Effect of stabilizer on synthesis of indium tin oxide nanoparticles

Indium tin oxide nanoparticles with shapes varying from sphere to cubic were synthesized by controlling the ratio of the concentrations of the protective polymer (PVP) to indium tin oxide precursor in their preparation by co-precipitation. Transmission electron microscopy was used to determine the size and shape. The XPS spectra of the particles revealed that the atomic ratios of In:Sn and (In + Sn):O are 10.0:1.0 and 1.0:1.5, respectively for both of the spheres and the cubes. X-ray diffraction study showed that these particles have the same crystalline structure. Thus, it is shown that the formation of the various shapes of the ITO particles could be achieved by using different ratios of protective polymer instead of varying the protective polymer or the sintering process.

There are two mechanisms in the stabilizing system with polymer, one of which is depletion stabilization. When the concentration of the polymer adsorbed on the nanoparticles’ surface is higher than that in the solution, stabilization is dominant. Conversely, when the concentration of the polymer adsorbed on the nanoparticles’ surface is lower than that in the solution, depletion flocculation is dominant, which resulted in the increase of the particle diameter. The co-existence of cubic and spherical particles obtained in a higher PVP concentration of 200% might be because of the competition to each other.Figure optionsDownload as PowerPoint slide