An analytical model for gas diffusion through fractal nanofibers in complex resources

© 2016 Elsevier B.V.Gas diffusion in porous nanofibers is of great interest in complex resources. In this work, a fractal analytical model is derived, to quantify gas diffusion across fibrous porous media composed of nanofibers in complex resources. The proposed model is expressed in terms of the porosity, the pore area fractal dimension, the tortuosity fractal dimensions, and the geometrical structures of porous nanofibers. It is found that the diffusion coefficient increases with the increase of pore area and porosity. However, it is shown that the diffusion coefficient increases with the decrease of the tortuosity fractal dimension in complex resources. Using the classical fractal theory, the analytical model of diffusion coefficient with clear physical importance reveals the important physical principles for gas diffusion through porous nanofibers in complex resources and is recommended. The normalized gas diffusivity predicted from the present model agrees well with the existing experimental data. The validity of the proposed analytical model can be thus verified. The present analytical model has revealed the important physical mechanisms for gas diffusion through porous nanofibers in complex resources.