Permeability of polymer/clay nanocomposites: A review

This is a review of the existing studies on the permeability of gas molecules in nanocomposite materials that consist of inorganic platelet-shaped fillers in polymeric matrices. We describe the dominant mechanisms for the transport of small molecules in polymers and polymer nanocomposites, as well as the procedures for the measurement of the permeability and the diffusivity. The emphasis is given on the various models that have been proposed for the prediction of permeability in polymer-clay nanocomposites. The influence of the characteristics of the inorganic particles on the barrier properties of the composite membrane is discussed and tested using the model and the available experimental data. Some aspects on the methods of improving the barrier properties of the nanocomposite are examined and a few applications of these materials as gas barriers are presented. (C) 2009 Elsevier Ltd. All rights reserved.