3D high spatial resolution visualisation and quantification of interconnectivity in polymer films
Journal article, 2020

A porous network acts as transport paths for drugs through films for controlled drug release. The interconnectivity of the network strongly influences the transport properties. It is therefore important to quantify the interconnectivity and correlate it to transport properties for control and design of new films. This work presents a novel method for 3D visualisation and analysis of interconnectivity. High spatial resolution 3D data on porous polymer films for controlled drug release has been acquired using a focused ion beam (FIB) combined with a scanning electron microscope (SEM). The data analysis method enables visualisation of pore paths starting at a chosen inlet pore, dividing them into groups by length, enabling a more detailed quantification and visualisation. The method also enables identification of central features of the porous network by quantification of channels where pore paths coincide. The method was applied to FIB-SEM data of three leached ethyl cellulose (EC)/hydroxypropyl cellulose (HPC) films with different weight percentages. The results from the analysis were consistent with the experimentally measured release properties of the films. The interconnectivity and porosity increase with increasing amount of HPC. The bottleneck effect was strong in the leached film with lowest porosity.

Geodesic paths


Scanning electron microscopy

Geodesic channels

Focused ion beam







Cecilia Fager

Chalmers, Physics, Nano and Biophysics

Sandra Eriksson Barman

Chalmers, Mathematical Sciences, Applied Mathematics and Statistics

Magnus Röding

RISE Research Institutes of Sweden

Anna Olsson

AstraZeneca AB

Niklas Lorén

RISE Research Institutes of Sweden

Chalmers, Physics, Nano and Biophysics

Christian von Corswant

AstraZeneca AB

David Bolin

King Abdullah University of Science and Technology (KAUST)

Holger Rootzen

Chalmers, Mathematical Sciences, Applied Mathematics and Statistics

Eva Olsson

Chalmers, Physics, Nano and Biophysics

International Journal of Pharmaceutics

0378-5173 (ISSN) 1873-3476 (eISSN)

Vol. 587 119622

Subject Categories

Polymer Chemistry

Polymer Technologies

Other Physics Topics

Areas of Advance

Nanoscience and Nanotechnology

Materials Science


Chalmers Materials Analysis Laboratory





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4/5/2022 1