Flake-polymer composites are commonly used in protection and barrier applications due to its low effective diffusivity. Effective diffusivity through flake-polymer composites depends on the local accelerated transport along the flakematrix interphase. This paper describes analytical models for predicting the effective diffusivity through the flake-polymer composite as a function of flake orientation, volume fraction, aspect ratio, and interphase properties. Estimates of effective diffusivity were also generated using random walk simulations. Results from the two methods agree well with each other. Using model-predicted effective diffusivities, solute penetration depths in systems with flakes aligned either orthogonal or parallel to the diffusion direction are calculated and compared to experimentally obtained penetration depths of acid solutes through glass flake-polymer composites.
2012 by The Society of Materials Science, Japan