Conductive ATO‐acrylate nanocomposite hybrid coatings: Experimental results and modeling

The electrical volume conductivity σ of antimony‐doped tin oxide (ATO)–acrylate nanocomposite hybrid coatings was investigated. The relation between σ 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 σ − p plot. The modified EMA model can successfully explain the multiple transition behavior and the variable percolation thresholds found for the ATO‐acrylate nanocomposite hybrid coatings.