• Title/Summary/Keyword: membrane chemistry

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Preparation and Permeation Characteristics of PDMS-b-PMMA Copolymer Membrane (PDMS-b-PMMA 공중합체 막의 제조 및 투과특성)

  • Kang, Tae-Beom;Cho, A-Ra;Lee, Hyun-Kyung
    • Membrane Journal
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    • v.18 no.3
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    • pp.219-225
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    • 2008
  • In this research, polydimethylsiloxane-polymethylmethacrylate (PDMS-PMMA) block copolymer was synthesized from polydimethylsiloxane (PDMS) and methylmethacrylate (MMA) monomer using atom transfer radical polymerization (ATRP). The synthesis characterization of the PDMS-b-PMMA copolymer membrane was carried out by a FT-IR, $^1H$-NMR, GPC and DSC. The permeabilities of nitrogen and hydrogen gases were observed being $1.2{\sim}l.5$ barrer and $6.2{\sim}10.5$ barrer, respectively. Simultaneously, selectivities of hydrogen against nitrogen were $5.3{\sim}6.9$. The permeability and selectivity of PDMS-b-PMMA copolymer membrane were showed lower than the PDMS membrane, but higher than the PMMA membrane.

Preparation and Characterization of PP-g-Poloxamer Membranes by UV Irradiation Methods and their Solutes Permeation Behaviors

  • Lee, S. H.;Shim, J. K.;Lee, Y. M.;Ahn, S. H.;Yoo, I. K.;Baek, K. H.
    • Proceedings of the Membrane Society of Korea Conference
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    • 1998.04a
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    • pp.97-98
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    • 1998
  • 1. Introduction : Polypropylene(PP) membrane is widely used in the field of microfiltration and ultrafiltration. However, the hydrophobicity of PP causes the adsorption of hydrophobic and amphoteric solutes in the feed. Surface modification techniques of membrane through the treatment of hydrophilizing agents, coating of hydrophilic compounds, UV, plasma and high energy irradiation, etc. can have a great effect on propensities to prevent the protein from staining membranes. Among them, the modification to hydophilize membrane surface using UV is very simple and effective. Recently many studies for more effective surface modification have been conducted. Iwata et al. prepared membranes by grafting polyethylene glycol diacrylate macromer(PEGDA) onto polysulfone with plasma using a glow discharge reactor which prevent the oil from staining the membrane. The primary mechanism contributing to the membranes is preventing the oil from directly contacting the surface of the membrane as the PEGDA chains dissolved into emulsion. To evaluate their feasibility for use as a anti-fouling separation membrane, we prepared hydrophilic membranes by UV irradiation method and investigated their characteristics.

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Utilization of Iodine for the Enhanced Permeance of Facilitated Olefin Transport Nanocomposite Membrane (올레핀 촉진수송 나노복합체 분리막의 투과도 향상을 위한 iodine의 활용)

  • Choi, Yeji;Lee, Eun Yong;Kang, Sang Wook
    • Membrane Journal
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    • v.24 no.6
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    • pp.448-452
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    • 2014
  • Nanocomposite membrane to show facilitated olefin transport was prepared for enhanced separation performance. Addtion of halogen molecules into PVP/AgNPs/ TCNQ nanocomposite membrane was expected to further polarize the surface of AgNPs for enhancing the separation performance. The formation of AgNPs and presence of iodine was confirmed by TEM and EDS analysis, respectively. The separation performance for propylene/propane mixture was compared with that of PVP/AgNPs/TCNQ nanocomposite membrane. The long-term stability of membrane was investigated with time.

The Novel SCN- Ion-selective Electrode Based on the 1-Benzyl-3-(4-nitrophenyl) thio-urea Ionophore

  • Lee, Kyungmi;Kang, Dong Hyeon;Choe, Ju Eun;Yun, Mira;You, Jung-Min;Go, Min Jeong;Lee, Junseong;Jeon, Seungwon
    • Bulletin of the Korean Chemical Society
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    • v.35 no.11
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    • pp.3175-3180
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    • 2014
  • A potentiometric sensor based on the 1-benzyl-3-(4-nitrophenyl) thio-urea was synthesized and tested as an ionophore in PVC based membrane sensor towards $SCN^-$ ions. This membrane exhibits a linear stable response over a wide concentration range ($1.0{\times}10^{-5}$ to $1.0{\times}10^{-2}M$) with a slope of -59.2 mV/dec., a detection limit of ${\log}[SCN^-]=-5.05$, and a selectivity coefficient for thiocyanate against perchlorate anion of ${\log}K^{pot}_{SCN^-j}=-0.133$. The selectivity series of the membrane is as follows: $SCN^-$ > $ClO_4{^-}$ > $I^-$ > $NO_3{^-}$ > $HSO_3{^-}$ > $Cl^-$ > $HSO_4{^-}$ > $F^-$ > $CH_3COO^-$ > $HCO_3{^-}$ > $Br^-$ > $H_2PO_4{^-}$ > $SO{_3}^{2-}$ > $SO{_4}^{2-}$ > $CO{_3}^{2-}$. The proposed electrode showed good selectivity and a good response for the $SCN^-$ ion over a wide variety of other anions in pH 6.0 buffer solutions and has a fast response time of about < 5s. The influences of the membrane by pH, ionophore, and plasticizer were studied.

The Synthesis and Characteristics of Covalently Cross-Linked SPEEK/Cs-substituted TPA/CeO2 Composite Membranes for PEMWE (PEMWE를 위한 Cs치환에 따른 공유가교 SPEEK/Cs(x)-TPA/Ceria막의 합성 및 특성 연구)

  • Hwang, Sungha;Park, Daeyoung;Oh, Seunghee;Yoon, Daejin;Oh, Yunsun;Seo, Hyeon;Kang, Aansoo;Moon, Sangbong;Chung, Janghoon
    • Transactions of the Korean hydrogen and new energy society
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    • v.25 no.2
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    • pp.151-160
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    • 2014
  • CL-SPEEK/Cs-TPA/$CeO_2$ composite membrane was prepared for polymer electrolyte membrane water electrolysis (PEMWE). In order to improve the electrochemical, mechanical, durabilities and electrocatalytic characteristics, engineering plastic of polyether ether ketone (PEEK) as polymer matrix was sulfonated and the organic-inorganic blend composite membranes was prepared by loading cesium-substituted tungstophosphoric acid (Cs-TPA) by titration method with cross-linking agent contents of 0.01mL. Ceria ($CeO_2$) was used to scavenge free radicals which attack the membrane in the PEMWE circumstance and to increase the duration of the membrane. CL-SPEEK/$Cs_{(1)}$-TPA/CeriaIn conclusion, 1% membrane showed the optimum results such as 0.119 S/cm at $80^{\circ}C$ of proton conductivity and 62MPa of tensile strength.