On the efficiency of UV-vis spectroscopy in assessing the dispersion quality in sonicated aqueous suspensions of carbon nanotubes

The present study evaluates carbon nanotube (CNT) dispersion quality in sonicated aqueous suspensions assisted by two types of dispersive agents, an ionic surfactant commonly used in nanocomposite development and a plasticizer-type dispersant relevant to cementitious matter. Dispersion quality is assessed by UV-vis spectroscopy and related to experimental parameters such as sonication duration/energy, dispersant type and concentration, and CNT loading. The results obtained from the versatile and straightforward methodology are compared to those obtained by the more complex and analytical Liquid Mode Laser Diffractometry (LMLD). The efficiency of UV-vis spectroscopy in effectively following the sonication process and in capturing its different stages is investigated and conclusions concerning the relation between surfactant concentration and sonication duration for achievement of monodisperse suspensions are drawn. The efficiency of the two assistive agents with regard to dispersion quality is compared and discussed in the text. (C) 2016 Elsevier B.V. All rights reserved.