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Iron oxyhydroxide colloid formation by gamma-radiolysis
P A Yakabuskie1, J M Joseph, P Keech
1Department of Chemistry, the University of Western Ontario, London, Ontario, Canada N6A 5B7.
Physical Chemistry Chemical Physics : PCCP
|March 15, 2011
Summary
Gamma irradiation of iron(II) sulfate solutions produces uniform colloidal iron oxyhydroxide (γ-FeOOH) nanoparticles. Particle size and dendritic structure formation are controlled by irradiation time and solution conditions, leading to a narrow size distribution.
Area of Science:
- Materials Science
- Radiochemistry
- Nanotechnology
Background:
- Gamma irradiation is a method for synthesizing nanoparticles.
- Controlling nanoparticle size and morphology is crucial for their applications.
Purpose of the Study:
- To investigate the formation and growth of colloidal γ-FeOOH particles using gamma irradiation.
- To understand the factors influencing particle size distribution and morphology.
Main Methods:
- Deaerated aqueous solutions of FeSO(4) were subjected to gamma irradiation.
- Particle formation and growth were monitored at varying irradiation times and initial Fe(2+) concentrations.
- Particle size and morphology were characterized.
Main Results:
- Uniform-sized colloidal γ-FeOOH particles were formed.
- Spherical particles (<10 nm) formed at short irradiation times or low [Fe(2+)](0).
- Dendritic structures (∼60 nm) formed with longer irradiation, exhibiting a narrow size distribution regulated by redox conditions.
Conclusions:
- Gamma irradiation provides a controlled method for synthesizing γ-FeOOH nanoparticles.
- Particle nucleation and growth kinetics are governed by radiolytic oxidation and solution chemistry.
- The final particle size is determined by steady-state redox conditions at the aqueous-solid interface.
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