Abstract
Novel thermal-sensitive ferrofluids (F127-ferrofluids) consisting of core-shell-type magnetic nanoparticles dispersed in Pluronic F127-containing aqueous solution were prepared. The core (magnet)-shell (Pluronic F127) nanoparticles were synthesized by in situ co-precipitation process, which were characterized using transmission electron microscope, X-ray diffraction and vibrating sample magnetometer. The F127-ferrofluids gelled above the lower critical solution temperatures (LCST) of approximately 23-28 °C, which were higher than that of pure Pluronic F127-fluids (21-25 °C). The increase in the LCST of the F127 ferrofluids may be attributed to a result of a physical interaction between the F127 molecules and the core-shell magnetic nanoparticles. © 2006 Elsevier B.V. All rights reserved.