Permanent Flow-Induced Phase Transitions in Wormlike Surfactant Micelle Solutions

It is well known that certain wormlike micelle solutions form flow-induced structures under shear flow. This structure transition is typically accompanied by an enhancement in the shear viscosity and the emergence of a new gel phase. However, such transitions are generally believed to be reversible, i.e., upon flow stoppage, the structure relaxes to equilibrium. In this work, we show that by subjecting translucent wormlike micelle solutions to high flow deformation over a rapid time scale, permanent flow-induced structures can be formed. We will discuss the phenomenology and plausible physical mechanisms underlying this discovery.