• Carbon letters
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• 제4권2호
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• pp.86-92
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• 2003

A series of micro- and mesoporous activated carbons were prepared from two kinds of phenolic resin using a metal treated chemical activation methodology. $N_2$-adsorption data were used to characterize the surface properties of the produced activated carbons. Results of the surface properties and pore distribution analysis showed that phenolic resin can be successfully converted to micro- and mesoporous activated carbons with specific surface areas higher than 973 $m^2/g$. Activated carbons with porous structure were produced by controlling the amount of metal chlorides ($CuCl_2$). Pore evolvement depends on the amount of additional metal chloride and precursors used. From the SEM and EDX data, copper contents were shown to be most effected by the incremental addition of metal chloride.

• 접착 및 계면
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• 제23권3호
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• pp.70-74
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• 2022

탄닌산은 식물 유래 폴리페놀 중 하나로, 대부분의 생체고분자와 분자간결합을 할 수 있어서 분자적 접착제로서 연구가 되어 왔으며, 표면 개질, 에너지 저장 및 발생 장치, 의료용 제재로서 활용이 되고 있다. 본 연구에서는 약물 전달과 바이오이미징 등 의생명공학 분야에서 다양하게 활용되는 다공성 실리카 나노입자를 합성하고, 탄닌산을 이용하여 다공성 실리카 나노입자의 표면을 개질 한 뒤, 나노입자의 표면을 분석하였다.

• 새물리
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• 제68권11호
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• pp.1173-1182
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• 2018

메조포러스 실리카는 강한 친수성과 구조적인 특성으로 인하여 저습환경에서도 이온교환막에 적절한 수화가 일어나도록 할 것이다. 그러므로 메조포러스 실리카와 나피온을 합성한 이온교환막은 낮은 상대습도에서도 우수한 양성자 전도도를 보일 것이다. 메조포러스 실리카와 나피온 합성이온교환막의 이온채널형성 그리고 네트워크를 통한 양성자 이동에 대한 이해는 합성이온교환막을 개발하고 최적화하기 위해 필수적이라 할 수 있다. 이 연구에서는 메조포러스 구조 (mesoporous cellular foam) $SiO_2/Nafion$ 합성이온교환막을 제작하고 양성자 전도도 및 성능을 평가하였다. 또한, 정전기력 현미경(electrostatic force microscopy, EFM)을 사용하여 메조포러스 구조 $SiO_2/Nafion$ 합성 이온교환막의 표면 전하 밀도 측정을 통한 이온 채널의 분포 및 밀도를 분석하였다. 연구는 몇 가지 주목할 만한 결과를 보여주었다. 첫째, 합성이온교환막은 저습환경에서 우수한 양성자 전도도 및 성능을 나타내었다. 둘째, 합성이온교환막은 국부적으로 이온채널의 밀도가 주목할 만하게 높은 지역이 형성되며 동시에 양성자 전도도가 극단적으로 낮은 지역 또한 동시에 형성됨을 확인하였다.

• 한국전기전자재료학회논문지
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• 제25권8호
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• pp.593-601
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• 2012

Ordered mesoporous oxide films have been focused because of their low density, high interior specific surface area, and high thermal insulation. Specially, the ordered mesoporous oxide films prepared by self-assembly has many advantages due to easy process and high reproducibility. In this work, ordered mesoporous $SiO_2$, $Al_2O_3$, and $TiO_2$ films were synthesized by control of composition and processing parameter. Also, their structural, thermal, and mechanical properties were characterized variously. In conclusion, ordered mesoporous oxides will be one of core materials in new technology due to their excellent and unique properties.

• 한국결정학회:학술대회논문집
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• 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
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• pp.49-49
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• 2002

A strategy for the synthesis of more stable and large periodic mesoporous organo-silica materials has been developed for the 2D hexagonal mesoporous organosilica by the core-shell approach using nonionic PEO-PLGA-PEO triblock copolymer templates. The BET surface area of the solvent-extracted hexagonal mesoporous organosilica is estimated to be 1,016 ㎡/g and the pore volume, pore diameter, and wall thickness are 1.447 ㎤/g, 65 Å, and 43 Å, respectively. More hydrophobic PLGA block than the PPO block used for templates of mesoporous silica proves to be quite effective in confining the organosilicates within the PEO phase. Reaction temperature and acid concentration of an initial solution as well as the chemical nature of the bloc k copolymer templates also demonstrate to be important experimental parameters for ordered organosilica mesophase. Moreover, the mesoporous organosilicas prepared with the PEO-PLGA-PEO block templates maintain their structural integrity for up to 25 days in boiling water at 100℃. The mesoporous materials with large pores and high hydrothermal stability prepared in this study has a potential for many applications.

