Template synthesis of ordered mesoporous organic polymeric materials using hydrophobic silylated KIT-6 mesoporous silica

Choi, Dae-Heung; Ryoo, Ryong

doi:10.1039/c0jm00671h

Cited by 57 publications

(54 citation statements)

References 51 publications

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“…The resultant solution was mixed to 1.00 g of trimethylsilyl-coated KIT-6. [23] Dichloromethane was then removed from this mixture by means of incipient drying and freeze-vacuum thaw cycles. Subsequently, polymerization was carried out with several heating steps to 150 8C.…”

Section: Synthesis Of Mesoporous Polymeric Supportmentioning

confidence: 99%

“…[18][19][20][21][22] In particular, Choi and Ryoo demonstrated that a fully cross-linked and rigid poly(divinylbenzene) MPM could be synthesized using a polymerization technique inside a mesoporous silica template. [23] The KIT-6 mesoporous silica used by Choi and Ryoo had a 3-dimensionally interconnected mesoporous structure belonging to the cubic Ia3 d space group. The resultant MPM exhibited a cubic Ia3 d structure, which corresponded to faithful replication of the KIT-6 pore system into a polymeric framework.…”

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confidence: 99%

“…This was the boundary condition for maintaining rigid polymer framework. [23] The boundary depended on the pore diameters, pore connectivity, and wall thickness of the mesoporous silica being used as a template. In the case of KIT-6 with 5 nm pores, at least 0.8 DVB mole fractions were necessary to obtain robust MPM samples ( Figure S1 in the Supporting Information for XRD, N 2 adsorption isotherm, and TEM image for MPM).…”

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confidence: 99%

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Mesoporous Polymeric Support Retaining High Catalytic Activity of Polyoxotungstate for Liquid‐Phase Olefin Epoxidation using H₂O₂

Maradur

Choi

et al. 2011

ChemCatChem

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Epoxides are important raw materials in many chemical syntheses, as well as in industrial processes for the production of epoxy resins, paints, and surfactants. [1][2][3] Gas phase epoxidation of olefins by O 2 can be used for the production of ethylene oxide. [4] For higher molecular epoxides, however, the gasphase reaction is not feasible because of low selectivity, owing to competing oxidation at the allylic CÀH bonds. Higher molecular epoxides are commonly produced through liquid-phase epoxidation by H 2 O 2 , using transition metal homogeneous catalysts. Among the catalysts, tungsten-based catalysts have attracted significant attention in recent years, owing to their very high efficiency of H 2 O 2 utilization and selectivity to epoxides. [5][6][7][8][9][10][11][12] Despite their remarkable efficiency, they have drawbacks of separation from products and recyclability. Ion-exchange resins are widely used as supports for the immobilization of tungsten catalysts. [13][14][15][16][17] However, polymer resin based porous supports typically have a wide distribution of pore diameters, ranging from micropores (< 2 nm) to macropores (>50 nm). A large portion of the catalytic groups can be supported within micropores under these circumstances, leading to serious diffusion limitations. Another problem is that the loosely cross-linked polymeric frameworks can easily swell in many organic solvents. This swelling can lead to the closing of pore mouths under reaction conditions with organic solvents. In addition, water (H 2 O 2 carrier and by-product) can inhibit the access of hydrophobic organic reactants to the catalytically active sites through hydration of hydrophilic quaternary ammonium groups Ordered mesoporous silicas are often used as supports for tungstate catalysts to circumvent limitations related to diffusion. Mesoporous silicas have various advantages as catalyst supports. The silica mesopore diameters are uniform as compared to polymeric resins. The pore diameters can be precisely tailored over a mesoporous range, i.e., 2-50 nm. The mesopore walls are built with robust silica frameworks, which are covered by silanol groups. In the case of the polyoxotungstate catalysts, however, the surface silanol groups often render the mesoporous environment too hydrophilic to be used as a catalyst support in epoxidation using H 2 O 2 . The silanol groups can also interact strongly with catalytic groups, reactants and/or the products, thereby causing a loss of catalytic activity and/or selectivity.A number of synthesis routes to obtain ordered mesoporous polymeric materials (MPMs) have been developed in recent years. The MPMs obtained in this manner have uniform mesopores built with hydrophobic organic frameworks. The pore diameters can be tailored and the organic frameworks can be functionalized through co-polymerization and/or post-synthesis organic reactions. [18][19][20][21][22] In particular, Choi and Ryoo demonstrated that a fully cross-linked and rigid poly(divinylbenzene) MPM could be synthesized using a polymeriza...

