Size-controlled nanometer zinc oxide were successfully prepared by a water-in-oil(w/o) microemulsion process by flowing gaseous ammonia(NH3) into microemulsion zones of zinc nitrate solution.The w/o microemulsion was formed by Triton X-100 / n-octanol / cyclohexane / zinc nitrate solution.The obtained nanometer zinc oxide was characterized by thermogravimetric-differential thermal analysis(TG-DTA),Fourier transform infrared spectroscopy(FT-IR),X-ray powder diffraction(XRD),and transmission electron microscopy(TEM).The size of nanometer zinc oxide was correlative with bake temperature,the ratio of n(H2O) / n(TX100) and zinc ion concentration.The results showed that the nanometer zinc oxide having average size of about 20 ～ 40 nm was obtained by vacuum drying at 110 ℃ for 4 h and baking at 300 ℃ of the nanometer zinc oxide precursor synthesized using(w/o) microemulsion process with zinc ion concentration of 1.5 mol/L and the ratio of n(H2O) / n(TX100) being 8 at 25 ℃.
