Electromagnetic interferences (EMI)-shielding, anticorrosion, antistatic, trace detector for radiation particles remain open subjects for nanocomposites to find appropriate solutions. In many practical aspects needs an appropriate combination between EMI-properties with high mechanical strength and thermal stability. In this respect, we report a new method to design nanocomposites films based on spin-coating in thereto-centrifugal field. The films are made of polyacrylonitrile (PAN) matrix with polyaniline (PAni) nanoparticles aligned in micron wires with a given periodicity dependent on spinning parameters. The films have a texture similar with diffraction grating, anisotropy in electrical conduction over percolation threshold determined by chain orientation. Structural, morphological and optical characterizations show a high degree of orientation of the macromolecular chains which follow the same anisotropy as in electrical conductivity. Loss tangent in the frequency range from 1 kHz to 0.2 GHz shows a strong attenuation. (c) 2005 Elsevier B.V. All rights reserved.