Change in the Dehydration and Crystallization Processes of V2O5 Xerogel due to Mechanical Pretreatment

✍ Scribed by Naoki Soga; Mamoru Senna

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 252 KB
• Volume: 107
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1993.1333

✦ Synopsis

Dehydration and crystallization processes of vanadium pentoxide xerogels, (\mathrm{V}{2} \mathrm{O}{5} \cdot 1.6 \mathrm{H}{2} \mathrm{O}), with and without preliminary mechanical pretreatment, were examined by thermal and structural analyses. During the final step of dehydration of as-prepared xerogel, crystallization into orthorhombic (\mathrm{V}{2} \mathrm{O}{5}) took place slowly but in one step, with a certain period of coexistence of the starting layer structure. The mechanically pretreated xerogel, in contrast, crystallized itself in two steps with a separated nucleation and growth, and allowed a smaller period of coexistence with the layer structure. These phenomena are associated with the disproportionation of the bonding state of interfoliar (\mathrm{H}{2} \mathrm{O} . \quad \odot 1993) Academic Press, Inc.