Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Spectroscopic monitoring for the formation of mesoporous MCM-41 materials upon microwave irradiation

Spectroscopic monitoring for the formation of mesoporous MCM-41 materials upon microwave irradiation The mesoporous MCM-41 materials were prepared in very short crystallization time (∼40 min) upon microwave irradiation in comparison with conventional hydrothermal heating method. With both microwave irradiation and hydrothermal heating, the MCM-41 formation via supramolecular templating method has been monitored by fluorescence and electron spin resonance (ESR) spectroscopy. Pyrene as a fluorescence probe and 4-(N,N-dimethyl-N-hexadecyl)ammonium-2,2,6,6-tetramethyl piperidinyloxy iodide (CAT16) as a spin probe were respectively dissolved into the micelle solutions to form the MCM-41 precursor gels. These probes allow the monitoring of the supramolecular interaction between the anionic silicate species and the cationic surfactant molecules during the MCM-41 formation. Analyses of fluorescence and ESR spectra indicate that the fast increase of hydrophobicity and microviscosity at the solubilzation sites of the probes results from the accelerated condensation of silicates onto the micelle surface upon microwave irradiation. The fluorescence change from the silicate L-center in the MCM-41 precursor gel also probes the fast silicate condensation upon microwave irradiation. It seems that the fast formation of MCM-41 upon microwave irradiation is ascribed to the microwave-susceptible head groups of surfactant molecules in addition to fast dissolution of the precursor gel. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Research on Chemical Intermediates Springer Journals

Spectroscopic monitoring for the formation of mesoporous MCM-41 materials upon microwave irradiation

Download PDF
12 pages

Loading next page...
 
/lp/springer_journal/spectroscopic-monitoring-for-the-formation-of-mesoporous-mcm-41-ygbahyUmbZ

References (27)

Publisher
Springer Journals
Copyright
Copyright © 2000 by VSP
Subject
Chemistry; Catalysis; Physical Chemistry; Inorganic Chemistry
ISSN
0922-6168
eISSN
1568-5675
DOI
10.1163/156856700X00787
Publisher site
See Article on Publisher Site

Abstract

The mesoporous MCM-41 materials were prepared in very short crystallization time (∼40 min) upon microwave irradiation in comparison with conventional hydrothermal heating method. With both microwave irradiation and hydrothermal heating, the MCM-41 formation via supramolecular templating method has been monitored by fluorescence and electron spin resonance (ESR) spectroscopy. Pyrene as a fluorescence probe and 4-(N,N-dimethyl-N-hexadecyl)ammonium-2,2,6,6-tetramethyl piperidinyloxy iodide (CAT16) as a spin probe were respectively dissolved into the micelle solutions to form the MCM-41 precursor gels. These probes allow the monitoring of the supramolecular interaction between the anionic silicate species and the cationic surfactant molecules during the MCM-41 formation. Analyses of fluorescence and ESR spectra indicate that the fast increase of hydrophobicity and microviscosity at the solubilzation sites of the probes results from the accelerated condensation of silicates onto the micelle surface upon microwave irradiation. The fluorescence change from the silicate L-center in the MCM-41 precursor gel also probes the fast silicate condensation upon microwave irradiation. It seems that the fast formation of MCM-41 upon microwave irradiation is ascribed to the microwave-susceptible head groups of surfactant molecules in addition to fast dissolution of the precursor gel.

Journal

Research on Chemical Intermediates – Springer Journals

Published: Jan 1, 2000

There are no references for this article.