Related Experiment Video
Updated: May 8, 2026

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Phase transition between layered tungstates and polyoxotungstates in aqueous solutions
Takayuki Ban1, Toshihiro Ito, Yutaka Ohya
1Department of Chemistry and Biomolecular Science, Gifu University , Yanagido 1-1, Gifu 501-1193, Japan.
Abstract:
Aqueous sols of colloidal layered tetramethylammonium (TMA) tungstate nanocrystals were obtained by diluting an aqueous suspension of TMA polyoxotungstate precipitates. The slow evaporation of the colloidal-layered tungstate sols led to the deposition of TMA polyoxotungstate and significantly decreased the amount of layered tungstate nanocrystals. Moreover, the increase in the amount of TMA(+) in the sols also facilitated precipitation of the polyoxotungstates because of a common ion effect. Thus, the dissolution and formation of polyoxotungstate were reversible phenomena. The reaction between the dissolved species, which were formed by the dissolution of TMA polyoxotungstate, likely provided the highly water-dispersible layered tungstate nanocrystals. Furthermore, transmission electron microscopy observation suggested that the layered tungstate nanocrystals had a layer structure similar to those of H2WO4 and H2WO4·H2O, which is a layered tungstic acid.
Related Concept Videos
Solid–Solid Solutions
Phase Transitions
Phase Transitions
Transition State Theory
Phase Diagrams of Ternary Systems
Phase Transitions: Sublimation and Deposition

