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Journal articles
New insights in the formation of silanol defects in silicalite-1 by water intrusion under high pressure
Abstract : The "water-silicalite-1" system is known to act as a molecular spring. The successive intrusion-extrusion cycles of liquid water in small crystallites (6 × 3 × 0.5 μm(3)) of hydrophobic silicalite-1 were studied by volumetric and calorimetric techniques. The experiments displayed a decrease of the intrusion pressure between the first intrusion-extrusion cycle and the consecutive ones, whereas the extrusion pressures remained unchanged. However, neither XRD studies nor SEM observations revealed any structural and morphological modifications of silicalite-1 at the long-range order. Such a shift in the value of the intrusion pressure after the first water intrusion-extrusion cycle is attributed to the creation of silanol groups during the first water intrusion. Detailed FTIR and solid-state NMR spectroscopic characterizations provided a molecular evidence of chemical modification of zeolite framework with the formation of local silanol defects created by the breaking of siloxane bonds.
https://hal-agrosup-dijon.archives-ouvertes.fr/hal-02510788
Contributor : Kevin Oudard Connect in order to contact the contributor
Submitted on : Wednesday, March 18, 2020 - 10:49:20 AM
Last modification on : Friday, May 20, 2022 - 9:06:16 AM
Contributor : Kevin Oudard Connect in order to contact the contributor
Submitted on : Wednesday, March 18, 2020 - 10:49:20 AM
Last modification on : Friday, May 20, 2022 - 9:06:16 AM
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