Thermal decomposition of the composite hydrotalcites of iowaite and woodallite
Frost, Ray L., Bouzaid, Jocelyn M., & Martens, Wayde N. (2007) Thermal decomposition of the composite hydrotalcites of iowaite and woodallite. Journal of Thermal Analysis and Calorimetry, 89(2), pp. 511-519.
The thermal stability and thermal decomposition pathways for synthesized composite iowaite /woodallite have been determined using thermogravimetry analysis in conjunction with evolved gas mass spectrometry. Dehydration of the hydrotalcites occurred over a range of 56-70 °C. The first dehydroxylation step occurred at around 255 °C and, with the substitution of more iron (III) for chromium (III) this temperature increased to an upper limit of 312 °C. This trend was observed throughout all decomposition steps. The release of carbonate ions as carbon dioxide gas initialised at just above 300 °C and was always accompanied by loss of hydroxyl units as water molecules. The initial loss of the anion in this case the chloride ion was consistently observed to occur at about 450 °C with final traces evolved at 535 to 780 °C depending of the Fe:Cr ratio and was detected as HCl (m/Z = 36). Thus for this to occur, hydroxyl units must have been retained in the structure at temperatures upwards of 750 °C. Experimentally it was found difficult to keep CO2 from reacting with the compounds and in this way the synthesized iowaite-woodallite series somewhat resembled the natural minerals.
Impact and interest:
Citation countsare sourced monthly fromand 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 downloadsdisplays 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.
Repository Staff Only: item control page