Single-walled carbon nanotubes (SWNT) are exceptional materials with unmatched electrical, thermal, mechanical, and optical properties. The combination of extraordinary length-to-diameter ratio coupled with its exceptionally high thermal and electrical conductivity as well as its mechanical strength make this material unique. The University of Oklahoma (OU) has a technological advantage in the production of SWNT, via the use of a proprietary catalyst and a truly scalable production process (6 key patents issued, strong position in the IP field). Based on this novel technology, an OU startup company (South-West Nanotechnologies, SWeNT) is developing a large-scale process (CoMoCat®) that will greatly increase the availability of SWNT of the highest quality.
The specific research objectives of the Center are:
Funding for this Center comes from DoE, OCAST (Oklahoma Center for the Advancement of Sci. and Tech.) and has supported research on applications of single-walled carbon nanotubes (SWNT) that are produced in large scale by our unique method. One of the exceptional features of this process is the possibility of producing nanotubes of controlled diameter and chirality (orientation of the carbon rings on the nanotube wall) with much narrower distribution than any other known process. The OU group has developed a strong characterization protocol that provides a full description of the structural features of the nanotubes. As a result, we plan to capitalize on our unique position of having available large quantities of well characterized single-walled carbon nanotubes. The research scope is multidisciplinary and incorporates experts from different areas who work in the development of nanotube applications of high impact in the energy, biological, and environmental sectors.
The Center contributes significantly in areas such as materials science, chemical science, biological and environmental science, advanced computer science, energy efficiency, and renewable energy science. Commercialization of nanotube-based products will have an impact on many economic sectors. Lighter, stronger materials will result in more energy efficient transportation without compromising safety. Improved heat transfer materials and electrical conductors will improve the efficiency of power generation and transmission, resulting in lower energy costs and improved manufacturing efficiency, which will result in economic growth. Improved sensors and medical diagnostics tools will improve environmental quality and health care. The research team includes experts in the fields of catalysis, carbon nanotubes, surfactants, materials science, sensors, biosensors, biological systems, and numerical simulations. The research labs in three different departments are well equipped with state-of-the-art facilities to produce, test, and characterize SWNT of high quality and in large scale; as well as to develop and characterize composites, optoelectronic devices, sensors, and electrochemical and biological systems for the proposed applications.
The role of water in carbon feed on the surface-guided growth of horizontally aligned single-walled carbon
nanotubes (HA-SWCNTs) was investigated. It is shown that the amount of water can be optimized to favor HA-SWCNT growth, which is proposed to be due to selective etching of carbon deposits at carbon–metal interface. Without water, nanotube–nanotube interaction and carbon accumulation at the interface are disproportionately large compared to the rate of nanotube growth, leading to catalyst deactivation. With excess water, suppression of nanotube growth occurs, resulting in reduced carbon yield on the surface.
Intermediate carbon/water feed ratios achieve cleaner growth with high efficiency.