Surface Properties of Metal and Metal Oxide Nanoparticles In Aqueous Environments and Their Toxicity
John M. Pettibone, Department of Chemical and Biochemical Engineering, University of Iowa, 4122 Seamans Center, Iowa City, IA 52242 and Vicki H. Grassian, Chemistry and Chemical and Biochemical Engineering, University of Iowa, 244 IATL, Iowa City, IA 52242.
Metal and metal oxide nanoparticles make up a large portion of the growing nanotechnology commercial market. Because these materials are being used in commercial products and the use of nanomaterials is expected to grow, it is paramount that the fate, transport, toxicity and surface chemistry of these materials be understood. In this study, commercially manufactured metal and metal oxide particles have been well-characterized and their physicochemical properties investigated using a wide range of techniques and methods. The surface chemistry, toxicity and properties of titanium dioxide nanoparticles of several sizes (5, 18 and 32 nm) were investigated. Titanium dioxide nanoparticle surface reactivity and toxicity was compared as a function of primary particle size, pH and aggregation state. For metal nanoparticles (Fe, Ag and Cu), dissolution studies in aqueous environments and simulated biological environments were also examined. These laboratory experiments can be used to better understand the environmental fate and the toxicity of these materials.