Molecular dynamics simulations of surfactant and nanoparticle self-assembly at liquid-liquid interfaces

Mingxiang Luo, Lenore Dai

Research output: Contribution to journalArticle

55 Citations (Scopus)

Abstract

We have performed molecular dynamics (MD) simulations to investigate selfassembly at water-trichloroethylene (TCE) interfaces with the emphasis on systems containing modified hydrocarbon nanoparticles (1.2 nm in diameter) and sodium dodecyl sulfate (SDS) surfactants. The nanoparticles and surfactants were first distributed randomly in the water phase. The MD simulations have clearly shown the progress of migration and final equilibrium of the SDS molecules at the water-TCE interfaces with the nanoparticles either at or in the vicinity of the interfaces. One unique feature is the 'attachment' of surfactant molecules to the nanoparticle clusters in the water phase followed by the 'detachment' at the water-TCE interfaces. At low concentrations of surfactants, the surfactants and nanoparticles co-equilibrate at the interfaces. However, the surfactants, at high concentrations, competitively dominate the interfaces and deplete nanoparticles away from the interfaces. The interfacial properties, such as interfacial thickness and interfacial tension, are significantly influenced by the presence of the surfactants, but not the nanoparticles. The order of the surfactants at the interfaces increases with increasing surfactant concentration, but is independent of nanoparticle concentration. Finally, the simulation has shown that surfactants can aggregate along the water-TCE interfaces, with and without the presence of nanoparticles.

Original languageEnglish (US)
Article number375109
JournalJournal of Physics Condensed Matter
Volume19
Issue number37
DOIs
StatePublished - Aug 1 2007
Externally publishedYes

Fingerprint

liquid-liquid interfaces
Surface-Active Agents
Self assembly
Molecular dynamics
self assembly
Surface active agents
surfactants
molecular dynamics
Nanoparticles
nanoparticles
Computer simulation
trichloroethylene
Liquids
Trichloroethylene
simulation
Water
water
Sodium dodecyl sulfate
sodium sulfates
Sodium Dodecyl Sulfate

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Molecular dynamics simulations of surfactant and nanoparticle self-assembly at liquid-liquid interfaces. / Luo, Mingxiang; Dai, Lenore.

In: Journal of Physics Condensed Matter, Vol. 19, No. 37, 375109, 01.08.2007.

Research output: Contribution to journalArticle

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