• Journal of Korean Society of Water and Wastewater
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• v.19 no.4
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• pp.455-461
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• 2005

This study was designed to investigate the fundamental aspects of a possible recovery of phosphorus strategy from wastewater by using the zirconium mesoporous structured materials as a new type of ion exchangers. Zirconium mesoporous structure material was synthesized by hydro-thermal synthesis. The synthesized zirconium mesoporous structure was examined by X-ray diffraction (XRD) and Transmission electron micrograph (TEM). From the results of XRD and TEM, it was found out that hexagonal mesoporous structure, pore size was about $47{\AA}$, was synthesized. Experimental results showed that the complex of zirconium sulfate tetrahydrate and surfactant micelles had very high ability for capture of phosphorus. The amount of phosphate ions exchanged into the solid was as great as 3.4mmol/g-ZS. And the ion exchange reaction was occurred between $PO_4{^{3-}}$ and $SO_4{^{2-}}$ and also between $PO_4{^{3-}}$ and $OH^-$. Therefore, it is possible to get the higher removal efficiency than other ion exchange media and adsorbent.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.313-317
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• 2010

Li, Zr doped mesoporous silica was synthesized in one pot and investigated for low temperature $CO_2$ adsorption. Herein CTAB and TEOS are used as structural directing agent and silica source respectively. The characteristics of the material was obtained from FT IR, XRD, SEM, TG and BET results. ICP AES results revealed the presence of lithium and zirconium. The material possesses high surface area ($962.22m^2g^{-1}$) with mono dispersed particles of about 2 nm. The maximum $CO_2$ adsorption capacity is 5 wt % (50 mg/g) of $CO_2$/g of sorbent at $25^{\circ}C$, which is regenerable at $200^{\circ}C$. This regeneration temperature of the adsorbent is lower than the reported lithium zirconium silicate powder. Until now, there is no report for the synthesis of Li, Zr doped mesoporous silica. The performance studies illustrate that Li, Zr doped mesoporous silica is tunable, regenerable, recyclable and selective sorbent and hence found to be a promising candidate for $CO_2$ adsorption.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.308-311
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• 2003

The mesoporous TiO2 film for the dye-sensitized solar cell was prepared by the spin coating using nano particle $TiO_2$ slurry. In order to obtain the good dispersion of nano size $TiO_2$ particles in slurry, the pH of solvent, the sort and quantity of solvent additive and the quantity of surfactant were adjusted. The experimental range of pH was $2\;{\sim}\;4$. The basic solvent for slurry was dilute $HNO_3$ and the solvent additives were ethylene glycol, propylene glycol and butylene glycol. The degree of particle dispersion was indirectly estimated by the viscosity of slurry and the microstructure after sintering. As results, the lower the pH of solvent was the lower the viscosity of the slurry became. The addition of ethylene glycol and propylene glycol to dilute $HNO_3$ brought about the lowering of viscosity and the enhancement of stability in slurry. The addition of surfactant lowered the viscosity of slurry. It was possible to obtain the homogeneous and uniformly dispersed mesoporous TiO2 film using the dilute HNO3 solvent of pH 2 with the addition of ethylene glycol, propylene glycol and neutral surfactant.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2155-2161
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• 2013

Composite materials of mesoporous carbon and carbon nanotubes were synthesized using Ni, Co and Pd-loaded CMK3 via a catalytic reaction of methane and $CO_2$. The CNTs grew from the pores of the mesoporous carbon supports, and they were attached tightly to the CMK3 surface in a densely tangled shape. The CNT/CMK3 composite showed both non-graphitic mesoporous structures, and graphitic characteristics originating from the MWCNTS grown in the pores of CMK3. The electrochemical properties of the materials were characterized by their electrorheological effects and cyclic voltammetry. The CNTs/CMK3 composites showed high electrical conductivity and current density. The CNT/CMK3 or KOH-modified CNT/CMK3 particles were incorporated in a PMMA matrix to improve the thermal and electrical conductivity. Even higher thermal conductivity was achieved by the addition of KOH-modified CNT/CMK3 particles.

• Journal of the Korean Applied Science and Technology
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• v.26 no.3
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• pp.328-334
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• 2009

Recently, much interest on mesoporous carbon has been shown in their use for both hydrogen and methane storage and as an electrode material for electric double layer capacitors. The mesoporous active carbons by ion exchange were prepared and physical properties such as specific surface area and pore structure of active carbon were investigated using BET. In this study, active carbons with mesopore fraction of $60{\sim}90%$ were obtained. The Fe/Ca-exchanged active carbons showed a greater mesoporosity compared with Fe-exchanged carbons. The mean mesopore size in active carbons using Ca- and Fe-exchange was about $5.5{\sim}6.0nm$ and was approximately 1nm higher than that of the Fe-exchanged active carbon.

