KIT | KIT-Bibliothek | Impressum | Datenschutz

Interlink between solubility, structure, surface and thermodynamics in the ThO$_2$(s, hyd)–H$_2$O(l) system

Kiefer, Christian 1; Neill, Thomas 1; Cevirim-Papaioannou, Nese ORCID iD icon 1; Schild, Dieter ORCID iD icon 1; Gaona, Xavier ORCID iD icon 1; Vitova, Tonya ORCID iD icon 1; Dardenne, Kathy ORCID iD icon 1; Rothe, Jörg ORCID iD icon 1; Altmaier, Marcus ORCID iD icon 1; Geckeis, Horst 1
1 Institut für Nukleare Entsorgung (INE), Karlsruher Institut für Technologie (KIT)

Abstract:

The impact of temperature on a freshly precipitated ThO$_2$(am, hyd) solid phase was investigated using a combination of undersaturation solubility experiments and a multi-method approach for the characterization of the solid phase. XRD and EXAFS confirm that ageing of ThO$_2$(am, hyd) at T = 80°C promotes a significant increase of the particle size and crystallinity. TG-DTA and XPS support that the ageing process is accompanied by an important decrease in the number of hydration waters/hydroxide groups in the original amorphous Th(IV) hydrous oxide. However, while clear differences between the structure of freshly precipitated ThO$_2$(am, hyd) and aged samples were observed, the characterization methods used in this work are unable to resolve clear differences between solid phases aged for different time periods or at different pH values. Solubility experiments conducted at T = 22°C with fresh and aged Th(IV) solid phases show a systematic decrease in the solubility of the solid phases aged at T = 80°C. In contrast to the observations gained by solid phase characterization, the ageing time and ageing pH significantly affect the solubility measured at T = 22°C. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000153768
Veröffentlicht am 16.12.2022
Originalveröffentlichung
DOI: 10.3389/fchem.2022.1042709
Scopus
Zitationen: 1
Web of Science
Zitationen: 1
Dimensions
Zitationen: 1
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Nukleare Entsorgung (INE)
Institut für Physikalische Chemie (IPC)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2022
Sprache Englisch
Identifikator ISSN: 2296-2646
KITopen-ID: 1000153768
HGF-Programm 32.11.01 (POF IV, LK 01) Nuclear Waste Disposal
Weitere HGF-Programme 32.11.03 (POF IV, LK 01) Fundamental Scientific Aspects
Erschienen in Frontiers in Chemistry
Verlag Frontiers Media SA
Band 10
Seiten Art.-Nr.: 1042709
Bemerkung zur Veröffentlichung Gefördert durch den KIT-Publikationsfonds
Vorab online veröffentlicht am 15.11.2022
Schlagwörter thorium, solubility, surface, temperature, thermodynamics, structure
Nachgewiesen in Web of Science
Scopus
Dimensions
KIT – Die Forschungsuniversität in der Helmholtz-Gemeinschaft
KITopen Landing Page