Reaction Specificity of Nanoparticles in Solution (PNNL Scope # 42184/44076)
EMSL Project ID
2573
Abstract
This User Proposal is being submitted as part of an approved NSET proposal under PIs Don Baer and Paul Tratnyek to perform fundamental basic science studies that will benefit a whole range of applications involving nanoparticles in solution, including environmental remediation, corrosion, magnetic-storage media, and heterogeneous catalysis. The following is an excerpt from the abstract of the NSET proposal. The reactivity of nanometer-sized materials is often quite different from that of either the bulk material or the individual atoms and molecules that comprise it. Much of this size-dependent reactivity stems from the development of unique electronic structures intermediate between those of bulk materials and free atoms. Zero-valent iron (Fe) represents one system whose chemistry exhibits intrinsic nanoscale reactivity as well as the transition from metallic to semiconducting behavior. Iron and iron bimetallic nanoparticles have been shown to have a greatly increased reactivity towards a variety of environmentally important solute species including chlorinated hydrocarbons and reducible oxyanions. Furthermore, the products of these reactions differ, often in an environmentally friendly manner, from those obtained when 0.1 to 1mm particles of Fe are used. These changes occur for particles of the size range where signficant variations in electronic and magnetic properties are induced for pure metal particles. However, the Fe particles will have the additional complication of a reaction layer that forms on the surface in solution. The differences in selectivity are believed to be related to unique structural and chemical features of Fe(0) near the solution and/or Fe(II) in the oxide coating. The differences may be induced by the changes in the electronic structure of the nano-sized particles or changes in the structure of the coatings formed on the particles in solution. In order to establish and quantify these effects, this proposal defines a coupled experimental and modeling research program for studying reactive metal, bimetallic, and oxide nanoparticles, using chlorinated hydroarbons and inorganic oxyanions as model compounds...Novel and established techniques will be used for preparing iron and iron bimetallic nanoparicles in both the solution and gas phases. These particles and their surfaces will be subjected to advanced characterizaiton studies that will include magnetic measurements, high resolution transmission electron microscopy (HRTEM), scanning tunneling microscopy (STM), x-ray photoelectron spectroscopy (XPS), electron paramagenetic resonance (EPR) and other methods.Work authorization text added 08/11/05:
Iron and iron bimetallic nanoparticles have been shown to have a greatly increased reactivity towards a variety of environmentally important solute species including chlorinated hydrocarbons, reducible oxyanions, and metal ions and produce different, and often more environmentally safe, reaction products in comparison to the byproducts using microscale iron surfaces. These changes occur for particles of the size range where significant variations in electronic and magnetic properties are induced for pure metal particles. However, the iron particles will have the additional complication of a reaction layer that forms on the surface in solution. The differences in selectivity are believed to relate to unique structural and chemical features of Fe(0) near the solution and/or Fe(II) in the oxide film layers. They may be induced by the changes in the electronic structure of the nano-sized particles or changes in the structure of the films formed on the particles in solution. In order to establish and quantify these effects, this project defines a coupled experimental and modeling research program for studying reactive metal, bimetallic and oxide nanoparticles toward chlorinated hydrocarbons and environmentally important mobile oxyanions. Please contact Don Baer, project manager, for further information. Assumptions - The DOE client (Basic Energy Sciences) expects us to conduct fundamental research to further our knowledge in areas of importance to DOE's mission, and to disseminate this knowledge through publications in peer-reviewed journals and presentations of results at scientific meetings. Products/Deliverables: - Publications in scientific journals - Presentations at scientific meetings and symposia.
Project Details
Project type
Exploratory Research
Start Date
2002-07-22
End Date
2005-06-27
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
The Chameleon Effect: Characterization Challenges Due to the Variability of Nanoparticles and Their Surfaces
Baer D.R. 2018. "The Chameleon Effect: characterization challenges due to the variability of nanoparticles and their surfaces." Frontiers in Chemistry 6. PNNL-SA-131780. doi:10.3389/fchem.2018.00145
Magnetic Nanocrystalline Films Softened by Obliquely Accelerating Iron Nanoclusters
Meyer DR, M Faheem, M Campanell, J Antony, AM Sharma, and Y Qiang. 2007. "Magnetic Nanocrystalline Films Softened by Obliquely Accelerating Iron Nanoclusters." IEEE Transactions on Magnetics 43(6):3010-3012. doi:10.1109/TMAG.2007.893477
Morphology and Electronic Structure of the Oxide Shell on the Surface of Iron Nanoparticles
Wang CM, DR Baer, JE Amonette, MH Engelhard, J Antony, and Y Qiang. 2009. "Morphology and Electronic Structure of the Oxide Shell on the Surface of Iron Nanoparticles." Journal of the American Chemical Society 131(25):8824–8832. doi:10.1021/ja900353f
XPS analysis of nanostructured materials and biological surfaces
Baer DR, and MH Engelhard. 2010. "XPS Analysis of Nanostructured Materials and Biological Surfaces." Journal of Electron Spectroscopy and Related Phenomena 178-179:415-432. doi:10.1016/j.elspec.2009.09.003
Biocompatible core-shell magnetic nanoparticles for cancer treatment
Sharma A, Y Qiang, DR Meyer, R Souza, A Mcconnaughoy, L Muldoon, and DR Baer. 2008. "Biocompatible core-shell magnetic nanoparticles for cancer treatment." Journal of Applied Physics 103(7):Art. No.07A308. doi:10.1063/1.2831791
Electron beam-induced thickening of the protective oxide layer around Fe nanoparticles
Wang CM, DR Baer, JE Amonette, MH Engelhard, JS Anthony, and Y Qiang. (2007). "Electron Beam Induced Thickening of the Protective Oxide Layer around Fe Nanoparticles." Ultramicroscopy March 2007 doi:10.1016/j.ultramic.2007.03.002