Self-assembled (SA) bilayer molecular coating on magnetic nanoparticles

Protectively and functionally coated magnetic nanoparticles are of special interest because of their important technological applications in diverse f ields, ranging from biotechnology to transportation. In this paper, monolay er and bilayer surfactant coating on magnetite (Fe3O4) nanoparticles has be en obtained using the self-assembly method. Magnetic properties such as mag netization, ZFC and FC curves, blocking temperature, hysteresis loop, coerc ivity and remanent magnetization of the SAM and bilayer coated magnetite na noparticles have been investigated. The results show the efficacy of our sy nthesis approach not only to protect magnetic nanoparticles via surfactant- mediated self-assembly but also their stable suspension in a variety of app ropriate liquid media. The superparamagnetic nature of the magnetic nanopar ticles remains unchanged with self-assembled coatings and paves the way for their use in colloid suspension for device applications. (C) 2001 Publishe d by Elsevier Science B.V.