A novel process has been developed to produce defect-free polyaniline-based composite membranes. These membranes consist of a thin polyaniline film (0.8-10.5 mu m) and polyvinylidene difluoride (PVDF) as support material. The composite structure enhances flexibility and ease of handling of the material. This is demonstrated through tensile testing of the membranes. The polyaniline composite membranes were subjected to gas permeability studies. Despite being prepared with a thickness of less than 1 mu m the dense supported polyaniline maintained its previously reported intrinsic selectivity for different gases. The novel fabrication process has the potential of producing nano scale membranes with much enhanced permeation rates. (c) 2005 Elsevier B.V. All rights reserved.