• Proceedings of the Membrane Society of Korea Conference
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• 1993.04a
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• pp.35-35
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• 1993

튜브형 $\alpha-Al_2O_3$ 담체에 졸-겔 침지코팅법과 가압코팅(pressurized coating) 법으로 boehmite 졸과 극미세 입자 SiO$_2$ 및 TiO$_2$ 졸을 코팅한 후 200$\circ$C~500$\circ$C 에서 열처리하여 복합분리막을 제조하였다.

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.199.1-199
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• 2002

• Membrane Journal
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• v.28 no.1
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• pp.21-30
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• 2018

In this study, homogeneous and defect-free ceramic ultrafiltration membranes were fabricated by using the sol-gel method. A boehmite sol was synthesized and coated onto the surface of alumina hollow fiber microfiltration membranes. The effect of sol viscosity and surface tension on the coating layer homogeneity and thickness was investigated. The optimum coating repetition using pristine sol was determined to be 3 times, as the samples coated more than 4 times showed delamination. Fixing the coating repetition to 3 times, the effect of sintering temperature was also studied in this work. The samples sintered at $1000^{\circ}C$ exhibited the highest pure water permeability with the molecular weight cut-off (MWCO) of approximately 51 kDa (10 nm dextran), and the samples sintered at 600, $800^{\circ}C$ displayed the MWCO of 12 kDa (5 nm dextran). The ultrafiltration membranes prepared in this work showed competitive performance compared to the reported ceramic ultrafiltration membranes.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.4
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• pp.264-270
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• 2010

Recently, the most promising methods for high purity hydrogen production are membranes separation such as polymer, metal, ceramic and composites. It is well known that Pd and Pd-alloys membranes have excellent properties for hydrogen separation. However, it has hydrogen embrittlement and high cost for practical applications. Therefore, most scientists have studied new materials instead of Pd and Pd-alloys. On the other hand, TiN powders are great in resistance to acids and chemically stable under high operating temperature. In order to get specimens for hydrogen permeation, the TiN powders synthesized were consolidated together with Co, Ni powders by hot press sintering (HPS). During the consolidation of powders at HPS, heating rate was 10 K/min and the pressure was 10 MPa. It was characterized by XRD, SEM. Also, we estimated the hydrogen permeability by Sievert's type hydrogen permeation membrane equipment.

• Membrane and Water Treatment
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• v.7 no.5
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• pp.451-462
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• 2016

The molecular weight of proteins and protein hydrolysis products (PHP) in the fractionated post-production marinating brines left after herring marination process was determined by the HPLC. The proteins and PHP retention was evaluated in the three-stage purification process with the usage of polypropylene bag ($25{\mu}m$) and ceramic membranes with the cut-off of 150 and 1 kDa. It was found that the process of marination contributes to high participation of compounds in the post-production marinating brines. Those are characterised by low molecular weight, formed as a result of protein hydrolysis. Each stage of the scavenging process was reducing the content of proteins and PHP. The lowest retention was observed in the stage at which a PP bag was used, while the highest in the UF process, with the usage of 150 kDa membrane. The total retention of proteins and PHP differed according to the type of post-production marinating brines and reached the level of 16-22%.

• Journal of the Korean Ceramic Society
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• v.45 no.2
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• pp.119-125
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• 2008

The FAS(Fluoroalkylsilane)/Nafion inorganic-organic composite electrolyte membrane was successfully fabricated through sol-gel method. The FAS having hydrophobic functional group and silanol ligands is impregnated in $Nafion^{(R)}$ membrane to reduce methanol crossover. The prepared FAS/Nafion inorganic-organic composite electrolyte membrane consist of the hydrophobic FAS-derived silicate nano-particles and $Nafion^{(R)}$ matrix showed decrease of methanol crossover and reduction of humidity dependence without large sacrifice of proton conductivity. The microstructural analysis of the composite membranes was performed using FESEM and FTIR. And the effect of the incorporation of the hydrophobic FAS-derived silicate nano-particles into $Nafion^{(R)}$ membrane was investigated via solvent uptake, membrane expansion rate, humidity dependency of proton conductivity and contact angle measurement.

