Critical thickness of thin liquid films: Theory and experiment

Bounding film drainage in common thin films

“…Coons et al [6] compared the thinning velocities predicted by the theoretical MTsR equation to the experimental measurements of Radoev et al [8] and determined that the predicted velocities were consistently higher than the experimental measurements. By plotting the velocity ratio [i.e., ( )…”

“…It has previously been shown that thin films generally exhibit faster thinning velocities than that predicted by the Reynolds equation [8,14]. The discrepancy has been attributed to a number of factors including finite tangential mobility [15,16], changes to the van der Waals interactions and Hamaker constant [17], the non-parallel nature of the flexible interfaces [8,18,19], and dynamic surface waves [20].…”

“…The discrepancy has been attributed to a number of factors including finite tangential mobility [15,16], changes to the van der Waals interactions and Hamaker constant [17], the non-parallel nature of the flexible interfaces [8,18,19], and dynamic surface waves [20]. Attempts have been made to limit the experimental data used in this study to film systems with tangentially immobile interfaces and with known physicochemical properties.…”

“…Radoev et al [8] observed that ε is independent of film thickness and a strong function of film radius. Sharma and Ruckenstein [21] provide a simple equation to estimate ε based on the film radius, but this is only applicable for the film systems studied by Radoev et al Tsekov [19] derived a film thickness dependent expression for ε , but did not identify a non-arbitrary reference thickness to determine the exact form of the dependency.…”

“…Interference patterns of monochromatic light reflecting and transmitting through the thin film allow precise measurement of the film thickness. By surrounding the film with a gas or immiscible liquid, both foam [8][9][10] and emulsion films [9,11] can be studied. In this paper, the thinning velocities and drainage times of thin films predicted from various drainage models are compared to experimental measurements reported in the literature.…”