Carbon Nanotube Microspheres Produced by Surfactant-Mediated Aggregation

Using the inherent self-organizing nature of nanotubes we have prepared mechanically robust, stable, surfactant mediated carbon nanotube microspheres (CNMs). This work reveals the effects of a series of surfactants with cationic, anionic, and nonionic charges. on the formation of CNMs. This occurs through the spherical entanglement of carboxylic acid-terminated multiwalled carbon nanotubes (CNTs). The morphology, electrochemical and electrical performance, and the surface charge of CNMs were systemically-observed with SEM, focused ion beam (FIB) milling, four point probe, cyclic voltammetry, and zeta-potential analysis. The SEM results revealed that surfactant-wrapped CNMs were densely packed with relatively smooth exterior surfaces possessing large reactive areas. In addition, FIB milling observation provided cross-sectional views of CNMs and demonstrated the similarity to those of the external surface. The surfactants concentration (0.01-1% w/v) influenced the properties of CNMs;:leading to a slight variation in zeta-potential, resistance, and electrochemical properties. The water stabilized CNMs, with a range of diameters and porosities, can offer new approaches to various potential new applications.