Influence of anionic surfactants on the stability of multi-walled carbon nanotubes-based nanofluid

Abstract

This study aims to assess the influence of anionic surfactants such as sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS) on the stability of nanofluids of multi-walled carbon nanotube (MWCNT). The influence of different surfactant concentrations on the stability of the nanofluids was also evaluated. The nanofluids were prepared by dispersing MWCNT in deionized water with SDS and SDBS as dispersant at different MWCNT/surfactant ratio, which includes 1:2, 1:1 and 2:1. The stability of the nanofluids was evaluated using zeta potential analysis and ultra-violet visible spectroscopy. The results indicated that SDS and SDBS sufficiently improve the stability of MWCNT in the suspension. Nevertheless, SDBS was found to perform much better than SDS. The optimal MWCNT/surfactant ratio for SDS and SDBS was reported to be 1:1 and 2:1, respectively. This study further confirms that the zeta potential result is consistent with that of the ultra-violet visible spectroscopy.