In this work silica nanoparticles were incorporated in a polymeric matrix (fibers) aiming at the production of new composite materials that can be useful for the development of nanomaterials and/or microanalysis systems. Polyethyleneoxide and Ludox TM-50 were used as phases for electrospinning. Due to the high amount of effective charge present in the solutions, a new setup for electrospinning was devised by adding another electrode to a conventional deposition system. The presence of this electrode was investigated numerically using electrostatic application mode of the COMSOL Multiphysics 3.2b package. The simple model developed to explain the nanoparticle behavior for the used electrospinning setup showed good agreement with the experimental results and can be useful for simulations in the production of similar composites. Fibers with a high amount of particles were obtained using this third electrode biasing the flow in a preferred direction. Infrared spectra, EDX and SEM microscopy analysis show nanoparticle incorporation in the fibers. (c) 2007 Elsevier Ltd. All rights reserved.