Investigation of the Effect of the Tortuous Pore Structure on Water Diffusion through a Polymer Film Using Lattice Boltzmann Simulations
Journal article, 2015

Understanding how the pore structure influences the mass transport through a porous material is important in several applications, not the least in the design of polymer film coatings intended to control drug release. In this study, a polymer film made of ethyl cellulose and hydroxypropyl cellulose was investigated. The 3D structure of the films was first experimentally characterized using confocal laser scanning microscopy data and then mathematically reconstructed for the whole film thickness. Lattice Boltzmann simulations were performed to compute the effective diffusion coefficient of water in the film and the results were compared to experimental data. The local porosities and pore sizes were also analyzed to determine how the properties of the internal film structure affect the water effective diffusion coefficient. The results show that the top part of the film has lower porosity, lower pore size, and lower connectivity, which results in a much lower effective diffusion coefficient in this part, largely determining the diffusion rate through the entire film. Furthermore, the local effective diffusion coefficients were not proportional to the local film porosity, indicating that the results cannot be explained by a single tortuosity factor. In summary, the proposed methodology of combining microscopy data, mass transport simulations, and pore space analysis can give valuable insights on how the film structure affects the mass transport through the film.

Lattice Boltzmann method

transport through a porous material

Author

Tobias Gebäck

University of Gothenburg

SuMo Biomaterials

Chalmers, Mathematical Sciences, Mathematics

M. Marucci

SuMo Biomaterials

AstraZeneca AB

Catherine Boissier

AstraZeneca AB

Johan Arnehed

AstraZeneca AB

Alexey Geynts

University of Gothenburg

Chalmers, Mathematical Sciences, Mathematics

Journal of Physical Chemistry B

1520-6106 (ISSN) 1520-5207 (eISSN)

Vol. 119 16 5220-5227

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Materials Science

Subject Categories

Physical Chemistry

Computational Mathematics

Biomaterials Science

DOI

10.1021/acs.jpcb.5b01953

More information

Latest update

11/22/2018