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Section: Synthesis Of Mesoporous Polymeric Supportmentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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Mesoporous Polymeric Support Retaining High Catalytic Activity of Polyoxotungstate for Liquid‐Phase Olefin Epoxidation using H₂O₂

Maradur

Choi

et al. 2011

ChemCatChem

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“…are used as templates [34][35][36][37][38][39][40][41] while for macro porous materials, use of bacterial templates [30] has also been reported. As the size of the formed pore is governed by the size of template [38,40,42], it is often difficult to incorporate hierarchical pore-systems (i.e., combination of meso as well as macro pores in the same material) just by using single template. From the application point of view, as in case of catalysis, the active sites are often located in the micro-pores and meso-pores, while the macro-pores aid mass transfer.…”

Section: Introductionmentioning

confidence: 99%

Porous nano-structured micro-granules from silica-milk bi-colloidal suspension: Synthesis and characterization

Biswas

Sen

Mazumder

et al. 2017

Colloids and Surfaces B: Biointerfaces

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“…Traditional preparation methods for porous polymers include the hard template method [1,2] and the soft template method [3,4]. It is difficult to accurately control the pore size and pore size distribution of the porous polymer by these methods.…”

Section: Introductionmentioning

confidence: 99%

Polymerization of MMA in polyHIPEs by RATRP

Sun

Chen

et al. 2014

J Polym Res

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A series of polymerized high internal phase emulsions (polyHIPEs) with different cavities and windows (named PSD) were used as microreactors. Then methyl methacrylate (MMA) was polymerized in the spaces of the polyHIPE by reverse atom transfer radical polymerization (RATRP). The resulting materials and PMMA in the polyHIPEs were characterized by scanning electron microscopy, gel permeation chromatography, Fourier transform infrared spectroscopy, thermogravimetry, hydrogen nuclear magnetic resonance and differential scanning calorimetry. The results suggest that the monomer MMA is polymerized in the PSDs by RATRP. The confinement effect of the different cavities and pores is obvious but it weakens with the increase of the pore size. Compared with the conventional PMMA by RATRP, the number-average molecular weight and temperature of the initial decomposition of the PMMA obtained from PSDs is significantly high, which suggests that the confined space in the PSDs plays an active role in RATRP.

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Template synthesis of ordered mesoporous organic polymeric materials using hydrophobic silylated KIT-6 mesoporous silica

Cited by 57 publications

References 51 publications

Mesoporous Polymeric Support Retaining High Catalytic Activity of Polyoxotungstate for Liquid‐Phase Olefin Epoxidation using H₂O₂

Mesoporous Polymeric Support Retaining High Catalytic Activity of Polyoxotungstate for Liquid‐Phase Olefin Epoxidation using H₂O₂

Porous nano-structured micro-granules from silica-milk bi-colloidal suspension: Synthesis and characterization

Polymerization of MMA in polyHIPEs by RATRP

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Template synthesis of ordered mesoporous organic polymeric materials using hydrophobic silylated KIT-6 mesoporous silica

Cited by 57 publications

References 51 publications

Mesoporous Polymeric Support Retaining High Catalytic Activity of Polyoxotungstate for Liquid‐Phase Olefin Epoxidation using H2O2

Mesoporous Polymeric Support Retaining High Catalytic Activity of Polyoxotungstate for Liquid‐Phase Olefin Epoxidation using H2O2

Porous nano-structured micro-granules from silica-milk bi-colloidal suspension: Synthesis and characterization

Polymerization of MMA in polyHIPEs by RATRP

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Product

Resources

About

Mesoporous Polymeric Support Retaining High Catalytic Activity of Polyoxotungstate for Liquid‐Phase Olefin Epoxidation using H₂O₂

Mesoporous Polymeric Support Retaining High Catalytic Activity of Polyoxotungstate for Liquid‐Phase Olefin Epoxidation using H₂O₂