  We report on the Rayleigh-Plateau instability in films of giant micelles
solutions coating a vertical fibre. We observe that the dynamics of thin films
coating the fibre could be very different from the Newtonian or standard
Non-Newtonian cases. By varying the concentration of the components of the
solutions and depending on the film thickness, we show for the first time that
the Rayleigh-Plateau instability can be stabilized using surfactant solutions.
Using global rheology and optical visualisations, we show that the development
of shear-induced structures is required to stabilize the micellar film along
the fibre. Assuming that the viscoelastic properties of the shear-induced state
can be described by a simple model, we suggest that, in addition to the
presence of shear-induced structures, the latter must have an elastic modulus
greater than a critical value evaluated from a linear stability analysis.
Finally, our analysis provides a way of estimating the bulk elasticity of the
shear-induced state.
