• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.573-574
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• 2018

• Environmental Engineering Research
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• v.20 no.4
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• pp.342-346
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• 2015

Haloacetonitriles (HANs) are nitrogenous disinfection by-products (DBPs) that have been reported to have a higher toxicity than the other groups of DBPs. The adsorption process is mostly used to remove HANs in aqueous solutions. Functionalized composite materials tend to be effective adsorbents due to their hydrophobicity and specific adsorptive mechanism. In this study, the removal of dichloroacetonitrile (DCAN) from tap water by adsorption on thiol-functionalized mesoporous composites made from natural rubber (NR) and hexagonal mesoporous silica (HMS-SH) was investigated. Fourier-transform infrared spectroscopy (FTIR) results revealed that the thiol group of NR/HMS was covered with NR molecules. X-ray diffraction (XRD) analysis indicated an expansion of the hexagonal unit cell. Adsorption kinetic and isotherm models were used to determine the adsorption mechanisms and the experiments revealed that NR/HMS-SH had a higher DCAN adsorption capacity than powered activated carbon (PAC). NR/HMS-SH adsorption reached equilibrium after 12 hours and its adsorption kinetics fit well with a pseudo-second-order model. A linear model was found to fit well with the DCAN adsorption isotherm at a low concentration level.

• Korean Chemical Engineering Research
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• v.44 no.3
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• pp.248-253
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• 2006

In order to develope an efficient drug delivery system, experimental researches on the supercritical impregnation of ibuprofen onto mesoporous silica, MCM-41,and its drug release characteristics were performed. Supercritical carbon dioxide was adapted as an alternative solvent as it is harmless and able to avoid defects of organic solvents in drug manufacturing processes. The procedure was composed of three steps, that is, as hydrothermal synthesis of MCM-41, supercritical impregnation of ibuprofen onto MCM-41 and release of impregnated ibuprofen. Supercritical impregnation reached equilibrium within 2 h for all cases of this research and the amount of equilibrium impregnation increased with solubility of ibuprofen in supercritical carbon dioxide. Release profiles of impregnated ibuprofen showed a similar behavior for all MCM-41 with different impregnated ibuprofen.

• Carbon letters
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• v.20
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• pp.66-71
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• 2016

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.167-172
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• 2011

In this work, the effect of surface treatment on mesoporous carbons (MCs) supports was investigated by analyzing surface functional groups. MCs were prepared by a conventional templating method using mesoporous silica (SBA-15) for using catalyst supports in direct methanol fuel cells (DMFCs). The MCs were treated with different phosphoric acid ($H_3PO_4$) concentrations i.e., 0, 1, 3, 4, and 5 M at 343 K for 6 h. And then Pt-Ru was deposited onto surface treated MCs (H-MCs) by chemical reduction method. The characteristics of Pt-Ru catalysts deposited onto H-MCs were determined by specific surface area and pore size analyzer, X-ray diffraction, X-ray photoelectron, transmission electron microscopy, and inductive coupled plasma-mass spectrometer. The electrochemical properties of Pt-Ru/H-MCs catalysts were also analyzed by cyclic voltammetry experiments. From the results of surface analysis, an oxygen functional group was introduced to the surface of carbon supports. From the results, the H4M-MCs carbon supports surface treated with 4 M $H_3PO_4$ led to uniform dispersion of Pt-Ru onto H4M-MCs, resulting in enhancing the electro-catalytic activity of Pt-Ru catalysts.

• Journal of the Korean Electrochemical Society
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• v.17 no.1
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• pp.57-64
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• 2014

Carbon electrodes for capacitive deionization were fabricated through mixing two different carbon powders (activated carbon powder, carbon black) with different particle sizes to investigate physical or electrochemical properties and finally desalination performances of the electrodes with various compositions of two carbon powders in weight and were compared with the electrode consisting of activated carbon. As a result, the electrode structure became more packed as increasing the amount of carbon black and resulted in 10% increase in mesopore fraction. The specific capacitance obtained from cyclic voltammograms of various electrodes showed that the electrode containing carbon black only had 107.4 F/g, while the specific capacitance of the electrode having more amount of carbon black increased and was higher than the one having no carbon black. The results of desalination runs in a capacitive deionization cell exhibited that the electrode having the highest amount of carbon black (1 wt%) in this study had the highest desalting efficiency, and no significant pH variation was observed during the runs. It was analyzed using accumulated charge that the fraction of non-Faraday current increased as the amount of carbon black increased in the electrodes. It can be concluded that the addition of carbon black changed the electrode structure resulting in an increase in the fraction of mesopore and finally enhanced the desalting efficiency by decreasing Faraday current.

• Proceedings of the Korean Vacuum Society Conference
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• 2007.08a
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• pp.381-381
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• 2007

• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.10-14
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• 2011

The electrode material performances of electric double layer capacitor(EDLC) were investigated using mesopous active carbon fiber(ACF), which was prepared by the iron exchange method. The mesoporous ACF had pore characteristics of specific surface area around 1249, 664 $m^2$/g, mesoporous fraction around 70.6-81.3% and meanpore size around 2.78-4.14 nm. The results showed that as HNO3 treatment time decreased, the specific surface area increased and mesoporous fraction decreased. To investigate electrochemical performance of EDLC, unit cell was manufactured using mesoporus ACF, conducting material and binder; organic elctrolyte was used on this experiment. The specific capacitance of ACF treated with HNO3 for 2 hours turned out to be 0.47 $F/cm^2$and the results of the cyclic charge-discharge tests were stable. Thus, the electrochemical performance of EDLC was mainly dependent on specific surface area of ACF electrode and the diffusion resistance of charge decreased as the mesopore increased.

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.310-317
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• 2010

The electrochemical properties of electric double layer capacitor(EDLC) was studied by controlling pore size distribution and specific surface area of the activated carbon fiber(ACF). The mesoporous ACF, which was prepared by the iron exchange method, showed the tendency of increasing average pore size and decreasing total surface area. The mesoporous ACF (surface area = 2225 $m^2$/g, pore size=1.93 nm) showed increased mesopore(pore size=1~3nm) volume from 0.055 cc/g to 0.408 cc/g compared to its raw ACF. The charging capacity of the EDLC which uses the prepared mesoporous ACF also increased from 0.39 F/$cm^2$ to 0.55 F/$cm^2$. From these results, it can be known that the electrochemical properties of EDLC are mainly dependent on the specific surface area, but above the surface area 2200 $m^2$/g, it is the mesopore volume that affects the performance of the capacitor considerably. Because the increased mesopore volume results in a decreased ion mobility resistance, the charge capacitance is enhanced.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.8
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• pp.833-837
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• 2015

Li-air batteries have a promising future for because of their high energy density, which could theoretically be equal to that of gasoline. However, substantial Li-air cell performance limitations exist, which are related to the air cathode. The cell discharge products are deposited on the surfaces of the porous carbon materials in the air electrode, which blocks oxygen from diffusing to the reaction sites. Hence, the real capacity of a Li-air battery is determined by the carbon air electrode, especially by the pore volume available for the deposition of the discharged products. In this study, a simple and fast method is reported for the large-scale synthesis of carbon nanoballs (CNBs) consisting of a highly mesoporous structure for Li-air battery cathodes. The CNBs were synthesized by the solution plasma process from benzene solution, without the need for a graphite electrode for carbon growth. The CNBs so formed were then annealed to improve their electrical conductivity. Structural characterization revealed that the CNBs exhibited both an pore structure and high conductivity.