• Title/Summary/Keyword: stability of membrane

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The Characteristics and Stability of Ion Exchange Membrane in All-Vanadium Redox Flow Battery (전바나듐계 레독스-흐름 2차전지에서 이온교환막의 특성 및 안정성)

  • 신석재;강안수
    • Proceedings of the Membrane Society of Korea Conference
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    • 1993.10a
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    • pp.63-64
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    • 1993
  • 레독스-흐름 2차전지는 발전소의 잉여전력, 태양전지 및 전기자동차 등 응용 분야가 넓은 유망한 에너지 저장 방법의 하나이다[1,2]. Fe-Cr계 2차전지와 비교하여 수소 가스의 발생이 없고 양쪽 액의 확산에의한 혼합으로 전지의 용량이 떨어지지 않고 rebalance의 필요가 없는 등 많은 장점을 가지고 있으며 조작이 간단하며 기전력 (1,4 V)과 에너지 밀도가 높기 때문에 compact화가 가능하다[1].

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The PVC Membrane Electrode for Measuring Hazardous Anion in Waste Water Process (폐수처리 공정중 유해음이온을 측정하기 위한 PVC 막 전극)

  • Woo, In-Sung;An, Hyung-Hwan
    • Journal of the Korean Society of Safety
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    • v.10 no.4
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    • pp.47-59
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    • 1995
  • The perchlorate, thiocyanate, and nitrate ion-selective PVC membrance electrode for measuring hazardous anion in waste water were developed by incorporating the quaternary ammonium salts as active material. Ion-selective characteristics in waste water were studied by the useful pH range, the selective coefficients to various interfering anions, and the stability of electrode potential. DBP was best as a plasticizer. The effect of the membrane thickness on the electrode characteristics was improved with decreasing the membrane thickness, but below the optimum membrane thickness the electrode exhibited an inverse trend. The electrode potential of perchlorate, thiocyanate, and nitrate electrode with TDDA, as active material, was stable within the pH range 4-11, 3-12, and 4-10 repectively. And the long-term potential stability of these electrodes were 3.0, 3.5, and 3.5 months respectively. The order of the selectivity coefficients was as shown below ; $ClO_4{^-}$ > $SCN^-$ > $I^-$ > $NO_3{^-}$ > $Br^-$ > $CN^-$ > $F^-$ > $Cl^-$ > $Ac^-$ > $H_2PO_4{^-}$, $SO_4{^-}$.

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Desalting enhancement for blend polyethersulfone/polyacrylonitrile membranes using nano-zeolite A

  • Mansor, Eman S.;Jamil, Tarek S.;Abdallah, Heba;Youssef, H.F.;Shaban, Ahmed M.;Souaya, Eglal R.
    • Membrane and Water Treatment
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    • v.10 no.6
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    • pp.451-460
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    • 2019
  • Thin film composite membranes incorporated with nano-sized hydrophilic zeolite -A were successfully prepared via interfacial polymerization (IP) on porous blend PES/PAN support for water desalination. The thin film nanocomposite membranes were characterized by SEM, contact angle and performance test with 7000 ppm NaCl solution at 7bar. The results showed that the optimum zeolite loading amount was determined to be 0.1wt% with permeate flux 29LMH.NaCl rejection was improved from 69% to 92% compared to the pristine polyamide membrane where the modified PA surface was more selective than that of the pristine PA. In addition, there was no significant change in the permeate flux of the thin film nanocomposite membrane compared with that of the pristine PA in spite of the formation of the dense polyamide layer. The stability of the polyamide layer was investigated for 15 days and the optimized membrane presented the highest durability and stability.

The comparison of stability among three types of emulsions in the emulsion liquid membrane separation processes

  • Liu, Hongjing;He, Gaohong;Chen, Guohua
    • Proceedings of the Membrane Society of Korea Conference
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    • 2004.05a
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    • pp.47-50
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    • 2004
  • Since emulsion liquid membrane (ELM) was found by Li in the late 1960s$^{[1]}$ , a great amount of work has been conducted on the research and application of ELM$^{[2-8]}$ . Generally, during a process of ELM separation, three types of emulsions will be shown in turn. They are primary emulsion, multiple emulsion, namely ELM, and recovered emulsion respectively. Those three types of emulsions inevitably share some common properties, and at the same time, because those three types of emulsions emerge in different stages of ELM separation, some differences will be observed.(omitted)

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Son transport characteristics through random or block polymer electrolyte membranes (랜덤 및 블록 공중합에 따른 고분자 전해질막의 이온전도특성)

  • Park, Chi-Hoon;Lee, Chang-Hyun;Nam, Sang-Yong;Park, Ho-Bum;Lee, Young-Moo
    • Proceedings of the Membrane Society of Korea Conference
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    • 2004.05b
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    • pp.57-60
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    • 2004
  • Polymer electrolyte membranes have been studied widely in chloro-alkali electrolysis, cationic exchange resins, and fuel cell applications. Especially, sulfonated polyimide membranes have been suggested as a potential polymer electrolyte in PEMFC due to their excellent thermal stability and high proton conductivity.(omitted)

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Selectivity and structural integrity of a nanofiltration membrane for treatment of liquid waste containing uranium

  • Oliveira, Elizabeth E.M.;Barbosa, Celina C.R.;Afonso, Julio C.
    • Membrane and Water Treatment
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    • v.3 no.4
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    • pp.231-242
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    • 2012
  • The performance of a nanofiltration membrane for treatment of a low-level radioactive liquid waste was investigated through static and dynamic tests. The liquid waste ("carbonated water") was obtained during conversion of $UF_6$ to $UO_2$. In the static tests membrane samples were immersed in the waste for 24, 48 or 72 h. The transport properties of the samples (hydraulic permeability, permeate flow, selectivity) were evaluated before and after immersion in the waste. In the dynamic tests the waste was permeated in a permeation flow front system under 0.5 MPa, to determine the selectivity of NF membranes to uranium. The surface layer of the membrane was characterized by zeta potential, field emission microscopy, atomic force spectroscopy and infrared spectroscopy. The static test showed that the pore size distribution of the selective layer was altered, but the membrane surface charge was not significantly changed. 99% of uranium was rejected after the dynamic tests.

