In-situ transition of amorphous gels to Na-P1 zeolite in geopolymer: Mechanical and adsorption properties

Zheng, Zhao and Ma, Xue and Zhang, Zuhua and Li, Yuxiang (2019) In-situ transition of amorphous gels to Na-P1 zeolite in geopolymer: Mechanical and adsorption properties. Construction and Building Materials, 202. pp. 851-860. ISSN 0950-0618


Abstract

Turning amorphous gels of fly ash-based geopolymers into zeolite(s) can improve their adsorption properties for the potential use of wastewater treatment. This study investigates the optimal crystallization conditions under which Na-P1 zeolite forms and the relationship between the extent of crystallization, the resulting microstructure, and the compressive strength. The results indicate that a curing temperature of 90 °C is more effective when forming Na-P1 zeolite in geopolymers than a curing temperature of 60 °C. The most suitable alkali concentration (wt% Na2O/fly ash) and alkali activator modulus (n(SiO2)/n(Na2O)) are 15 and 1.5, respectively. The transition of amorphous gels into crystalline zeolites, i.e., more ordered structures, leads to a certain loss of compressive strength. However, the optimal matrix still retains 13.5 MPa of compressive strength. The cation exchange capacity (CEC) of the geopolymer matrix is demonstrated to be a function of the crystalline extent, and the highest CEC occurs in the optimal in-situ transformed geopolymer.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Date Deposited: 28 Jan 2020 04:08
Last Modified: 30 Jan 2020 02:58
Uncontrolled Keywords: Geopolymers, Na-P1 zeolite, Crystallization conditions, Compressive strength, Cation exchange capacity
Fields of Research : 09 Engineering > 0905 Civil Engineering > 090503 Construction Materials
Socio-Economic Objective: B Economic Development > 87 Construction > 8703 Construction Materials Performance and Processes > 870301 Cement and Concrete Materials
Identification Number or DOI: 10.1016/j.conbuildmat.2019.01.067
URI: http://eprints.usq.edu.au/id/eprint/37698

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