Center for Functional Nanomaterials Seminar

Single-walled carbon nanotubes (SWNTs) exhibit extraordinary mechanical, thermal and electrical properties due to their unique one dimensional all-carbon structure. However, as-produced carbon nanotubes are typically bundled mixture of various species due to strong inter-tube van der Waals interactions and hydrophobic interactions in aqueous environments. Thus, SWNTs have to be first dispersed in organic or aqueous solvents before solution-phase processing, separation, and assembly can become successful. Here we designed a “polysoap” surfactant which not only disperses SWNTs in aqueous solution, but also acts as templates for the binding of metal ions and nanoparticles (NPs) to synthesize SWNT-metal NP assemblies in solution. In many potential applications, it is desirable to control the dispersion or aggregation of SWNTs in solvents with external stimuli. I will report two “smart” SWNT dispersions that respond to temperature and pH changes in poly(N-isopropylacrylamide) (PNIPAAm) and poly-L-lysine (PLL) solutions. I will also introduce biocatalytic electrodes based on transparent and conducting SWNT thin films and glucose oxidase (GOx) catalyzed direct electron transfer via simple immobilization with PLL and Nafion.