University of Oulu

Sreenivasan H, Cao W, Hu Y, Xiao Q, Shakouri M, Huttula M, et al. (2020) Towards designing reactive glasses for alkali activation: Understanding the origins of alkaline reactivity of Na-Mg aluminosilicate glasses. PLoS ONE 15(12): e0244621. https://doi.org/10.1371/journal.pone.0244621

Towards designing reactive glasses for alkali activation : understanding the origins of alkaline reactivity of Na-Mg aluminosilicate glasses

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Author: Sreenivasan, Harisankar1; Cao, Wei2; Hu, Yongfeng3;
Organizations: 1Faculty of Technology, Fibre and Particle Engineering Research Unit, University of Oulu, Oulu, Finland
2Faculty of Science, Nano and Molecular Systems Research Unit, University of Oulu, Oulu, Finland
3Canadian Light Source Inc., Saskatoon, Canada
4Department of Materials Science and Engineering, The University of Sheffield, Sheffield, United Kingdom
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 2.3 MB)
Persistent link: http://urn.fi/urn:nbn:fi-fe202102185323
Language: English
Published: Public Library of Science, 2020
Publish Date: 2021-02-18
Description:

Abstract

Alkali-activated materials (AAMs), sometimes called geopolymers, are eco-friendly cementitious materials with reduced carbon emissions when compared to ordinary Portland cement. However, the availability of most precursors used for AAM production may decline in the future because of changes in industrial sectors. Thus, new precursors must be developed. Recently there has been increased interest in synthetic glass precursors. One major concern with using synthetic glasses is ensuring that they react sufficiently under alkaline conditions. Reactivity is a necessary, although not sufficient, requirement for a suitable precursor for AAMs. This work involves the synthesis, characterization, and estimation of alkaline reactivity of Na-Mg aluminosilicate glasses. Structural characterization showed that replacing Na with Mg led to more depolymerization. Alkaline reactivity studies indicated that, as Mg replaced Na, reactivity of glasses increased at first, reached an optimal value, and then declined. This trend in reactivity could not be explained by the conventional parameters used for estimating glass reactivity: the non-bridging oxygen fraction (which predicts similar reactivity for all glasses) and optical basicity (which predicts a decrease in reactivity with an increase in Mg replacement). The reactivity of the studied glasses was found to depend on two main factors: depolymerization (as indicated by structural characterization) and optical basicity. Depolymerization dominated initially, which led to an increase in reactivity, while the effect of optical basicity dominated later, leading to a decrease in reactivity. Hence, while designing reactive synthetic glasses for alkali activation, structural study of glasses should be given due consideration in addition to the conventional factors.

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Series: PLoS one
ISSN: 1932-6203
ISSN-E: 1932-6203
ISSN-L: 1932-6203
Volume: 15
Issue: 12
Article number: e0244621
DOI: 10.1371/journal.pone.0244621
OADOI: https://oadoi.org/10.1371/journal.pone.0244621
Type of Publication: A1 Journal article – refereed
Field of Science: 116 Chemical sciences
114 Physical sciences
Subjects:
Funding: The authors gratefully acknowledge the financial support received from European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie COFUND Grant Agreement no. 713606 (I4FUTURE) https://ec.europa.eu/research/mariecurieactions/. P.K. acknowledges financial support from Academy of Finland (grants 322085, 329477 and 326291) https://www.aka.fi/en.
EU Grant Number: (713606) I4FUTURE - Novel Imaging and Characterisation Methods in Bio, Medical, and Environmental Research and Technology Innovations
Academy of Finland Grant Number: 322085
329477
326291
Detailed Information: 322085 (Academy of Finland Funding decision)
329477 (Academy of Finland Funding decision)
326291 (Academy of Finland Funding decision)
Copyright information: © 2020 Sreenivasan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
  https://creativecommons.org/licenses/by/4.0/