水相溶胶路线制备钇掺杂ZrO2纳滤膜及其分离性能研究

以氧氯化锆为前驱体, 采用环境友好的水相溶胶路线制备出完整无缺陷的管式钇掺杂的ZrO₂(YSZ)纳滤膜。并考察了溶胶粒径, 材料晶型与孔结构的关系。结果表明: 前驱体浓度越低, 所制备的溶胶粒径越小, 经400℃煅烧得到的粉末中单斜相含量越高, 堆积孔径增大; 向ZrOC₂O₄溶胶中添加8mol%钇, 有效抑制了ZrO₂四方相向单斜相的转变, 延缓晶粒生长, 同时防止膜层开裂。经纳滤测试表明, 实验制备的YSZ纳滤膜对PEG的截留分子量为860 Da, 纯水渗透率为200 L/(m²·h·MPa)。实验还详细考察了YSZ纳滤膜在pH=6, 压力0.8 MPa的条件下对NaCl、Na₂SO₄、CaCl₂和MgCl₂ 4种溶液的截留性能, 结果显示YSZ纳滤膜对0.005 mol/L CaCl₂和MgCl₂溶液的离子截留率分别达到65%和78%。

Fabrication and Characterization of Y-doped ZrO2 Nanofiltration Membranes by Aqueous Sol-Gel Process

Crack-free tubular yttria-stabilized-zirconia (YSZ) nanofiltration membranes was fabricated via an aqueous Sol-Gel process, using zirconium oxychloride as precursor and water as solvent. This procedure was completely free of organic solvent and thus was environmentally friendly. The influences of precursor concentration and calcination temperature on the particle size of sols, crystal and pore structure were investigated. The results revealed that the sol prepared with lower precursor concentration and calcined at 400℃, has higher content of monoclinic phase, thus leading to the increase of pore size. Subsequently, addition of 8mol% yttrium into the sol inhibits phase transformation from tetragonal to monoclinic and grain growth, as well as avoid membrane cracking. In addition, retention experiment result shows that the YSZ nanofiltration membrane exhibits a molecular weight cut-off (MWCO) of 860 Da and a water permeability of 200 L/(m²·h·MPa). Furthermore, ions retention properties of YSZ nanofiltration membrane towards four solutions like NaCl, Na₂SO₄, CaCl₂, and MgCl₂, were conducted at pH 6 and a transmembrane pressure of 0.8 MPa. The retention properties of YSZ nanofiltration membrane towards CaCl₂ and MgCl₂ solutions reach maximum values of 65% and 78%, respectively.