Three-Dimensional Percolation Properties Simulation of a Marine Coating Based on Its Real Structure Obtained from Ptychographic X-Ray Tomography

B. Chen[1], M. Guizar-Sicairos[2], G. Xiong[1], L. Shemilt[1], A. Diaz[2], J. Nutter[1], N. Burdet[1], S. Huo[1], F. Vergeer[3], A. Burgess[4], I. Robinson[1]
[1]London Centre for Nanotechnology, University College London, London, UK
[2]Paul Scherrer Institute, Villigen, Switzerland
[3]AkzoNobel Co. Ltd., Sassenheim, Netherlands
[4]AkzoNobel (UK) Co. Ltd., Tyne and Wear, UK
Published in 2014

We present quantitative nano-scale analysis of the 3D spatial structure of an anticorrosive aluminium epoxy barrier marine coating obtained by ptychographic X-ray computed tomography (PXCT) [1-3]. We then use COMSOL Multiphysics® software to perform simulations on the acquired real 3D structure to demonstrate how percolation through this actual 3D structure impedes ion diffusion in the materials. We found the aluminium flakes causing the perpendicular diffusion resistance of the coating to be over twice of the pure epoxy’s [1]. The work demonstrated an approach for validating mechanistic assumptions of materials and potentially provides a practical method to engineer the efficacy of anti-corrosion coatings by modelling electrochemical process in the materials based on the actual 3D structures of the materials themselves [1].