous reports. This study indicates another way to enhance SPR measurement, and it is generally applicable to other SPR-based immunoassays.

Calix-Arene based phase transfer catalysts fornucleophilic fluorination

  • Minji Nam;Dong Wook Kim
    • 대한방사성의약품학회지
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    • 제7권2호
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    • pp.141-146
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    • 2021
  • With increasing interest in fluorinated compounds, nucleophilic fluorination reaction has been generally used for synthesizing fluorine-containing chemicals. However, alkali metal fluorides (MFs) generally have low solubility and reactivity in organic solvent. To overcome these problems, various phase transfer catalysts (PTCs) have been investigated. Calix-arene is known as to capture the metal cation(M+), and therefore in this review, we would like to introduce several kinds of calix-arene based PTCs, such as bis-tert-alcohol-functionalized crown-6-calix[4]arene (BACCA), oligo-ethylene glycol linked bis-triethyleneglycol crown-5-calix[4]arene (BTC5A), and ionic liquid functionalized calix-arene based catalyst, as well as ion-pair receptor crown-6-calix[4]arene-capped calix[4]pyrrole.

Synthesis, Self-assembly, and Catalytic Activity of 1H-Imidazole Amphiphiles

  • Park, Jun-Ha;Kim, Min-Soo;Seo, Sang-Hyuk;Chang, Ji-Young
    • Bulletin of the Korean Chemical Society
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    • 제32권7호
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    • pp.2193-2198
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    • 2011
  • We prepared polycatenar 1H-imidazole amphiphiles having a structure in which a 1H-imidazole head was connected through a benzene ring to a pheny group having two or three oligo(ethylene glycol) chains and studied their supramolecular assembly by fluorescence spectroscopy, transmission electron microscopy (TEM) and atomic force microscopy (AFM). When the aqueous solutions of the amphiphiles ($5{\times}10^{-5}M{\sim}10^{-3}M$) were deposited onto a carbon-coated copper grid and dried, twisted structures with diameters of ~200-300 nm were imaged by TEM and AFM. We presume that the structures comprised a chain of the amphiphile dimers formed via successive hydrogen bonding between the 1H of the imidazole group and 3N of the neighboring one. In a solution of pH 4, entangled fibers with diameters of several nanometers were observed by TEM. In a pH 10 solution, film-like aggregates formed exclusively. The 1H-imidazole amphiphiles hydrolyzed tetraethoxysilane to induce gelation to form fibrous and spherical silica structures at neutral pH in aqueous solutions. No silica was formed when imidazole was used instead of the amphiphiles, suggesting that the selfassembled aggregates of the amphiphiles were responsible for the gelation.