title: One-step synthesis and functionalization of hydroxyl-decorated magnetite nanoparticles.
abstract: Magnetite nanoparticles covered by a layer of omega-hydroxycarboxylic acid were synthesized in one step by high-temperature decomposition of iron(III) omega-hydroxycarboxylates in tri- and tetra-ethylene glycol. The nanoparticles were characterized by TEM, XRD, IR, XPS and NMR techniques in order to show that they comprise a crystalline magnetite core and actually bear on the outer surface terminal hydroxy groups. The latter ones are convenient "handles" for further functionalization as opposed to the chemically-inert aliphatic chains which cover conventionally synthesized nanoparticles. This was shown by several examples in which the hydroxy groups on the nanoparticle surface were easily transformed in other functional groups or reacted with other molecules. For instance, the hydroxyl-decorated nanoparticles were made water soluble by esterification with a PEGylated acetic acid. The reactive behavior of the surfactant monolayer was monitored by degrading the nanoparticles with aqueous acid and isolating the surfactant for NMR characterization. In general, the reactivity of the terminal hydroxyl groups on the nanoparticle surface parallels that observed in the free surfactants. The reported hydroxyl-decorated magnetite nanoparticles can be thus considered as pro-functional nanoparticles, i.e., a convenient starting material to functionalized magnetic nanoparticles.
authors.affiliation: Istituto di Scienze e Tecnologie Molecolari, Consiglio Nazionale delle Ricerche, via Golgi 19, 20133 Milano, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Mondini
authors.forename: Simone
authors.initials: S
authors.lastname: Cenedese
authors.forename: Giorgio
authors.initials: G
authors.lastname: Marinoni
authors.forename: Giorgio
authors.initials: G
authors.lastname: Molteni
authors.forename: Nadia
authors.initials: N
authors.lastname: Santo
authors.forename: Claudia L
authors.initials: CL
authors.lastname: Bianchi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ponti
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D001672:Biocompatible Materials / Q000138:chemical synthesis*; D002264:Carboxylic Acids / Q000737:chemistry*; D004952:Esters / Q000737:chemistry; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D006358:Hot Temperature; D008422:Materials Testing; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011092:Polyethylene Glycols / Q000737:chemistry; D012995:Solubility; D013057:Spectrum Analysis; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D002264:Carboxylic Acids; D004952:Esters; D013501:Surface-Active Agents; D014867:Water; D011092:Polyethylene Glycols; D019342:Acetic Acid; D052203:Ferrosoferric Oxide