The electrospinning technique is used to obtain functionalized polymeric fibers. Blends of polyethyleneoxide (PEO) and poly-3-dodecylthiophene (P3DDT) have been spun from chlorofonn solution. The fibers diameter is approximately 1 mu m and both polymer components occur in the fibers as separated phases. By washing the fibers with acetonitrile the PEO matrix is completely removed. This process is fast and it leaves long and homogeneous fibers of P3DDT. The morphology and structure of the fibers have been studied with microscopy (SEM and fluorescence confocal microscopy), whereas infrared spectroscopy has been used to check the removal of PEO matrix, to understand the conformation of the polythiophene chains and their orientation in the fibers. Measurements with confocal and SEM microscopes show the homogeneity of the washed fibers; from polarized infrared spectroscopy, the polythiophene chains are mostly aligned along the fiber axis. The electrospinning process followed by a suitable washing step makes possible to orient fibers with a high molecular order. (c) 2007 Elsevier B.V. All rights reserved.