Carbon Nanotubes

Since their discovery in 1991, carbon nanotubes have been considered as one of the most promising materials for a wide range of applications, in virtue of their outstanding properties. During the last two decades, both single-walled and multi-walled CNTs probably represented the hottest research topic concerning materials science, equally from a fundamental and from an applicative point of view. There is a prevailing opinion among the research community that CNTs are now ready for application in everyday world. This book provides an (obviously not exhaustive) overview on some of the amazing possible applications of CNT-based materials in the near future

Humidity Sensing Behavior of Endohedral Li-Doped and Undoped SWCNT/SDBS Composite Films

We have investigated single-walled carbon nanotube (SWCNT) networks wrapped with the cationic surfactant sodium dodecyl-benzenesulfonate (SBDS) as promising candidates for water detection. This is the first time that the humidity behavior of endohedral Li-doped (Li@) and undoped SWCNTs/SDBS has been shown. We identified a strong and almost monotonic decrease in resistance as humidity increased from 11 to 97%. Sensitivities varied between −3 and 65% in the entire humidity range. Electrical characterization, Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM) analysis revealed that a combination of the electron donor behavior of the water molecules with Poole-Frenkel conduction accounted for the resistive humidity response in the Li@SWCNT/SDBS and undoped SWCNT/SDBS networks. We found that Li@SWCNTs boosted the semiconducting character in mixtures of metallic/semiconducting SWCNT beams. Moreover, electrical characterization of the sensor suggested that endohedral Li doping produced SWCNT beams with high concentration of semiconducting tubes. We also investigated how frequency influenced film humidity sensing behavior and how this behavior of SWCNT/SDBS films depended on temperature from 20 to 80 ° C. The present results will certainly aid design and optimization of SWCNT films with different dopants for humidity or gas sensing in general