Thinning and break up of freestanding polymer solutions

The stability and break-up of thin liquid polymer films is a fascinating subject and reflects a complex interplay between intermolecular forces, hydrodyanic and viscoleastic phenomena, osmotic pressure and the effects of confinement. We have studied the thinning dynamics of concentrated polymer-solutions liquid films experimentally using a modified thin film balance technique. The variation of the capillary pressure that is driving the thinning of the film allows us to control the ratio of the the competing timescales of drainage and rupture. It is shown that rupture occurs through the random evolution of thickness fluctuations, whereas the drainaige dyanmcis are described well by continuum approaches, even down to lenght scales on the order of the radius of gysration of the films. Using time dependent positive, negative and oscillatory pressure jumps accros the interface, a wide range of dynamical phenomena can be evidenced. The implications of these results on macroscopic stability of multiphase systems and modelling events such as coalescence will be discussed.