• 제목/요약/키워드: alkyl chain

검색결과 305건 처리시간 0.026초

Anion Exchange Membrane Having Permselectivity specific Anion in Electrodialysis

  • Sata, Toshikatsu
    • 한국막학회:학술대회논문집
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    • 한국막학회 1998년도 춘계 총회 및 학술발표회
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    • pp.1-6
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    • 1998
  • To change permselectivity between anions through the anion exchange membrane in electrodialysis, the various modified anion exchange membranes were prepared: highly crosslinked anion exchange membranes, anion exchange membranes having benzyl trialkylammonium groups with different carbon number of alkyl chain as anion exchange groups and anion exchange membranes having pyridinium groups with a hydrophilic or hydrophobic substituent at a different position as anion exchange groups. It became clear from the evaluation of these membranes that the degree of the hydrophilicity of the anion exchange membranes greatly affects the permselectivity between two artions. To increase the hydrophiticity of the anion exchange membranes further, electrodialysis was carried out in the presence of ethylene glycols and the permeation of strongly hydrated anions increased and that of less-hydrated anions decreased. It became clear that the change in the permselectivity between two artions is due to the change in the affinity of anions to the membranes, not the change in mobility ratio of the anions in the membranes phase.

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실란 카르복실 표면을 사용한 단백질 칩 기판의 기능 분석 (Functional Analysis of Protein Chip Plate Using Silane Carboxylate Surface)

  • 김지현;송예신;윤미영;피재호
    • 한국표면공학회지
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    • 제37권4호
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    • pp.215-219
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    • 2004
  • We fabricated protein chip plates coated with silane carboxylate. The silane compound was immobilized by hydrogen bond and/or other chemical bonds on the surface of the plate. The plates were then prepared by binding $Ni^{2+}$ to surfaces terminated with silane carboxylate groups. The carboxylic acid surface was generated by chemical oxidation of the terminal double-bond functions of the silane-deposited layer. The $Ni^{2+}$ ions on the surface reacted readily to His-tagged proteins. A significant increase in His-tagged protein adsorption was achieved on the surface terminated with silane carboxylate with longer alkyl chain, suggesting better availability of these protein chip plates for proteomic studies.

2-(1-Hydroxyiminoalkyl)-1,4-dimethoxy-9,10-anthraquinones: Synthesis and Evaluation of Cytotoxicity

  • Tam, Mai-Ngoc;Nam, Nguyen-Hai;Jin, Guang-Zhu;Ahn, Byung-Zun
    • Archives of Pharmacal Research
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    • 제23권4호
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    • pp.283-287
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    • 2000
  • A series of 2-(1-hydroxyiminoalkyl)-1,4-dimethoxy-9,10-anthraquinones (oximes) was synthesized and evaluated for cytotoxicity against L1210 cells and A549 cells. These oximes showed a greater cytotoxic activity compared to those of 2-(1-hyd roxyalkyl)-1,4-dimethoxy-9,10-anthraquinones as the hydroxyalkyl bioisosteres. The enhanced cytotoxiciy assumed to be due to the improved water solubility of the hydroxyimino group. Moreover, it was found that the cytotoxicity of the oximes decreased with elongation of alkyl groups at the side chain. All of the synthesized compounds showed higher cytotoxicity against L1210 cells than A549 cells.

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Solvent-Assisted Soft-Lithographic Patterning of Lyotropic Liquid Crystalline Polymer Film by Flow Control through Patterned Channels

  • Park, Chang-Sub;Park, Kyung-Woo;Kang, Shin-Won;Kwak, Gi-Seop;Kim, Hak-Rin
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.641-644
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    • 2009
  • We demonstrated a solvent-assisted soft-lithographic patterning method for producing patterned structure and patterned ordering with lyotropic liquid crystalline polymer (LCP) film. Experimental results showed that the liquid crystalline ordering of lyotropic film could be controlled by shearing effects of the fluidic solvent though the patterned mold channels. In this work, two types of lyotropic LCPs were used to investigate the effects of the alkyl chain length of the lyotropic LCP on producing liquid crystalline ordering through the solvent-assisted fluidic patterning.

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LB법에 의해서 제작된 DLPC 지질막의 캐패시턴스 특성 (The Capacitance Properities of DLPC Liquid Membrance Fabricatied by LB Method)

  • 정용호;이우선
    • 한국전기전자재료학회논문지
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    • 제11권8호
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    • pp.628-636
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    • 1998
  • LB layers L-$\alpha$-DLPC deposited by LB method were deposited onto n-type silicon wafer as Z-type film. Films made up of 8, 16 layers of lipid with long alkyl chain and the thickness of monolayer and multiayers was determined by ellipsometry. Ut was deposited Ag and Al onto LB layers and silicon wafer for electrode and small electrode exhibit high capacitiance and low lekage current. The C-V curves of the MLS capacitor shows very high saturation value of capacitance. And cross-sectional SEM image of MLD capacitor indicated the presence of pore with Al electrode and we found that the Ag is good for electrode metal.

