Investigation of sodium dodecyl benzene sulfonate assisted dispersion and debundling of single-wall carbon nanotubes

The dispersion limit of HiPco single-wall carbon nanotubes (SWCNT) in 1% by weight sodium dodecyl benzene sulfonate (SDBS) assisted dispersions in water is reported. The starting concentration of the tubes in water surfactant solution was 5 mg/mL which was diluted sequentially by a factor of 2 down to 1.2 x 10(-3) mg/mL. Sonication and centrifugation were performed to obtain a homogeneous dispersion of HiPco SWCNTs in water surfactant solution. Concentration-dependent absorption and Raman spectroscopic studies were used to analyze the SWCNTs behavior in water-based solution, and atomic force microscopy (AFM) was employed to examine the aggregation state of the nanotubes over the concentration range. Both spectroscopic techniques demonstrate a clear concentration below which the nanotube bundles become significantly dispersed in the solution. The concentration limit at which debundling starts was found to be 0.07 +/- 0.03 mg/mL. The dispersion behavior and optical parameters determined are compared with those established for other solvent media.