• Title/Summary/Keyword: Thin membrane

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Enhanced performance of thin-film nanocomposite RO/NWF membrane by adding ZnO nanospheres in aqueous phase during interfacial polymerization process

  • Li, Hongbin;Shi, Wenying;Su, Yuheng;Hou, Hongxiang;Du, Qiyun;Zhang, Haixia;Qin, Xiaohong
    • Membrane and Water Treatment
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    • v.8 no.3
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    • pp.225-244
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    • 2017
  • A novel thin-film nanocomposite (TFN) reverse osmosis (RO)/non-woven fabric (NWF) membrane was prepared by adding zinc oxide (ZnO) nanospheres ($30{\pm}10nm$) during the interfacial polymerization process of m-phenylenediamine (MPD) and trimesoyl chloride (TMC) on self-made polysulfone (PSF) membrane/polyester (PET) non-woven fabric support. The improved performance of TFN RO membrane was verified in terms of water contact angle (WCA), water flux, salt rejection, antifouling properties and chlorine resistance. The results showed that the WCA value of TFN RO surface had a continuous decrease with the increasing of ZnO content in MPD aqueous solution. The water flux of composite TFN RO membranes acquired a remarkable increase with a stable high solute rejection (94.5 %) in $1g{\cdot}L^{-1}$ NaCl aqueous solution under the optimized addition amount of ZnO (1 wt%). The continuous testing of membrane separation performance after the immersion in sodium hypochlorite solution indicated that the introduction of ZnO nanospheres also dramatically enhanced the antifouling properties and the chlorine resistance of composite RO membranes.

Experimental Study on Enhanced Structural Properties of Sprayable Waterproofing Membrane (구조적 성능이 보강된 차수용 박층 멤브레인의 기초 물성평가)

  • Lee, Chulho;Kim, Jintae;Choi, Myung-Sik;Chang, Jun-Hee;Kang, Tae-Ho;Choi, Soon-Wook
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.4
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    • pp.93-102
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    • 2018
  • A sprayable waterproofing membrane which is composed of polymer-based material is relatively easy to install due to its construction method comparing with sheet-type membranes. And a sprayable waterproofing membrane has very similar material composition to the TSL which is for a permanent support. In this study, material composition of the sprayable waterproofing membrane was changed to enhance structural properties of membrane while maintaining waterproofing performance. In order to compare with a previous research for the TSL, series of tests were performed according to the performance criteria used for permanent support material (TSL) by EFNARC (2008). From the test result, the structural performance of the sprayable waterproofing membrane considered in this study showed a performance that could be used as a permanent support material.

Micromachinng and Fabrication of Thin Filmes for MEMS-infrarad Detectors

  • Hoang, Geun-Chang;Yom, Snag-Seop;Park, Heung-Woo;Park, Yun-Kwon;Ju, Byeong-Kwon;Oh, Young-Jei;Lee, Jong-Hoon;Moonkyo Chung;Suh, Sang-Hee
    • The Korean Journal of Ceramics
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    • v.7 no.1
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    • pp.36-40
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    • 2001
  • In order to fabricate uncooled IR sensors for pyroelectric applications, multilayered thin films of Pt/PbTiO$_3$/Pt/Ti/Si$_3$N$_4$/SiO$_2$/Si and thermally isolating membrane structures of square-shaped/cantilevers-shaped microstructures were prepared. Cavity was also fabricated via direct silicon wafer bonding and etching technique. Metallic Pt layer was deposited by ion beam sputtering while PbTiO$_3$ thin films were prepared by sol-gel technique. Micromachining technology was used to fabricate microstructured-membrane detectors. In order to avoid a difficulty of etching active layers, silicon-nitride membrane structure was fabricated through the direct bonding and etching of the silicon wafer. Although multilayered thin film deposition and device fabrications were processed independently, these could b integrated to make IR micro-sensor devices.

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Preparation of Disulfonated Poly(arylene ether sulfone) Random Copolymer Thin Film Composite Membranes Using a Benign Solvent (친환경용매 기반의 술폰화 폴리아릴렌 에테르 술폰 랜덤 공중합체 Thin Film Composite 제조)

  • Lee, Chang Hyun;McGrath, James E.;Freeman, Benny
    • Membrane Journal
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    • v.24 no.4
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    • pp.292-300
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    • 2014
  • Chlorine-resistant sulfonated poly(arylene ether sulfone) random copolymer (SPAES)-thin film composite (TFC) membranes for desalination are prepared using monoglyme as a selective solvent, which dissolves SPAES, but should be inert to porous polysulfone layer (e.g., Udel$^{(R)}$). Different from formic acid and diethylene glycol used as other selective solvents, monoglyme is environmentally friendly and has much lower boiling temperature. After a pretreatment of Udel$^{(R)}$ support film in isopropyl alcohol-glycerine mixture to minimize pore penetration leading to fairly reduced water flux, coating of SPAES solution in monoglyme onto the support and stepwise drying processes are conducted for defect-free TFC formation. The transport behavior through SPAES-TFC membranes is observed, correlating with the effects of sulfonation level, protonation, and physical and chemical crosslinking of SPAES selective layers.

