Synthesis protocol influence on aqueous magnetic fluid properties

Magnetic colloids containing superparamagnetic Fe(3)O(4) nanoparticles have been prepared by co-precipitation method. Three samples of citric acid coated magnetic colloids containing magnetic nanoparticles (ultra-fine particles of Fe(3)O(4)) have been obtained following three different preparation protocols. Physical tests have been performed on these samples of the magnetic colloids prepared by us (consisting mainly of Fe(3)O(4) ultra-fine Particles stabilized with citric acid (C(6)H(8)O(7)) and immersed in water), in order to reveal their microstructural and rheological features. Transmission electron microscopy (TEM) and magnetic measurements were the investigation methods used for the assessing of the magnetic nanoparticles size. The dimensional distribution of the ferrophase physical diameter was comparatively presented using the box-plot statistical method. Infrared absorption spectra have been recorded aiming to get some information on the magnetic fluid composition. (C) 2008 Elsevier B.V. All rights reserved.