Production
Different types of nanotubes are produced using electric arc and CVD (chemical vapor deposition) techniques. The group currently has several reactors for the production of nanotubes – in Belo Horizonte, Curitiba, Ribeirão Preto and Santa Maria. The current production capacity of nanotubes is of the order of a few grams per day, and the next goal is the development of new reactors capable of producing kilograms of nantoubes per day, in order to meet the national demand. Samples of graphene have started to be produced by the INCT team in 2007, initially using the mechanical exfoliation method of a natural graphite crystal. This realization had the participation of the company Nacional de Grafite Ltda., which is part of the INCT. The graphene samples initially produced were used for the development, on a laboratory scale, of electronic devices and for the characterization of their optical properties.
In order to develop a method for the large-scale production of graphene, the group has dedicated successful efforts to the production of graphene by chemical exfoliation. New graphene production methods have been tested: chemical carbon vapor deposition (CVD) on copper and nickel films and epitaxial growth of graphene from a silicon carbide substrate.
Post-synthesis chemical methods of carbon nanomaterials are implemented with the aim to purify the samples by functionalizing them, that is, to add new chemical structures to the nanotubes, and to dispense these nanomaterials in an aqueous medium.