Room 303, MAE-A
939 Sweetwater Drive
Gainesville, FL 32611-6250
Long-Range Order CNT Assemblages for High-Performance Structural Composite Applications and Progress of Additive Manufacturing for Multifunctional Products
Richard Liang, Professor and Director
Dept. of Industrial and Manufacturing Engineering,
FAMU-FSU College of Engineering
High-Performance Materials Institute, Florida State University
Carbon nanotubes (CNTs) demonstrate great potential for developing new electronics and high-performance multifunctional composites for aerospace applications. This presentation examines different approaches for engineering CNT networks to realize high mechanical and electrical performance. For heavily entangled and randomly dispersed CNT networks, a mechanical stretching process provides a scalable and affordable approach for achieving a high degree of alignment. We discovered that the unique geometrically constrained self-assembling and graphitic crystal packing of flattened and aligned CNTs during the stretching process can improve the ultimate surface contact among the CNTs to substantially improve load transfer and mechanical properties. Graphitic CNT packing permits the observation of a number of interesting microstructural features of the CNT assemblages, including nanotube collapses, flattened packing, and preferred stacking, very similar to graphitic crystalline microstructures in high-strength carbon fibers. These self-assembling behaviors provide the potential to realize microstructures on a long-range order, fewer defects, and ordered crystalline packing, which are essential for fully transferring the CNT mechanical properties into macroscopic composite materials. The resultant nanocomposites are demonstrating high mechanical properties comparable to the state-of-the-art unidirectional carbon fiber composites, with high electrical conductivity along the alignment direction. Using CNT sheets and yarns to produce lightweight electrical conductors will be briefly discussed. The talk will also briefly summarize our recent research progress in additive manufacturing for developing safer helmets, lightweight heatsinks and senor studies. A short overview of the research capabilities and expertise at the High-Performance Materials Institute (HPMI) will be presented at the end of the presentation.
Dr. Zhiyong (Richard) Liang is a professor at the Department of Industrial and Manufacturing Engineering of FAMU-FSU College of Engineering, and professor of the Interdisciplinary Materials Science and Engineering Ph.D. program at FSU. He also serves as the Director of the FSU High-Performance Materials Institute (HPMI), and the Deputy Director for the recently established NASA Space Technology Research Institute for Ultra-Strong Composites by Computational Design (US-COMP, NASA STRI). He received his Ph.D. degree in Materials Science and Engineering from the Beijing University of Aeronautics and Astronautics. His research experience and expertise are in the areas of advanced composites, multifunctional nanomaterials and scale-up manufacturing of nanomaterials and devices. Since joining FSU in 2001, as PI and Co-PI, he has worked on more than 60 research grants. He holds approximately 25 US patents and pending applications. He has published more than 120 refereed journal papers. He has advised 15 Ph.D., 31 MS and 10 honors thesis students, as well as 25 postdocs since joining FSU. With his colleagues and students, he has won over 20 awards for outstanding research, best papers, innovations and student advising.