Preparation of ultra-fine dispersions of zinc oxide by simple ball-milling: Optimization of process parameters

•For ZnO, a lower milling time (preferably 6 h) resulted in lower particle size.•Ball-milling followed by sonication resulted to particles with nano-sized dimension.•Lower span was observed for ZnO with 3 wt.% PCA concentration.

Ultra-fine aqueous dispersions of zinc oxide were prepared by a combination of wet ball-milling and ultrasonication in the presence of various concentrations of a process control agent (PCA). The particles in the dispersions were characterized by dynamic light scattering (DLS) and zeta potential measurements. Six hours of ball-milling of the zinc oxide dispersion containing 3 wt.% PCA followed by ultrasonication resulted in the formation of particles having size below 500 nm.

Graphical abstractIn the case of ZnO, a lower milling time (preferably 6 h) resulted in lower particle size whereas higher milling time yielded particle agglomerations. Six-hour ball-milling followed by sonication with 3 wt.% PCA gives more number of particles in the ultra-fine size range with a lower span value of 1.57.Figure optionsDownload full-size imageDownload as PowerPoint slide