Synthesis of Amino-functionalized Carbon Nanotubes and their Applications

Carbon nanotubes (CNTs) because of one-dimensional structure and high surface area as well as their exceptional properties such as excellent mechanical, thermal, electrical and optical properties, are considered as one of the most popular carbon-based nanomaterials in the field of research. These nanoscale tubes have a wide range of applications, including their use in materials science, energy management, electronics, chemical processing, and many other fields. In the present work, the most commonly used methods for amino-functionalization of CNTs have been reviewed. These CNT functionalization methods are generally divided into two groups, covalent and non-covalent modifications which ultimately leads to the formation of the amino (-NH2) functional groups on the CNT surfaces. The amino functional groups because of their excellent chemical properties, such as high electron donating effect and good nucleophilicity, can act as a convenient linker between the CNTs and nanoparticles, ions or the matrix epoxy etc. and thus enables numerous potential applications for amino-functionalized CNTs (NH2-CNTs). Therefore, the applications of NH2-CNT in several fields such as, absorbent for metal ions, the support for preparation of the electrocatalysts, fabrication of (bio) sensors, preparation of NH2-CNT/epoxy nanocomposites, and as vectors for gene therapy, have also been reviewed.