Materials, Methods and Characterizations

Abstract

Carbon nanotube behaves like one-dimensional quantum wire that can be either metallic or semiconducting, depending on their chirality and diameter. The structure, quality and quantity of CNTs are dependent on the method of production—which controls the degree of graphitization, the helicity and the diameter. Due to their unusual properties, a wide variety of scientific and technological research has been focused on the use of CNTs, in terms of their potential applications as well as their large scale synthesis. For the production of carbon nanotubes, there exist several techniques. Most of the methods, the growth conditions for preparing CNTs need expensive experimental equipments and laborious synthesis procedures. Therefore, quest is still on to obtain suitable various carbon nanomaterials by a low cost simple technique to meet the demand of its applications in science and technology. On this regard, a new method to synthesize various carbon nanostructures is an achievement. This technique is ever simplest, low cost and easy to operate for the production of different carbon nanostructures. Using this technique, entangled, aligned, iron filled, helical carbon nanotubes, and carbon nanoribbons could be prepared on large scale. Preparation of graphene by a simple ntechnique is presented. The prepared materials have been characterized by SEM,XRD,TEM,Raman. Controllable resistance of multi-walled carbon nanotube bundles for the possible application in nanoscale electronics is discussed. The resistance as well as the variation of resistance with temperature depends on the bundle diameter. The larger the diameter smaller is the resistance and weaker is the variation of resistance with temperature that makes the bundles advantageous in nanoscale electronics and in some other applications. As the resistance and the variation can be controlled by monitoring the bundle diameter, the temperature dependency of resistance can be employed in temperature thermometry. Electrical anisotropy transport properties of aligned carbon nanotubes mat is discussed. Electron field emission of semi-aligned carbon nanofibers grown on cylindrical surface, which provides better emission current due to its self focusing with higher enhancement value, is also discussed.