Mechanism of permeation of gas through Newton black films at different temperatures

Abstract

The permeability coefficients K for permeation of air through Newton black foam films (bilayer films) from sodium dodecyl sulfate plus sodium chloride aqueous solutions have been measured. The dependencies of the permeability coefficienta on surfactant concentration C at temperatures 23,25,27, and 30 O C have been obtained. The K values strongly depend on C at low concentrations, but they remain constant at higher C. The permeability increases with increasing temperature. The experimental data have been discussed on the basis of the nucleation theory of fluctuational formation of holes in amphiphile bilayers. The results are in favor of an essential contribution of hole-mediated permeability at low surfactant concentrations and higher temperatures.

A simulation study of the kinetics of passage of CO2 and N2 through the liquid/vapor interface of water

“…The permeation rates of thin soap films have been thoroughly investigated; see, for example, the review by Exerowa et al 15 It was established that the permeability is dependent on temperature, the type of electrolyte, type of surfactant, and their concentrations. [16][17][18][19][20][21] The thinnest soap films, known as Newton black films, consist of two surfactant monolayers absorbed onto each other. Somewhat thicker thin soap films, for which the monolayers are separated by a water layer, are known as common black films.…”

Foam Films Obtained with Ionic Liquid

“…Finally, it should be stressed that conventional foam films have been studied mainly from the viewpoint of physicochemical properties under controlled humidity. [1][2][3][4][8][9][10][11][12] In sharp contrast, we provide herein a novel materials processing system based on the transfer of free-standing liquid films, in which a centimeter-scale film is converted into submillimeter films with nanometer thickness. Such processing will be useful for the fabrication of nanoseparation membranes and organic optical devices.…”

“…Thus, Newton black films are much thinner than common black films. [8][9][10][11][12] Even though black films were discovered more than 300 years ago, [13,14] they have been studied mainly in aqueous systems. [15] Herein, we report the unprecedented properties of foam films obtained with an ionic liquid.…”

Effect of Foam Films on Gas Diffusion

“…It is of importance to note that at very dilute acid concentrations (pH > 6), a small percentage ammonia also reacts incompletely with water to make some OH − according to Eq. [13]. This reaction implies that small amounts of ammonia trapped in the solution will not be detected by the measurement of the pH change.…”

“…These two conceptual models have been expanded by Princen and Mason (10,11) to interpret experimental results on surfactant-stabilized film permeability, where a parallel-plane model was first used to describe the two monolayers constituting the film. Nedyalkov et al (12)(13)(14), and Platikanov et al (15) recently employed the nucleation theory to account for the overlapping adsorption phenomenon (bilayer structure) of the two monolayers. Despite some limitations mentioned later, this theory contributes appreciably to a better understanding of bilayer-structured film.…”