Multiscale Structures in Polymers and Nanocomposites Sanjeeva Murthy, Rutgers University, DMR The influence of hierarchical structure in polymers and composites on their performance was studied by investigating the failure characteristics in different types of materials: a semicrystalline fiber (ultrahigh modulus polyethylene, Spectra  ), a liquid crystalline material (polyaramid,Kevlar  ), and a nanocomposite (PAN with carbon fibers). In the course of this research, a new and powerful method was developed for analyzing structural data at nanometer length scales obtained using small-angle scattering (SAS) with light, x-rays or neutrons. This method, illustrated in Figure 1, shows that almost all classes of SAS patterns can be conveniently described in elliptical coordinates (Polymer, 2007, 48: ). Investigation of the failure at quasi-static and ballistic strain-rates in high modulus fibers shows that the some of the differences in performance of on strain rate can be related to vastly different morphology at micrometer length scales (Figure 2). (a) (e) (d) (c) (b) Figure 1: Full pattern description of the SAS patterns in elliptical cylindrical coordinates: (a) Bar pattern; (b) Four-point tilted-in pattern; (c) Four-point butterfly pattern; (d) Overlay of the data on the elliptical grid (by Eigen Vector Research Inc.) (e) Double ellipse analysis of the butterfly pattern Figure 2: Comparison of Spectra 900 fibers damaged at ballistic (left) and quasi static (right) strain rates. The micrograph on the left displays crazing, while that on the right shows plate formation.

Multiscale Structures in Polymers and Nanocomposites Sanjeeva Murthy, Rutgers University, DMR Educational Activities A post doctoral student (Dr. Fahmi Bedoui), while being actively involved in this project over the past year, is helping several undergraduates and graduate students in their research. One of the student working on this project, Wenjie Wang, was selected through a competitive process to attend a the summer school on x-ray and neutron scattering at the Argonne National Laboratory. He and another student (Chuang Deng) spend two weeks getting trained on the use of molecular dynamics simulation software at Dr. Goddard’s lab (Caltech) hand have since been using this software. An undergraduate, Paul Mark, who was involved in this projects is now a going to be a graduate student in Materials Science. A McNair Scholar, a Junior undergraduate, Desmond Nzi, worked one summer in the PI’s laboratory preparing solvent-spun fibers. The PI developed and taught a graduate polymer course and a seminar course on polymers, both the first at the University of Vermont. Outreach ●The software developed in this program to fit the small-angle scattering data in elliptical coordinate is being rendered user-friendly by adding graphic-user interfaces for distribution to others in the polymer community, especially to the users of the beam-lines at the Argonne Photon source. ●PI’s lab hosted high school students (raising seniors) from NY city during one summer. They worked in the lab preparing nanoclay filled composites and correlating process, structure and properties. ●PI organized two polymer sessions and workshops (2003 and 2007) at the Denver X- ray conference. Both were successful as measured by the number of participants at the workshop and the special sessions. ●PI has integrated his laboratory with a Green Chemistry program, being spearheaded by University of Massachusetts, by working on microphase separated copolymers relevant to green polymers.