Effect of interfacial mobility on rupture of thin stagnant films on a solid surface due to random mechanical perturbations.
Previous analysis of Narsimhan [G. Narsimhan, J. Colloid Interface Sci. 287 (2005) 624-633] for the evaluation of rupture of a nondraining thin film on a solid support due to imposed random mechanical perturbations modeled as a Gaussian white noise has been extended for partially mobile gas-liquid interfaces. The average rupture time of film is evaluated by first passage time analysis (as the mean time for the amplitude of perturbation to become equal to film thickness). The interfacial mobility is accounted for through surface viscosity as well as Marangoni effect. The mean rupture time for partially mobile gas-liquid interface, as characterized by two dimensionless groups, dimensionless surface viscosity and Marangoni number, lies between the two extreme limits for fully mobile and immobile films. The critical wavenumber for minimum rupture time is shown to be insensitive to interfacial mobility. However, the critical dimensionless surface viscosity and critical Marangoni number at which the behavior of thin film deviates from that of fully mobile film and the behavior approaches that of fully immobile film are smaller for higher Hamaker constants, smaller film thickness and smaller surface potentials.
Narsimhan
Ganesan
G
Biochemical and Food Process Engineering, Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907, USA. narsimha@ecn.purdue.edu
Wang
Zebin
Z
D000465:Algorithms; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D008567:Membranes, Artificial; D008956:Models, Chemical; D044367:Phase Transition; D013314:Stress, Mechanical; D013499:Surface Properties
D008567:Membranes, Artificial