,
Emulsification of Partially Miscible Liquids Using Colloidal Particles: Nonspherical and Extended Domain Structures
Langmuir, 23 (11): 5984-5994 (2007)
Аннотация
Abstract: We present microscopy studies of particle-stabilized emulsions
with unconventional morphologies. The emulsions comprise pairs of
partially miscible fluids and are stabilized by colloids. Alcohol-oil
mixtures are employed; silica colloids are chemically modified so
that they have partial wettability. We create our morphologies by
two distinct routes: starting with a conventional colloid-stabilized
emulsion or starting in the single-fluid phase with the colloids
dispersed. In the first case temperature cycling leads to the creation
of extended fluid domains built around some of the initial fluid
droplets. In the second case quenching into the demixed region leads
to the formation of domains which reflect the demixing kinetics.
The structures are stable due to a jammed, semisolid, multilayer
of colloids on the liquid-liquid interface. The differing morphologies
reflect the roles in formation of the arrested state of heterogeneous
and homogeneous nucleation and spinodal decomposition. The latter
results in metastable, bicontinuous emulsions with frozen interfaces,
at least for the thin-slab samples, investigated here.
