We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Insertion of acetone molecules in the nanostructured tunnels of palygorskite.
- Authors
Wenxing Kuang; Detellier, Christian
- Abstract
The insertion of acetone molecules in the nanostructured tunnels of palygorskite (PFl-1) was studied by thermal gravimetric analysis connected with mass spectrometry and 29Si and 13C solid-state NMR techniques. In comparison with palygorskite, new weight losses appear at 130 and 340 °C for palygorskite previously heated at 150 °C for 20 h then exposed to acetone for a week. Two types of water molecules occupy the palygorskite tunnels: weakly bound zeolitic water and structural water molecules coordinated to Mg(II) cations at the edge of the octahedral sheets. Acetone molecules that intercalate in the nanostructured tunnels replace the zeolitic water and are H-bonded to structural water. The mass loss at 130 °C is accounted for by the release of structural water and acetone. The loss at 340 °C is due to the release of acetone molecules that coordinate directly to terminal cations in the nanostructured tunnels and to residual structural water. A nanostructured hybrid material, with a structure similar to the parent palygorskite, can be formed through the direct coordination of acetone molecules to the terminal cationic coordination sites in the nanostructured tunnels of palygorskite. There is evidence for the fixation of two different types of acetone on palygorskite: mobile acetone molecules on the external surface and acetone molecules more rigidly fixed inside the nanotunnels. The former ones are detected by the 13C magic-angle spinning NMR experiment and can be easily removed by gentle heating at 60 °C, while the latter ones are detected by 13C cross-polarization magic-angle spinning NMR. It is also demonstrated that nearly complete recovery of the original structure is achieved by exposing palygorskite previously dehydrated at 150 or 300 °C to acetone vapor at room temperature.
- Subjects
ACETONE; PALYGORSKITE; CLAY minerals; ETHANES; MOLECULES
- Publication
Canadian Journal of Chemistry, 2004, Vol 82, Issue 10, p1527
- ISSN
0008-4042
- Publication type
Article
- DOI
10.1139/V04-130