title: Complete Exchange of the Hydrophobic Dispersant Shell on Monodisperse Superparamagnetic Iron Oxide Nanoparticles.
abstract: High-temperature synthesized monodisperse superparamagnetic iron oxide nanoparticles are obtained with a strongly bound ligand shell of oleic acid and its decomposition products. Most applications require a stable presentation of a defined surface chemistry; therefore, the native shell has to be completely exchanged for dispersants with irreversible affinity to the nanoparticle surface. We evaluate by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) the limitations of commonly used approaches. A mechanism and multiple exchange scheme that attains the goal of complete and irreversible ligand replacement on monodisperse nanoparticles of various sizes is presented. The obtained hydrophobic nanoparticles are ideally suited for magnetically controlled drug delivery and membrane applications and for the investigation of fundamental interfacial properties of ultrasmall core-shell architectures.
authors.affiliation: Department of Nanobiotechnology, Institute for Biologically Inspired Materials, University of Natural Resources and Life Sciences Vienna , Muthgasse 11, 1190 Vienna, Austria.|School of Materials Science and Engineering, Centre for Biomimetic Sensor Science, Nanyang Technological University , 50 Nanyang Drive, Singapore 637553, Singapore.
authors.forename: Oliver
authors.initials: O
authors.lastname: Bixner
authors.affiliation: Department of Nanobiotechnology, Institute for Biologically Inspired Materials, University of Natural Resources and Life Sciences Vienna , Muthgasse 11, 1190 Vienna, Austria.
authors.forename: Andrea
authors.initials: A
authors.lastname: Lassenberger
authors.affiliation: Faculty of Chemistry, Department of Physical Chemistry, University of Vienna , Währingerstraße 42, 1090 Vienna, Austria.
authors.forename: Dieter
authors.initials: D
authors.lastname: Baurecht
authors.affiliation: Department of Nanobiotechnology, Institute for Biologically Inspired Materials, University of Natural Resources and Life Sciences Vienna , Muthgasse 11, 1190 Vienna, Austria.
authors.forename: Erik
authors.initials: E
authors.lastname: Reimhult
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D019301:Oleic Acid / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; C000499:ferric oxide; D019301:Oleic Acid