Observation of a re-entrant kinetic glass transition in a micellar system with temperature-dependent attractive interaction.

We detect in a tri-block co-polymer micellar system an ergodic-to-nonergodic-to-ergodic transition, as a function of temperature, in a range of concentrations, by photon correlation measurements. The shear viscosity is also shown to jump two order of magnitude at these transition temperatures. Surprisingly, the structure factor as measured by small angle neutron scattering shows a marked narrowing at the structural arrest state. Rationalization of these results with the existence of an attractive branch in the phase diagram of an attractive colloid system predicted by mode coupling theory is made.