The electrical volume conductivity sigma of antimony-doped tin oxide (ATO)-acrylate nanocomposite hybrid coatings was investigated. The relation between U and the volume filler fraction p was analyzed for the ATO-acrylate coatings containing ATO nanoparticles grafted with different amounts of 3-methacryloxy-propyl-trimethoxy-silane coupling agent. Percolation thresholds were observed at very low filler fractions (1-2 vol %) for the coatings containing ATO nanoparticles with a low amount of surface grafting. A modified effective medium approximation (EMA) model was introduced. This model takes into consideration different distances between adjacent semiconductive particles in the particle network. The model elucidates how self-arrangement of the particles influences the location of the percolation threshold in the log sigma - p plot. The modified EAU model can successfully explain the multiple transition behavior and the variable percolation thresholds found for the ATO-acrylate nanocomposite hybrid coatings. (c) 2007 Wiley Periodicals, Inc.