Major Research on a Small Scale: Group's Nanotechnology Projects Focus On Protecting Nation's Infrastructure
The Nano Infrastructure Research Group (NIRG) is studying nano materials that show promise in protecting the nation's infrastructure and, in doing so, has found a niche in the field of nanotechnology.
Nanotechnology refers to the use of matter on an atomic and molecular scale. Generally, it deals with structures that measure only 100 nanometers or smaller and involves developing materials or even tiny machines within that size. A nanometer is one-billionth of a meter. The nation's infrastructure includes buildings, bridges, tunnels, transportation systems, pipelines, and power transmission and communication systems.
“Many projects are showing promise,” said Alexander Cheng, School of Engineering dean and a member of the group. “The new structural/building technologies developed from this research can be used to improve the survivability of these structures. The findings, recommendations and tools derived can become a part of the decision support system for local, state, tribal and regional leaders, and emergency responders for better preparedness [against terrorist threats as well as natural disasters].”
The group's research on “Nano Composites for Blast Protection of Critical Infrastructures” is featured as a success story on the U.S. Department of Homeland Security's Southeast Region Research Initiative (SERRI) website, www.serri.org. Cheng said that as a result of success in this project, researchers in the group were invited to serve on steering committees for the Department of Homeland Security. Besides Cheng, other group members include Ahmed Al-Ostaz, Chung Song, Elizabeth Ervin, Chris Mullen and Ge Wang, all professors in UM's Department of Civil Engineering, and Raju Mantena from the Department of Mechanical Engineering.
Another NIRG project uses nanotechnology along with other structural, material and geotechnical solutions to retrofit flood-protection systems, such as levees in New Orleans, as well as other critical infrastructures in the nation. Nanotechnology in this project is focused on developing a new generation of lighter, stronger and noncorrosive materials to improve the performance of systems in terms of strength, durability and resistance to sabotage.
“This project created a keen interest in using modern nano and biotechnology to enhance the performance and safety of the nation's infrastructures,” Cheng said.
Before the group began its nano research in earnest, it started modestly four years ago with weekly study meetings to learn about the carbon nanotube.
“We started molecular dynamics simulations by utilizing free, 30-day trials offered by the software company,” Song said. “As one trial period expired, the next person would check out the software until Dr. Al-Ostaz obtained a NASA grant that purchased the software. Three years later, we were successful in securing more than $6 million in research funds and to make a notable contribution in the field. This helped bring into focus the nano-engineering-related research at The University of Mississippi and in the state of Mississippi.”
During this time, the research group published more than 20 journal articles and employed five postdoctoral research associates and more than 15 graduate students. The professors knew they didn't have the monetary resources to compete with the major nanotechnology centers, but they identified their existing strength in composite structures research.
“We made two strategic decisions: We would not conduct research in the nanoscience areas that discover and create nano objects as we did not have the facility and resources,” Cheng said. “We would focus on utilizing the existing nano objects and seeking their creative engineering applications. We sought to conduct research with a smaller investment but with a larger return.
“We planned to avoid the crowded fields, such as electronics, biomedicine and aerospace, at least in the beginning of our effort. We focused on a field that hardly received attention at that time, construction and structural materials, because of their traditional image of low-tech. Now we believe we have a firm lead in these fields.”
Since nano materials such as nanofibers and nanowires are very expensive, the UM researchers also sought out less expensive materials.
“Fortunately, not all nano materials are man-made and expensive,” Al-Ostaz said. “There are abundant naturally occurring and low-cost materials that are at or near nano size, such as nano clay, volcanic and fly ash, cellulose nano whiskers and many carbon- or silica-based minerals.
“Recent study of mechanics at the micro and nano level has confirmed that the material behavior can be controlled by constituents at the nano size. Mixing a small quantity of clay, graphene, POSS and carbon nano tubes with polymers can significantly alter the material strength and other mechanical properties. The strength of cement is strongly influenced by the packing of the calcium-silica-hydrate gel at the micro level. Hence, with the understanding of materials laws at the micro and nano level, it may be possible to design infrastructure materials such as green concrete and building-blast-protection materials such as nano-particle-enhanced polymer spray.”
The School of Engineering's Nano Infrastructure Research Group has established a niche of prominence in the national nanotechnology scene by conducting several unique research projects. About $6.5 million of research funding has been secured during the last five years, which includes:
- Nanotechnology: Modeling of polymer-carbon nanotube composites at multiple spatial and time scales, Mississippi Space Grant Consortium, A. Al-Ostaz, primary investigator (PI), A. H.-D. Cheng, P.R. Mantena, C.S. Song and E. Jao, $25,000, 2005.
- Dynamic response and simulations of nanoparticle-enhanced composites, Office of Naval Research, P.R. Mantena (PI), A. H.-D. Cheng and A. Al-Ostaz, $75,000, 2006-07.
- Nano-particle-reinforced composites for critical infrastructure protection, Southeast Region Research Initiative, Department of Homeland Security, A. H.-D. Cheng (PI), A. Al-Ostaz, P.R. Mantena and C. Mullen, $1.1 million, 2007-10.
- Blast- and impact-resistant composite structures for Navy ships, Office of Naval Research, P.R. Mantena (PI), A. H.-D. Cheng, and A. Al-Ostaz, $925,000 (from $1 million Congressional FY 07 earmark), 2007-08. FY 08 earmark: $1.6 million.
- Structural, material and geotechnical solutions to levee and floodwall construction and retrofitting, Southeast Region Research Initiative, Department of Homeland Security, C.S. Song (PI), A. H.-D. Cheng, A. Al-Ostaz and P.R. Mantena, $2 million, 2007-10.
- Nano-enhanced and bio-inspired composite materials for mitigation and protection of TIH (toxic inhalation hazard) railcars and stationary tanks against high-power impact. Southeast Region Research Initiative, Department of Homeland Security, A. Al-Ostaz (PI), A. H.-D. Cheng, C. Song