Sonication-assisted dispersion of carbon nanotubes in aqueous solutions of the anionic surfactant SDBS: The role of sonication energy

Abstract

Sonication is a powerful technique to promote the dispersion of carbon nanotubes (CNTs) and enhance their solubility; this is necessary for CNT applications, especially in the biochemical and biomedical fields. In this study, batch experiments were conducted to evaluate the role of sonication energy on the dispersion of CNTs in the presence of a widely used anionic surfactant, sodium dodecylbenzene sulfonate (SDBS). It was observed that the concentration of dispersed CNTs in the SDBS solution depended on the sonication energy, but not the sonication time or output power of the sonicator alone. The amount of dispersed CNTs was positively correlated with the concentrations of SDBS and CNTs, and the length of the CNTs. The promotion of oxygen-containing functional groups on the dispersed CNTs was observed at relatively low sonication energies. The optimal energy, i.e. the minimum energy supplied by sonication to achieve a saturated suspension of dispersed CNTs in the SDBS solution, was CNT diameter-dependent, because of the larger vdW forces between tubes of smaller diameter. An exponential decay curve was constructed for the optimal energy values as a function of the outer CNT diameter, to assist in determining the energy needed to disperse CNTs. carbon nanotubes, sonication energy, dispersion, surfactant Citation:Yang K, Yi Z L, Jing Q F, et al. Sonication-assisted dispersion of carbon nanotubes in aqueous solutions of the anionic surfactant SDBS: The role of sonication energy.

Effect of natural and synthetic surface coatings on the toxicity of multiwalled carbon nanotubes toward green algae

“…As a consequence, the hydrodynamic size of MWCNTs decreased from 389 ± 22 nm to a level ranging from 302 nm to 332 nm when DOMs were added. Similar DOM-MWCNT interactions, i.e., DOM adsorption and MWCNT dispersion, have been reported [14,31,33,39,40].…”

“…1B), higher OD values (Fig. 1C), and lower OD 1 values (Table S4) and could be attributed to the increased electrosteric repulsions among the DOM-coated MWCNTs [16,33,39,40]. The higher dispersity and stability of opaque MWCNTs in the presence of surfactants could increase the shading effect on the algal growth and thus increase the toxicity of MWCNTs.…”

Multi-walled carbon nanotube dispersion by the adsorbed humic acids with different chemical structures

“…It has been reported that CNTs with smaller outer diameters (Zhou et al, 2012) or shorter in length (Schwyzer et al, 2011) are more easily suspended by DOM; however, the preference of largediameter MWCNTs in stable suspension was also reported (Schwyzer et al, 2012;Yang et al, 2013). With regard to DOM, it has been reported that 1) hydrophilic (polar) DOMs suspended CNTs more effectively (Chappell et al, 2009;Lin et al, 2013), 2) both hydrophilic and hydrophobic fractions of DOM play important roles in suspending CNTs (Hyung et al, 2007).…”

Dispersion and aggregation of single-walled carbon nanotubes in aqueous solutions of anionic surfactants

“…Similar phenomena were observed by Bouchard et al (2012) for the CCC values of Na + for re-aggregation of suspended MWCNTs and the SDS concentration in the suspension. Yang et al (2013) also observed that the aggregate dimensions of stably suspended SWCNTs were not changed with the added SWCNT dose and SDBS concentrations, although a higher concentration of SWCNTs dispersed in the SDBS solution was observed when more SWCNTs or SDBS was added. Therefore, SWCNT dose and SDBS concentration cannot alter the CCC values of stably suspended SWCNTs because they cannot alter their aggregate dimensions.…”