Multi-scale model of gas transport through soap-film membranes used for Artificial Photosynthesis*

This activity is part of the recently funded SoFiA project aiming at a new concept of soap-film photosynthetic membrane for carbon dioxide conversion into fuel [1].
Here, we specifically focus on gas transport through those membranes realized in the form of functionalized soap-films. Diffusion phenomena in the water core and surfactant monolayers are described by Fick’s law [2, 3]. Molecular dynamics is used to compute the surfactant distribution and orientation in the membrane monolayers assuming hexaethylene glycol monododecyl ether (C12E6). The obtained atomistic details are then incorporated in a continuum model describing transport phenomena at a larger scale. Numerical predictions are validated against experimental data from literature and used to estimate the characteristic time for fuel-oxygen mixing when separated by photosynthetic soap film membranes.

[1] http://sofiaproject.eu/
[2] Farajzadeh, R., R. Krastev, and Pacelli LJ Zitha. "Foam film permeability: Theory and experiment." Advances in colloid and interface science 137.1 (2008): 27-44.
[3] Princen, H. M., and S. G. Mason. "The permeability of soap films to gases." Journal of Colloid Science 20.4 (1965): 353-375.