Selected topics on the synthesis, properties and applications of multiwalled carbon nanotubes
Carbon nanotubes (CNTs) have an astounding array of properties that make them interesting candidates for numerous applications. The geometric and chemical variations found in CNTs provide a rich area of study for both science and applications  and . These variations are created by the unique bonding configurations of carbon that make it a ubiquitous part of our environment. The one dimensional nature of the basic CNT structure enabling ultra-high surface area, the ability to act as a semiconductor or a metal, the existence of multiple direct bandgaps, the relative ease of attachment for numerous chemical functional groups and ability to decorate CNTs with nanoparticles, all drive an array of scientific and technology issues that have been studied by research groups across the globe in recent years  and . A variant of the standard nanotube can be found by integrating the CNT structure with another unique and valuable property of carbon; its anisotropy. The well-known difference between the basal plane and z-direction properties of graphite for example translates directly into anisotropy between the longitudinal and transverse properties of carbon nanotubes. This large anisotropy in structure and properties is the basis of research exploiting edge vs. basal plane properties of graphite and graphene and increases the variety of properties and applications for CNT systems . In particular, graphene edges are expected to be more reactive, hold a higher charge density and concentrate electric fields as in the case of nanowalls or nanosheets  and .