Critical thickness of rupture of chlorbenzene and aniline films

Abstract

The critical thickness of rupture of circular microscopic foam films with diameter from 3 × 10^–3 to 2.57 × 10^–2 cm of chlorbenzene (+ 2 × 10^–4 g/cm³ aerosol MA) and aniline (+ 10^–3 g/cm³ lauric alcohol) was measured. The isotherms of the disjoining pressure/foam thickness for both solutions^9,10 permit a comparison to be made of the experimental critical thickness data with the predictions of the theory. ^2,3. Good agreement was found for the influence of the surface tension on the critical thickness and for the independence of the critical thickness on the viscosity. However, the absolute values of the critical thickness are lower than (though close to) those, predicted by the theory. It seems that they do not tend to zero when the film radius decreases, as might be expected theoretically. An attempt was made to determinary the smallest critical thickness, which was found to be about 100–150 Å. A preliminary investigation was made about the most probable distribution of the critical thickness data.