Self assembly of positively charged carbon nanotubes with oppositely charged metallic surface

Surface modification of implants (or scaffolds) with CNTs is one of the most effective methods to create important surface properties such as electrical conductivity, new nanotopography, and favorable wettability, leading to effective control of the initial response of cells. A simple strategy to coat carbon nanotubes (CNTs) on the negatively charged and curved surface with a complex nanotopography of metal oxides and metallic substrates that are usually used as implants and scaffolds for medical purposes was developed. Positively modified CNTs (CNT-Cl) were used to ionically attach to the oppositely charged surface of the substrates. Model substrates such as TiO2 and SiO2 powders, Ti disc, and Ti-implants, which were curved, nano-structured and porous figures, were dipped into positively modified CNT solution (CNT-Cl/THF) and dried to create a uniform CNT-Cl coating layer. The uniformity of the CNT-Cl layer was confirmed by SEM images, and the physicochemical properties of the new surface were analyzed by XPS and contact angle measurement.