Enhancement of the twisted carbon nanotube fibers properties by drawing processing and acid treatment

In this work, we report a promising processing methodology for enhancing the comprehensive properties of twisted carbon nanotube (CNT) fibers by combining drawing treatment with a copper capsule and subsequent acid treatment. This strengthening methodology enables the accurate control of the diameter of the as drawn CNT fibers, and provides an effective way to minimize surface damage to the CNT fibers during processing. The results show that the density, the CNT bundle alignment and the CNT fiber purity were improved after the combined strengthening treatment. Consequently, the tensile strength, electrical conductivity and thermal conductivity were significantly enhanced. Owing to the excellent properties, the strengthened CNT fibers have potential applications as an electric wire material. (C) 2018 Published by Elsevier Ltd.