Structure, Properties, and Processing of Chirality-Resolved Single-Walled Carbon Nanotubes

Northwestern University, Evanston IL

Investigators

Abstract

Technical: This project addresses a critical obstacle to the widespread use of carbon nanotubes, that of controlled sorting. The project approach involves surfactant mixtures and density gradient ultracentrifugation (DGU) to sort single wall nanotubes (SWNTs) by diameter, chirality and electronic structure. Preliminary results for DGU on surfactant encapsulated SWNTs have demonstrated potential for the approach. The following tasks will be pursued: understanding and tuning the structure-density relationship for surfactant encapsulated SWNTs as a function of surfactant type, co-surfactant ratio, density gradient, and pH; optimizing iterative separations where the DGU conditions are sequentially varied to achieve concurrent diameter and metal/semiconductor separation; improved characterization of the structure and properties of chirality-resolved SWNTs using a complementary suite of characterization techniques including optical absorption spectroscopy, photoluminescence spectroscopy, pump-probe spectroscopy, Raman spectroscopy, scanning probe microscopy, and charge transport measurements; exploring the utility of chirality-resolved SWNTs in a wide range of device and materials applications such as complementary logic, transparent conductors, ultra-fast optical spectroscopy, templated assembly, nanocomposites, multi-analyte biosensors, and cell growth substrates. Non-technical: The project addresses basic research issues in a topical area of electronic/photonic materials science with high technological relevance. An important component of the proposed activity is an education and outreach plan that complements and is well integrated with the research objectives. Education and outreach activities will include: undergraduate curriculum development in the form of nanoscience modules that can be directly inserted into the Materials Science and Engineering undergraduate curriculum; undergraduate research opportunities both in the PI's laboratory and across campus as enabled by the his role as Director of the Nanoscale Science and Engineering Center Research Experience for Undergraduates Program; outreach to pre-college students by collaborating with the Boy Scouts, Girl Scouts, and Explorer Scouts on nanoscience events and a Nanotechnology Merit Badge; dissemination to the general public via the PI's membership on the Chicago Museum of Science and Industry (MSI) Physical Sciences Exhibit Advisory Panel.