Real-time monitoring of carbon nanotube dispersion using dynamic light scattering and UV-vis spectroscopy

A process for continuously monitoring the ultrasonic dispersion process of carbon nanotubes (CNTs) was discovered by integrating dynamic light scattering (DLS) and UV-vis spectroscopy. Through a continuous flow approach adapted to the dispersion system, the CNT suspension could be quantitatively characterized in real time. By continuously monitoring and identifying the evolution of mean particle size distribution and transparency of CNT suspension, the effective dispersion parameters and dispersion quality was quantified. Two types of MWNTs of different diameters and lengths were studied. For longer MWNTs with smaller diameters, the dispersion process achieved at a steady 100 nm of agglomerate size with 40 min of sonication. For shorter and large diameter and less entangled MWNTs, after 60 min of sonication, an agglomerate size of 100 nm was achieved, yet the stability decrease. The results show the potential ability of the system to optimize nanoparticle dispersion process for in-line dispersion quality control.