The transport properties of select volatile organic compounds were measured in polyurethane/clay nanocomposite barrier membranes as a function of clay content. The nanocomposites were fabricated by two different processing methods involving stirring and sonication of the clay particles. The concentration of Cloisite (R) 30B in the nanocomposite was varied from 0 to 50 wt%. Characterization of membrane transport properties was achieved via a gravimetric sorption method. Material-phase diffusivity coefficients (D) decreased with increasing Cloisite (R) concentration, while changes in the material/VOC partition coefficients (K) depended on the molecular interactions of the VOCs with the membrane material. (C) 2009 Elsevier Ltd. All rights reserved.