The FEM Analysis of Membrane for LNG Storage Tank (LNG 저장탱크용 멤브레인 개발을 위한 유한요소해석)

  • Oh B.T.;Hong S.H.;Yoon I.S.;Kim Y.K.;Seo H.S.
    • Journal of the Korean Institute of Gas
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    • v.6 no.4 s.18
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    • pp.47-52
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    • 2002
  • Analytical studies have been performed to investigate the strength of the membrane and the reaction force at the anchor point. Using nonlinear FEM code and experiments, the stress analysis of the corrugated membrane related the cryogenic liquid pressure and thermal loading is performed to ensure the stability and fatigue strength of the membrane. This paper reports on the FEM results of membrane.

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Phenol removal by tailor-made polyamide-fly ash composite membrane: Modeling and optimization

  • Vandana, Gupta;Anandkumar, J.
    • Membrane and Water Treatment
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    • v.10 no.6
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    • pp.431-440
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    • 2019
  • A novel composite membrane was synthesized using crosslinked polyamide and fly ash ceramic substrate for phenol removal. Glutaraldehyde was used as crosslinker. Characterization shows that synthesized membrane possesses good permeability ($0.184l.m^{-2}.h^{-1}.kPa^{-1}$), MWCO (1.7 kDa), average pore size (1.08 nm) and good chemical stability. RSM was adopted for phenol removal studies. Box-Behnken-Design using quadratic model was chosen for three operating parameters (feed phenol concentration, pH and applied pressure) against two responses (phenol removal, flux). ANOVA shows that model is statistically valid with high coefficient of determination ($R^2$)value for flux (0.9897) and phenol removal (0.9302). The optimum conditions are obtained as pH 2, $46mg.l^{-1}$ (feed phenol concentration) and 483 kPa (applied pressure) with 92.3% phenol removal and $9.2l.m^{-2}.h^{-1}$ flux. Data validation with deviation of 4% confirms the suitability of model. Obtained results reveal that prepared composite membrane can efficiently separate phenol from aqueous solution.

The effect of thermodynamic stability of casting solution on the membrane inversion process morphology and permeation properties in phase inversion process

  • Kim, Jeong-Hoon;Lee, Kew-Ho
    • Proceedings of the Membrane Society of Korea Conference
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    • 1995.04a
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    • pp.26-27
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    • 1995
  • Most of synthetic polymeric membranes used in ultrafiltration, reverse osmosis and microfiltration processes are prepared by phase inversion(or phase separation) technique. In this technique, a homogeneous polymer solution is cast into thin film or hollow fiber shape and then immersed into a nonsolvent coagulant bath. The exchange of solvent and nonsolvent across the interface between casting solution and coagu!ant can make the casting solution phase-separate and form a membrane with a symmetric or asymmetric structure. Because of importance of this technique in membrane field, many investigations have been dedicated to elucidate the mechanism of membrane formation by phase inversion technique.[1-10] These investigation have suggested that the structure formation and permeation properties of phase inversion membrane depend on the variables such as the nature and content of casting solution and coagulant, temperature of casting solution and coagulant, and the diffusional exchange rate of solvent and nonsolvent etc. which can be related to the thermodynamic and kinetic properties of the casting system. The variables such as the nature and content of casting solution can also be the important factor affecting the structure formation and permeation property of the phase inversion membrane.

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Preparation of Cation Exchange Membrane using Block Copolymer of Polysulfone and Poly(Phenylene Sulfide Sulfone) and its Electrochemical Characteristics (Polysulfone과 Poly(Phenylene Sulfide Sulfone)의 블록 공중합체를 이용한 양이온 교환막의 제조 및 전기화학적 특성)

  • 임희찬;강안수
    • Membrane Journal
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    • v.10 no.2
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    • pp.66-74
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    • 2000
  • In consideration that a high tensile strength and ion exchange capacity are maintained as the swelling of membrane is controlled by the coagulation of PSf with the introduction of ion exchange groups and PPSS without the introduction of ion exchange groups, the block copolymer of PSf and PPSS were synthesized. The cation exchange membrane was prepared by sulfonation with CSA and casted. The synthesized block copolymer and cation exchange membrane were characterized by FT-IR and their thermal stability was confirmed by TGA. The optimum sulfonation could be accomplished at a mole ratio of BPSf to CSA 1:3. The best electrochemical properties obtained by the optimal condition were area resistance of 4.37 $\Omega$$\textrm{cm}^2$, ion exchange capacity of 1.71 meq/g dry membrane, water content of 0.2941 g $H_2O$/g dry membrane, and fixed ion concentration of 5.81 meq/g $H_2O$. When GBL was used as an additive, area resistance was increased by 13.7 % and ion exchange capacity was increased by 14.6%. When the membrane was fabricated in a form of composite using non woven cloth as a support. the tensile strength of membrane could be improved, but the electrochemical characteristics were not influenced.

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