“Toward the Next Generation of Multiscale Multifunctional Hybrid Composites”
Dr. Marwan Al-Haik, University of New Mexico
The seminar will cover some results of ongoing investigations on generating novel composite materials based on carbon nanostructures. One approach utilizes the alignment of single wall carbon nanotubes in a bulk composite. An epoxy/single wall carbon nanotubes (SWCNTs) composite was processed inside high magnetic fields (15-25 Tesla) to mediate the reorientation of the carbon nanotubes. The alignment process was characterized by environmental scanning electron microscopy, atomic force microscopy and wide angle X-ray diffraction. Based on this study, it was evident that magnetic alignment is a phenomenon closely related to the self-organizing process of the polymeric system. The thermal and electrical properties of the nanocomposite were significantly enhanced by the alignment of the carbon nanotubes during the magnetic processing. These experimental investigations were complemented by numerical simulations based on molecular dynamics at constant temperature and pressure.
A second approach aims to develop hybrid composites with enhanced blast-resistance capabilities. This approach entails the growth of carbon nanofibers/nanotubes on structural microscale carbon fibers and fiberglass to improve the strength, deformability and energy absorption characteristics of the polymeric and cementitious structural composites. Different hypotheses have been developed to optimize the surface growth of carbon nanotubes on carbon/glass fibers. A novel technology, graphitic structures by design (GSD), has been developed to eliminate the high-vacuum and high-temperature environments typically needed for standard chemical vapor deposition technology. GSD is applicable for a wide range of catalysts, and it requires atmospheric pressure and much lower temperatures, making the growth process more affordable. Experimental investigations of the composite under tensile and shear stresses showed the significance of the fabrication parameters on the mechanical characteristics of the composite. Preliminary simulations also showed the promising potential for the newly generated hybrid composites for blast-resistance applications.
Marwan Al-Haik is an assistant professor of mechanical engineering at the University of New Mexico. He received his PhD from Florida State University in 2002. He worked as a postdoc at the National High Magnetic Field Laboratory from 2002 to 2004. His current research interests include the synthesis and characterization of nanomaterials for structural, electrical and bio applications. His research also includes constitutive modeling of engineering materials at multiscale. He is an NSF Career awardee (2009), and he received the Air Force Research Lab Summer Fellowship (2008) and the Army Office of Research DURIP award (2009). He is the author/co-author of 38-refereed journal articles and three issued US patent applications.