An investigation into repeptization of zirconyl oxalate xerogels

Stable and clear zirconyl oxalate sols were prepared by repeptization of zirconyl oxalate xerogels, which could be a low-cost precursor of homogeneous yttria-stabilized zirconia nanomaterials. It was found that appropriate amount of hydrochloric acid in xerogels and high degree of supersaturation in repeptization resulted in excellent stability of sol and fine colloid particles. Three different processes of repeptization were compared: stilly aging, ultrasonic stirring and mechanical stirring, wherein the mechanical stirring was conducted above the xerogels. Both ultrasonic stirring and mechanical stirring could effectively limit the growth of particles, and resulted in fine particle with diameters of in the range 8–10 nm.