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An X-ray micro computed-tomography system (Skyscan 1172) has been installed and operated successfully at UCLA. The system is used for non-destructive characterization of 3-D microstructures of multifunctional composites for advanced aerospace systems and is found to be a very powerful instrument for various composites. The composites and devices under study include graphite nanoplatelet (GNP) and carbon nanotube (CNT) composites, energy harvesting/storage composites, ink jet printed electrodes, and thin film batteries. The tomographic images can show agglomeration of nanoparticles such as GNPs and CNTs as well as microvoids. They can also show internal damages in thin-film solar cells and batteries., The original document contains color images.

Chapter 1: Distributed Detection of Attacks/Intrusions and Prevention of Resource-Starvation Attacks in Mobile Ad Hoc Network by Jong Kim and Kang G. Shin; Chapter 2: Electronic, Photonic and Magnetic Properties of Modified DNAs Complexed with Heavy Metal Ion by Dong Hoon Choi and A. J. Steckl; Chapter 3: Ultra-Sensitive Biological Detection via Nanoparticle-Based Magnetically Amplified Surface Plasmon Resonance (Mag-SPR) Techniques by Jinwoo Cheon and A. Paul Alivisatos (AOARD-094060); Chapter 4: Hierarchical Carbon Fiber Composites by Kun-Hong Lee, Sang-gi Lee, H. Thomas Hahn, Eugene Oh, Yu Sung Chun, Ju Yeon Shin and Cho-Long Park., This document contains results from four different basic research projects under the Phase I of US-Korea NBIT Program (2007-2010). It is the 2nd year results covering research results from 2008-2009. Prepared in cooperation with Pohang University of Science and Technology, University of Michigan, Korea University, University of Cincinnati, Yonsei University, University of California Berkeley, Ewha Womans University, and University of California Los Angeles. The original document contains color images. All DTIC reproductions will be in black and white.

Graphite nanoplatelets (GNPs) are an attractive class of reinforcement materials as they offer both high modulus and high strength. GNPs have a thickness of less than 100 nm although their planar dimensions can be as large as a few micrometers. As with any other nanoscale particles, their effectiveness as a reinforcement phase depends on the surface functionalization, which controls dispersion and interfacial bonding. A simple surface oxidation using nitric acid is shown to yield as good an improvement in composite properties as a few other functional groups chemically bonded to the surface do. The properties discussed include modulus, strength, fracture toughness, adhesive strength, thermal and electrical conductivities, and dielectric constants. Methods of further exfoliating graphite nanoplatelets are discussed together with the associated benefits on composite properties. Potential applications of graphite nanoplatelet composites are presented to conclude the report.

The report contains final reports from four separate projects co-funded by AFOSR/AOARD and Korean MEST. The four projects were (1) Ultra-Sensitive Biological Detection via Nanoparticle-Based Magnetically Amplified Surface Plasmon Resonance (Mag-SPR) Techniques; (2) Electronic, Photonic and Magnetic Properties of Natural and Modified DNA Complexes with Heavy Metals Ions; (3) Hierarchical Carbon Fiber Composites; and (4) Distributed Detection of Attacks/Intrusions and Prevention of Resource-Starvation Attacks in Mobile Ad Hoc Networks., Prepared in cooperation with Korea University, Seoul; Pohang University of Science and Technology(POSTECH), Pohang; Ehwa Women's University, Seoul, all of South Korea and University of California-Berkeley, Berkeley, CA; University of Cincinnati, Cincinnati, OH; and University of California-Los Angeles, Los Angeles, CA. The original document contains color images.

A Joint Meeting of the 3rd US-Korea Workshop on Nanoelectronics and the 5th US-Korea Workshop Nanostructured Materials and Nanomanufacturing was held at the University of California, Los Angeles on 8-9 August 2006. The Meeting started with 6 overview presentations on research programs in the subject areas supported by the AFOSR and the Center for Nanostructured Materials Technology, Korea, respectively. The Nanoelectronics Workshop included 10 U.S. papers and 14 Korean papers while the Nanostructured Materials Workshop included 15 U.S. papers and 9 Korean papers. CDs containing copies of presentations are available from AFOSR., Document consists of workshop agenda only.

The main objective of the proposed research was to develop the science base necessary for full utilization of nanoreinforcements into polymers and fiber composites to improve mechanical, thermal and electrical properties. Two types of nanoreinforcements were studied: 0-dimensional SiC nanoparticles and 2-dimensional graphite nanoplatelets. As property improvements are possible only when the nanoreinforcements are uniformly dispersed in and well bound to the polymer matrix, the emphasis was on developing methods to optimally functionalize these nanoreinforcements. A coupling agent methacryloxy propyl trimethoxy silane (MPS) was found to be effective for the SiC nanocomposite. As for the graphite nanoplatelets, the effects of the following parameters on properties were investigated: size reduction through vibratory milling, thickness reduction through intercalation/expansion/exfoliation, and oxidation though nitric acid treatment. The most effective parameter was found to be the proper oxidation by acid treatment. Material properties studied were tensile strength and modulus, flexural strength and modulus, thermal conductivity, and electrical conductivity. The effects of adding GNPs into fiber composites as well as of using thinner prepreg plies were also studied to a limited extent. The properly oxidated GNPs were found to improve not only mechanical properties but also thermal and electrical properties of GNP/epoxy nanocomposites.

This letter describes the magnetoresistance (MR) behavior of the heat-treated polyurethane composites reinforced with iron nanoparticles. The flexible nanocomposites were fabricated by the surface-initiated-polymerization method. The uniformly distributed nanoparticles within the polymer matrix, well characterized by field emission scanning electron microscopy, favor a continuous carbon matrix formation, rendering the transition from insulating to conductive composites. The coercive forces reflect strong particle loading and matrix dependent magnetic properties. By simply annealing in a reducing environment, the obtained nanocomposites possess a MR of 7.3 % at room temperature and 14 % at 130 K occurring at a field of 90 kOe., Sponsored in part by National Science Foundation. Prepared in cooperation with Louisiana State University, Baton Rouge.

Highly innovative work towards development of a new class of materials called "Multifunctional Composites (MCs)" for multi-role structural aircraft skin applications possessing both self-healing and morphing functionality has been achieved. Proof of concept was demonstrated showing that a low volume-fraction (5-10%) of magnetic particles is sufficient for enabling self-healing of an approximate 150 micron x 5000 micron crack in a mendomer polymer using inductive heating. It was also demonstrated that a carbon-fiber-composites can be fabricated to morph using an apparent shape memory effect of the same mendomer that was used to demonstrate the self-healing. Studies of particle composition and mendomer were performed to determine the relative optimal material components for self-healing and morphing functionality. Department of Defense applications of the technology were articulated in collaboration with a major ballistic missile defense integrator. Future work is also briefly discussed., See also ADM002075. Presented at the Army Science Conference (25th) held in Orlando, Florida on 27-30 November 2006. The original document contains color images.

This paper is concerned with the investigation of the effective material properties of internally defective or particle-reinforced composites. An analysis was carried out with a novel method using the two-dimensional special finite element method mixing the concept of equivalent homogeneous materials. A formulation has been developed for a series of special finite elements containing an internal defect or reinforcement in order to assure the high accuracy especially in the vicinity of defects or reinforcements. The adoption of the special finite element can greatly simplify numerical modeling of particle-composites. The numerical result provides the effective material properties of particle-reinforced composite and explains that the size of particles has great influence on the material properties. Numerical examples also demonstrate the validity and versatility of the proposed method by comparing with existing results from literatures.