Coiled carbon nanotubes

Coiled carbon nanotubes (CCNTs) are CNTs with spiral structure. The CCNTs possess unique properties of helix, chirality and nonlinear mechanical behavior. It attracts great interests in the synthesis, growth mechanisms and application developments. The CCNTs is commonly synthesized by catalyst-supported chemical vapor deposition (CVD) and ñoating catalyst CVD. The selective production of CCNTs has been achieved. Based on the analysis of the formation mechanism of CCNTs, the prospects on structure modulation of CCNTs are investigated. The challenges in this field include delicate control of parameters in structure, the synthesis of CCNTs in ring, double helix and the selective production of CCNTs with chirality. Due to the unique properties, some CCNTs have potential applications in nano-electromechanical devices, composite reinforcements, etc. The applications based on single CCNT, CCNTs array and macroscopic quantity of CCNTs are briefly outlined as well.