ZrO_2纳米晶涂层修饰改性的陶瓷微滤膜性能

Study on the Properties of the Ceramic Microfiltration Membrane Modified Via Nano-Crystalline ZrO_2 Coat

对α-Al2O3陶瓷膜进行四方相的ZrO2纳米涂层修饰。陶瓷膜分别经5,8.5,12nm3种不同尺寸的四方相ZrO2纳米晶涂层修饰改性后,ZrO2纳米晶的尺寸越小,Zeta电位的绝对值也就越大,等压下的水通量也就越大。经修饰改性后的陶瓷微滤膜在平均孔径相对于支撑体缩小约10倍后,在相同压差下其水通量明显大于支撑体的水通量。过膜后水的渗透压呈略微上升的趋势及电导率产生突跃性的增加。在陶瓷膜表面羟基的亲水性和荷电特征等因素的作用下,过膜后较大的水分子团簇(结构)断裂为较小的团簇。

The α-Al2O3 ceramic microfiltration membranes were modified via the nano-sized tetragonal ZrO2 coats with crystal size of 5nm, 8.5 nm and 12 nm. The absolute value of zeta potential and the water-flux at a fixed pressure increases with the decreasing of the size of the nano-crystalline ZrO2 The average pore size reduced to one-tenth of the pore size of the supporter after modifying, and then the water-flux became obviously greater under the same pressure. After filtration, water osmotic pressure increased slightly and water conductivity showed an abrupt increase. The water clusters with the larged structures were separated into the water clusters with smalled structure under the effect of the hydrophilicity and charged characteristics for the surface hydroxyl group on the membrane.