CARBON NANOTUBES: A REVIEW ON PREPARATION TECHNIQUES AND APPLICATIONS IN VARIOUS FIELDS

Carbon nanotubes (CNTs) are allotropes of carbon with a nanostructure that can have a length-to-diameter ratio greater than 1,000,000. Different types of carbon nanotubes can be produced by different methods: Arc discharge, laser ablation, chemical vapour deposition and flame synthesis. Purification of the tubes can be divided into a couple of main techniques: oxidation, acid treatment, annealing, sonication, filtering and functionalisation techniques. Economically feasible large-scale production and purification techniques still have to be developed. Fundamental and practical nanotube researches have shown possible applications in the fields of energy storage, molecular electronics, nanomechanic devices, composite materials and immobilization of enzymes. Various immobilization methods have been developed, and in particular, specific attachment of enzymes on carbon nanotubes has been an important focus of attention. With the growing attention paid to cascade enzymatic reaction, it is possible that multi enzyme co-immobilization would be one of the next goals in the future. In this paper, we focus on preparation techniques, various applications of CNTs and enzyme immobilization on carbon nanotubes.