Quantitative kinetic and structural analysis of geopolymers. Part 1. The activation of metakaolin with sodium hydroxide
Article
Article Title | Quantitative kinetic and structural analysis of geopolymers. Part 1. The activation of metakaolin with sodium hydroxide |
---|---|
ERA Journal ID | 1511 |
Article Category | Article |
Authors | Zhang, Zuhua (Author), Wang, Hao (Author), Provis, John L. (Author), Bullen, Frank (Author), Reid, Andrew (Author) and Zhu, Yingcan (Author) |
Journal Title | Thermochimica Acta |
Journal Citation | 539, pp. 23-33 |
Number of Pages | 11 |
Year | 2012 |
Place of Publication | Amsterdam, Netherlands |
ISSN | 0040-6031 |
1872-762X | |
Digital Object Identifier (DOI) | https://doi.org/10.1016/j.tca.2012.03.021 |
Abstract | Isothermal conduction calorimetry (ICC) is used here to measure the kinetics of geopolymerisation of metakaolin by reaction with NaOH solution under a variety of conditions. Three exothermic peaks are observed in the calorimetric curve, and are assigned to the dissolution of metakaolin, the formation of geopolymer with disordered or locally-ordered structure, and finally the reorganization and partial crystallization of this inorganic polymer gels. For the purpose of further quantifying the ICC data, the geopolymeric reaction products are assumed to have an analcime-like local structure, and their standard formation enthalpies are estimated from the available data for this structure. This assumption enables ICC to be used for the first time in a quantitative manner to determine the real reaction kinetics of geopolymerization. Increasing the NaOH concentration up to a molar overall Na/Al ratio of 1.1 is seen to enhance the reaction extent observed at 3 days, up to a maximum of around 40% in the high liquid/solid ratio systems studied here, and accelerates the crystallization process. However, further addition of NaOH does not give any additional reaction within this period, or any further acceleration. Raising the reaction temperature from 25°C to 40°C increases the initial reaction rate but has little effect on the final reaction extent, particularly when Na/Al>1. |
Keywords | geopolymer; isothermal conduction calorimetry; metakaolin; kinetics |
ANZSRC Field of Research 2020 | 340306. Polymerisation mechanisms |
401601. Ceramics | |
340601. Catalysis and mechanisms of reactions | |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions. |
Byline Affiliations | Faculty of Engineering and Surveying |
Centre of Excellence in Engineered Fibre Composites | |
University of Melbourne | |
Haald Engineering, Australia | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q153z/quantitative-kinetic-and-structural-analysis-of-geopolymers-part-1-the-activation-of-metakaolin-with-sodium-hydroxide
2013
total views14
total downloads0
views this month0
downloads this month