Measurement of a two-step glass transition induced by repulsive and attractive forces between ellipsoidal particles in quasi-two-dimensional colloidal solutions
Chandan K. Mishra, Amritha Rangarajan, and Rajesh Ganapathy
Accepted
We study experimentally the glass transition dynamics in quasi-2 dimensional suspensions of colloidal ellipsoids, aspect ratio a = 2.1, with repulsive as well as attractive interactions. For the purely repulsive case, we find that the orientational and translational glass transitions occur at the same area fraction. Strikingly, for intermediate depletion attraction strengths, we find that the orientational glass transition precedes the translational one. By quantifying structure and dynamics, we show that quasi-long range ordering is promoted at these attraction strengths which subsequently results in a two-step glass transition. Most interestingly, within experimental certainty, we observe reentrant glass dynamics only in the translational degrees of freedom.