Influence of thermal fluctuations on draining thin liquid films

Thermal fluctuations have been shown to influence the evolution of planar, non-draining thin liquid films, bringing predicted rupture times closer to experimental values. This work explores how thermal fluctuations, characterized by the dimensionless noise strength, θ, alter rupture times of films subjected to drainage. This drainage is induced by adding a curved part to a planar film, which is characterized by the dimensionless curvature, κ. For strong drainage (κ≥1), we find that the film ruptures due to the formation of a dimple that appears at the same location, irrespective of θ. The resulting mean rupture times are insensitive to thermal noise. By contrast, for weak drainage (κ<<1), the film ruptures at a random location on the flat portion of the film with the rupture time, T_r, insensitive to κ and governed by the noise strength, as T_r ∼(√(2θ))^-4.2,where the exponent 4.2 is nearly 1/ω_max, ω_max , being the growth rate of the dominant wavelength based on linear stability theory. These insights, together with the transition between the drainage-dominated and the noise-dominated regime further improves our understanding on the relevance of thermal fluctuations in determining lifetime of the non-planar draining thin films found in emulsions and foams.