FABRICACIÓN Y PURIFICACIÓN DE NANOTUBOS DE CARBONO PARA EL DESARROLLO Y CARACTERIZACIÓN DE CONDUCTORES ELÉCTRICOS TRANSPARENTES

Abstract

This work presents the fabrication of multiwall carbon nanotubes (MWCNTs), its purification and the development of transparent electrical conductors (CETS) using these nanotubes, to achieve these objectives, the work proposed a complete methodology. The most appropriate method to produce the nanotubes was the Chemical Vapor Deposition method, because the nanotubes obtained by this method showed excellent values of length, a parameter that is critical to the development of transparent electrical conductors. Because the materials used had some impurities and these impurities would decrease the electrical and optical performance of the CETs, the nanotubes was purified for 3 different techniques to eliminate or reduce percent of impurities. The three methods used for purification of the MWCNTs were selective oxidation in air and HCl treatment, selective oxidation by H2O2 and HCl treatment, and treatment of the mixture of H2O2 and HCl. The better result of these three methods was obtained with the treatment of the mixture of H2O2 and HCl. With this method we obtained MWCNTs with purities up to 94%. The MWCNTs were dispersed in solutions of different solvents without using surfactant and these inks were deposited on substrates of glass by combining two of the most widely used techniques, a combination that has never before been done. This combination included the spraying of the suspension of MWCNTs on glass substrates that were spinning at high rpm. This method succeeded in generating uniform deposits with very thin layers of nanotubes. In order to prevent the material is detached from the substrate; nail polish was added to the solution to ensure adhesion of the thin film in the glass. The transparent electrical conductors were characterized in transparency and surface resistivity to evaluate them with respect to the results reported in the literatura. The values showed that manufactured CETs had a good transparency, about 60%, with a surface resistivity of 5.8 kΩ/.