|AVS 57th International Symposium & Exhibition|
|Thin Film||Wednesday Sessions|
|Session:||ALD: Nanostructure, Magnetics and Biological Applications|
|Presenter:||J.C. Shearer, Colorado State University|
|Authors:||J.C. Shearer, Colorado State University
E.R. Fisher, Colorado State University
|Correspondent:||Click to Email|
Fe2O3 and other magnetic nanoparticles are becoming key components of both chemical and biological applications, including drug delivery schemes and magnetic resonance imaging contrast agents. Nanoparticles coated with organic and inorganic films have distinct properties and enhanced functionalities over those of uncoated nanoparticles. Plasma-enhanced chemical vapor deposition (PECVD) was employed to conformally coat Fe2O3 with SiO2 or polyallyl alcohol films, thereby creating composite nanomaterials. Comparisons will be made between composite nanoparticles created with an in-house atmospheric pressure plasma system and similar composite materials created in a traditional low-pressure PECVD system. In other studies, surface sites were activated with O2 and Ar plasmas to plasma graft SiO2 and polyallyl alcohol monolayer films onto the nanoparticles. Compositional and morphological data demonstrate that conformal SiO2 and polyallyl alcohol coatings were achieved and that the use of PECVD methods allowed specific tailoring of the film structure, composition, and growth characteristics. The performance of the composite materials was explored through dispersion, UV-vis spectroscopy, and chemical functionalization studies. Further insight into the deposition process is provided by actinometric optical emission spectroscopy (AOES) and laser induced fluorescence spectroscopy (LIF), which allow characterization of the gas-phase species and their energetics (i.e. internal and kinetic energies) for each system. Preliminary data from our Imaging of Radicals Interacting with Surfaces (IRIS) technique provides additional information on the molecular-level chemistry that occurs at the interface between gaseous plasma species and nanoparticle substrates.