Self-assembly of iron oxide nanoparticles into oriented nanosheets by one-pot template-free synthesis at low pH

Single-crystalline Fe3O4 nanosheets were obtained for the first time by simply adjusting the pH of a magnetite particle dispersion, using a hydrophilic terpolymer as stabilizer. We experimentally observed the magnetite nanoparticles spontaneous, template-free organization into nanosheets. This transformation Occurs in an acidic environment at the zeta potential minimum by the abrupt. oriented self-assembly of polymer-stabilized magnetite particles at room temperature. The driving forces of the oriented self-assembly process includes the interplay of anisotropic dipolar forces. electrostatic interactions and isotropic van der Waals forces. (C) 2009 Elsevier B.V. All rights reserved.