• Title/Summary/Keyword: mesoporous surface

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Influence of Magnesium Oxide on Carbon Dioxide Adsorption Behaviors of Mesoporous Carbons (메조포어러스카본의 마그네슘 옥사이드의 처리에 따른 이산화탄소 흡착 거동)

  • Jang, Dong-Il;Park, Soo-Jin
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.221.2-221.2
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    • 2011
  • In this study, we prepared the magnesium oxide decorated ordered mesoporous carbons processed by the reduction of magnesium oxide precursor on the CMK-3 surfaces in order to investigate the characterization and the effect on their carbon dioxide adsorption behaviors. The magnesium contents of the prepared samples were characterized using XPS. The textural properties of the prepared samples were investigated by $N_2$/77 K adsorption isotherms by BET equation. The carbon dioxide adsorption capacities of the prepared samples were investigated by the amounts of carbon dioxide adsorptions at 298 K and 1.0 atm. The results showed that the magnesium oxide on the CMK-3 surface enhanced interaction between carbon dioxide and adsorbents. Consequently, it was found that the magnesium oxide led to an increase in the carbon dioxide adsorption capacity of the CMK-3.

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Electrical Instabilities of Mesoporous Silica Thin Films

  • Dung, Mai Xuan;Jeong, Hyun-Dam
    • Journal of Integrative Natural Science
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    • v.3 no.4
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    • pp.219-225
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    • 2010
  • On the surface of mesoporous silica thin films (MSTF) which were fabricated by sol-gel approach there are existences of water and three different silanol types including chained, germinal and isolated silanol. Their amounts changes as a function of aging time of used sol solution, as confirmed by FT-IR. The adsorbed water generates ionic carriers such as H+ and OH- and passivates the Si dangling bonds at the interface of silicon wafer-MSTF. The ionic carriers can not only transport across the thickness of thin film to enhance the leakage current but also diffuse toward the silicon wafer-MSTF interface to depassivate Si dangling bonds. On the other hand, chained silanols or germinal silanols promote the moisture adsorption of MSTF and tend to form strongly hydrogen bonded systems with adsorbed water molecules resulting in very high dielectric constant. Isolated silanol, on the contrary, affects less on electrical properties of thin film.

Synthesis of new black pigment; Carbon black pigment capsulated into the meso-pore of silica as black pigment in cosmetic

  • Jang, Hye-In;Lee, Kyung-Chul;Park, Jong-Eul;Lyoo, Hee-Chang
    • Proceedings of the SCSK Conference
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    • 2003.09b
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    • pp.308-312
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    • 2003
  • Recently the trend of new materials development is extensively and very actively progressing in the study of physical and chemical characteristics developing a totally new material along with the study field of recently discovered material modifying physically and chemically characteristics. Among these fields of studies, one method to improve adaptation of inorganic material is the study of mesoporous materials. The most general way to synthesize mesoporous materials is to mold the very systematical mesopore into a corpuscle by using templates(omitted)

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Morphological Control of Periodic Mesoporous Organosilica with Agitation

  • Park, Seong Su;Lee, Chi Heon;Jeon, Jong Hyeon;Jo, Sang Jun;Park, Dong Ho
    • Bulletin of the Korean Chemical Society
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    • v.22 no.9
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    • pp.948-952
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    • 2001
  • Periodic mesoporous organosilicas with rope-based morphology from a reaction gel composition of 1 BTME : 0.57 ODTMABr : 2.36 NaOH : 353 H2O were synthesized. While long rope-shaped product dominated in case of static synthesis condition , gyroid type products instead of rope shaped product appeared and rope shaped product disappeared with agitation. PMO with such a long rope shaped morphology is firstly reported. Additionally, various rope-based morphologies depending on the degree of bending, twisting, folding and winding of rope such as spirals, discoids, toroids, and worm-like aggregates were observed. White powdered products were characterized by X-ray diffraction, N2 sorption measurement, SEM and TEM. From XRD pattern and TEM image, ODTMA-PMO with hexagonal symmetry was identified. The pore diameter and BET surface area of ODTMA-PMO are $32.9{\AA}$ and 799 m2g-1 , respectively. Hexagonally arrayed channels run with long axis of rope and rope-based shapes with various degree of curvature, which was elucidated by using TEM images.

