Effect of Hydrothermal Synthesis Conditions on the Morphology and Negative Thermal Expansivity of Zirconium Tungstate Nanoparticles

TitleEffect of Hydrothermal Synthesis Conditions on the Morphology and Negative Thermal Expansivity of Zirconium Tungstate Nanoparticles
Publication TypeJournal Article
Year of Publication2012
AuthorsWu HC, Badrinarayanan P, Kessler MR
Journal TitleJournal of the American Ceramic Society
Volume95
Pages3643-3650
Date Published11
Type of ArticleArticle
ISBN Number0002-7820
Accession NumberWOS:000310600900047
Keywordsphase-transitions, zrw2o8
Abstract

Zirconium tungstate (ZrW2O8) is a unique ceramic material that exhibits isotropic negative thermal expansion behavior, which can be produced at relatively low temperatures using hydrothermal synthesis and subsequent heat treatment. In this work, the effect of reaction conditions on morphology and crystallite size of ZrW2O8 nanoparticles is characterized through careful selection of initial reactants, acid types and concentration, reaction time, and temperature. Three types of ZrW2O8 nanoparticles with distinct morphologies and crystallite size scales were chosen to characterize and compare thermal and physical properties. Nano-sized ZrW2O8 particles for two of the morphologies exhibit a negative coefficient of thermal expansion (CTE) that is about 30% larger than the CTE of bulk ZrW2O8 in the alpha-phase (ca. -11.4 vs.-8.8 ppm/degrees C). A dependence of CTE on crystallite size and crystalline structure is demonstrated. It is also found that the morphology of the zirconium tungstate has a significant effect on the pore structure and level of hydration in the nanoparticles.

URL<Go to ISI>://WOS:000310600900047
DOI10.1111/j.1551-2916.2012.05457.x
Alternate JournalJ. Am. Ceram. Soc.