Dynamic light scattering characterization of hard–soft gel phase transition in micellar crystal and comparison with rheological data

Abstract

Abstract We report the dynamic light scattering study of polymer dynamics in the broad vicinity of the hard-soft gel phase transition in micellar crystal. Inside the region of micellar crystal phase with increasing temperature the ratio of the magnitudes of two dynamic modes (slow and fast) monotonously decreases below 54 °C in the hard gel. Above 54 °C in the soft gel it is almost independent of temperature, remaining at a minimum. The method provides phenomenon details inaccessible with conventional rheological method, where simple detection of sharp phase transition is available. We show that the diffusion dynamic mode, which is common for a liquid phase, is also present in a micellar crystal despite the obvious difference in the rheological properties of micellar liquid and micellar crystal. This study demonstrates the advantages of the dynamic light scattering method at micro-scale level.