• 한국환경과학회지
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• 제17권7호
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• pp.711-717
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• 2008

The use of support materials on the nanoparticle synthesis and applications has advantages in many aspects; resisting the aggregation and gelation of nanoparticles, providing more active sites by dispersing over the supports, and facilitating a filtering process. In order to elucidate the influence of the supports on the nitrate reduction reactivity, the supported iron nanoparticles were prepared by borohydride reduction of an aqueous iron salt in the presence of supports such as activated carbon, silica and polyethylene. The reactivity for nitrate reduction decreased in the order of unsupported Fe(0) > activated carbon(AC) supported Fe(0) > polyethylene(PE) supported Fe(0) ${\ge}$ silica supported Fe(0). Rate constants decrease with increasing initial nitrate concentration implying that the reaction is limited by the surface reaction kinetics.

• 동력기계공학회지
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• 제15권4호
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• pp.75-78
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• 2011

There are various types of materials used in electronic industry, such as electrode material, conductor, insulator, anode, cathode and semiconductor. Electrode material type is Cu, Ti, ZnO and so on. Especially if we use mixed ZnO in soil cement or silica gel, we can have advantages in ice road to prevent freezing. We have great impact if we use supported in inorganic substances like silica gel. In this paper we have studied that ZnO supported silica gel and its properties. Zinc acetate dissolved in distilled water were loaded on the silica gel by the reaction with ammonia at $80^{\circ}C$. And we investigated particle structures of ZnO by scanning electron microscopy(SEM) and X-ray diffraction(XRD).

• 공업화학
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• 제27권2호
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• pp.190-194
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• 2016

Tricyclopentadiene (TCPD)는 차세대 고밀도에너지 연료인 tetrahydrotricyclopentadiene의 전구체로서 중요한 화합물이다. 본 연구에서는 이온성 액체가 담지된 메조포로스 실리카 촉매를 이용하여 dicyclopentadiene 소중합 반응을 통한 TCPD 합성에 관한 연구를 수행하였다. 나노기공의 크기가 다른 대표적인 메조포로스 실리카인 MCM-41과 SBA-15에 이온성 액체(IL)를 함침법을 이용하여 담지하고 소중합 촉매를 제조하였다. 음이온 전구체로 copper(I) chloride (CuCl) 또는 iron(III) chloride ($FeCl_3$), 양이온 전구체로 triethylamine hydrochloride (TEAC) 또는 1-butyl-3-methylimidazolium chloride(BMIC)를 사용하여 4가지 종류의 IL을 메조포로스 실리카에 담지하였다. 이온성 액체가 담지된 메조기공의 실리카를 사용하였을 때 이온성 액체만 사용하였을 때보다 TCPD 수율과 dicyclopentadiene (DCPD)의 전환율 측면에서 우수하였다. 특히, MCM-41에 루이스 산도가 낮은 CuCl계 이온성 액체를 담지할 때 TCPD 수율이 가장 높았다.

• Bulletin of the Korean Chemical Society
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• 제26권8호
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• pp.1297-1299
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• 2005

• 한국응용과학기술학회지
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• 제25권1호
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• pp.65-72
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• 2008

The ion exchangers supported on silica gel containing primary, secondary, or tertiary amine groups show a behaviour that is weakly acidic, while the quaternary salts are strongly acidic. These properties change according to the hydrophilicities of the modifier functional groups. Ammonium salt derivatives supported on silica gel were prepared from silica modified with 3-Aminopropyltriethoxysiliane and N-3-(Trimethoxysilyl)propylehtylene diamine. The preparation and the ion exchange properties of two systems were discussed. Two systems have different hydrophilicities and contain ammonium chloride derivatives of 3-amminopropyltriethoxysilane and N-3-(triehtoxysilyl)propyl ethylene diamine supported on silica gel, $SA^+/Cl^-$ and $SA^+/Cl^-$, respectively. The high affinity to perchlorate ion presented by the $SA^+/Cl^-$ through the equilibrium studies of ion exchange led us to its application as an ion selective electrode for the perchlorate ion. The determination of the perchlorate ion in the presence of other anions and in complexes is very difficult. Few analytical methods are available and most of them are indirect. Both materials showed potential use as an ion exchanger; they are thermically stable, achieve equilibrium rapidly in the presence of suitable exchanger ions, and are easily recovered.

