Solubilization of gelatin by water–AOT–iso-octane reverse micelles studied by dynamic laser light scattering

The water cores of reverse micelles of water–AOT–iso-octane were characterized through dynamic laser light scattering and viscometry measurements performed at room temperature T=25°C. The water to iso-octane ratio Wo was chosen between 30 and 50, and AOT concentration was varied from 100 to 500 mM. Gelatin molecules of hydrodynamic radius, Rh=14.5 nm (for a 0.5% (w/v) solution) were hosted inside these water cores. Three regimes were explored: water core radius, Rw less than Rh, equal to Rh and greater than Rh. Measurements revealed that when Rw⩽Rh, there was substantial rearrangement of the AOT molecules enabling volume expansion of the water core to accommodate the guest gelatin molecules. Viscometry studies showed nonspheroidal conformations for these micelles. Results are discussed in the light of short-range and perturbation type of intermicellar potentials.