Dipole-interaction mediated hyperthermia heating mechanism of nanostructured Fe3O4 composites.

Abstract: A correlation between the DC magnetization and hyperthermia heating rate in high frequency magnetic fields was established for two distinctively different magnetic nanoparticle (MNP) systems: (1) polystyrene (PS)/Fe3O4 based composites, consisting of 10nm diameter Fe3O4 nanoparticles embedded in the matrix of polystyrene (PS) spheres (~100nm), and (2) similar Fe3O4 nanoparticles coated with polyacrylic acid (PAA) and dispersed in water. Due to physical confinement of Fe3O4 nanoparticles in the former, the PS/Fe3O4 composite exhibited much lower magnetic hyperthermia heating compared to the latter. The reduced magnetic hyperthermia heating in the polystyrene (PS)/Fe3O4 based composites was found to be associated with strong dipolar interactions. [Copyright &y& Elsevier]