Li, Zr doped mesoporous silica: One pot synthesis and its application to $CO_2$ adsorption at low temperature (Li, Zr 담지 메조포러스 실리카 합성 : One pot 합성 및 저온 이산화탄소 흡착 응용)

  • Ganesh, Mani;Bhagiyalakshmi, Margandan;Peng, Mei Mei;Hemalatha, Pushparaj;Jang, Hyun-Tae
    • Proceedings of the KAIS Fall Conference
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    • 2010.11a
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    • pp.313-317
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    • 2010
  • Li, Zr doped mesoporous silica was synthesized in one pot and investigated for low temperature $CO_2$ adsorption. Herein CTAB and TEOS are used as structural directing agent and silica source respectively. The characteristics of the material was obtained from FT IR, XRD, SEM, TG and BET results. ICP AES results revealed the presence of lithium and zirconium. The material possesses high surface area ($962.22m^2g^{-1}$) with mono dispersed particles of about 2 nm. The maximum $CO_2$ adsorption capacity is 5 wt % (50 mg/g) of $CO_2$/g of sorbent at $25^{\circ}C$, which is regenerable at $200^{\circ}C$. This regeneration temperature of the adsorbent is lower than the reported lithium zirconium silicate powder. Until now, there is no report for the synthesis of Li, Zr doped mesoporous silica. The performance studies illustrate that Li, Zr doped mesoporous silica is tunable, regenerable, recyclable and selective sorbent and hence found to be a promising candidate for $CO_2$ adsorption.

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Removal of Indoor Formaldehyde Using Mesoporous Carbon Activated with KOH (KOH 활성화처리된 메조기공 탄소를 이용한 실내 포름알데히드 제거)

  • Yu, Mi Jin;Park, Sung Hoon;Jeon, Jong-Ki;Park, Young-Kwon
    • Applied Chemistry for Engineering
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    • v.23 no.1
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    • pp.42-46
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    • 2012
  • In this study, a mesoporous carbon (CMK-3) activated using KOH was applied to the adsorption of formaldehyde, a representative indoor air pollutant. Activation process was carried out by putting KOH-treated CMK-3 in a reactor maintained at $700^{\circ}C$ in $N_2$ atmosphere. The activated sample was characterized using BET, XRD, XPS and FT-IR analysis. The formaldehyde adsorption performance of the mesoporous carbon was improved, which is attributed to the formation of oxygen and nitrogen functional groups on the mesoporous carbon surface by the activation process.

Fabrication of nitrogen doped ordered mesoporous carbon derived from glucosamine with hybrid capacitive behaviors

  • Zhang, Deyi;Han, Mei;Li, Yubing;Wang, Bing;Wang, Yi;Wang, Kunjie;Feng, Huixia
    • Carbon letters
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    • v.23
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    • pp.9-16
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    • 2017
  • This paper introduces a nitrogen-doped ordered mesoporous carbon (NOMC) derived from glucosamine with hybrid capacitive behaviors, achieved by successfully combining electrical double-layer capacitance with pseudo-capacitance behaviors. The nitrogen doping content of the fabricated NOMC reached 7.4 at% while its specific surface area ($S_{BET}$) and total pore volume reached $778m^2g^{-1}$ and $1.17cm^3g^{-1}$, respectively. A dual mesoporous structure with small mesopores centered at 3.6 nm and large mesopores centered at 9.9 nm was observed. The specific capacitance of the reported materials reached up to $328Fg^{-1}$, which was 2.1 times higher than that of pristine CMK-3. The capacitance retention rate was found to be higher than 87.9% after 1000 charge/discharge cycles. The supplementary pseudocapacitance as well as the enhanced wettability and conductivity due to the incorporation of nitrogen heteroatoms within the carbon matrixes were found to be responsible for the excellent capacitive performance of the reported NOMC materials.

