Optically transparent conductive network formation induced by solvent evaporation from tin-oxide-nanoparticle suspensions

This investigation describes an optically transparent antistatic film composed of antimony-doped tin oxide (ATO) nanoparticles dispersed in a polymer matrix, with remarkably improved electrical and optical properties. The film is fabricated on the basis of a synergistic interaction between self-assembling nanoparticles and self-organizing matrix materials. The antistatic property of the film is obtained at ATO concentrations above a threshold value. A scaling analysis of the data yields an extremely low critical concentration (0.0020 volume fraction), which is considerably lower than the value predicted by percolation theory. Microscopic observations of the film have revealed a characteristic microstructure: "single-stranded" chainlike (linear form or fibrous) aggregates consisting of ATO nanoparticles and large ATO-depleted areas. The experiment results suggest that the high optical transparency and the low critical concentration are derived from the characteristic microstructures of the film.