In this research, we study the effects of ion beam welding on structural and property changes of carbon nanotube yarn. The approach of this research will be creating carbon nanotube yarn by continuous pulling from self-aligned nanotube arrays, and immediately irradiating the yarn by using an ion beam in air. The key is to use ion bombardment to introduce inter-tube displacements as stable contacts between tubes or to locally weld the junction of two joining carbon nanotubes, in order to enhance inter-tube electrical conduction, phonon transport and tube sliding friction. Ion beam treated yarns are expected to have significantly enhanced thermal, electrical and mechanical properties. The ion irradiation effects are characterized by using electron microscopy, Raman spectroscopy, tensile testing, electrical resistance and heat conduction experiments. This research includes multi-scale modeling to reveal atomic-scale details of evolution of defects created by ion irradiation, how subsequent structural relaxation leads to stable defect configurations, and how defects influence various properties at spatial and temporal scales linkable to experiments.
If successful, the benefits of this research will include development of an industry-ready ion beam technique for creation of yarns or ropes of high strength and conductivity. The technique can be extended to other non-carbon systems for materials applications under harsh environments. The project will also have broad impact with its educational plans to increase minority student participation, develop curricula, and create e-learning resources to promote public learning in frontiers of nanotechnology. The research activities will be integrated with existing Undergraduate Student Research Scholar Program and Enrichment Experience in Engineering for Teachers Program at the Texas A&M University to promote undergraduate student and high school teacher participation.
