Amphiphilic Comb Polymers as New Additives in Bicontinuous Microemulsions.

It has been shown that the thermodynamics of bicontinuous microemulsions can be tailored via the addition of various different amphiphilic polymers. In this manuscript, we now focus on comb-type polymers consisting of hydrophobic backbones and hydrophilic side chains. The distinct philicity of the backbone and side chains leads to a well-defined segregation into the oil and water domains respectively, as confirmed by contrast variation small-angle neutron scattering experiments.

Anchoring vs bridging: new findings on polymer additives in bicontinuous microemulsions.

We show for the first time the effect of telechelic polymers as additives in bicontinuous microemulsions. We combined macroscopic observations of the phase behavior with microscopic measurements of the structure by small-angle neutron scattering (SANS) to recover the two elastic moduli, κ and κ̅, namely the bending rigidity and saddle-splay modulus. On the basis of these results, we could classify the effect of telechelic polymers along with confinement, expressed as the ratio of the polymer end-to-end distance Ree and the oil-water domain size d.

Cluster formation in polyelectrolyte-micelle complex coacervation.

The temperature-induced liquid-liquid phase transition (complex coacervation) of a polycation-anionic/nonionic mixed micelle system was examined over a range of macroion concentrations and polycation molecular weights (MW) using turbidimetry and dynamic light scattering (DLS). DLS revealed a progressive increase in complex/aggregate size with temperature up to the phase transition at T(φ), followed by splitting of these clusters into respectively smaller and larger particles. We present two explanations: (1) large (200-400 nm) clusters (soluble aggregates) are necessary and sufficient coacervation precursors, and (2) the process of coacervation itself is accompanied by the expulsion of smaller aggregates to form submicrometer droplets.