Dispersion of single-walled carbon nanotubes by intense turbulent shear in micro-channels

Dispersion of carbon nanotubes (CNTs) in solvents is a prerequisite for arriving at their expected performances in applications. Our objective is twofold. We first assess an intense turbulent shear (ITS) method in a micro-channel system, with a shear rate of 3 × 106 s−1, in preparing single-walled CNT (SWCNT) dispersions in aqueous solution of sodium dodecyl benzene sulfonate, and compare it with sonication. We conclude that the ITS method is much more effective than sonication, with respect to preparation time, exfoliation of the SWCNT bundles, and the obtained SWCNT concentration in the dispersion, thus proposed in practical applications. Then, a method based on the depolarized dynamic light scattering, combined with the wide-angle (static) light scattering, has been proposed to characterize the average length and diameter of the dispersed SWCNTs. Its reliability in the estimated values of the average length and diameter of the SWCNTs has been assessed and caution has been given in its applications.