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Updated: May 31, 2026

Stable Aqueous Suspensions of Manganese Ferrite Clusters with Tunable Nanoscale Dimension and Composition
Published on: February 5, 2022
Preparation and properties of water-based magnetic fluids
S Campelj1, D Makovec, M Drofenik
1Department for Materials Synthesis, 'Jozef Stefan' Institute, Jamova 39, SI-Ljubljana, Slovenia.
Abstract:
Stable suspensions of superparamagnetic iron oxide nanoparticles in water (water-based ferrofluids) were prepared using citric acid (CA) as a surfactant. The influences of different factors on the amount of nanoparticles in a stable suspension were systematically studied. These factors, including the temperature, the pH value and the concentration of CA applied during the adsorption of the CA onto the nanoparticles and during their suspension in water, were evaluated. The highest content of nanoparticles in a stable suspension was obtained when the CA was absorbed at pH values of around 5.2, where two carboxyl groups are dissociated, and when the nanoparticles were suspended at a pH of around 10, where all three carboxyl groups of the CA are in a dissociated state.
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