Magnetically Controlled Release of Dispersed Iron Oxide Nanoparticles from Imprinted Organic Thin Films

摘要

Iron oxide nanoparticles (Fe_3O_4-NP) were compressed together with oleic acid (OA) in a Langmuir-Blodgett trough. Optimized dilution of the NP allowed the transfer of two-dimensional nanocomposites of Fe_3O_4-NP and OA to gold substrates. The characterization of the two-dimensional composite by scanning force microscopy (SFM) showed the existence of a sub-monolayer coverage with a few NP being pushed into the second layer. Polarization modulation infrared reflection absorption spectra (PM IRRAS) showed the presence of oleic acid. The nanoparticles could be removed in an external magnetic field of a permanent magnet as evidenced by SFM while the OA monolayer was left on the gold substrate as shown by PM IRRAS. Such composite layers can be used for the controlled release of specified small amount of intact NP.