KIT | KIT-Bibliothek | Impressum | Datenschutz

Comprehensive examination of dehydroxylation of kaolinite, disordered kaolinite, and dickite: Experimental studies and density functional theory

Izadifar, Mohammadreza; Thissen, Peter; Steudel, Annett; Kleeberg, Reinhard; Kaufhold, Stephan; Kaltenbach, Jonas; Schuhmann, Rainer; Dehn, Frank; Emmerich, Katja

Abstract (englisch):
Kaolins and clays are important rawmaterials for production of supplementary cementitious materials and geopolymer precursors
through thermal activation by calcination beyond dehydroxylation (DHX). Both types of clay contain different polytypes and disordered
structures of kaolinite but little is known about the impact of the layer stacking of dioctahedral 1:1 layer silicates on optimum thermal activation
conditions and following reactivity with alkaline solutions. The objective of the present study was to improve understanding of the impact of
layer stacking in dioctahedral 1:1 layer silicates on the thermal activation by investigating the atomic structure after dehydroxylation. Heating
experiments by simultaneous thermal analysis (STA) followed by characterization of the dehydroxylated materials by nuclear magnetic
resonance spectroscopy (NMR) and scanning electron microscopy (SEM) together with first-principles calculations were performed. Density
functional theory (DFT) was utilized for correlation of geometry-optimized structures to thermodynamic stability. The resulting volumes of
unit cells were compared with data from dilatometry studies. ... mehr



Originalveröffentlichung
DOI: 10.1007/s42860-020-00082-w
Scopus
Zitationen: 1
Dimensions
Zitationen: 1
Zugehörige Institution(en) am KIT Institut für Funktionelle Grenzflächen (IFG)
Institut für Massivbau und Baustofftechnologie (IMB)
Kompetenzzentrum für Materialfeuchte (CMM)
KIT-Zentrum Klima und Umwelt (ZKU)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2020
Sprache Englisch
Identifikator ISSN: 0009-8604, 1552-8367
KITopen-ID: 1000123235
HGF-Programm 34.15.01 (POF III, LK 01) Mineralische Konstruktionsmaterialien
Erschienen in Clays and clay minerals
Verlag Clay Minerals Society
Vorab online veröffentlicht am 28.08.2020
Schlagwörter Density functional theory, Dickite, Geopolymer, Kaolinite, Metadickite, Metakaolin
Nachgewiesen in Dimensions
Scopus
KIT – Die Forschungsuniversität in der Helmholtz-Gemeinschaft
KITopen Landing Page