• 한국재료학회지
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• 제27권4호
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• pp.192-198
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• 2017

Carbon nanofiber (CNF) is used as an electrode material for electrical double layer capacitors (EDLCs), and is being consistently researched to improve its electrochemical performance. However, CNF still faces important challenges due to the low mesopore volume, leading to a poor high-rate performance. In the present study, we prepared the unique architecture of the activated mesoporous CNF with a high specific surface area and high mesopore volume, which were successfully synthesized using PMMA as a pore-forming agent and the KOH activation. The activated mesoporous CNF was found to exhibit the high specific surface area of $703m^2g^{-1}$, total pore volume of $0.51cm^3g^{-1}$, average pore diameter of 2.9 nm, and high mesopore volume of 35.2 %. The activated mesoporous CNF also indicated the high specific capacitance of $143F\;g^{-1}$, high-rate performance, high energy density of $17.9-13.0W\;h\;kg^{-1}$, and excellent cycling stability. Therefore, this unique architecture with a high specific surface area and high mesopore volume provides profitable synergistic effects in terms of the increased electrical double-layer area and favorable ion diffusion at a high current density. Consequently, the activated mesoporous CNF is a promising candidate as an electrode material for high-performance EDLCs.

• 한국재료학회지
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• 제27권11호
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• pp.617-623
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• 2017

Mesoporous carbon nanofibers as electrode material for electrical double-layer capacitors(EDLCs) are fabricated using the electrospinning method and carbonization. Their morphologies, structures, chemical bonding states, porous structure, and electrochemical performance are investigated. The optimized mesoporous carbon nanofiber has a high sepecific surface area of $667m^2\;g^{-1}$, high average pore size of 6.3 nm, and high mesopore volume fraction of 80 %, as well as a unifom network structure consiting of a 1-D nanofiber stucture. The optimized mesoporous carbon nanofiber shows outstanding electrochemical performance with high specific capacitance of $87F\;g^{-1}$ at a current density of $0.1A\;g^{-1}$, high-rate performance ($72F\;g^{-1}$ at a current density of $20.0A\;g^{-1}$), and good cycling stability ($92F\;g^{-1}$ after 100 cycles). The improvement of the electrochemical performance via the combined effects of high specific surface area are due to the high mesopore volume fraction of the carbon nanofibers.

• Macromolecular Research
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• 제16권3호
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• pp.200-203
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• 2008

A conducting polymer layer was introduced into the pore surface of mesoporous carbon via vapor infiltration of a monomer and subsequent chemical oxidative polymerization. The polypyrrole, conducting polymer has attracted considerable attention due to the high electrical conductivity and stability under ambient conditions. The mesoporous carbon-polypyrrole nanocomposite exhibited the retained porous structure, such as mesoporous carbon with a three-dimensionally connected pore system after intercalation of the polypyrrole layer. In addition, the controllable addition of pyrrole monomer can provide the mesoporous carbon-polypyrrole nanocomposites with a tunable amount of polypyrrole and texture property. The polypyrrole layer improved the electrode performance in the electrochemical double layer capacitor. This improved electrochemical performance was attributed to the high surface area, open pore system with three-dimensionally interconnected mesopores, and reversible redox behavior of the conducting polypyrrole. Furthermore, the correlation between the amount of polypyrrole and capacitance was investigated to check the effect of the polypyrrole layer on the electrochemical performance.

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.2961-2965
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• 2012

Mesoporous carbons with tailored pore size were prepared by using sucrose as the carbon source and silicas as the templates. The silica templates were obtained from a hydroxypropyl-${\beta}$-cyclodextrin-silica hybrids using ammonium perchlorate oxidation at different temperatures to remove the organic matter. The structures and surface chemistry properties of these carbon materials were characterized by $N_2$ adsorption, TEM, SEM and FTIR measurements. The catalytic performances of these carbon materials were investigated through the reduction of nitroaromatic using hydrazine hydrate as the reducing agent. Compared with other carbon materials, such as active carbon, and carbon materials from the silica templates obtained by using calcination to remove the organic matter, these carbon materials exhibited much higher catalytic activity, no obvious deactivation was observed after recycling the catalyst four times. Higher surface area and pore volume, and the presence of abundant surface oxygen-containing functional groups, which originate from the special preparation process of carbon material, are likely responsible for the high catalytic property of these mesoporous carbon materials.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.229.1-229.1
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• 2010

We investigated the effect of chemical acid treatments on hydrogen storage behaviors of the ordered mesoporous carbons (MCs). The surface functional groups and specific elements of the MCs were characterized with Fourier Transform Infrared (FT-IR) spectrometry and X-ray photoelectron spectroscopy (XPS). Also, the changes in the surface functional groups of the MCs were quantitatively detected by Boehm's titration method. The structural properties of the MCs were investigated using X-ray diffraction (XRD). The hydrogen adsorption capacity of the MCs was evaluated by means of adsorption isotherms at 77 K/1 bar. The formation of surface functional groups by the acidic treatments could influence on the hydrogen storage capacity of the MCs.