A Transient Network Structure in Sucrose Stearate/Water Systems

The rheological properties of an industrial-grade sucrose stearate aqueous solution were studied. This solution at 1 to 8 wt % appeared translucent or turbid from 20 to 48 ℃; however, it became transparent above 48 ℃ and its viscosity increased. Furthermore, the apparent viscosity of the sample solution increased with temperature, and showed peak value at 48 ℃ for all such samples. On the other hand, small angle laser-light scattering studies revealed that the molecular-assembly size of the surfactant abruptly decreased at the same temperature. The dynamic modulus of the sample at approximately 48 ℃ was successfully analyzed with a bimodal Maxwell model, which showed that sucrose stearate formed several types of molecular assemblies and the shape was dependent on temperature. In particular, the rheological properties at approximately 48 ℃ strongly suggest that the surfactant formed thread-like molecular assemblies