Study of dispersion of carbon nanotubes by Triton X-100 surfactant using molecular dynamics simulation

Abstract

In this study, the dispersion mechanism of aggregated carbon nanotubes (CNTs) using Triton X-100 surfactant under various concentrations is investigated with and without water molecules via molecular dynamics simulation. The obtained results showed that because of interaction between water molecules and hydrophilic segments of surfactant, water molecules play a significant role in the manner of adsorption of the surfactant on the CNT surface. In the presence of water molecules, the surfactant molecules are not able to wrap the CNTs, and they are located in the neighborhood of the CNTs. The results suggested that the creation of space between two CNTs in the absence of the surfactant is performed slowly, while, in the presence of the surfactant molecules, the creation of space between two CNTs which leads to the dispersion of the CNTs is remarkably rapid. The surfactant molecules cause to introduce more numbers of water molecules in the vicinity of and between the CNTs, and with the increasing radial distances between two CNTs, the number of water molecules is rapidly increased. The interfacial angle between two CNTs, surfactant gyration radius, and diagrams of radial distribution function between water molecules, the CNTs, and the surfactant molecules were calculated for a better description of dispersion mechanism of the CNTs by the surfactant and water molecules.