A Review on Carbon Nanotubes (CNT): Structure, Synthesis, Purification and Properties for Modern day Applications

Abstract

Carbon nanotubes (CNTs), composed of graphene/graphite sheets, have been used since the 1990s and become one of the most important materials owing to its massive applications in energy, environmental and life sciences. In general, there are two types of known CNTs such as single-walled CNTs (SWCNTs) and multi-walled CNTs (MWCNTs). They have broader and novel fields of application in the fabric and textile industries, wastewater treatment, energy storage, and also as structural reinforcement materials. CNTs are reported to synthesize by arc discharge, laser ablation and chemical vapor deposition (CVD) methods where CVD technique is found to be the most versatile and largely used method. In all the methods synthesized CNTs contain various degrees of impurities which are purified by oxidation treatment, ultra-sonication, magnetic purification, etc. CNTs have wide range of industrial applications due to their remarkable mechanical, thermal, electrical, chemical and biological properties. In this review, medical and biomedical applications of CNTs and CNTs-based composites are specially focused due to their significant applications in these fields along with their structure, classification, preparation and related properties. Besides, CNTs’ toxicity and biosafety, especially on the human body, are also discussed in this review article.

Atomic and Electronic Structure of Metal–Salen Complexes [M(Salen)], Their Polymers and Composites Based on Them with Carbon Nanostructures: Review of X-ray Spectroscopy Studies

“…CNTs can be obtained by using the following different methods: arc discharge, laser ablation, chemical vapor deposition (CVD), plasma-enhanced CVD, liquid pyrolysis, solid-state pyrolysis, flame pyrolysis, bottom-up organic approach, etc. [80,82,83]. Graphene is a 2D allotrope of carbon, first discovered by Geim and Novoselov in 2004 [84].…”