Redox equilibria of iron oxides in aqueous-based magnetite dispersions:Effect of pH and redox potential

The effect of pH and redox potential on the redox equilibria of iron oxides in aqueous-based magnetite dispersions was investigated. The ionic activities of each dissolved iron species in equilibrium with magnetite nanoparticles were determined and contoured within the Eh–pH framework of a composite...

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Main Authors: Pang, S.C., Chin, Suk Fun, Anderson, Marc A.
Format: Article
Language:English
Published: Elsevier 2007
Subjects:
Online Access:http://ir.unimas.my/id/eprint/9894/
http://ir.unimas.my/id/eprint/9894/1/Redox%20equilibria%20of%20iron%20oxides%20in%20aqueous-based%20magnetite%20dispersions%20Effect%20of%20pH%20and%20redox%20potential%20%28abtract%29.pdf
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author Pang, S.C.
Chin, Suk Fun
Anderson, Marc A.
author_facet Pang, S.C.
Chin, Suk Fun
Anderson, Marc A.
author_sort Pang, S.C.
building UNIMAS Institutional Repository
collection Online Access
description The effect of pH and redox potential on the redox equilibria of iron oxides in aqueous-based magnetite dispersions was investigated. The ionic activities of each dissolved iron species in equilibrium with magnetite nanoparticles were determined and contoured within the Eh–pH framework of a composite stability diagram. Both standard redox potentials and equilibrium constants for all major iron oxide redox equilibria in magnetite dispersions were found to differ from values reported for noncolloidal systems. The “triple point” position of redox equilibrium among Fe(II) ions, magnetite, and hematite shifted to a higher standard redox potential and an equilibrium constant which was several orders of magnitude higher. The predominant area of magnetite stability was enlarged to cover a wider range of both pH and redox potentials as compared to that of a noncolloidal magnetite system.
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spelling unimas-98942015-12-03T07:38:32Z http://ir.unimas.my/id/eprint/9894/ Redox equilibria of iron oxides in aqueous-based magnetite dispersions:Effect of pH and redox potential Pang, S.C. Chin, Suk Fun Anderson, Marc A. GE Environmental Sciences QD Chemistry The effect of pH and redox potential on the redox equilibria of iron oxides in aqueous-based magnetite dispersions was investigated. The ionic activities of each dissolved iron species in equilibrium with magnetite nanoparticles were determined and contoured within the Eh–pH framework of a composite stability diagram. Both standard redox potentials and equilibrium constants for all major iron oxide redox equilibria in magnetite dispersions were found to differ from values reported for noncolloidal systems. The “triple point” position of redox equilibrium among Fe(II) ions, magnetite, and hematite shifted to a higher standard redox potential and an equilibrium constant which was several orders of magnitude higher. The predominant area of magnetite stability was enlarged to cover a wider range of both pH and redox potentials as compared to that of a noncolloidal magnetite system. Elsevier 2007 Article NonPeerReviewed text en http://ir.unimas.my/id/eprint/9894/1/Redox%20equilibria%20of%20iron%20oxides%20in%20aqueous-based%20magnetite%20dispersions%20Effect%20of%20pH%20and%20redox%20potential%20%28abtract%29.pdf Pang, S.C. and Chin, Suk Fun and Anderson, Marc A. (2007) Redox equilibria of iron oxides in aqueous-based magnetite dispersions:Effect of pH and redox potential. Journal of Colloid and Interface Science, 311 (1). pp. 94-101. ISSN 0021-9797 http://www.researchgate.net/publication/51378536_Redox_equilibria_of_iron_oxides_in_aqueous-based_magnetite_dispersions_Effect_of_pH_and_redox_potential DOI: 10.1016/j.jcis.2007.02.058
spellingShingle GE Environmental Sciences
QD Chemistry
Pang, S.C.
Chin, Suk Fun
Anderson, Marc A.
Redox equilibria of iron oxides in aqueous-based magnetite dispersions:Effect of pH and redox potential
title Redox equilibria of iron oxides in aqueous-based magnetite dispersions:Effect of pH and redox potential
title_full Redox equilibria of iron oxides in aqueous-based magnetite dispersions:Effect of pH and redox potential
title_fullStr Redox equilibria of iron oxides in aqueous-based magnetite dispersions:Effect of pH and redox potential
title_full_unstemmed Redox equilibria of iron oxides in aqueous-based magnetite dispersions:Effect of pH and redox potential
title_short Redox equilibria of iron oxides in aqueous-based magnetite dispersions:Effect of pH and redox potential
title_sort redox equilibria of iron oxides in aqueous-based magnetite dispersions:effect of ph and redox potential
topic GE Environmental Sciences
QD Chemistry
url http://ir.unimas.my/id/eprint/9894/
http://ir.unimas.my/id/eprint/9894/
http://ir.unimas.my/id/eprint/9894/
http://ir.unimas.my/id/eprint/9894/1/Redox%20equilibria%20of%20iron%20oxides%20in%20aqueous-based%20magnetite%20dispersions%20Effect%20of%20pH%20and%20redox%20potential%20%28abtract%29.pdf