Ti/Zr复合纳滤膜的制备及其性能

通过聚合溶胶路线制备出稳定的Ti/Zr(摩尔比=1:1)复合溶胶。采用浸浆法,在平均孔径为5~6 nm的片状--Al2O3/--Al2O3载体上制备出完整无缺陷的Ti/Zr复合纳滤膜。详细考察了焙烧温度对Ti/Zr粉体的影响,并考察了Ti/Zr复合纳滤膜的性能。结果表明:在较高烧成温度下(500℃),Ti/Zr粉体依然呈无定形态且保持微孔结构。在400℃烧成温度下制备出孔径为1.49 nm的Ti/Zr复合纳滤膜,该膜的截留分子量(MWCO)为880,纯水通量为4.3 L·m-2·h-1·MPa-1。在p H=6,压力0.8 MPa的条件下,该膜对0.005 mol·L-1的Mg Cl2、Ca Cl2的截留率分别为85%和78%。

Fabrication and properties of Ti/Zr composite nanofiltration membrane

A stable Ti/Zr composite polymeric sol with Ti:Zr molar ratio of 1:1 was synthesized through the polymeric sol route. Disk a-Al₂O₃ supported mesoporous g-Al₂O₃ membrane with an average pore size of 5-6 nm was used as support for nanofiltration membranes deposition. A defect-free Ti/Zr composite nanofiltration membrane superimposed on the support was fabricated via the dip-coating method followed by drying and calcination. The influence of calcination temperature on Ti/Zr powders was studied. The properties of Ti/Zr composite nanofiltration membrane were also investigated. Ti/Zr powders maintained amorphous state and microporous structure up to a calcination temperature of 500℃. The MWCO, mean pore size and pure water flux of Ti/Zr composite nanofiltration membrane calcined at 400℃ were 880, 1.49 nm and 4.3 L·m^-2·h^-1·MPa^-1, respectively. Under the condition of pH=6 and transmembrane pressure 0.8 MPa, the retention properties of Ti/Zr composite membrane towards 0.005 mol·L^-1 MgCl₂ and CaCl₂ solutions were 85% and 78%, respectively.