Functionalization of Carbon Nanotubes: Manufacturing Techniques and Properties of Customized Nanocomponents for Molecular-level Technology

Carbon nanotubes (CNTs) since their discovery have been the focus of research on account of exceptional chemical, mechanical and electrical properties. However, manipulation and processing of CNTs have been limited by their compatibility with other materials. Considerable efforts have therefore been devoted to the surface modification of CNTs to pave the way to many useful applications and to realize the potential applications in successful products, especially composite manufacturing. The chemical modification, dispersion and solubilization of CNTs represent an emerging area in the research on nanotubes-based materials. Several research groups have reported successful and doable functionalization techniques for single-walled (SWCNT) and multi-wall (MWCNT) carbon nanotubes. This paper presents an overview of the functionalization of the carbon nanotubes covering both covalent and non-covalent techniques at tips and walls of SWCNTs and MWCNTs, and summarizes recent patents possessing significant commercial value and large-scale practicality. The principle aim is to review main approaches to chemical functionalization of CNTs and to account for the advances that have been made so far.