• Membrane Journal
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• v.26 no.5
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• pp.391-400
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• 2016

In this work, novel thin film composite (TFC) forward osmosis (FO) membranes are developed via interfacial polymerization on the polysulfone (PS) substrate, using TEOS as the a sol-gel reagent to form hydrophilic interlayer polymer between PS and polyamide (PA). The PS substrate was cast on a very thin polyester nonwoven to reduce membrane resistance. With the incorporation of TEOS (tetraethoxy silane) polymer in the interface between PS and PA, the formed TFC FO membrane exhibits better hydrophilicity and improved water flux, and therefore superior membrane performance. By changing the polymerization sequence of PA interfacial polymerization and TEOS sol-gel condensation, the surface properties and performance of FO membranes are changed significantly. The permeability of FO membranes were estimated using the bench-scale FO test equipment. The distribution of the polysiloxane on composite membrane and morphology are also studied with FE-SEM and EDAX. The PS_PA_TEOS membrane showed highly enhanced water flux (79.2 LMH) but reverse salt flux (RSF) value (7.10 GMH) also increased. However, the flux of PS_TEOS_PA membrane increased moderately (54.1 LMH) without increasing RSF value (1.60 GMH) compare with PS_PA membrane.

• The Journal of the Korean Society for Microbiology
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• v.5 no.1
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• pp.9-18
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• 1970

The present study is of ultra-fine structures of Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis and Epidermophyton floccosum by means of electron microscopy and reveals the following. 1. In contrast to the bacteria, the normal fungus contains nuclear membrane, mitochondria, endoplasmic reticulun, distinct cell wall and cell membrane and secretory granules as observed in the higher plants and animals. 2. Thickening of the cell wall, inapparent cell wall, inapparent cell membrane with the appearance of electron thin area(ETA) and increase of inclusions were observed in the L-1 treated groups. 3. Thickening of cell wall and increase of ETA were more apparent in the Epidermophyton floccosum than the other groups. 4. Increase of electron thin area was thought to be associated with autolysis.

• Textile Coloration and Finishing
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• v.18 no.3 s.88
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• pp.31-41
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• 2006

Functional properties are available with sputtering. But sputtering treatment alone cannot got a good fastness performance to washing, rubbing and light. This research was objected to investigate optimum condition by sputtering on polyester through various processing conditions such as ion current and treatment time, and then various resin treated onto metal coated polyester fabrics in order to increase washing fastness of metal membrane. As the results, the optimum conditions revealed 1500 mA of ion current, 2 min of treatment time in sputter, and suitable resin concentrations were 2% of o.w.s (on the weight of solution) in resin treatment. Therefore, we could get enhanced anti-static effect and flex stiffness as well as washing fastness in sputtered polyester fabric with various resin treatment, for example, melamine and polyurethane.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.1
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• pp.24-30
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• 2011

PC-TEMs (Polycarbonate Track-Etched membranes) were micro-drilled for biomedical applications by ultrafast pulsed laser. The ablation and damage characteristics were studied on PE-TEMs by assuming porous thin membranes. The experiments were conducted in the range of 2.02 $J/cm^2$ and 8.07$J/cm^2$. The ablation threshold and damage threshold were found to be 2.56$J/cm^2$ and 1.14$J/cm^2$, respectively. While a conical shaped drilled holes was made in lower fluence region, straight shaped holes were drilled in higher fluence region. Nanoholes made the membrane as porous material and ablation characteristics for both bulk and thin film membranes were compared.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.10a
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• pp.87-89
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• 1997

1. 서론 : 막을 이용한 분리기술의 실용화의 최대 과제는 선택성이 높고 용매의 투과용매의 투과속도가 높은 막재질 및 처리 면적이 큰 막의 개발이 필요하게 되었다. 이러한 성능 개발은 1960년대 cellulose acetate 계통의 막개발 이후 1980년대 지지층 고분자위에 다른 고분자 물질을 도포한 복합막(thin film composite layer)이 개발되어 막의 성능을 급격히 발전시켰다. 그 중에서 초박막화(ultrathin membrane)는 분리막에 의한 분리공정의 최대 결점인 낮은 투과량의 개선을 꾀할 수 있다는 장점 때문에 다양한 시도가 이루어지고 있다. 이러한 박막 제조 방법에는 박층분산법, 침지코팅법, 기상증착법, 계면중합법이 있으나, 섞이지 않는 두 계면 사이에서 고분자를 형성시키는 계면중합법은 수용상에 함침된 지지막위에 유기상을 계변에서 중합시켜 박막을 얻는 기술이다. 중합과정에서 일어나는 계면의 형성과정에 대한 연구는 미흡하기에 이에 본 연구는 시간에 따른 계면중합 반응 형성과정을 고찰하는 방법을 소개하고, 형성된 박막의 아론적, 실험적 두께 측정을 비교하였다.

