• Title/Summary/Keyword: Periodic mesoporous organosilicas

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Periodic Mesoporous Organosilicas (유/무기 하이브리드형 실리카 나노세공체)

  • Park, Sung Soo;Ha, Chang-Sik
    • Journal of Adhesion and Interface
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    • v.21 no.3
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    • pp.113-122
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    • 2020
  • Mesoporous materials are a sort of promising materials with a wide spectrum of applications due to their unique well-defined porous structures that provide high surface area and controllable pore size. Among mesoporous materials, periodic mesoporous organosilicas (PMOs) are highly emerging materials in sense of applications due to their large pore sizes and organic functionality in the frame. The organic functional groups in the frameworks of these solids allow tuning of the surface properties and modification of the bulk properties of the material. This article provides a comprehensive overview of PMOs and discusses their different functionalities, morphology and applications, such as catalysis, environmental applications, and adsorption, for which PMOs have been used after their discovery. The review article will provide fundamental understanding of PMOs and their advanced applications to readers.

Preparation of Poly(ethylene oxide)/Periodic Mesoporous Organosilica Composite (폴리에틸렌옥사이드와 주기적인 중간세공 유리실리카 복합재료 제조)

  • Li, Dun;Sur, G. S.
    • Applied Chemistry for Engineering
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    • v.20 no.5
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    • pp.527-531
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    • 2009
  • Periodic mesoporous organosilicas (PMO) were synthesized using bis(triethoxy silyl) benzene as the precursor and dodecyl trimethyl ammonium bromide (DTMA) as the templating agent. From these results of XRD, TEM, and NMR, the pore structure of the material was confirmed to have a well-organized hexagonal structure. Poly(ethylene oxide) (PEO) was penetrated into PMO. From the DSC and XRD experiments, the polymer melting transition of crystalline polyethylene oxide (PEO) decreased then finally disappeared. These results prove that the polymer chains penetrate into the PMO channels, and penetrated polymer chains are constrained inside channels of PMO.

Preparation of Periodic Mesoporous Organosilica/Polymer Composite (주기적인 메조포러스 유기실리카/고분자 복합재료 제조)

  • Dun, Li;Sur, Gil-Soo
    • Polymer(Korea)
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    • v.34 no.4
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    • pp.289-293
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    • 2010
  • Periodic mesoporous organosilicas (PMO) were synthesized using bis(triethoxy silyl) ethane (BTEE) as the precursor and dodecyl trimethyl ammonium bromide(DTMA), cetyl trimethyl ammonium bromide(CTMA), and octadecyl trimethyl ammonium bromide(ODTMA) as the templating agents. The surface area and pore volume of PMO decrease with the increasing of chain length of templating agents. However, the chain length of templating agents almost has no effect on the pore diameter of PMO. From the XRD and the DSC experiments, we found that the chain length of surfactants using as the templating agents has an effect on the melting transition of polyethylene. But it has no effect on the melting transition of poly(ethylene oxide). The results of TGA prove that the thermal decomposition temperature of polymer which was penetrated into PMO was increased.

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.

메조기공 유기실리케이트 제조에 대한 템플레이트의 영향

  • 차국헌;조은범;김상철;조휘랑
    • Proceedings of the Korea Crystallographic Association Conference
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    • 2002.11a
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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.

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