• Journal of the Korean Chemical Society
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• v.64 no.6
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• pp.334-344
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• 2020

The adsorption of various atmospheric harmful gases (COx, NOx, SOx) on graphene-like Germanene 2D sheet was theoretically investigated using density functional theory(DFT) method. The structures were fully optimized at the B3LYP/cc-pvDZ and CAM-B3LYP/cc-pvDZ levels of theory and confirmed to be a local minimum by the calculation of the harmonic vibrational frequencies. The adsorptions of gases on the Germanene sheet were predicted to be a physisorption process for CO, CO2, NO, and SO2 gases but to be a chemisorption process for NO2, SO, and SO2 gases.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.849-860
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• 1996

Natural zeolites which were known to occur in sedimentary clinoptilolite, were treated by thermal and chemical methods, and their adsorption characteristics of Cu(II) were studied. Analyses by FT-IR, S. E. M, TGA/DSC, and XRD showed that the adsorption capacity of Cu(II) on the zeolite decreased gradually at the temperatures of above $400^{\circ}C$. The zeolites, which treated with NaOH and NaCl, show higher absorbility in acid solution. The adsorption rate of Cu(II) in the presence of surfactants(LAS, POE AE) on the thermally or chemically treated zeolites varied depending on pH, anion or nonion surfactants.

• Korean Chemical Engineering Research
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• v.57 no.2
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• pp.219-224
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• 2019

In this study, the adsorption characteristics of cephalomannine on commercial adsorbent Sylopute were investigated using different parameters such as adsorption temperature, time, and initial cephalomannine concentration for the efficient separation of Taxus chinensis-derived cephalomannine by adsorption process. The Temkin isotherm model showed good fit to the equilibrium adsorption data. The adsorption capacity decreased with increasing temperature and the adsorption of cephalomannine onto Sylopute was physical in nature. Adsorption kinetic data fitted well with pseudo-second-order kinetic mode. According to the intraparticle diffusion model, film diffusion and intraparticle diffusion did not play a key role in the entire adsorption process. The process of cephalomannine adsorption onto Sylopute was exothermic and spontaneous. In addition, the isosteric heat of adsorption was constant even with variation in surface loading indicating homogeneous surface coverage.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.311-316
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• 1998

The adsorption equilibrium properties of bovine serum albumin(BSA-protein) for three kinds of porous microgels with different physical and chemical features were investigated. The adsorption amount of BSA-protein on poly(butyl methacrylate)(PBMA) microgels was higher than those on poly(vinyl pyridine)(PVP) and poly(acrylonitrile) (PAN) microgels due to the hydrophobic interaction between polymer and protein in an aqueous solution. And PBMA microgels had more irreversible adsorption equilibrium properties the PVP and PAN microgels. It implies that hydrophobic interaction plays a more important role in adsorption properties of BAS-protein than physical properties of polymer and electrostatic attraction between protein and polymer microgels. Characteristics of the microgels used in this study followed Langmuir equation better than the Freundlich equation.

• Applied Chemistry for Engineering
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• v.27 no.1
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• pp.62-67
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• 2016

In this study, a pellet-type adsorbent was prepared by using the water-treatment sludge as a raw material, and its physical and chemical properties were analyzed through $N_2$-adsorption, XRD, XRF, and $NH_3$-TPD measurements. Adsorption performance for gaseous ammonia and formaldehyde was compared between the pellet-type adsorbents prepared from water-treatment sludge and the impregnated activated carbon. Although the surface area and pore volume of the pellet-type adsorbent produced from water-treatment sludge were much smaller than those of the impregnated activated carbon, the pellet-type adsorbent produced from water-treatment sludge could adsorb ammonia gas even more than that of using the impregnated activated carbon. The pellet-type adsorbent prepared from water-treatment sludge showed a superior adsorption capacity for ammonia which can be explained by chemical adsorption ascribed to the higher amount of acid sites on the pellet-type adsorbent prepared from water-treatment sludge. In the case of formaldehyde adsorption, the impregnated activated carbon was far superior to the adsorbent made from the water-treatment sludge, which can be attributed to the increased surface area of the impregnated activated carbon.

• Environmental engineer
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• s.123
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• pp.42-43
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• 1996

중금속을 함유하는 폐수는 일반적으로 단일성분의 원소로 되어 있지 않고 여러 종류의 금속성분이나 유기물이 혼합된 상태로 발생되기 때문에 화학적인 중화나 분해로서 처리하기 곤란하므로 흡착성이 풍부한 광물질의 무기화학성분을 추출하여 흡착, 침전, 분리하는 방법을 이용할 수 있다. Aqua # 219는 폐수 처리용 약품으로 현재 사용하고 있는 설비를 일부 개조하거나 또는 기존설비를 그대로 사용하여 저렴한 가격으로 처리할 수 있는 중금속 흡착제이다.

