Gas-phase modifications of carbon nanostructures

Low dispersibility in aqueous medium caused by van der Waals forces results in the agglomeration and bundle formation during the processing and storage of most of the carbon nanostructures. Modifying the surface of carbon nanostructures is necessary to ensure their dispersion and compatibility with other materials. Chemisorption or physisorption processes can be utilized to achieve modifications of carbon nanostructures. This chapter discusses the utility and relevance of gaseous phase modifications of carbon nanostructures in the context of various industrial and scientific applications of these materials. Gas-phase modification on carbonaceous nanostructures includes the treatment with various reactive gases (oxygen, nitrogen, etc.) under controlled conditions. These methods differ from liquid phase modification, which makes use of reactants and reactions in the liquid phase. Basic aspects and current status of the developments in the existing approaches for the gas-phase modification of carbon nanostructures, such as chemical vapor deposition, doping, plasma treatment, functionalization, gas-phase polymerization, modification using metal nanoparticles and nanocomposites, vapor phase bromination, surface itching, and oxidation, etc., are explained and discussed in this chapter.