Rupture of newtonian black foam films by α- Particle irradiation: Hole mechanism

Abstract

The stability of Newtonian black (NB) foam films with respect to rupture by α-particle irradiation is studied in order to establish how it is influenced by the concentration C of surfactant in the solution. An expression for the dependence of the irradiation-affected film mean lifetime on C is derived on the basis of the nucleation theory for formation of microscopic holes in the films by clustering of vacancies of surfactant molecules. The t (C) -dependence is determined experimentally for NB foam films obtained from aqueous solutions of sodium dodecyl sulfate and irradiated by α particles at a constant rate. A good agreement between theory and experiment is found and a value of 2 × 10 −8 mJ m −1 for the specific edge free energy of the holes in these films is calculated. It is concluded that the passage of one α-particle through a hole is responsible for the rupture of NB foam films by α-particle irradiation and that both the irradiation-stimulated and the irradiation-free rupture of the films are describable from a unified point of view by the fluctuation theory of nucleation.