9413424 Jang This project, between Dr. Bor Jang, Auburn University, and Gan Yongxue, Beijing University of Aeronautics and Astronautics is supported under the U.S.-China Cooperative Research Program. Scientists at Beijing University of Aeronautics and Astronautics (BUAA) and Auburn University will form an international research team to investigate the interactions between electromagnetic (EM) waves and advanced fiber reinforced composites. The reflection, transmission, and absorption effects of EM waves in a composite will be correlated with the characteristics of the constituent fiber, matrix and their interfaces. Models will be developed to analyze EM wave-composite interactions in terms of correlations between basic EM parameters (permeability and permittivity) and the constituent materials properties. This investigation will initially be concentrated on a model class of functional fibers and composites that can exhibit an unusually wide spectrum of electrical behaviors, covering more than 12 orders of magnitude in conductivity ranging from highly insulating to highly conducting. The fibers, termed "quasi-carbon" (QC) fibers, will be obtained by oxidizing (stabilizing) and then partially or fully carbonizing polyacrylonitrile (PAN) fibers. The QC fiber reinforced QC matrix composites (QC/QC) will be prepared by impregnating QC fibers with a PAN or phenolic resin and then stabilizing and carbonizing the matrix resin. Correlation between the electrical properties and the molecular and crystal structures of these thermally treated fibers and composites will be established. Proper heat treatment conditions will be identified for the fabrication of advanced composites with good structural integrity, high thermal stability, and a unique EM wave-absorbing capability.
