• Journal of the Korean Chemical Society
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• v.30 no.1
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• pp.63-68
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• 1986

Elution behavior of rare earth elements have been investigated with the EDTA solution as an eluent using cation exchange resin. Definite amount of the complexed rare earth ions at pH 8.4 is adsorbed through the cation exchanger containing cupric ion as a retaining ion and eluted with EDTA solution. The rare earth ions are eluted more rapidly in the above method than in the method in which uncomplexed rare earth ions are adsorbed on the cation exchange resin bed. In this method, the elution time and amount of eluent are saved but the resolution values also decreased a little. The elution order of complexed ion was determined in accordance with the stability constant of complexes with rare earth elements.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.4
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• pp.571-583
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• 1996

The electrochemical behavior on electrographite and graphite foil electrode with porous surface in 0.5 M $K_{2}SO_{4}$ solution with 1 mM $[Fe(CN)_{6}]^{3-}/[Fe(CN)_{6}]^{4-}$ have been characterized by impedance spectroscopy. In cyclic voltammograms, relative high current according to structure of porous surface for graphite materials was represented, and indicated hgih double layer capacitance on graphite foil. The faraday-impedance and the change of impedance spectrum on both graphite materials were not remarkable during polarization by reaction of field transport. Chemical adsorption was represented on electrographite and was depended highly at anodic polarization.

• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.449-456
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• 2020

When you move to a new home, or when you change the wallpaper or flooring of your home, office, etc., you can enjoy the joy of opening your new home with the sick house syndrome, such as the stinging smell and stinging eyes that may appear after the interior work. It is only a moment. Volatile organic compounds from building materials, adhesives, wallpaper, and paints used in new buildings or new furniture cause residents' health and discomfort in indoor life. These volatile organic compounds include benzene, toluene, acetone, and styrene, as well as the representative formaldehyde, and these substances are slowly released over a long period of time, causing acute or chronic diseases to residents. As a method for removing organic volatile substances, physical methods using adsorption, chemical methods for converting volatile substances to other substances, or a mixture of the two are mainly used. In this paper, a sustained release chlorine dioxide gel pack obtained by a method for controlling the reaction rate of a reactant and the release of a product is mixed with a zeolite adsorbent having an optimized hole diameter to adsorb and decompose and remove formaldehyde suspended in the air. I would suggest an effective method.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.321-328
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• 2004

Nano silica ball and nano carbon ball are developed commercially by template synthesis method. Adsorption of unpleasant smelling substances such as ammonia, trimethylamine, acetaldehyde and methyl mercaptane onto nano carbon ball with hollow macroporous core/mesoporous shell structures, nano carbon ball, was investigated and compared with that onto odor adsorbent materials, activated carbon, commercially available. The adsorption and decomposition of malodor at nano carbon ball exhibited superior than those onto activated carbon. The physicochemical properties such as mesopore size distributions, large nitrogen BET specific surface area and large pore volume and decomposition of malodor were studied to interpret the predominant adsorption performance. The nano carbon ball is expected to be useful in many applications such as deodorizers, adsorbent of pollutants.

• Journal of Radiation Protection and Research
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• v.11 no.2
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• pp.104-113
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• 1986

The ion exchange behaviour of the $Cs^{+1},\;Sr^{+2},\;and\;Th^{+4}$ in the system of $Cs^{+1},\;Sr^{+2},\;Th^{+4},\;and\;7Cl^{-}-H^{+}$ from Dowex HCR-W2, was examined in the loading and elution processes. $Th^{+4}$ was slowly adsorbed through the entire contact time between resin and solution and $Cs^{+1}\;and\;Sr^{2+}$ were adsorbed fast for the first few minutes of contact time. Because of the strong affinity of $Th^{+4}$, the longer contact time was allowed, the less amount of $Cs^{+1}\;and\;Sr^{2+}$ was adsorbed on the resin. The peak concentration of the resin phase $Cs^{+1}$ in the solution concentration of $Cs^{+1}:Sr^{+2}:Th^{+4}$ in the ratio of 2 : 2 : 1 in normality with total normality of 0.1N was produced at about 4 minutes of contact time and the peak time for $Sr^{+2}$ was 20 minutes. The loaded ions were eluted using hydrochloric acid. The loaded $Cs^{+1}$ was eluted at the low eluent concentration of less than 0.1N with less than 5% contamination of $Sr^{+2}$. The loaded $Th^{+4}$ was eluted at the high eluent concentration of greater than 1N. The best eluent concentration for eluting $Th^{+4}$ was 4N.

• Journal of the Korean Chemical Society
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• v.47 no.3
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• pp.220-228
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• 2003

This study was to examine the thermodynamic features of polyelecrolytic adsorption of polyamidoamine-epichlorohydrin(PAE) in a papermaking wet-end. The PAE adsorption experiments were conducted in a stirred jar containing an aqueous fibrous suspension and evaluated in terms of Langmuir and Freundlich parameters. The electrokinetic property of a stock was examined by measuring the zeta potential of each colloidal suspension. The polyelectrolytic PCD titration was employed to determine the adsorbed amounts of PAE polymer. The zeta potential of a stock, being varied significantly depending upon the addition of PAE polymer, showed initially a sharp increase and later an exponential decay as a function of time . The PAE adsorption exhibited a pseudo-Langmuir adsorption behavior at$20^{\circ}C$ , whereas its Freundlich power(v) increased in a proportional way at an elevated temperature. The train numbers calculated on the basis of adsorption thermodynamics were 7 to 8. The length of the extended loop of PAE was calculated as 215 nm at $20^{\circ}C$ and increased at a rate of 9% at every $10^{\circ}C$ rise in temperature. The PAE adsorption was proven to be an exothermic physisorption with the estimated adsorption enthalpy of -27 to -29 kJ/mol.

