Abstract：
The high surface area of nanomaterials dictates that the interface with their surroundings is important in determining their properties or functionality. For example, all atoms in single-walled carbon nanotubes (SWCNTs) exist on the surface and, therefore, have excellent sensing capabilities. The interface of SWCNTs with their surroundings is also important to their application in polymer composites, devices, drug delivery, bioimaging and biosensing. Understanding and ultimately controlling these surface layers is important because of its influence on reactivity, adsorption of pollutants, and interaction with biological materials. SWCNT interfaces are often altered with surfactants to improve their dispersion in aqueous suspensions. While the surfactant surrounding the nanotube provides many benefits, the inability to alter or control this interface often limits the performance or functionality of the nanotube. A lack of information on the effect of the surrounding environment on SWCNT properties further complicates the development of processes to control these interfaces. Our group has focused on characterizing and controlling SWCNT interfaces. The ability to reorganize the surfactant structure surrounding SWCNTs is achieved through both chemical and mechanical manipulations. Using our understanding of the surfactant structure surrounding SWCNTs, we have shown that the surfactant orientation on the SWCNT surface is an important parameter during the selective adsorption of semiconducting SWCNTs onto agarose gels. Understanding the mechanism behind these separations has enabled high-fidelity separations based on a single elution profile in a single column. The structure of the surfactant or other molecules around the SWCNTs also has important implications in toxicology.

Biography

Dr. Ziegler completed his Ph.D. in Chemical Engineering at the University of Texas at Austin. He then received the Enterprise Ireland Postdoctoral Fellowship and conducted research at University College Cork followed by postdoctoral research at Rice University with Nobel Laureate Richard Smalley. In 2005, Professor Ziegler joined the faculty in the Chemical Engineering Department at the University of Florida. His research group focuses on understanding the role of interfaces in one-dimensional nanostructures, such as SWCNTs and vertical arrays of nanowires.