Results 231 to 240 of about 37,643 (291)
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Vapor-phase silylation of MCM-41 and Ti-MCM-41
Microporous and Mesoporous Materials, 2003Abstract MCM-41 mesoporous molecular sieves have been silylated with trimethylchlorosilane (TMCS) and trimethylethoxysilane (TMES) under anhydrous, vapor-phase reaction conditions. The silylation reactions were performed at 473 and 623 K following pre-treatment at either 523 or 973 K.
Robert R Sever +3 more
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Flexibility of the MCM-41 structure: pore expansion and wall-thickening in MCM-41 derivatives
Applied Catalysis A: General, 2002Utilizing the flexibility of the structure of MCM-41 type mesoporous metal silicates pore size modification was successfully performed for some MCM-41 samples including materials which contain Al or Ti heteroatoms in the wall or organic modifiers covalently bounded to the wall. Changing, i.e.
D. Méhn +6 more
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Photoluminescence study of mesoporous MCM-41 and Ti-grafted MCM-41
Research on Chemical Intermediates, 2003Photoluminescence combined with diffuse reflectance UV—Vis spectroscopy was used to characterise both the pure siliceous MCM-41 and Ti-MCM-41 containing tetrahedral Ti(IV) species anchored onto the inner walls of the siliceous MCM-41. Both Ti-MCM-41 and MCM-41 showed complex photoemission signals and this study allows, for the first time, the ...
GIANOTTI, Enrica +5 more
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Characterisation and catalytic properties of MCM-41 and Pd/MCM-41 materials
Catalysis Letters, 1997Pure silica MCM-41 mesoporous molecular sieve material was synthesised and characterised by in situ synchrotron XRD, TEM, TGA/DTA and DRIFTS techniques. In situ energy dispersive XRD (EDXRD) confirmed the exact nature of the pore diameter of MCM-41 and the change in crystal structure on calcination. The IR band at 1057 cm-1 of as-synthesised MCM-41 was
C.A. Koh, R. Nooney, S. Tahir
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Dyes and Pigments, 2009
Abstract 4-Piperazinyl- N -methyl-1,8-naphthalimide (PMN) was synthesized and encapsulated into mesoporous molecular sieves. The fluorescent emission spectra and fluorescence decay of PMN/M-MCM-41 (where M = Si, Ce, Al) were used to investigate the photophysical properties of the hybrid composites. The emission intensity of 4-piperazinyl- N -methyl-1,
G CHEN, L WANG, J ZHANG, F CHEN, M ANPO
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Abstract 4-Piperazinyl- N -methyl-1,8-naphthalimide (PMN) was synthesized and encapsulated into mesoporous molecular sieves. The fluorescent emission spectra and fluorescence decay of PMN/M-MCM-41 (where M = Si, Ce, Al) were used to investigate the photophysical properties of the hybrid composites. The emission intensity of 4-piperazinyl- N -methyl-1,
G CHEN, L WANG, J ZHANG, F CHEN, M ANPO
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The photoluminescence of coumarin derivative encapsulated in MCM-41 and Ti-MCM-41
Dyes and Pigments, 2005Coumarin derivative encapsulated in various mesoporous sieves was prepared by impregnation method. The effects of pore size and Ti-containing amounts on the fluorescence properties were investigated. High dispersion of the dye molecules could be realized on the composite of mesoporous sieves, and the electron transfer from the excited dye molecule to ...
Wenjuan Zhao +5 more
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H3PW12O40 supported on mesoporous MCM-41 and Al–MCM-41 materials: preparation and characterisation
Journal of Materials Science, 2011MCM-41 and Al–MCM-41 has been synthesized using cetyl-trimethylammonium bromide (CTAB) surfactant as template and adding the silica precursor to aqueous solutions containing CTAB. The obtained solids were calcined at 600 °C for 4 h. HPW heteropolyacid supported on the mesoporous were prepared using the incipient wetness method.
Kraleva, E +4 more
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Langmuir, 2000
Temperature-programmed desorption (TPD) of benzene on Si−MCM-41, Na−AlSi−MCM-41, and H−AlSi−MCM-41 mesoporous materials from 323 to 673 K at different linear heating rates (5, 10, 20, and 25 K min-1) and that on Si−MCM-41 at different adsorbate loadings (0.45−10.7 μmol g-1) has been investigated.
Vasant R. Choudhary, Kshudiram Mantri
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Temperature-programmed desorption (TPD) of benzene on Si−MCM-41, Na−AlSi−MCM-41, and H−AlSi−MCM-41 mesoporous materials from 323 to 673 K at different linear heating rates (5, 10, 20, and 25 K min-1) and that on Si−MCM-41 at different adsorbate loadings (0.45−10.7 μmol g-1) has been investigated.
Vasant R. Choudhary, Kshudiram Mantri
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Photovoltaic activity of Ti/MCM‐41
ChemPhysChem, 2009AbstractTi/MCM‐41 is a well‐known heterogeneous catalyst for alkene epoxidation with organic peroxides. This titanosilicate contains isolated titanium atoms forming part of a framework of mesoporous silica whose structure is formed by parallel hexagonal channels 3.2 nm in diameter.
Pedro, Atienzar +3 more
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Synthesis of MCM-41 with a Phosphonium Template
Chemistry of Materials, 2005Cetyltrimethyl phosphonium bromide was successfully used as a template in the synthesis of MCM-41. The material was characterized by small-angle X-ray diffraction, transmission electron microscopy, nitrogen adsorption, and 2 9 Si, 1 3 C, and 3 1 P solid-state NMR spectroscopy.
Baute, D. +4 more
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