Graduation Semester and Year
Summer 2024
Language
English
Document Type
Dissertation
Degree Name
Master of Science in Materials Science and Engineering
Department
Materials Science and Engineering
First Advisor
Efstathios Meletis
Second Advisor
Erika La Plante
Third Advisor
Maria Konsta-Gdoutos
Fourth Advisor
Surendra Shah
Fifth Advisor
Ye Cao
Abstract
Currently approximately 8% of global greenhouse gas emissions can be attributed to the construction industry; of these emissions, a little over half of these emissions are due to the production of traditional calcium-based cements. Magnesium carbonate cements present a promising alternative to traditional calcium-based cements, both in terms of emission reductions and in terms of strength. The primary drawback to magnesium carbonate cements is that ambient curing is not yet viable. The objective of this dissertation is to therefore develop greater understanding of the precipitation pathways undertaken by hydrated magnesium carbonates under near-ambient conditions. In the first section of this dissertation, the precipitation pathways of hydrated magnesium carbonates under a range of varying were systematically investigated and characterized using a variety of techniques such as XRD, FTIR, and AFM. Analysis both confirmed literature models of growth while also bringing to light certain unexpected behaviors wherein increasing solution concentration delayed precipitation of hydromagnesite. The second section investigates the effects of Rb+ and Cs+ on precipitation of hydrated magnesium carbonates under near-ambient conditions. Characterization through Raman and FTIR spectroscopy revealed that the inclusion of these additives accelerated the phase evolution of hydrated magnesium carbonates towards hydromagnesite, indicating potential for use in magnesium carbonate cements. Finally, the nano-mechanical properties of various hydrated magnesium carbonate phases were investigated using AM-FM, establishing the elastic moduli of these phases while also showing that AM-FM is a useful tool for phase identification of hydrated magnesium carbonates.
Keywords
Cements, Magnesium Carbonates, Atomic Force Microscopy, Nanoscale
Disciplines
Geochemistry | Materials Chemistry
License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
Recommended Citation
Shortt, Ian, "Nanoscale Studies of Magnesium Carbonate Precipitation at Ambient Conditions" (2024). Material Science and Engineering Dissertations. 86.
https://mavmatrix.uta.edu/materialscieng_dissertations/86