Carbon nanotube (CNT) yarn was functionalized using sulfuric and nitric acid solutions in 3:1 volumetric ratio. Successful functionalization of CNT yarn with carboxyl and hydroxyl groups (e.g., COOH, COO–, OH, etc.) was confirmed by attenuated total reflectance spectroscopy. X-ray diffraction revealed no significant change to the atomic in-plane alignment in the CNTs; however, the coherent length along the diameter was significantly reduced during functionalization. A morphology change of wavy extensions protruding from the surface was observed after the functionalization treatment. The force required to fracture the yarn remained the same after the functionalization process; however, the linear density was increased (310%). The increase in linear density after functionalization reduced the tenacity. However, the resistivity density product of the CNT yarn was reduced significantly (234%) after functionalization.
International Journal of Smart and Nano Materials
Misak, H. E., Asmatulu, R., O’Malley, M., Jurak, E., & Mall, S. (2014). Functionalization of carbon nanotube yarn by acid treatment. International Journal of Smart and Nano Materials, 5(1), 34–43. https://doi.org/10.1080/19475411.2014.896426