A new family of mesoporous molecular sieves prepared with liquid crystal templates

Beck, Jeffrey S.; Vartuli, J.C.; Roth, Wiesław J.; Leonowicz, M. E.; Kresge, Charles T.; Schmitt, Kirk D.; Chu, Cynthia T-W.; Olson, David H.; Sheppard, E. W.; McCullen, S.B.; Higgins, John B.; Schlenker, J.L.

doi:10.1021/ja00053a020

Cited by 10,781 publications

(6,615 citation statements)

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“…Since the MCM-41 mesoporous silica (with a hexagonal arrangement of the pores with 2-5 nm diameter) was invented at the beginning of the 1990's [15][16][17], applications of mesoporous molecular sieves in controlled polymerization have attracted much attention [18,19]. In contrast to zeolites these materials have the ability to encapsulate relatively large molecules.…”

Section: Introductionmentioning

confidence: 99%

Monomer- and polymer radicals of vinyl compounds: EPR and DFT studies of geometric and electronic structures in the adsorbed state

Lund

Danilczuk

2012

Spectrochimica Acta Part A: Molecular and Biomolecular Spectros

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Electron paramagnetic resonance (EPR) spectroscopy was applied to study the paramagnetic species formed from styrene, 1,1-diphenylethylene, α-methylstyrene, β-methylstyrene and methylmethacrylate adsorbed on amorphous silica gel after -irradiation at 77 K. Radicals formed by the hydrogen atom addition at the vinyl group of the monomers were observed in all samples. The hydrogen atoms were shown to originate to a large extent from the adsorbent by using silica gel with deuterated silanol groups. An EPR spectrum assigned to a propagating radical was observed at increased temperature for samples containing methylmethacrylate (MMA). The structures of the adsorption complexes, the respective hyperfine coupling constants and the adsorption energies were calculated by applying DFT quantum chemical methods. The reaction between an MMA molecule and the MMA radical and the structure of the propagating radical was modeled. The calculated hyperfine coupling constants for all radicals confirmed the assignment of the experimental spectra.3

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Section: Introductionmentioning

confidence: 99%

Monomer- and polymer radicals of vinyl compounds: EPR and DFT studies of geometric and electronic structures in the adsorbed state

Lund

Danilczuk

2012

Spectrochimica Acta Part A: Molecular and Biomolecular Spectros

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“…However, the discovery of the M41S family 7) generated a great deal of interest in the synthesis of organically functionalized, mesoporous materials for application in the fields of catalysis, sensing, and adsorption, based on their high surface areas and large ordered pores ranging from 20 to 100 Å 8) with narrow size distributions. Their high chemical and thermal stabilities are also promising for the reactions of bulky substrate molecules.…”

Section: Introductionmentioning

confidence: 99%

Reaction Kinetics of Carbon Dioxide with Phenyl Glycidyl Ether by TEA-CP-MS41 Catalyst

Choe

Park

et al. 2010

J. Jpn. Petrol. Inst.

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CP-MS41 was synthesized by hydrolysis of tetraorthosilicate, as a silicon source, with 3-chloropropyltriethoxysilane as an organosilane using cetyltrimethylammonium bromide as a template. TEA-CP-MS41 was synthesized by immobilization of triethylamine on the mesoporous MCM-41 and was dispersed in organic liquid as a mesoporous catalyst for the reaction between carbon dioxide and phenyl glycidyl ether (PGE). Carbon dioxide was absorbed into the PGE solution in a stirred batch tank with a planar gas-liquid interface within a range of 0-2.0 kmol/m 3 of PGE and 333-363 K at 101.3 kPa. The measured values of absorption rate were analyzed to obtain the reaction kinetics using the mass transfer mechanism associated with the chemical reactions based on the film theory. The overall reaction of CO2 with phenyl glycidyl ether (PGE), which is assumed to consist of two steps: (i) A reversible reaction between PGE (B) and catalyst of TEA-CP-MS41 (QX) to form an intermediate complex (C1), and (ii) irreversible reaction between C1 and CO2 to form QX and five-membered cyclic carbonate (C), was used to obtain the reaction kinetics through the pseudo-first-order reaction model. Polar solvents such as N, N-dimethylacetamide, N-methyl-2-pyrrolidinone, and dimethyl sulfoxide affected the reaction rate constants.

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“…Since the first reports of mesoporous silica prepared using surfactants in the early 1990 s [1][2][3], ordered mesoporous silica has attracted great attention because of its structural 6 Present address: Department of Civil and Environmental Engineering, Indian Institute of Technology (IIT), Kanpur, India. features, such as tunable mesopores, high surface area, large adsorption capacity and ordered pore arrangement [4][5][6][7]. In general, mesoporous structures are constructed using supermolecular assemblies formed through the self-organization of amphiphilic molecules as structure-directing agents.…”

Section: Introductionmentioning

confidence: 99%

“…It has been considered that ordered mesoporous materials are potentially applicable to biosensors, drug-delivery systems and adsorption systems, and in biomedicine on the basis of their structural characteristics [4][5][6][7]. For further functionalization of ordered mesoporous silica, the organic modification of silicate surfaces is vital, and functional organic layers are grafted onto mesopore surfaces [3,[8][9][10][11][12][13][14][15][16][17]. However, such organically functionalized mesoporous silica has unsatisfactory properties because organic moieties cannot be distributed homogeneously on silicate surfaces.…”

Section: Introductionmentioning

confidence: 99%

“…In contrast, organic fragments are dispersed homogeneously in periodic mesoporous organosilica (PMO) [17][18][19][20][21][22]. PMO with embedded organic groups is prepared through the hydrolysis and condensation of bridged silsesquioxanes, such as (R O) 3 Si-R-Si(OR ) 3 (R, R ; organic group). Problems in the reduction of mesostructural ordering have been addressed by further design of organic groups with large molecular sizes and/or with an increase in organic content [21,22].…”

Section: Introductionmentioning

confidence: 99%

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Aerosol-assisted synthesis of mesoporous organosilica microspheres with controlled organic contents

Yamauchi

Suzuki

Gupta

et al. 2009

Science and Technology of Advanced Materials

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Periodic mesoporous organosilica (PMO) spherical particles with different organic contents were synthesized in one pot by reacting 1,2-bis(triethoxysilyl)ethane (BTSE) with tetraethylorthosilicate (TEOS) using a spray-drying technique. The scanning electron microscopy observation of spray-dried products clearly showed the formation of spherical particles. The 29 Si magic angle spinning nuclear magnetic resonance data revealed that the organic contents due to ethane fragments embedded in the frameworks were controllable and consistent with the BTSE/TEOS molar ratios of precursor solutions. Transmission electron microscopy, small-angle x-ray scattering, and N 2 adsorption data of PMO with controlled organic contents indicated that the ethane fragments were embedded in the frameworks with the formation of ordered mesostructures. PMO with a high organic content (BTSE/TEOS = 0.50) only showed a hydrophobic property. According to the same procedure, benzene groups were also integrated to a similar degree in the frameworks by using 1,4-bis(triethoxysilyl)benzene.

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A new family of mesoporous molecular sieves prepared with liquid crystal templates

Cited by 10,781 publications

References 57 publications

Monomer- and polymer radicals of vinyl compounds: EPR and DFT studies of geometric and electronic structures in the adsorbed state

Monomer- and polymer radicals of vinyl compounds: EPR and DFT studies of geometric and electronic structures in the adsorbed state

Reaction Kinetics of Carbon Dioxide with Phenyl Glycidyl Ether by TEA-CP-MS41 Catalyst

Aerosol-assisted synthesis of mesoporous organosilica microspheres with controlled organic contents

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