| Attributs | Valeurs |
|---|
| type
| |
| Is Part Of
| |
| Subject
| |
| Title
| - Experimental Study of Entrainment and Drainage Flows inMicroscale Soap Films
|
| has manifestation of work
| |
| related by
| |
| Author
| |
| Abstract
| - The thickness of freely suspended surfactant films during vertical withdrawal and drainage is investigatedusing laser reflectivity. The withdrawal process conducted at capillary numbers below 10-3 generatesinitial film thicknesses in the micrometer range; subsequent thinning is predominantly impelled by capillaryand not gravitational forces. Under these conditions, our results show that film thinning above and belowthe critical micelle concentration (cmc) is well approximated by a power law function in time whose exponents,which range from −0.9 to −1.8, are inconsistent with current descriptions of capillary-viscous drainagein inextensible films which predict exponents close to −0.5. Correlations between the experimental fittingparameters illustrate important differences in film behavior across the cmc. In addition, normalizationof the drainage data yields a collapse to a single functional form over 3 decades in time for a wide rangeof initial withdrawal rates. We demonstrate that modification of the interface boundary condition in currentmodels to account for Marangoni stresses through an effective slip parameter yields values of the exponentsand other key parameters in excellent agreement with experiment. This modification also successfullydescribes the withdrawal thickness below the cmc.
|
| article type
| |
| is part of this journal
| |
