Theoretical investigation of chirality control in single walled carbon nanotube growth

• Main Author: Wang, Qiang
• Other Authors: Chen Yuan
• Format: Theses and Dissertations
• Language: English
• Published: 2012
• Subjects: DRNTU::Engineering::Nanotechnology; DRNTU::Science::Chemistry::Physical chemistry::Quantum chemistry
• Online Access: https://hdl.handle.net/10356/48045
• Institution: Nanyang Technological University

The present thesis focuses on theoretical investigation of chirality control in single walled carbon nanotube (SWCNT) growth. Chirality controlled growth of SWCNTs is an essential prerequisite for their many potential applications. The experimental studies have found similar chirality selectivity toward higher chiral angle SWCNTs, in particular small diameter nanotubes such as (6,5) and (7,5). Also, experimental observations show that SWCNT chirality selectivity might be determined by the dynamic interplay between metal catalyst clusters and carbon caps/networks sprouted on metal cluster surfaces. In current work, two main factors on SWCNT chirality selectivity are studied theoretically: (1) the growth and chirality change mechanism for a series of higher chiral angle caps/tubes; (2) the nature of interaction between metal clusters and growing carbon structures in chirality selective growth for the higher chiral angle SWCNTs. The simulation works in this thesis imply potential opportunities exist in achieving the chirality selective growth of SWCNTs by: (1) controlling the ratios of single C atoms and C2 dimers at different growth stages; (2) engineering charge transfer, which could be achieved by proper design of catalytic clusters with defined composition and morphology.