Abstract: Using zinc nitrate and urea as raw materials,modificative zinc oxide nano-coating on the surface of α-alumina microfitration membrane was prepared by a co-precipitation process.The influences of reactant concentration,reaction temperature and reaction time on the microstructure of zinc oxide nano-coating were studied systemically.Results show that the grain size of zinc oxide nanoparticles is about 5 nm and zinc oxide nano-coating is dense and has homogeneous surface when zinc nitrate concentration is 0.3 mol/L,urea concentration is 0.6 mol/L,reaction temperature is 95 ℃ and reaction time is 4 h.The filtration efficiency of α-alumina microfiltration membrane modified by zinc oxide nano-coating is improved significantly and the maximum increment of the water flux reaches 45.6;.

Key words: Using zinc nitrate and urea as raw materials,modificative zinc oxide nano-coating on the surface of α-alumina microfitration membrane was prepared by a co-precipitation process.The influences of reactant concentration,reaction temperature and reaction time on the microstructure of zinc oxide nano-coating were studied systemically.Results show that the grain size of zinc oxide nanoparticles is about 5 nm and zinc oxide nano-coating is dense and has homogeneous surface when zinc nitrate concentration is 0.3 mol/L,urea concentration is 0.6 mol/L,reaction temperature is 95 ℃ and reaction time is 4 h.The filtration efficiency of α-alumina microfiltration membrane modified by zinc oxide nano-coating is improved significantly and the maximum increment of the water flux reaches 45.6;.