UM nanomaterials research helping to improve national infrastructure

Imagine seeing metal-penetrating bullets stopped by a substance less than an inch thick but stronger than steel. Visualize a bomb explosion inside a building, but the blast is practically neutralized by flexible outer walls that contain the spread of debris.

These are just two examples of the groundbreaking research under way in the University of Mississippi’s Nano Infrastructure Research Group, or NIRG, where School of Engineering scientists are developing bio-inspired nanomaterials to improve resilience of the nation’s infrastructure.

Ahmed Al-Ostaz, professor of civil engineering and director of the research team; and collaborators Alex Cheng, dean of the School of Engineering; A.M. Rajendran, chair and professor of mechanical engineering; and Hunain Alkhateb, assistant professor of civil engineering; were awarded a grant from NASA to also design new materials for spacecraft that will be able to withstand impacts of extremely fast-moving space debris, meteoroids and subatomic particles.

The three-year project, “Hyper Velocity Impact Environmental Resistant and Self-Healing Nanomaterials for Space Applications,” is aimed at exploring the revolutionary properties of bio-inspired and nano-enhanced multifunctional nanocomposites for ultra-lightweight space structural applications under extreme environments and loading conditions.

“In our laboratory we design new materials and study the process of existing materials that can withstand extreme environments and improve the resilience of our nation’s infrastructure against man-made threats (such as bomb blasts, fire or projectiles) and natural disasters (tornadoes, earthquakes and hurricanes,” Al-Ostaz said. “We are also preparing future engineers and scientists to better understand and meet both today’s needs and tomorrow’s challenges.”

In the past five years, under Cheng’s leadership, NIRG researchers have studied materials at extreme sizes (from nano-scale to full structures), extreme distances (from oil and gas shales deep in the ground to space applications, including the International Space Station), extreme loading rates (from static blast to ballistic to hypervelocity impact), extreme temperatures (from freezing to boiling) and extreme times (from a femtosecond – or one quadrillionth of a second – to years).

“These materials are often referred to as multifunctional materials,” Alkhateb said. “They merge modeling, designing and manufacturing new materials with actual testing of these products in simulated environments.”

Examples include materials that can resist blast loading with improved fire performance, and new materials and structures to enhance the performance of New Orleans’ levees during extreme hurricane seasons.

“One project’s outcome was the designing of new materials that can resist a 50-caliber bullet by self-sealing after impact,” Al-Ostaz said. “This has potential applications for the hazmat transportation industry.”

Research results have been published in major academic journals and technical reports.

“NIRG has established a niche of prominence in the national nanotechnology scene with our capabilities to model, design, build and test new nanomaterials, especially drawing inspiration from the abundant, low-cost nanomaterials of nature,” Cheng said.

Grants for NIRG projects have come from the Office of Naval Research, Department of Homeland Security, Mississippi Space Grant Consortium and North Carolina Agricultural & Technical State University/U.S. Army. In just the last three years, the team has received about $8 million to support its research.

The late theoretical physicist Richard P. Feynman’s vision of a powerful and general nanotechnology driven by nano-machines that build with atom-by-atom control promises great opportunities and, if abused, great dangers.

“New classes of nanomaterials – such as carbon nanotubes, nanofibers, nanowires and quantum dots – are being assembled atom-by-atom, with various high-tech applications in mind: electronics, biomedicine, energy, environment and so forth,” Al-Ostaz said. “However, these materials are still very expensive and can only be produced at a relatively small quantity.”

To help protect the nation’s critical infrastructure, including buildings, bridges, tunnels, transportation systems, pipelines, power transmission and communication systems, against natural and man-made threats, officials need nanomaterials that can be produced at low cost and in huge quantities.

“Fortunately, not all nanomaterials 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.”