THE RECEDENCE OF THICK AQUEOUS FILMS IN THE DEWETTING OF SOLID-SURFACES

The recedence of relatively thick aqueous films from flat solid surfaces was investigated experimentally for two different substrates: paraffin wax and polished Pyrex glass. The wettability of Pyrex was controlled by the addition of dodecylammonium acetate. Using the conservation of energy principle, a model was developed to analyzed steady state recedence velocity in terms of the surface free energy change, kinetic energy of the receding liquid, friction loss, kinetic energy loss and gravitational potential energy of the system. A numerical solution of the model was utilized and compared with the experimental data. The model indicates an insensitivity to viscous disspation and corroborates not only the thermodynamic theory for film recedence, but also the general conceptions of other workers on film movement.