The Fabrication of Flow Sensors Using Pt Micro Heater (백금 미세발열체를 이용한 유량센서의 제작)

  • Noh, Sang-Soo;Chung, Gwiy-Sang
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.609-611
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    • 1997
  • Pt thin films flow sensors were fabricated by using aluminum oxide films as medium layer and their characteristics were investigated after annealing at $600^{\circ}C$ for 60min. Aluminum oxide improved adhesion of Pt thin films to $SiO_2$ layer without any chemical reactions to Pt thin films under high annealing temperatures. Output voltages increased as gas flow rate and gas conductivity increased because heat loss of heater, which was integrated with a sensing resistor in the flow sensor, increased. Output voltage of flow sensor fabricated on membrane structure was 101mV at $O_2$ flow rate of 2000sccm, heating power of 0.8W while flow sensor fabricated on Si substrate without membrane had output voltage of 78mV under the same conditions.

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Clinical and Pathologic Analysis of Thin Glomerular Basement Membrane Disease in Children (소아 비박형 기저막신증의 임상 및 병리학적 분석)

  • Ko Myoung Jin;Yang Tae Jin;Kim Young Ju;Chung Woo Yeong
    • Childhood Kidney Diseases
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    • v.5 no.1
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    • pp.1-8
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    • 2001
  • Purpose : Clinical manifestations and pathologic findings of thin glumerular basement membrane disease, recognized as a common underlying disease of benign, familaiar and asymptomatic hematuria has not been reported systemically in Korera. We analyzed clinical and pathologic findings of patients who were diagnosed as thin glomerular basement membrane disease Methods : We analyzed clinical and pathologic findings of twenty-six patients who were diagnosed as thin glomerular basement membrane disease by renal biopsy among who complained asymptomatic hematuria from 1990 to 2000. Results : The subjects were aged 9.4${\pm}$3.2 (3.0-15.8) years-old at onset of hematuria, and 11.1${\pm}$2.2 (4.7-16.3) years-old at renal biopsy. Sexual discrepancy was more common in girls (eight boys and eighteen girls). A family history of hematuria was found in 8 patients(30.7$\%$). Major clinical manifestation on admission was microscopic hematuria according to the findings of 3case(11.5$\%$) of gross hematuria, 23cases(88.5$\%$9) of microscopic hematuria, and 1 case(3.8$\%$) of proteinuria. Microscopic hematuria persisted in all cases. Kidney biopsy showed few changes by light microscopy, but IgM, C3 and fibrinogen deposit in mesangium was found by immunofluorescent microscopy in a few cases. Electron microscopic findings have revealed thinning of the glomerular basement membrane varied from 180.9${\pm}$35.8nm. Conclusion : Thin glomerular basement membrane disease might be a common cause of microscopic hematuria of children and family history was revealed in about 30$\%$. Clinical progression was good in majorities.(J. Korean Soc Pediatr Nephrol 5 : 1-8, 2001)

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Accelerating repaired basement membrane after bevacizumab treatment on alkali-burned mouse cornea

  • Lee, Koon-Ja;Lee, Ji-Young;Lee, Sung Ho;Choi, Tae Hoon
    • BMB Reports
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    • v.46 no.4
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    • pp.195-200
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    • 2013
  • To understand the corneal regeneration induced by bevacizumab, we investigated the structure changes of stroma and basement membrane regeneration. A Stick soaked in 0.5 N NaOH onto the mouse cornea and 2.5 mg/ml of bevacizumab was delivered into an alkali-burned cornea (2 ${\mu}l$) by subconjunctival injections at 1 hour and 4 days after injury. At 7 days after injury, basement membrane regeneration was observed by transmission electron microscope. Uneven and thin epithelial basement membrane, light density of hemidesmosomes, and edematous collagen fibril bundles are shown in the alkali-burned cornea. Injured epithelial basement membrane and hemidesmosomes and edematous collagen fibril bundles resulting from alkali-burned mouse cornea was repaired by bevacizumab treatment. This study demonstrates that bevacizumab can play an important role in wound healing in the cornea by accelerating the reestablishment of basement membrane integrity that leads to barriers for scar formation.

Preparation of Titanium Microfiltration Membrane by Field-flow Fractionation Deposition

  • Wang, QiangBing;Tang, HuiPing;Zhang, QianCheng;Qiu, QunFeng;Wang, JianYong
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.312-313
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    • 2006
  • The primary aim pursued by the preparation of separation membrane is the preparation of the membrane thin as well as with no defect. The field-flow fractionation deposition is a new molding technology which can overcome the traditional disadvantages such as multi-preparation to the preparation of great area of separation membrane with no defect. Therefor the mainly ingredients which influence the appearance and performance of titanium membrane layer are investigated by scanning electricity mirror (SEM) as well as porous material testing instrument: powder performance prepared and confected; selection of supporting body; sintering system such as temperature and time. It is shown that the membrane thickness can be controlled at $50{\mu}m$ or so; the filtration precision mainly rests with powder performance and selection of supporting body and little sintering system

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