Titanium Containing Solid Core Mesoporous Silica Shell: A Novel Efficient Catalyst for Ammoxidation Reactions

  • Venkatathri, N.;Nookaraju, M.;Rajini, A.;Reddy, I.A.K.
    • Bulletin of the Korean Chemical Society
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    • v.34 no.1
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    • pp.143-148
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    • 2013
  • Novel titanium containing solid core mesoporous shell silica has been synthesized by using octadecyltrichloro silane and triethylamine. The synthesized material was characterized by various physicochemical techniques. The mesoporous character of the material has been revealed from PXRD studies. The presence of octadecyltrichloro silane and triethylamine in the sample has been confirmed from EDAX studies. TG/DTA analysis reveals the thermal characteristics of the synthesized material. The presence of titanium in the frame work and its coordination state has been studies by UV-vis DR studies and XPS analysis. Chemical environment of Si in the framework of the material has been studied by $^{29}SiMASNMR$ studies. The surface area of the material is found to be around $550\;m^2g^{-1}$ and pore radius is of nano range from BET analysis. The spherical morphology and particle size of the core as well as shell has been found to be 300 nm and 50 nm respectively from TEM analysis. The catalytic application of this material towards the synthesis of caprolactam from cyclohexanone in presence of hydrogen peroxide through ammoxidation reaction has been investigated. The optimum conditions for the reaction have been established. The plausible mechanism for the formation of core silica and conversion of cyclohexanone has been proposed.

In situ FT-IR Study of 1,2-dichlorobenzene Decomposition over VOx/Mesoporous Titania by Prepared Spray Pyrolysis (분무 열분해법을 이용해 제조된 VOx/Mesoporous Titania 상에서 1,2-dichlorobenzene의 분해반응에 대한 in situ FT-IR 연구)

  • Jeon, Jong-Ki;Jung, Kyeong Youl;Park, Young-Kwon
    • Applied Chemistry for Engineering
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    • v.22 no.5
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    • pp.582-585
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    • 2011
  • In this study, surface-adsorbed species of 1,2-dichlorobenzene (1,2-DCB) on mesoporous $V_2O_5/TiO_2$ catalysts synthesized by spray pyrolysis were investigated through the adsorption/desorption performed using in situ FT-IR cell. Also, the comparison of adsorbed species with $TiO_2$ and $V_2O_5/TiO_2$ synthesized by the incipient wetness was carried out.

Synthesis of Mesoporous Zeolite Y and Its Application for Adsorptive Removal of Heavy Metals (Mn2+, Fe2+) (메조 세공 제올라이트 Y 합성 및 이를 이용한 중금속(Mn2+, Fe2+)의 흡착)

  • Pak, Seo-Hyun;Park, Chan-gyu
    • Journal of Korean Society of Water Science and Technology
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    • v.26 no.6
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    • pp.125-132
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    • 2018
  • We studied a simple approach for synthesis of mesoporous Y(M-Y) from commercial zeolite Y precursors by treating of NaOH with $CH_3(CH_2)_{15}N(Br)(CH_3)_3$ as template. The physicochemical properties of the mesoporous zeolites Y were then analyzed using XRD, nitrogen full-isotherms at 77 K, SEM and TEM. The nitrogen adsorption-desorption analysis showed that surface area and pore diameter of synthesized mesoporous zeolite Y(M-Y) were $1072m^2/g$ and ~3.3 nm, respectively. And M-Y was applied for the removal of $Mn^{2+}$ and $Fe^{2+}$ from aqueous solution. This material, which introduces mesoporosity with zeolite Y character, displayed a superior adsorption capacity than commercial zeolite Y when used as an adsorbent for the removal of $Mn^{2+}$ and $Fe^{2+}$.