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Evolution of calcite surfaces upon thermal decomposition, characterized by electrokinetics, in-situ XRD, and SEM

Ban, Matea; Luxbacher, Thomas; Lützenkirchen, Johannes 1; Viani, Alberto; Bianchi, Sabrina; Hradil, Klaudia; Rohatsch, Andreas; Castelvetro, Valter
1 Institut für Nukleare Entsorgung (INE), Karlsruher Institut für Technologie (KIT)

Abstract:

The present study analyses transformation pathways of pristine and thermally treated porous limestone and dense marble surfaces by means of time-resolved streaming current and potential measurements coupled with scanning electron microscopy and in-situ X-ray diffraction. The results reveal that under nonequilibrium conditions the zeta potential (ζ) of natural carbonates may exhibit positive and negative signs and ζ drifts in opposite directions. Sample surface roughness influences ζ because it contributes to dissolution, as observed particularly in the initial period of time-resolved measurements. Thermal treatment causes a temporary charge reversal from negative to positive. The reactivity of calcium hydroxide on calcite surfaces governs the net electrokinetic potential and isoelectric point (IEPpH), even at low surface coverage, as cross-validated by in-situ XRD. It was also found that pore conductivity may lead to ~90% underestimation of ζ when assessed by streaming potential. SEM studies revealed micro cracks inducement on marble after thermal treatment, which can result in underestimation of ζ up to the same extent as for the porous limestone. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000134255
Veröffentlicht am 23.06.2021
Originalveröffentlichung
DOI: 10.1016/j.colsurfa.2021.126761
Scopus
Zitationen: 3
Web of Science
Zitationen: 3
Dimensions
Zitationen: 3
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Nukleare Entsorgung (INE)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 05.09.2021
Sprache Englisch
Identifikator ISSN: 0927-7757, 1873-4359
KITopen-ID: 1000134255
HGF-Programm 32.11.01 (POF IV, LK 01) Nuclear Waste Disposal
Erschienen in Colloids and Surfaces A: Physicochemical and Engineering Aspects
Verlag Elsevier
Band 624
Seiten Art.-Nr.: 126761
Vorab online veröffentlicht am 06.05.2021
Nachgewiesen in Dimensions
Scopus
Web of Science
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