• Current Applied Physics
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• v.18 no.12
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• pp.1480-1485
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• 2018

Mesoporous carbon-silica composites supported Pt nanoparticle catalysts (Pt/MCS) were firstly applied to the heterogeneous asymmetric hydrogenation of ethyl 2-oxo-4-phenylbutyrate (EOPB). A series of different silica contents were investigated in the fabrication of this mesoporous material. When the volume of added tetraethyl orthosilicate (TEOS) during the preparation of composites is 8 mL, Pt/MCS-8 holds carbon and silica as the main components and possesses relatively strong acidity, mesoporous structures with micropores, appropriate Pt nanoparticle size and high dispersibility showing by XRD, XPS, TPD, $N_2$ sorption and TEM. These properties cause its good catalytic performance in the heterogeneous asymmetric hydrogenation of EOPB with the enantiomeric excess value and conversion up to 85.6% and 97.8%, respectively.

• Korean Journal of Materials Research
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• v.27 no.11
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• pp.617-623
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• 2017

Mesoporous carbon nanofibers as electrode material for electrical double-layer capacitors(EDLCs) are fabricated using the electrospinning method and carbonization. Their morphologies, structures, chemical bonding states, porous structure, and electrochemical performance are investigated. The optimized mesoporous carbon nanofiber has a high sepecific surface area of $667m^2\;g^{-1}$, high average pore size of 6.3 nm, and high mesopore volume fraction of 80 %, as well as a unifom network structure consiting of a 1-D nanofiber stucture. The optimized mesoporous carbon nanofiber shows outstanding electrochemical performance with high specific capacitance of $87F\;g^{-1}$ at a current density of $0.1A\;g^{-1}$, high-rate performance ($72F\;g^{-1}$ at a current density of $20.0A\;g^{-1}$), and good cycling stability ($92F\;g^{-1}$ after 100 cycles). The improvement of the electrochemical performance via the combined effects of high specific surface area are due to the high mesopore volume fraction of the carbon nanofibers.

• Journal of Surface Science and Engineering
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• v.40 no.1
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• pp.16-22
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• 2007

Recently, mesoporous metallic materials are becoming more and more important in various applications like catalysts, electrochemical detectors, batteries, and fuel cells because of their high surface area. Among the various methods for manufacturing mesoporous structure, surfactant templating method followed by electroplating has been tried in this study. A mesoporous metallic film was prepared by electrodeposition from electroplating solution mixed with surfactant template. Nonionic type lyotropic liquid crystalline surfactant, Brij56, and nickel acetate based solution were selected as a template material and electroplating solution, respectively. To determine the content of surfactant forming a hexagonal column structure, the phase diagram of electroplating solution and surfactant mixture has been exploited by polarized optical microscopy equipped with heating and cooling stage. Nickel films were electroplated on Cu foil by stepwise potential input method to alleviate the concentration polarization occurred during the electroplating process. TEM and XRD analyses were performed to characterize the size and shape of mesostructures in manufactured nickel films, and electrochemical characterization was also carried out using cyclic voltammetry.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1481-1486
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• 2013

Bifunctional Fe-SBA-15-$SO_3H$ mesoporous materials with different Si/Fe molar ratios (3, 5, and 7) have been synthesized via a simple direct hydrothermal method and characterized by XRD, $N_2$-adsorption/desorption, TG/DTG and FT-IR techniques, and used as solid acid catalysts in the esterification of lactic acid with methanol. XRD and $N_2$ sorption characterizations show successful iron doping within the mesoporous channels of SBA-15-$SO_3H$. The FT-IR and TG/DTG characterizations also reveal the presence of iron. With the incorporation of Fe ions into the SBA-15-$SO_3H$, the acid sites substantially increased because of the self-separated acidity of the hydrolysis of $Fe^{3+}$ solutions. However, in the Si/Fe = 3 molar ratio, the catalytic conversion decreased which is caused by the reduced cooperation effect between the acid pairs due to the weakened hydrogen bonds and collapse of the pore structure. This further suggests that the mesoporous structure decreases with the decrease in Si/Fe ratio.

• Korean Journal of Materials Research
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• v.27 no.4
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• pp.192-198
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• 2017

Carbon nanofiber (CNF) is used as an electrode material for electrical double layer capacitors (EDLCs), and is being consistently researched to improve its electrochemical performance. However, CNF still faces important challenges due to the low mesopore volume, leading to a poor high-rate performance. In the present study, we prepared the unique architecture of the activated mesoporous CNF with a high specific surface area and high mesopore volume, which were successfully synthesized using PMMA as a pore-forming agent and the KOH activation. The activated mesoporous CNF was found to exhibit the high specific surface area of $703m^2g^{-1}$, total pore volume of $0.51cm^3g^{-1}$, average pore diameter of 2.9 nm, and high mesopore volume of 35.2 %. The activated mesoporous CNF also indicated the high specific capacitance of $143F\;g^{-1}$, high-rate performance, high energy density of $17.9-13.0W\;h\;kg^{-1}$, and excellent cycling stability. Therefore, this unique architecture with a high specific surface area and high mesopore volume provides profitable synergistic effects in terms of the increased electrical double-layer area and favorable ion diffusion at a high current density. Consequently, the activated mesoporous CNF is a promising candidate as an electrode material for high-performance EDLCs.