The Hydrodynamic Stability of Thin Films

This chapter examines the hydrodynamic stability of fluid films whose characteristic thicknesses are of the order of 10-100 nanometer. The stability of such ultrathin films is an important question in many diverse areas of science and technology. It provides a description of the continuum formulation of the long range intermolecular forces and elastic interactions in an ultrathin film. The chapter reviews the mathematical framework of the theory of linear thin film stability. It describes how van der Waals forces can destabilize a thin film, and how film elasticity can act to stabilize this instability. The chapter studies the stabilizing influence of overlapping double layers of charge, and the destabilization which occurs when an electric field is applied across a dielectric film. It deals with a section on Marangoni instabilities induced by surface chemical reactions in a thin film.