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Fractal Concepts And Aggregation Of Iron Oxides

Published online by Cambridge University Press:  28 February 2011

R. Amal
Affiliation:
University of New South Wales, School of Chemical Engineering, P.O. Box 1, NSW 2033, Australia.
J.A. Raper
Affiliation:
University of New South Wales, School of Chemical Engineering, P.O. Box 1, NSW 2033, Australia.
T.D. Waite
Affiliation:
Australian Nuclear Science and Technology Organization (A.N.S.T.O.), Private Mail Bag 1, Menai, NSW, Australia.
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Abstract

The modelling of the aggregation kinetics of iron oxides has been succesful in predicting the increase in aggregate size as determined by dynamic light scattering measurements. The aggregates were found to exhibit fractal behaviour with fractal dimensions obtained from the scattering exponent in static light scattering studies dependent on the aggregation mechanism and ranging from 2.3 for rapid (diffusion limited) to 2.8 for slow (reaction limited) aggregation. Polydispersity and restructuring of aggregates were found not to affect the relationship between scattering exponent and aggregate fractal dimension. Excellent correspondence over a range of temperatures and ionic strengths has been obtained between results of sizing experiments using dynamic light scattering and sizes predicted using a modified Smoluchowski model incorporating fractal dimensions.

Type
Research Article
Copyright
Copyright © Materials Research Society 1990

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References

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