Design and testing of a device for the characterization of gas transfer through soap films and measurement protocol based on color matching

Soap films are interesting for their potential utilization as soft, self-assembled, self-healing and possibly recyclable membranes. The intrinsic possibility of tuning their properties, such as e.g. surface and bulk elasticity or permeability, via tailored chemistry makes them flexible enough for a wide range of physical-chemical applications. Here we introduce a novel device that can serve as a research platform for the detailed experimental characterization of the soap film permeability to gases. The design and manufacturing of the novel platform are discussed, along with a sample characterization protocol based on a color-matching procedure for dioxygen diffusion through typical soap films. The experimental data is compared with the results obtained from a numerical model, specifically developed for the problem, and good agreement is found. In perspective, the proposed platform can serve for the precise characterization of gas transfer properties of soap films made from different surfactant mixtures and in the presence of different gases.