In this work polystyrene (PS) nanofibers are electrospun from recycled expanded polystyrene (EPS). These fibers are mixed with micro glass fibers to modify the glass fiber filter media. The filter media are tested in the separation of water droplets from an emulsion of water droplets in oil. Water-in-oil emulsion separations are important to the petrochemical industries for product quality, safety, ecologic and economic reasons. The experimental results in this work show that polystyrene nanofibers with diameters of around 600 nm were produced by the electrospinning method. The addition of the nanofibers to conventional micron sized fibrous filter media improves the separation efficiency of the filter media from 68 to 88%. (c) 2005 Elsevier B.V. All rights reserved.