Samit Roy - US grants

Low-density, high strength composites play a critical role in a wide range of technological areas including aerospace, defense, sports, transportation, and renewable energy. One of the most important classes of low-density materials is polymer matrix composites, which are now used as primary structural materials for large airliners, and in other applications, such as wind turbines and ship structures. The use of nanostructured reinforcements in composites has been shown to improve strength, resulting in structural weight reduction, thereby leading to fuel savings and reduced ecological impact. There is an increasing interest and a strong need for nanomanufacturing technologies for making the nanostructured reinforcement materials and their composites that are scalable in throughput and quantity. Through this Scalable NanoManufacturing (SNM) award, an interdisciplinary research team will work with industry to develop a continuous nanomanufacturing process to fabricate light-weight, high-strength structural composites. Nanometer thick carbon nanotube fabric will be wrapped around individual fibers to create "fuzzy" carbon fibers to enhance their bonding strength with the surrounding polymer. The nanostructured composites will be tested to evaluate their performance under service environments. The use of the carbon nanotube fabric wrapped carbon fiber composites can potentially reduce the structural weight of aircraft, increase energy efficiency and reduce travel time. This project will make an important contribution to the continued success of the NanoExplorer program. A large number of high school and college students will be involved in all aspects of this multi-disciplinary project. Efforts will be made to recruit students from minority and under-represented groups.

In this project, a continuous nanomanufacturing line will be designed, built and assembled to wrap individual fibers with carbon nanotube fabric, without degrading in-plane carbon fiber properties. The concept of "false twist" will be employed to scale-up the wrapping process and make it fully automatic. The individually wrapped "fuzzy" fibers will be subsequently consolidated to form a tow of fibers. The fiber tows will be impregnated in polymer to form prepregs, which will then be stacked and fully cured to prepare composite laminates. The laminates will be characterized for thermal stability and mechanical behavior. The nanomanufacturing process as well as the material preparation configurations will be investigated through computer simulations and models. The successful completion of the project will provide a unique scalable nanomanufacturing process to provide composites with significantly enhanced interfacial shear and compressive strength without degrading fiber tensile properties.