Sedimentation and growth of Carbon Nanotube in supersaturated catalyst (based on PhD in Nano-Microelectronics) PhD in Education
Researcher and author: DR. Afshin Rashid
Note: When the carbon atom in the catalyst reaches supersaturation, precipitation and growth of carbon nanotubes begin. If the interaction of the catalyst with the substrate is weak (the metal has an acute contact angle with the substrate), the nanotube at the bottom of the catalyst (tipgrowth) and if the catalyst interacts with the substrate is strong, the metal has an open contact angle with the substrate.
The nanotube grows on top of the catalyst (growth base). In the first case, it is possible to produce nanotubes with an open end. Physical form of deposited carbon Single-walled, multi-walled, amorphous, and graphite-layered carbon nanotubes covering catalyst nanoparticles depend on many factors, such as catalytic particle size and deposition rate. When the deposition rate is equal to or less than the carbon penetration rate, Graphite layer forms around catalytic nanoparticles, when the deposition rate is higher than the rate of carbon penetration, carbon nanotubes are formed.The size of catalytic nanoparticles plays an important role in the growth of nanotubes (usually small size catalytic nanoparticles) Less than 01 nm (are active for nucleation and growth of carbon nanotubes. If the particle size is one nanometer, a single-walled nanotube is formed. Catalytic nanoparticles with a size of 01 Up to 51 nm leads to the growth of multi-walled nanotubes. Catalytic nanoparticles larger than 51 nm are also coated with amorphous graphite sheets . And the construction of chips and nanotransistors shows the effect of the crystal structure of the catalyst on the shape and structure of carbon nanotubes.
Various definitions of changes in the structure of materials for the production of nanoscience electronic chips and electrons have been proposed. Nanoelectronics is the study of phenomena and the manipulation of materials at scales in atomic, molecular and macromolecular dimensions that lead to drastic changes (properties of nanomaterials) compared to large-scale materials. In nanoscience and nanoelectronics, the structure of material computation, fracture toughness or fracture toughness, is a property that describes the resistance of fissured objects to failure . This parameter is important for all solids design applications and is denoted by KIc. Fracture toughness is a computational method for brittle failure when present in crack material. If the fracture toughness of a material is low, that material will break brittle, and the higher the fracture toughness, the higher the chance of soft failure.
Conclusion :
When the carbon atom in the catalyst reaches supersaturation, precipitation and growth of carbon nanotubes begin. If the interaction of the catalyst with the substrate is weak (the metal has an acute contact angle with the substrate), the nanotube at the bottom of the catalyst (tipgrowth) and if the catalyst interacts with the substrate is strong, the metal has an open contact angle with the substrate.
Author: Dr. ( Afshin Rashid)