title: Controlled synthesis of iron oxide nanoparticles over a wide size range.
abstract: We report on the effect of using decanoic acid as capping ligand on the synthesis of iron oxide nanoparticles by thermal decomposition of an organic iron precursor in organic medium. This procedure allowed us to control the particle size within 5 nm and about 30 nm by modifying the precursor-to-capping ligand ratio in a systematic fashion and to further expand the particle size range up to about 50 nm by adjusting the final synthesis temperature. The nanoparticles also showed high saturation magnetization of about 80-83 emu/g at low temperature, almost size-independent and close to the value for the bulk counterpart. Decanoic acid-coated nanoparticles were transferred to water by using tetramethylammonium hydroxide, which allowed further coating with silica in a tetraethyl orthosilicate solution. Consequently, these iron oxide nanoparticles are tunable in size and highly magnetic, and they could become suitable candidates for various biomedical applications such as contrast agents for magnetic resonance imaging and magnetic carriers for drug delivery.
authors.affiliation: Departament de Física Fonamental and Institut de Nanociència i Nanotecnologia, Universitat de Barcelona, 08028 Barcelona, Catalonia, Spain. pablo@ffn.ub.es
authors.forename: Pablo
authors.initials: P
authors.lastname: Guardia
authors.forename: Nicolás
authors.initials: N
authors.lastname: Pérez
authors.forename: Amilcar
authors.initials: A
authors.lastname: Labarta
authors.forename: Xavier
authors.initials: X
authors.lastname: Batlle
mesh_terms: D003652:Decanoic Acids / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013696:Temperature
chemical_list: D003652:Decanoic Acids; D005290:Ferric Compounds; D000644:Quaternary Ammonium Compounds; D012821:Silanes; C000499:ferric oxide; C040733:tetraethoxysilane; C031071:decanoic acid; D012822:Silicon Dioxide; C027917:tetramethylammonium