• 센서학회지
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• 제16권6호
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• pp.395-400
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• 2007

Ambient drying sol-gel processing was used for monolithic silica ambigels in the temperature range of $130-250^{\circ}C$. A new method of mesopore ambigels, which mean the aerogels prepared by ambient pressure drying process synthesis, is suggested at first. This method includes two important approaches. The first point is that $SiO_{2}$ surface modification of wet gel was performed by trimethylchlorosilane in n-butanol solution. This procedure is provided the silica gel mesopore structure formation. The second point is a creation of the ternary azeotropic mixture water/n-butanol/octane as porous liquid, which is effectively provided removing of water such a low temperature by 2 step drying condition under ambient pressure. The silica aerogels, which were prepared by ambient pressure drying from azeotropic mixture of water/n-butanol/octane, are transparent, crack-free and mesoporous (pore size ${\sim}$ 5.6 nm) with surface area of ${\sim}$ $923{\;}m^2/g$, bulk density of $0.4{\;}g/cm^3$ and porosity of 85 %.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4015-4022
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• 2012

Manganese(III) 5-(4-carboxyphenyl)-10,15,20-triphenyl porphyrin chloride (Mn(TCPP)Cl) was grafted through amide bond on silica zeolite Y (HY), zeolite beta ($H{\beta}$) and hexagonal mesoporous silica (HMS). XRD, ICP-AES, $N_2$ physisorption, SEM, TEM, FTIR and thermal analysis were employed to analyse these novel heterogeneous materials. These silica supported catalysts were shown to be used for epoxidation and good shape selectivity was observed. The effect of support structure on catalytic performance was also discussed. The catalytic activity remained when the catalysts were recycled five times. The energy changes about epoxidation of alkenes by $NaIO_4$ and $H_2O_2$ were also computationally calculated to explain the different catalytic efficiency.

• Carbon letters
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• 제20권
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• pp.66-71
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• 2016

• 한국가스학회:학술대회논문집
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• 한국가스학회 2005년도 추계학술발표회 논문집
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• pp.163-166
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• 2005

• Bulletin of the Korean Chemical Society
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• 제28권1호
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• pp.121-124
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• 2007

• Bulletin of the Korean Chemical Society
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• 제24권5호
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• pp.613-616
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• 2003

Effect on hydrothermal treatment of lamellar vanadium oxides was investigated and the formation of hexagonal and cubic mesophase was found. This lamellar materials were prepared by mixing of cetyltrimethylammonium-bromide and pH-controlled sodium metavanadate solution. Thermal method and UV/O₃treatment were applied to extract organic template. The structure of resulting product was studied by powder X-ray diffraction and transmission electron microscopy (TEM).

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1507-1510
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• 2011

In this study, mercury vapor adsorption behaviors for some kinds of porous materials having various pore structures were investigated. The specific surface area and pore structures were studied by BET and D-R plot methods from $N_2$/77 K adsorption isotherms. It was found that the micropore materials (activated carbons, ACs) showed the highest mercury adsorption capacity. In a comparative study of mesoporous materials (SBA-15 and MCM-41), the adsorption capacity of the SBA-15 was higher than that of MCM-41. From the pore structure analysis, it was found that SBA-15 has a higher micropore fraction compared to MCM-41. This result indicates that the mercury vapor adsorptions can be determined by two factors. The first factor is the specific surface area of the adsorbent, and the second is the micropore fraction when the specific surface areas of the adsorbent are similar.

• Journal of Ceramic Processing Research
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• 제20권1호
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• pp.30-34
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• 2019

Copper (Cu)-incorporated silica aerogel was synthesized by a sol-gel process with two-step drying process for color modification. The microstructure of the silica aerogel was not affected significantly by the Cu concentration and an amorphous structure was maintained without any crystalline impurity phases. The textural properties of the silica aerogels investigated by using N2 adsorption-desorption isotherms exhibited the typical features of mesoporous materials. The pore size and porosity were not changed significantly even with the incorporation of Cu up to 1.5 M, which indicates negligible variation of thermal insulating properties. However, the color of the aerogel changed from white and light greenish to dark greenish with increasing Cu content. The color change of the silica aerogel was due to the modification of the electron energy band structure of silica by the Cu atomic levels. Therefore, the color of the silica aerogel powders could be manipulated by incorporating Cu without degrading the thermal insulating properties.

• 전기화학회지
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• 제17권2호
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• pp.86-93
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• 2014

5 nm의 중형기공(mesopore)을 지녔으며 5~7 nm 굵기의 산화주석($SnO_2$) 나노선 다발이 잘 정렬된 meso-$SnO_2$를 주형합성법을 이용해서 제조하였다. 또한 주형합성법을 변형시켜서 5~7 nm 굵기의 동일한 나노선 다발 사이에 존재하는 중형기공에 주형으로 사용되었던 실리카($SiO_2$)를 일부 남긴 meso-$SnO_2$와 실리카의 복합체인 meso-$SnO_2$/$SiO_2$도 제조하였다. X-선 회절, 질소흡착법, 투과전자현미경을 이용해서 meso-$SnO_2$와 meso-$SnO_2$/$SiO_2$의 구조를 확인하였다. meso-$SnO_2$/$SiO_2$는 meso-$SnO_2$에 비해서 충방전시 발생하는 부피 팽창을 완화할 수 있을 것으로 예측했으며, 순환전압전류곡선, 교류 임피던스 분석, 충방전 전압 Profile 변화를 통해 부피 팽창 완화 효과를 확인하였다. 하지만, 수명 특성 측면에서는 구조 제어 효과가 미비하여, 향후 이를 개선하는 연구가 진행되어야 한다.

• 공업화학
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• 제25권4호
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• pp.396-400
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• 2014

메조포러스 물질, SBA-15와 MCM-41의 세공 표면을 유기실란인 3-aminopropyltrimethoxysilane (1NS)와 N-[(3-trimethoxysilyl) propyl]ethylenediamine (2NS)를 이용하여 그라프팅법으로 표면 기능화하였다. 표면 기능화된 메조포러스 물질에 $(n-BuCp)_2ZrCl_2$와 조촉매 methylaluminoxane (MAO)를 담지하여 에틸렌 중합을 실시하였다. SBA-15/2NS/$(n-BuCp)_2ZrCl_2$ 촉매는 그라프팅되는 2NS의 양이 증가할수록 담지된 Zr와 Al 함량은 감소하였으며, MCM-41/2NS/(n-BuCp)2ZrCl2 촉매는 2NS의 양이 증가할수록 Zr 함량은 증가하지만 Al 함량은 감소하였다. SBA-15/2NS/$(n-BuCp)_2ZrCl_2$ 촉매의 중합 활성은 2NS의 투입량을 증가할수록 감소하였다. 이는 많은 양의 2NS가 표면에 그라프팅되는 경우 기공부피와 기공크기가 작아지게 되고 따라서 MAO와 메탈로센 촉매 담지량이 감소하게 되기 때문이다. 그러나 SBA-15보다 작은 기공을 갖는 MCM-41을 2NS로 표면 기능화되면 큰 분자 크기를 갖는 조촉매 MAO는 담지 되기 어려워 낮은 MAO 담지량을 갖게 된다. 따라서 메탈로센 담지량은 약간 증가하게 되고 이에 따라 중합 활성이 증가하였다.