• Proceedings of the Membrane Society of Korea Conference
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• 2002.05a
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• pp.35-41
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• 2002

Dense oxygen ionic conducting materials can be used for oxygen separation membranes at high temperatures. However, they show relatively low permeation flux because of their large resistances. To reduce resistances and improve the oxygen permeation flux, thin dense yttria-stabilized-zirconia (YSZ)/Pd composite dual-phase membranes were fabricated by a new approach that combines the reservoir method and chemical vapor deposition (CVD). A thin porous YSZ layer was coated on a porous alumina support by dip-coating the YSZ suspension. A continuous Pd phase was formed inside pores of the YSZ layer by the reservoir method. The residual pores of the YSZ/Pd layer were plugged with yttria/zirconia by CVD to ensure the gas tightness of the membranes. The oxygen permeation fluxes through these composite membrane were 2.0$\times$10$^{-8}$ mol/cm$^2$.s and 4.8$\times$10$^{-8}$ mol/cm$^2$.s at 105$0^{\circ}C$ when air and oxygen were used as the permeate gases, respectively. These oxygen permeation values are about 1 order of magnitude higher than those of pure YSZ membranes prepared under similar conditions.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.442-445
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• 1999

In this work, to detect of hydrogen in DI water in the generator area of nuclear power plants was fabricated Pd/Pt gate MISFET sensor using Pd membrane. $H_2$ permeation through Pd accounts for external mass transfer, surface adsorption and desorption, transitions to and from the bulk metal, and diffusion within the metal. The identification of pinholes in the generator area of plant is an important safety consideration, as hydrogen build-up gives rise to explosion. For this type of application the sensor needs to be isolated in DI water, accordingly, a Pd membrane was used to separate the DI water. The hydrogen in the DI water was then absorbed on the Pd thin film and diffused into the oil through the thin film. The Pd/Pt gate MISFET sensor, encapsulated by oil, will thereby detect permeated hydrogen.

• Applied Chemistry for Engineering
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• v.8 no.2
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• pp.276-285
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• 1997

The theoretical and experimental analysis on polyamide used for reverse osmosis thin-film composite membrane had been conducted. The physicochemical properties of polyamide had been varied by preparation recipes which depends on kinds of monomer, solvents and polymerization time. These properties and performance as a reverse osmosis membrane had been calculated by group contribution method. The experimental results has the same trends with theoretical preview.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.8
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• pp.708-713
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• 2005

An alumina membrane with nano-sized pore array by anodic oxidation using the thin film aluminum deposited on silicon wafer was fabricated. It Is important that the sample prepared by metal deposition method has a flat aluminum surface and a good adhesion between the silicon wafer and the thin film aluminum. The oxidation time was controlled by observation of current variation. While the oxalic acid with 0.2 M was used for low voltage anodization under 100 V, the chromic acid with 0.1 M was used for high voltage anodization over 100 V. The nano-sized pores with diameter of $60\~120$ nm was obtained by low voltage anodization of $40\~80$ V and those of $200\~300$ nm was obtained by high voltage anodization of $140\~200$ V. The pore widening process was employed for obtaining the one-channel with flat surface because the pores of the alumina membrane prepared by the fixed voltage method shows the structure of two-channel with rough surface. Finally, the sample was immersed to the phosphoric acid with 0.1 M concentration to etching the barrier layer.

• Membrane and Water Treatment
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• v.6 no.4
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• pp.309-321
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• 2015

We report in this study the synthesis of mixed matrix reverse osmosis membranes by interfacial polymerization (IP) of thin film nanocomposite (TFNC) on porous polysulfone supports (PS). This paper investigates the synthesis of ZnO nanoparticles (NPs) using the sol-gel processing technique and evaluates the performance of mixed matrix membranes reached by these aerogel NPs. Aqueous m-phenyl diamine (MPD) and organic trimesoyl chloride (TMC)-NPs mixture solutions were used in the IP process. The reaction of MPD and TMC at the interface of PS substrates resulted in the formation of the thin film composite (TFC). NPs of ZnO with a size of about 25 nm were used for the fabrication of the TFNC membranes. These membranes were characterized and evaluated in comparison with neat TFC ones. Their performances were evaluated based on the water permeability and salt rejection. Experimental results indicated that the NPs improved membrane performance under optimal concentration of NPs. By changing the content of the filler, better hydrophilicity was obtained; the contact angle was decreased from $74^{\circ}$ to $32^{\circ}$. Also, the permeate water flux was increased from 26 to 49 L/m2.h when the content of NPs is 0.1 (wt.%) with the maintaining of lower salt passage of 1%.