Filling of Carbon Nanotubes: Containers for Magnetic Probes and Drug Delivery

Nanotechnology is a broad scientific field but one of the most explored materials in nanotechnology is carbon nanotube (CNT). A large proportion of research on CNTs is focused on their huge potential for biomedical applications. Within this context, the synthesis of carbon nanotubes filled with magnetic materials has been widely investigated, especially with iron due to its excellent ferromagnetic characteristics. Pure iron-filled carbon nanotubes (Fe-CNT) can be prepared following diverse routes. Here, an overview of the different preparation routes of Fe-CNT, using the chemical vapour deposition (CVD) synthesis method will be presented. Several working parameters were varied and investigated, the most significant being the pressure of the system, the iron and the carbon sources. The consequence of these modifications is reflected in the structure of the final material, which varies in respect of the amount of iron encapsulated in the cavity, tube diameter and the number of graphitic walls forming the CNT. The filling of hollow CNT through wet chemistry reactions (as a post-synthesis route) and CVD process (filling during the synthesis of CNTs) will also be addressed in this chapter.