In-situ evaluation of particle size distribution of ZrO2-nanoparticles obtained by sol–gel

In this study the in-situ synthesis of zirconia via sol–gel was investigated in order to relate the influence of the processing parameters on particle size distribution. Zirconium n-propoxide was used as the precursor, n-propanol as solvent and several parameters were investigated, such as pH, reaction medium, synthesis time and temperature. The particle sizes and the polydispersion of colloidal dispersions were determined in situ using dynamic light scattering. In acetic medium, the particle size remained mostly below 100 nm. With the introduction of NaCl, the maximum particle size reached 71 nm. For other reaction media (HNO3 and without acid or base), the largest particle size was in the order of micrometers. The comparison of the different synthesis routes investigated did not enable us to observe one trend related to increased particle size when compared to reaction times in the synthesis of zirconia. This work aims to show how the reaction medium influence in obtaining a colloidal dispersion with nanometric sizes obtained from the sol–gel process.