Vogt, Oliver ; Ballschmiede, Conrad ; Ukrainczyk, Neven ; Koenders, Eddie (2021)
Evaluation of Sulfuric Acid-Induced Degradation of Potassium Silicate Activated Metakaolin Geopolymers by Semi-Quantitative SEM-EDX Analysis.
In: Materials, 2020, 13 (20)
doi: 10.26083/tuprints-00019250
Artikel, Zweitveröffentlichung, Verlagsversion
Kurzbeschreibung (Abstract)
Geopolymers are synthesized by mixing powdery solids, rich in amorphous silicon and aluminum species, with an alkaline solution, which leads to the formation of an inorganic alumosilicate network. Their acid resistance is affected by the composition, the porosity, and pore size distribution of the hardened binder as well as the type and concentration of the acidic solution. In the present study, two geopolymer mixtures with varying liquid-to-solid ratios and Si/Al ratios were exposed to a sulfuric acid solution (pH = 1) and analyzed after different durations of exposure (7, 14, 28, 56, and 70 days) by using a light microscope and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). SEM-EDX elemental mapping was used to evaluate the degradation from depth profiles of silicon (Si), aluminum (Al), and potassium (K) leaching. The results clearly show the leaching kinetics of potassium and the dealumination of the network. The separate consideration of specific reaction steps in the course of degradation, namely the depth of erosion (DE), the depth of deterioration (DD), and the depth of reaction for certain elements (DR(e)), indicate a combination of chemical and diffusion controlled degradation mechanisms.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2021 |
| Autor(en): | Vogt, Oliver ; Ballschmiede, Conrad ; Ukrainczyk, Neven ; Koenders, Eddie |
| Art des Eintrags: | Zweitveröffentlichung |
| Titel: | Evaluation of Sulfuric Acid-Induced Degradation of Potassium Silicate Activated Metakaolin Geopolymers by Semi-Quantitative SEM-EDX Analysis |
| Sprache: | Englisch |
| Publikationsjahr: | 2021 |
| Publikationsdatum der Erstveröffentlichung: | 2020 |
| Verlag: | MDPI |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Materials |
| Jahrgang/Volume einer Zeitschrift: | 13 |
| (Heft-)Nummer: | 20 |
| Kollation: | 23 Seiten |
| DOI: | 10.26083/tuprints-00019250 |
| URL / URN: | https://tuprints.ulb.tu-darmstadt.de/19250 |
| Zugehörige Links: | |
| Herkunft: | Zweitveröffentlichung aus gefördertem Golden Open Access |
| Kurzbeschreibung (Abstract): | Geopolymers are synthesized by mixing powdery solids, rich in amorphous silicon and aluminum species, with an alkaline solution, which leads to the formation of an inorganic alumosilicate network. Their acid resistance is affected by the composition, the porosity, and pore size distribution of the hardened binder as well as the type and concentration of the acidic solution. In the present study, two geopolymer mixtures with varying liquid-to-solid ratios and Si/Al ratios were exposed to a sulfuric acid solution (pH = 1) and analyzed after different durations of exposure (7, 14, 28, 56, and 70 days) by using a light microscope and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). SEM-EDX elemental mapping was used to evaluate the degradation from depth profiles of silicon (Si), aluminum (Al), and potassium (K) leaching. The results clearly show the leaching kinetics of potassium and the dealumination of the network. The separate consideration of specific reaction steps in the course of degradation, namely the depth of erosion (DE), the depth of deterioration (DD), and the depth of reaction for certain elements (DR(e)), indicate a combination of chemical and diffusion controlled degradation mechanisms. |
| Status: | Verlagsversion |
| URN: | urn:nbn:de:tuda-tuprints-192500 |
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 600 Technik, Medizin, angewandte Wissenschaften > 600 Technik 600 Technik, Medizin, angewandte Wissenschaften > 690 Hausbau, Bauhandwerk |
| Fachbereich(e)/-gebiet(e): | 13 Fachbereich Bau- und Umweltingenieurwissenschaften 13 Fachbereich Bau- und Umweltingenieurwissenschaften > Institut für Werkstoffe im Bauwesen |
| Hinterlegungsdatum: | 03 Aug 2021 07:25 |
| Letzte Änderung: | 10 Aug 2021 15:00 |
| PPN: | |
| Zugehörige Links: | |
| Export: | |
| Suche nach Titel in: | TUfind oder in Google |
 |
Frage zum Eintrag |
Optionen (nur für Redakteure)
 |
Redaktionelle Details anzeigen |
Drucken
Impressum