• Korean Chemical Engineering Research
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• 제46권4호
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• pp.752-755
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• 2008

메조포러스 SBA-15 silica와 (1R,2R)-N-(trimethoxysilylpropyl-N-sulfonyl)-1,2-cyclohaxanediamine 또는 (1R,2R)-N-(trimethoxysilylpropyl-N-sulfonyl)-1,2-diphenylethylenediamine과의반응을통하여 메조포러스 silica SBA-15-supported TsCHDA와 TsDPEN가 각각 제조되어졌다. SBA-15-supported TsCHDA로부터 얻어진 ruthenium complex들은 microwave하에서의 케톤의 비대칭 수소 전달반응에서 우수한 촉매능과 만족할 만한 거울상 입체선택도를 주었다. 이불균일상 SBA-15-supported ruthenium 촉매는 사용이 용이하게 안정할 뿐 만 아니라, 재사용 할 수 있었다. 비대칭 수소전달반응을 위한 microwave를 사용한 효율적인 공정이 개발되었다.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2369-2377
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• 2012

The gas-phase dehydration of glycerol to acrolein was carried out over silicotungstic acid ($H_4SiW_{12}O_{40}{\cdot}xH_2O$, HSiW) catalysts supported on $SiO_2$, ${\eta}-Al_2O_3$, and silica-aluminas with different Al contents. The HSiW catalysts supported on silica-aluminas showed higher glycerol conversions and acrolein yields during the initial 2 h at $315^{\circ}C$ than did $SiO_2$- and ${\eta}-Al_2O_3$-supported HSiW catalysts. Among the tested catalysts, HSiW/$Si_{0.9}Al_{0.1}O_x$ exhibited the highest space-time yield during the initial 2 h. The loaded HSiW species can change the acid types and suppress the formation of carbonaceous species on Al-rich silica-aluminas. The deactivated HSiW supported on silica-aluminas can be fully regenerated after calcination in air at $500^{\circ}C$. As long as the molar ratio between water and glycerol was in the range of 2-11, the acrolein selectivity increased significantly with increasing water content in the feed, while the surface carbon content decreased owing to the suppression of heavy compounds.

• Bulletin of the Korean Chemical Society
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• 제31권1호
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• pp.250-252
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• 2010

• Macromolecular Research
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• 제17권5호
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• pp.346-351
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• 2009

$TiCl(O-i-Pr)_3/SiO_2$ and $Ti(O-i-Pr)_4/SiO_2$ were prepared by immobilizing chlorotitanium (IV) isopropoxide ($TiCl(O-i-Pr)_3$) and titanium (IV) isopropoxide ($Ti(O-i-Pr)_4$), to pretreated silica. The effect of the polymerization reaction conditions on the catalytic activity and characteristics of the resulting PLA were investigated. The catalytic conversion, molecular weight and polydispersity index (PDI) of the PLA produced on the titanium alkoxide supported catalysts increased proportionally with the reaction temperature. When the PLA was synthesized in bulk polymerization, the PLA produced with the supported catalysts had higher molecular weight than those with homogeneous catalysts. The melting temperature of the polymer produced with silica supported alkoxide catalysts was approximately $170-180^{\circ}C$.

• 공업화학
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• 제27권3호
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• pp.239-244
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• 2016

본 총설에서는 $CO_2$와 에폭시 화합물의 부가반응에서 무정형, SBA, MCM 또는 상업적으로 쉽게 이용 가능한 다양한 silica 지지체에 담지된 이온성 액체의 촉매적 적용가능성에 대하여 검토하였다. $CO_2$ 부가반응에 의한 5원환 카보네이트의 합성에 대하여 담지된 이온성 액체의 구조적인 영향과 silica 지지체의 종류에 따른 촉매 활성을 검토한 바, 관능기 또는 금속을 보유한 이온성 액체인 경우에 촉매 성능이 개선됨을 알 수 있었다. 또한 silica에 담지된 이온성 액체(SSIL) 촉매의 재사용성과 반응메커니즘을 조사하여 제시하였다.