Growth mechanism and kinetics of vertically aligned carbon nanotube arrays

Carbon nanotubes (CNTs) exhibit excellent mechanical, electrical, thermal, and chemical properties and show promising application potentials in numerous fields. Among different types of CNTs, vertically aligned CNT arrays (VACNTs) exhibit more superiors due to their good alignment, controllable structures and morphologies, and easy mass-production, and so forth. During the past years, extensive efforts were put into the controlled synthesis of VACNTs with desired structures and morphologies. Among these efforts, it should be noted that, it is of significant importance to improve the array lengths of VACNTs, especially for the fabrication of VACNTs-based fibers, transparent flexible films, and other functional materials, and so forth. However, it still remains a big challenge to synthesize VACNTs with length over centimeters. In this review, we summarize the growth mechanism, kinetics, growth factors of VACNTs, and the strategies for how to improve their array lengths. Finally, we also propose our outlook on the future development of VACNTs.