Self-assembly in drying complex fluid at low capillary number

We study the pattern formation induced by drying colloidal suspensions and polymer solutions in a vertical Hele-Shaw cell immersed in a reservoir. The contact line speed is controlled by pumping out the solution from the reservoir. At low capillary number stick–slip motion of the receding contact line can be observed for silica suspensions. Periodic strips spontaneously form during drying. We study the strip periodicity and deposit morphology as a function of the receding velocity and pH of the solution. In the same conditions, dried polymer films are almost flat.