Ultrafine zirconia powders via microemulsion processing route

Nanosized zirconia powders have been prepared via inverse microemulsion processing routes, in which cyclohexane was used as the oil phase, mixed poly (oxyethylene)₅ nonyl phenol ether(NP5) and poly (oxyethylene)₉ nonyl phenol ether (NP9) as the non-ionic surfactant, and an aqueous solution containing zirconium oxynitrate solution as the water phase. The precipitation reaction between zirconium oxynitrate and oxalic acid to form zirconium oxalate was made to take place in the nanosized microemulsion domains. Subsequent calcination of the oxalate precursors at 600°C led to the formation of ultrafine zirconia powders. Two synthesis routes, namely, a single-microemulsion processing route and a double-microemulsion processing route, were studied and compared.