Large-Scale Encapsulation of Magnetic Iron Oxide Nanoparticles via Syngas Photo-Initiated Chemical Vapor Deposition.

Photo-initiated chemical vapor deposition (PICVD) has been adapted for use in a jet-assisted fluidized bed configuration, allowing for the encapsulation of magnetic iron oxide nanoparticles on a larger scale than ever reported (5 g). This new methodology leads to a functional coating with a thickness of 1.4-10 nm, confirmed by HRTEM and TGA. XPS and TOF-SIMS characterization confirm that the coating is composed of both aliphatic and polymerized carbon chains, with incorporated organometallic bonds and oxygen-containing moieties. UV-Vis absorbance spectra show that the coating improved dispersion in non-polar solvents, such as n-dodecane. This process represents a first step towards the large-scale, solvent-free post-synthesis processing of nanoparticles to impart a functional coating.