• Applied Chemistry for Engineering
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• v.28 no.4
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• pp.473-478
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• 2017

In this study, the guanidine compound, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) was impregnated to three kinds of silica to prepare $CO_2$ adsorbents, and the $CO_2$ adsorption and physicochemical properties of the resulting adsorbents were investigated. The TBD amount of impregnation was changed and its effect on adsorption capacity and characteristics were studied. The physicochemical properties of TBD-impregnated silica were evaluated with $N_2$ adsorption/desorption, FT-IR, elemental analysis, and thermogravimetric analysis. The TBD-impregnated silica lowered the surface area and pore volume, and the increased impregnation amount of TBD made them further decrease. When TBD was 6 mmol/g, the $CO_2$ adsorption capacity was the highest at 7.3 wt%, and the adsorption capacity decreased due to the blocking phenomenon when the TBD amount increased.

• Applied Biological Chemistry
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• v.25 no.2
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• pp.99-104
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• 1982

Natural zeolite rock was pulverized and dispersed in water. Clay fraction was collected by sedimentation method. The dominant clay mineral was Clinoptiolite with some Mordenite and Smectite. $P^{32}$ adsorption on Na-zeolite was determined in different ionic strengths using $P^{32}$ isotope by sludge method. The lower the pH of suspension, the longer the contact time, and the more the amount of zeolite, the more inorganic P was adsorbed by Na-zeolite, whereas the more P adsorption per unit gram of zeolite was observed at a 100mg addition than a 200mg in same volume of P-NaCl solution (20ml), indicating that the whole positively charged surface of Na-zeolite was not occupied by inorganic P. Furthermore, the more P adsorption on Na-zeolite was observed in higher ionic strength than in the lower. The maximum P adsorption on Na-zeolite was about 1me/g, and the zero point charge (ZPC) is assumed to be below pH 3.7.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.121-121
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• 2017

본 연구는 비전도성 폴리머 표면을 개질하여 감광성 금속을 유전체 표면에 흡착시키고, 감광성 금속의 광화학 반응을 이용하여 귀금속 촉매를 비전도성 폴리머 표면에 선택적으로 흡착시켜 무전해 Cu 도금을 수행하여 금속패턴을 형성하였다. 기능성 유연 필름은 일반적으로 투명한 플라스틱 고분자 기판을 기반으로 전기 전자, 에너지, 자동차, 포장, 의료 등 다양한 분야에서 폭넓게 활용 되고 있으며, 본 연구에서는 습식 도금 공정을 이용하여 폴리이미드 필름상에 $10{\mu}m$ 이하의 미세패턴을 형성하기 위한 공정을 개발하고자 하였다. 비전도성 폴리머 표면에 무전해 도금을 위해서 우선 폴리머 필름의 표면을 개질하는 공정이 필요하다. 이에 KOH 또는 NaOH 알카리 용액을 이용하여 표면을 개질하였으며 개질된 표면에 감광성 금속이온의 흡착시키기 위한 감광성 금속이온은 주석을 사용하였으며, 주석 용액의 안정성 및 퍼짐성 향상을 위해 감광성 금속 용액의 제조 및 특성을 관찰하였으며, 감광성 금속화합물이 흡착된 비전도성 유전체 표면을 포토마스크를 이용하여 특정 부위, 즉 표면에 금속패턴 층을 형성하고자 하는 곳은 포토마스크를 이용하여 광원을 차단하고 그 외 부분은 주 파장이 365nm와 405nm 광원을 조사하여 선택적으로 감광성 금속화합물의 산화반응을 유도하는 광조사 공정을 수행하였다. 광원이 조사되지 않은 부분에 귀금속 등의 촉매 입자를 치환 흡착시켜 금속 패턴이 형성될 수 있는 표면을 형성하였다. 위의 활성화 공정이후에 활성화 처리된 표면을 세척하는 수세 공정을 거친 후 무전해 도금공정에 바로 적용할 경우 미세한 귀금속 입자가 패턴이 아닌 부분 즉 자외선(UV) 조사된 부분에도 남아있어 도금시 번짐 현상이 발생한다. 이에 본 연구에서는 활성화 처리 후 약 알칼리 용액에 카르복실산을 혼합하여 잔존하는 귀금속 입자를 제거한 후 무전해 Cu 도금액을 이용하여 $10{\mu}m$ 이하의 Cu 금속 패턴을 형성하였다.

• Journal of Soil and Groundwater Environment
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• v.12 no.1
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• pp.1-35
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• 2007

In the last decades, the decrease in biological or chemical availability of sorbed contaminants as contact time passed, is generally accepted. This phenomenon so called as "aging" or "sequestration" is known to directly affect risk of the contaminats. This was observed for mainly for hydrophobic organic contaminants (HOCs), but also reported for heavy metals. Aging is known to be directly related to sorption-desorption hysteresis, irreversible sorption, desorption-resistance, nonequilibrium sorption, etc. The decrease in bioavailability due to aging or sequestration indicates realistic decrease in risk potential. Recently a risk-based management concept by scientific evidences but not the simple measurement of contaminant concentration has been attempted to determine environmentally acceptable remedial endpoint. This is because selection of remedial endpoint based on not total concentration but the bioavailability and toxicity of contaminants can reduce both the treatment cost and remedial activities of the contaminated sites. The bioavailability and toxicity of the residual contaminants are highly affected by the fate and transport and also directly affect the exposure pathways and bioaccumulation of contaminants in the living biota. In this paper, scientific feasibility on the risk-based clean-up and management of contaminated sites is reviewed.