Effects of Carbon Nanotube Diameter on the Fabrication and Performance of Collagen-Inspired Carbon Nanotube Films

Abstract

High-performance carbon nanotube (CNT) fibers have long been pursued in many academic and industrial communities, and recent decades have witnessed continuous progress in the CNT fiber design and fabrication, although their commercial applications have not been well realized. Inspired by the microstructure of type I collagen fibers, we have proposed a high-throughput route to fabricate CNT fibers/ films by domino-pushing and ion bombarding as-grown CNT forest. With CNTs of small diameter, numerical simulations have demonstrated that the route can well produce collagen-mimicked high-performance CNT fibers with unidirectionally aligned and transversally crosslinked CNTs. As CNT diameter increases, the complex mechanical behaviors such as collapse will probably occur, and hence the influence of the CNT diameter on the fabrication and performance of the fibers needs to be further studied. This work revealed that during the fabrication process the round-to-dumbbell CNT collapse happens with their diameter larger than 2[Formula: see text]nm. Before the collapse, the mechanical performance of the acquired CNT fibers decreases with CNT diameter, but reverses to increase after the collapse, mainly due to the reversed porosity-diameter relation by the collapse behavior. The varying of the fiber mechanical properties with the bombardment energy and dosage was also shown for different CNT diameters. Further, some useful guidelines on the mechanical property and fabrication process design of the bioinspired CNT fibers are concluded.