Polymer-modified w/o microemulsions - with tunable droplet-droplet interactions

Water soluble polymers can be incorporated into reverse microemulsion droplets without leaving the isotropic phase region. When the polymer is attached to the surfactant film the bending elasticity is changed, and droplet-droplet interactions are influenced. Different methods are available for studying the droplet-droplet interactions in more detail, e.g. SANS, SAXS and DLS. Conductometric measurements are very useful for detecting exchange processes between the droplets. In presence of polyampholytes a pH dependent tuning of the membrane properties becomes possible, experimentally detectable by conductometry.

Conductometric measurements show the direct influence of the location of the polyampholyte (PaIH) on droplet-droplet interactions. If the PaIH is fixed at the surfactant film (pH 4) droplet-droplet interactions are weakened and the conductivity is decreased. At pH 9, PaIH in the more compact conformation is formed inside The droplets and the conductivity increases.Figure optionsDownload high-quality image (65 K)Download as PowerPoint slideHighlights
► change of the bending elasticity of the surfactant film with regard to droplet-droplet interactions in reverse microemulsions
► shift of the percolation boundary determined by conductometry
► polymer-surfactant interactions influencing the film stability
► pH dependent film tuning in polyampholyte-modified microemulsions