Molecular dynamics simulations of aggregation behavior of sodium dodecyl sulfate on SiO₂ and CaCO₃ surfaces

Abstract

Molecular dynamics simulations were carried out to investigate the aggregation behavior of anionic surfactant sodium dodecyl sulfate (SDS) on the surfaces of SiO 2 and CaCO 3 . The results indicate that SDS molecules formed a spherical micelle structure near the SiO 2 surface; moreover, there were more head groups near the SiO 2 surface. However, they could form a self-assemble film on the CaCO 3 surface. The self-assemble film of SDS on the CaCO 3 surface was more stable than that on the SiO 2 surface. Our simulation results have a certain significance to understand the aggregation behavior of SDS on different surfaces on molecular level.

Hyperbranched polyglycerols derivatives as cetyltrimethylammonium bromide nanocarriers on enhanced oil recovery processes

“…The interaction between surfactants may be affected by the medium. Wang et al, 35 for example, through MD simulations, found that the electrostatic repulsion between the SDS headgroups and the SiO 2 surface induces the formation of spherical micelles, while the electrostatic attraction between the SDS headgroups and the CaCO 3 surface makes the SDS molecules absorb, inducing the formation of a self‐assembled film. Li et al, 36 using dissipative particle dynamics (DPD), analyzed the ability of the SDS and non‐ionic surfactants to form dodecane droplets in water as a function of the headgroup concentration.…”

Surface Decoration of Cetyltrimethyl Ammonium Bromide on SiC Particles and Its Effects on the Co-Deposition Process

“…The morphologies of these aggregations depend on complex conditions, including the concentration of surfactants, the concentration and the surface charge condition of the particles, pH conditions, and so forth . As it is difficult to observe the dynamic adsorption process directly from experimental approaches, molecular dynamics (MD) simulation provides a reasonable alternative to study the decorating process of surfactants . Researchers had studied the surfactant adsorption process using MD simulations. − For example, Jiménez-Ángeles et al established all-atomic (AA) MD models to study the adsorption and aggregation of cetyltrimethyl ammonium bromide (CTAB) on the SiO 2 substrate surface.…”

Molecular Dynamics Simulations of Aqueous Nonionic Surfactants on a Carbonate Surface

“…A similar study was also done to investigate adsorption structures of anionic surfactants on silica. 40 The unfavorable electrostatic interactions led to spherical micellar aggregates in the case of silica, whereas a selfassembled film of surfactants was observed on the oppositely charged calcite surface. Anionic and nonionic surfactant aggregates have been observed on silica and MD simulations, which reveal that surface hydroxylation to be the critical factor determining adsorption mechanism.…”

“…The adsorption of ionic surfactants on mineral surfaces has been studied using atomistic and coarse-grained MD simulations. − The competitive adsorption of water and organic surfactants on scheelite (a calcium tungstate mineral with the chemical formula CaWO 4 ) was studied using atomistic simulations, and it was found that the strongest adsorption happened when the molecules formed multiple interactions with the substrate . The surface-bulk partition of anionic surfactants was predicted using works employing coarse-grained MD simulations .…”

“…Zwitterionic surfactants displayed a composite behavior with charge-driven adsorption and hydrophobic interaction-driven aggregation. A similar study was also done to investigate adsorption structures of anionic surfactants on silica . The unfavorable electrostatic interactions led to spherical micellar aggregates in the case of silica, whereas a self-assembled film of surfactants was observed on the oppositely charged calcite surface.…”