S. Zhang, Yu. Dessureault, C. Jolowsky, A. Hao, J.G. Park, R. Liang
Florida State University,
Keywords: carbon nanotube, electrical conductor, lightweight
Summary:Carbon nanotube (CNT) yarn materials have the potential to achieve exceptional high mechanical and electrical properties due to nanotube self-assembling into long-range-order morphology as well as to realize scale-up manufacturing and affordability. In this research, we studied CNT yarn/carbon composites materials for potential lightweight, high-temperature and non-metal electrical conductor application. The CNT yarns used in the research are commercially available and the resultant CNT/C fiber conductor can be potential for scale-up production. The research studied the tensile properties of various CNT yarns with a large gauge length (100-120mm) to reveal performance reproducibility. We also focus on simultaneously improving both mechanical strength and electrical conductivity. In this study, pyrolyzed polydopamine (py-PDA) with selected surface treatments is introduced as an interface enhancer between CNTs and carbon matrix. Due to the presence of py-PDA, the effective physical interlocking and conductive pathways are rebuilt at the interface area between CNTs and carbon matrix, resulting in improved load transfer and electron transport. The CNT/py-PDA/C composite fibers demonstrated remarkable improvements in electrical conductivity (2.1 × 103 S∙cm-1) and tensile strength (up to 727 MPa). The study of detailed microstructures of CNT yarns using advanced STEM/FIB approach also will be discussed. Strong geometrically constrained self-assembling and graphitic crystal packing of CNTs were revealed, which can lead to new approach to develop long-range-order in CNT fiber materials for effective load transfer, and achieving high structural performance properties.