Magnetic nanoparticles are of interest in several different scientific fields and have many potential applications, such as data storage and drug delivery. However, in order to study or make use of the unique properties of nanosize materials it is crucial to be able to isolate the nanostructures and also to assemble them in a controlled manner.
We have developed a solution-based technique for deposition of magnetic carbon-coated iron nanoparticles on a surface. The nanoparticles are first organically functionalized by a two-step method. The resulting functionalized nanoparticles are dispersible in non-polar liquid solvents such as chloroform. The particles used in this study were fabricated by photolytic gas-phase dissociation of ferrocene using an excimer laser. In this process, a coating of both amorphous and graphitic carbon forms around the single crystal iron nucleus. In the first step of the functionalization, the carbon coating is partially etched and carboxylic functionalities are introduced. In the second step, the carboxylic groups are esterified, making the particles less prone to agglomerate in the solvent. From solution, the nanoparticles can then be assembled onto a surface by dipping. The functionalized nanoparticles and nanoassemblies have been analysed using scanning electron microscopy, transmission electron microscopy, and energy dispersive x-ray spectroscopy.
The potential of the organic functionalization method to obtain dispersions of magnetic nanoparticles will be demonstrated. Also the possibility of combining organic functionalization with solution-based deposition techniques and self-assembly will be discussed.
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