Abstract
We present a model for spontaneous emulsification resulting from a transiently
negative interfacial tension between water and oil regions, which may be achieved under conditions of strong adsorption of surfactant molecules to the interface. While our approach builds
on a linear stability analysis, it addresses the essential non-linear coupling of surface growth to
the diffusion flux of surfactants to the interface. We consider a large drop of oil of radius R
embedded in a dilute surfactant solution and predict that undulations develop with a characteristic wavelength I*, which at long times t obeys I* ~w t~/~- This suggests that the size of
the droplets created spontaneously at the interface scales as f(/~, where to is a diffusion length
which is comparable to R under steady state diffusion conditions. We discuss the regimes of
applicability of our results to various experimental systems.
negative interfacial tension between water and oil regions, which may be achieved under conditions of strong adsorption of surfactant molecules to the interface. While our approach builds
on a linear stability analysis, it addresses the essential non-linear coupling of surface growth to
the diffusion flux of surfactants to the interface. We consider a large drop of oil of radius R
embedded in a dilute surfactant solution and predict that undulations develop with a characteristic wavelength I*, which at long times t obeys I* ~w t~/~- This suggests that the size of
the droplets created spontaneously at the interface scales as f(/~, where to is a diffusion length
which is comparable to R under steady state diffusion conditions. We discuss the regimes of
applicability of our results to various experimental systems.
| Original language | English GB |
|---|---|
| Pages (from-to) | 829-849 |
| Journal | Journal de Physique II |
| Volume | 3 |
| Issue number | 6 |
| State | Published - Jun 1993 |