A review on carbon nanotube: An overview of synthesis, properties, functionalization, characterization, and the application

A foremost and inimitable invention in the part of nanotechnology is carbon nanotubes (CNT). Crystal structures are nearly analogous to the nuclear atomic arrangement of graphite and diamond. While graphite belongs to sp2 – bonded carbon whereas diamond is owned by sp3– hybridized carbon. The evolution of CNTs began in 1991. CNTs contain some important traits such as lightweight, small in size, good strength, and high conductivity. CNT make useful in various materials like polymers, ceramics, and metallic surfaces. From an application perspective of CNTs, it can use in the nanotechnology field, nanomedicine, transistor, vacuum electronic devices, biosensors, membranes, and capacitors. Various types of synthesis techniques for CNTs are the arc-discharge method, laser ablation method; chemical vapor deposition method, vapor-phase growth, flame synthesis method, and plasma-assisted growth of CNTs. CNTs have inimitable kind of properties like mechanical, electrical, and optical. These properties can even be measured on single nanotubes. For commercial application, large quantities of purified nanotubes are needed. This present review covers the types, synthesis, characterization method, properties, applications, and toxic effect. The purification and sorting process of CNTs for applications are also presented in a summarized form.