Submicron Structure in Biocompatible Ferrofluids

G. Mateia, A. Airineib, D.E. Creangaa aUniv. Al. I. Cuza, Fac. of Physics, Iasi, Romania bP. Poni Macromolecular Chemistry Institute, Iasi, Romania

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Received: 2005 20 05;

This paper presents a comparative study between the microstructural features of two water-ferrofluids intended for biological applications. In both cases the ferrophase was prepared by auto-catalytic reaction between ferrous and ferric salts and resulted in magnetite and some maghemite precipitates. The difference is given by the stabilizer molecule: tetramethylammonium hydroxide and, respectively, citric acid. Transmission electron microscopy and atomic force microscopy were utilized for ferrophase size investigation. The evidence of short chains and large aggregates was obtained mainly by atomic force microscopy analysis (the tip diameter being equal to 5 nm). Their role in the ferrofluid rheological properties was studied by carrying out comparative measurements of viscosity and surface tension. Complementary investigation of the ferrofluid composition was done by means of IR absorption spectra. The suitability of the prepared ferrofluids for biological goals was proved by their convenient ferrophase diameter as well as by their stability in time.

DOI: 10.12693/APhysPolA.109.405 PACS numbers: 68.37.Lp, 68.37.Ps, 78.30.-j