PERMEATION OF GAS THROUGH NEWTON BLACK FILMS AT DIFFERENT CHAIN-LENGTH OF THE SURFACTANT

The gas permeability coefficients K (cm/s) of Newton black foam films stabilized by four alkyltrimethylammonium chloride homologues have bee n measured. The experimental results demonstrate well pronounced depen dence: K decreases with increasing surfactant alkyl chain length. The temperature dependence of K has been studied as well. The experimental data are discussed on the basis of the nucleation theory of fluctuati on formation of holes in the foam bilayers, assuming that the gas perm eation occurs both through holes and through hole-free part of the fil m (background permeability). The mechanism of permeation through the h ole-free film is discussed using the theories of monolayer permeabilit y. The results are in favour of the energy-barrier theory.