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A Study on the Absorption Mechanism of Drugs through Biomembranes

  • Lee, Chi-Ho;Kim, Heun-Jo
    • Archives of Pharmacal Research
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    • 제17권3호
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    • pp.182-189
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    • 1994
  • The effect of lipophilicity on the mechanisms of drug absorption through biomembranes was investigated empolying HPLC system and the fluorescence technique. Human erythrocyte ghost membranes were used as a model biomembrane. A series of four parabens (methyl, ethyl, rpopyl, and butyl) and p-hydroxybenzoic acid were used as the model drugs for lipophilicities and their partition coefficients were measured in Sorensen's phosphate buffer solution (pH 5)/octanol system. Absorption amount of parabens through erythrocyte ghost membranes increased with an increase of lipophilicity resulted from the addition of methylene group to the n-alkyl chain of parabens. And the effect of parabens on the fluidity of ghost membrane also increased with an increase of their lipophilicities.

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Effects of the Superlattices on STM Imaging of Self-organized Substituted Alkyl Chain Monolayers on a Graphite Surface

  • Son, Seung Bae;Hahn, Jae Ryang
    • Bulletin of the Korean Chemical Society
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    • 제33권12호
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    • pp.4155-4160
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    • 2012
  • We characterized the physisorption of p-iodo-phenyl octadecyl ether molecules (I-POE) onto superlattice regions of graphite surfaces using scanning tunneling microscopy (STM). The formation of self-organized I-POE monolayers does not affect the overall structures of moir$\acute{e}$ patterns and their modulation periods. However, the packing density of the I-POE monolayer and the orientations of lamella structures were sensitive to the underlying superlattice structure. Depending on the bias voltage, the STM images selectively showed moir$\acute{e}$ pattern, I-POE layer, or both. Reflecting the local density of states at a certain energy level, the STM images thereby revealed the relative energy level scale of the superlattice with respect to the molecular orbitals of I-POE.

Acyclic Anhydrides를 이용한 피리다진아민의 아실레이션; N-치환된 3-아미노-6-클로로피리다진 유도체의 합성 (Acylation of Pyridazinylamines by Acyclic Anhydrides; Synthesis of N-Substituted 3-Amino-6-chloropyridazines)

  • 박은희;박명숙
    • 약학회지
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    • 제49권1호
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    • pp.56-59
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    • 2005
  • We synthesized new N-substituted 3-amino-6-chloropyridazine derivatives which were expected to retain biological activity. All synthetic process from pyridazine to 3-aminopyridazines could be carried out conveniently in high yield. N-Substituted 3-amino-6-chloropyridazine derivatives were prepared through amination and acylation from 3,6-dichloropyridazine. 3-Amino-6-chloropyridazine was prepared from the reaction of 3,6-dichloropyridazine with liquid ammonia under autoclave for 6 hrs. The refluxing of 3-amino-6-chloropyridazine and the corresponding acid anhydride for $1{\sim}2$ hrs afforded the N-substituted 3-amino-6-chloropyridazines. Alkyl chain of N-substituent was prolonged to six carbon (hexanoic acid).

Polyamic Acid 알킬아민 염 랭뮤어-블로젯막의 분자 배향에 관한 연구 (A Study on the Molecular Orientation of Polyamic Acid Alkylamine Salt Langmuir-Blodgett Films)

  • 정순욱;임현성
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.53-56
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    • 2000
  • Langmuir-Blodgett(LB) technique is the best candidate for the future molecular electronic devices. But, these molecular thin film devices require the bulk properties that are influenced by the molecular orientations. So, this is of current interest in molecular electronic device fabrications of new materials. In this study, quantitative evaluation of molecular orientation in LB films of PAAS was performed by comparing the absorption intensities of the FT-IR transmission and reflection-absorption spectra and the polarized UV/visible absorption spectra. It was found that the polar angle( $\theta$ ) of the dipole moment is about 68$^{\circ}$ and the tilting angle of the alkyl chain is about 11.5$^{\circ}$

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TCNQ 유기초박막의 분자 배향 및 전기적 특성 (Molecular orientation and electrical properties of TCNQ ultrathin organic films)

  • 이용수;신동명;김태완;강도열
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 추계학술대회 논문집
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    • pp.5-8
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    • 1997
  • A study on the electrical conduction characteristics of the ultrathin organic films is one of the important factors for the development of molecular electronic devices. The Langmuir- Blodgett(LB) technique has recently been attracted interest as a method of the deposition ultrathin films. We hate fabricated N-docosyl N\`-methyl viologen-diTCNQ(DMVT) anion radical LB film and investigated the molecular orientation and electrical conduction characteristics. We have measured infrared transmission-reflection spectra. The alkyl chain is found to he well-ordered with the tilt angle of 13$^{\circ}$ with respect to the substrate surface normal and the TCNQ plane is tilted at 76$^{\circ}$ the surface normal. In ESR spectrum, we confirmed that a half-amplitude linewidth is clearly dependent on the incident angle, which indicates conducting species change. The in-plane conductivity of 31 lagers is approximately 1.33$\times$10$^{-6}$ S/cm. The ohmic behaviour was observed below 0.6 V, when current-voltage(I-V) characteristics was measured verically.

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