以铝为支撑体的一种新型阳极氧化铝膜的制备与表征

阳极氧化铝膜在分离方面有许多优点如均一的孔径、高的热力学稳定性、独特的孔结构等,作为无机膜有较好的商业应用价值,但膜的脆性问题一直是公认的难题.用一次阳极氧化铝膜的铝面做阳极在盐酸中电解后,再在磷酸中扩孔,制得了两面贯通以大孔铝为支撑体的阳极氧化铝膜.研究了扩孔时间对膜的纯水通量、平均孔径、截留率的影响.结果表明,膜的平均孔径为65.5~119.2 nm;膜的孔径分布窄,孔隙率为28.6%~32.7%;随着扩孔时间的增加,膜的平均孔径、纯水通量均增大,而膜对聚乙二醇20 000的截留率减小;当扩孔时间为30min时,对聚乙二醇20 000截留率达到了26.5%;膜的纯水通量随着时间的增加而减小;膜的脆性问题在一定程度上得以改善.

Preparation and characterization of a new type of anodic alumina membrane supported by aluminum

Anodic alumina membrane enjoys a number of advantages such as uniform diameter,high thermal stability,its unique structure for separation,and it has better commercially applied value as an inorganic membrane.But it is a recognized problem to solve the brittleness of membrane.Aluminum of anodic alumina membrane by first oxidation was electrolyzed in hydrochloric acid as anode.After the membrane had been immersed in phosphoric acid,anodic alumina membrane supported by aluminum with big holes was prepared.The effects of broadening diameter of pore time on pure water flux,mean pore diameter,rejection were investigated.The results show that the mean pore diameter is from 65.5 nm to 119.2 nm.Pore diameter distribution of membrane is narrow;porosity is from 28.6% to 32.7%.Mean pore diameter of membrane and pure water flux increase with the increase of broadening diameter of pore time,while rejection of membrane for PEG 20 000 decreases.When broadening diameter of pore time is 30 minutes,the rejection of membrane is 26.5%.Pure water flux of membrane decreases as time increases.Brittleness of membrane is improved in a certain extent.