• Applied Chemistry for Engineering
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• v.9 no.4
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• pp.574-578
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• 1998

Electrochemical Ion Exchang(EIX) electrode containing Amberlite IRP-64 as a cation ion exchange resin and Stylene-Buthylene-Rubber(SBR) as a binder was fabricated by the compressed diecasting method. The adsorption and elution characteristics in copper sulfate solution were investigated at the various electrode potentials and electrolyte pHs. In the adsorption process, it was found that the maximum adsorption rate of copper was obtained at -1800 mV and the ratio of adsorption was 92% during 90 min. In the elution process, the elution rate of copper was increased in proportion to anodic potential in the present experimental range and the ratio of elution was 88% during 50 mins at 3600 mV. The adsorption and elution processes were significantly affected by the variation of local pH in the vicinity of electrochemical ion exchange electrode. The higher performances of adsorption and elution were elution were obtained at basic and acidic eletrolytes.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.432-432
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• 2005

사용후핵연료시료 중에 함유된 요오드(I-127 및 129)를 정량하기 위하여 화학적 방법으로 분리 회수하고 중성자방사화분석법을 이용하였다. 사전실험으로 모의사용후핵연료를 이용하여 회수율을 측정하였다. 모의 및 실제사용후핵연료시료를 $90^{\circ}C$에서 8 M $HNO_3$ 용액으로 용해하고 용해 후 용해용액 중의 잔류 요오드, 응축 및 휘발된 요오드 각각을 정량하였다. 응축 요오드는 핵연료 용해 후 재증류하여 회수하였다. 잔류 및 응축 요오드는 시료의 산화상태를 조절한 후 용매추출로 요오드를 회수한 다음 이온교환 또는 침전법으로 방사화학적으로 분리한 후 중성자방사화분석(RNAA)으로 정량하였다. 제작한 이온교환분리관 및 여과키트에 요오드를 흡착 또는 침전시켜 분리한 다음 중성자조사를 위한 삽입체(Insert)로 이용하였다. 휘발 요오드는 제조한 흡착체(Ag-silica gel)를 담은 흡착관에 포집하고 홉착체를 구간별 균질시료로 만든 다음 비파괴중성자 방사화분석(INAA)으로 정량하였다. 침전 및 흡착 요오드의 화학적 특성을 EPMA(electron probe microanalysis) 분석으로 조사하였다. 요오드 정량결과를 다른 방법으로 비교분석하기 위하여 음이온교환수지상에서 요오드를 정제 및 회수하기 위한 용리거동을 조사하였다.

• Journal of the Korean Chemical Society
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• v.19 no.6
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• pp.420-422
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• 1975

The chemisorption of hydrogen and carbon monoxide, as well as the hydrogen titration of prechemisorbed oxygen was studied at $110^{\circ}$C on evaporated platinum and platinum-tungsten films. The results suggest that hydrogen titration of prechemisorbed oxygen may be used to determine the platinum surface area of platinum-tungsten film.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.343-343
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• 2010

Tetra(4-carboxyphenyl)porphine(TCPP) 흡착으로부터 그래핀 표면의 기능화에 대하여 방사광을 이용한 광전자 분광법으로 연구하였다. 최근 들어 그래핀을 이용한 소자개발에 있어서 그래핀의 우수한 전기적 특성을 저해하지 않으며 그 표면의 화학적 활성도를 개선하고자 하는 필요성이 대두되고 있다. 따라서 기능성 작용기를 가지고 있는 유기반도체 물질을 이용하여 그래핀 표면의 화학적 활성화를 촉진시킴과 동시에 보호층을 형성시키고자 하는 연구가 보고되고 있다. 그러나 일반적으로 그 유기분자들이 그래핀 표면에 흡착되었을 때 전하의 이동을 유도함으로서 원래 그래핀의 물리적 특성을 변화시킬 가능성을 가지고 있다. 본 연구에서는 6H-SiC 표면 위에 두층으로 에피텍셜 성장된 그래핀에 TCPP 분자를 흡착시킴으로서 그래핀의 고유 특성을 거의 저해하지 않음과 동시에 기능성 작용기의 역할을 충실히 수행할 수 있음을 보여 주고 있다. 이는 valence band dispersion과 일함수 변화 측정으로 관찰할 수 있었다. 또한 TMA를 이용한 TCPP의 수산화 작용기의 반응 과정은 일반적인 실리콘 산화막에 적용했을 때 일어나는 화학적 반응 과정과 다른 메커니즘으로 진행됨을 관찰하였다.