Interoduction: Ultrasound images have often low contrast due to small differences in acoustic impedance between different tissues. Air or gas microbubbles that surrounded by membrane are most of the contrast agents in ultrasound imaging. Problems such as instability in sound pressure and inability in penetrating from the blood vessel into body tissues limited the use of microbubbles into the in...

In the present work, stable ferrofluids containing oleic acid capped magnetite nanoparticles were synthesized via low temperature hydrothermal method. The physical and chemical properties of the synthesized particles were studied using TEM, XRD, AFM, VSM and PCS techniques. Mean particles size of the samples was between 4.5 and 10 nanometers, depending on experimental conditions. Effect ...