In this project funded by the Chemical Measurement and Imaging Program of the Division of Chemistry, Professor R. Bruce Weisman of Rice University is developing new ways to characterize and purify a scientifically and technologically important class of nanomaterials: single-walled carbon nanotubes (SWCNTs). These nanotubes display many remarkable properties that make them of great current interest to researchers pursuing basic science as well as real-world applications. However, progress in this field is often limited by difficulties in finding the amounts of specific nanotube structures that are present in samples, assessing the nanotube quality, detecting them in trace quantities in biological and environmental specimens, and sorting nanotube mixtures into pure structural forms. This project addresses these challenges using novel experimental methods. This research will provide broader impacts through the participation and professional development of underrepresented minority and women science students. In addition, the experimental methods and findings of the project should speed the development of new and economically valuable commercial technologies based on carbon nanotubes.
The project will explore and develop variance spectroscopy, a new optical technique that serves as a bridge between bulk and single-particle regimes and can reveal nanoparticle concentrations, emission efficiencies, inhomogeneities, and aggregation. A recently developed method will be used to directly measure the absolute, structure-specific absorption cross-sections needed to quantify the compositions of single-walled carbon nanotube (SWCNT) samples. Improved analysis methods will support efforts to more effectively sort SWCNTs by length. The project will also focus on enhancing the sensitivity limits for detecting and imaging SWCNTs present in complex samples at trace concentrations.