• Membrane and Water Treatment
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• v.11 no.4
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• pp.275-282
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• 2020

Hranfa's marl, a local natural mineral, is selected for the decontamination by adsorption of aqueous effluents in textile industry. Its physicochemical characterization is first performed. It is composed mainly of Calcite, Quartz, Ankerite and Muscovite. Its specific surface area is 40 ㎡ g^-1. Its adsorption performance is then tested in batch conditions using an industrial organic dye, Bemacid Red E-TL, as a model pollutant. The measured adsorption capacity of Hranfa's marl is 16 mg g^-1 which is comparable to that of other types of natural adsorbents. A hybrid process is tested coupling adsorption of the dye on marl in suspension and microfiltration. An adsorption reactor is inserted into the circulation loop of a microfiltration pilot using ceramic membranes. This makes possible a continuous extraction of the treated water provided that a periodic replacement of the saturated adsorbent is done. The breakthrough curve obtained by analyzing the dye concentration in the permeate is close to the ideal one considering that no dye will cross the membrane as long as the adsorbent load is not saturated. These first experimental data provide proof of concept for such a hybrid process.

• Korean Journal of Materials Research
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• v.12 no.3
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• pp.205-210
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• 2002

The HPS(High Porosity Support, 39.3%) and the LPS( Low Porosity Support, 18.7%) were fabricated to investigate the phase transformation and the chance of microstructure with porosity of alumina support. Alumina sol was made using aluminum tri-sec $butoxide(ATSB,\; Al(O-Bu)_3)$, the membrane on porous support with different porosity and the membrane without support were fabricated. The $\theta$-to ${\alpha}-A1_2O_3$ phase transformation in the membranes was investigated using thin film X-ray diffraction (XRD), and the change of microstructure was observed using scanning electron microscopy(SEM). XRD patterns showed that the membrane on LPS and HPS had 10$0^{\circ}C$, 5$0^{\circ}C$ higher $\theta$-to ${\alpha}-A1_2O_3$ transformation temperature compared to the unsupported membrane. A similar effect was also observed in microstructure of the membranes, theoritical temperature difference were 97$^{\circ}C$ and 44$^{\circ}C$ by Crapeyron equation.

• Journal of the Korean Ceramic Society
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• v.33 no.9
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• pp.1064-1072
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• 1996

The synthetic conditions and characteristics of ZSM-5 type zeolites (ZSM-5/silicalite) for the preparation of the zeolite composite membranes for gas separation were investigated. ZSM-5 zeolites could be synthesized by the hydrothermal treatment of the mixture of colloidal silica sol aluminum nitrate sodium hydroxide and TPABr at a temperature range of 150-17$0^{\circ}C$ in the autoclave. Silicalties were done from the solution of water glass water and TPABr. Their crystalline structures transformed from orthorhombic to monoclinic from and their pore structures of three-dimensional channels were opened as TPABr filling channels was burned off at the calcination temperature of 50$0^{\circ}C$. The specific surface area of the calcined zeolite was about 360 m3/g and its surface property was hydrophobic. Crystal sizes of ZSM-5 and silicalite were 0.5-1.0${\mu}{\textrm}{m}$ and 8-10${\mu}{\textrm}{m}$ respectively having no change due to the calcination. In particular the shape and the size of the ZSM-5 type zeolite were sensitively varied with silica sources and concentrations of reaction solutions/sols.

• Membrane Journal
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• v.31 no.1
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• pp.80-85
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• 2021

In this study, we developed an evaporation-driven self-assembly coating method for an ceramic intermediate layer on an ultrapermeable ��-Al2O3 support with large pore size of ~1.5 ㎛. The method led to the formation of a ceramic intermediate layer with higher surface homogeneity and less surface roughness than the conventional dip-coating method. A mesoporous ��-Al2O3 layer was deposited on the support to evaluate support quality. A supported ��-Al2O3 membrane was defect-free even without repeated coating. Furthermore, the membrane showed 2.3 times higher nitrogen permeance than one prepared on a macroporous support with pore size range of 100~200 nm, which is widely used for ceramic membrane coating.