Thermal treatment of whewellite-a thermal analysis and Raman spectroscopic study
Thermal transformations of natural calcium oxalate monohydrate known in mineralogy as whewellite have been undertaken using a combination of thermal analysis and Raman microscopy with the use of a thermal stage. High resolution thermogravimetry shows that three mass loss steps occur at 162, 479 and 684 degrees Celsius. Evolved gas mass spectrometry shows that water is evolved in the first step and carbon dioxide in the second and third mass loss steps. The changes in the molecular structure of whewellite can be followed by the use of the in-situ Raman spectroscopy of whewellite at the elevated temperatures. The whewellite is stable up to around 161 degrees Celsius, above which temperature the anhydrous calcium oxalate is formed. At 479 degrees Celsius, the oxalate transforms to calcium carbonate with loss of carbon dioxide. Above 684 degrees Celsius, calcium oxide is formed.
Impact and interest:
Citation counts are sourced monthly from and citation databases.
These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.
Citations counts from theindexing service can be viewed at the linked Google Scholar™ search.
Full-text downloads displays the total number of times this work’s files (e.g., a PDF) have been downloaded from QUT ePrints as well as the number of downloads in the previous 365 days. The count includes downloads for all files if a work has more than one.
|Item Type:||Journal Article|
|Keywords:||oxalate, whewellite, weddellite, glushinskite, Raman spectroscopy, thermogravimetry|
|Subjects:||Australian and New Zealand Standard Research Classification > CHEMICAL SCIENCE (030000) > INORGANIC CHEMISTRY (030200)|
|Divisions:||Past > QUT Faculties & Divisions > Faculty of Science and Technology|
|Copyright Owner:||Copyright 2004 Elsevier|
|Copyright Statement:||Reproduced in accordance with the copyright policy of the publisher.|
|Deposited On:||14 Mar 2005|
|Last Modified:||29 Feb 2012 13:08|
Repository Staff Only: item control page