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通过相转化法制备了纳米PVDF/Mg(OH)_2共混超滤膜,研究了负载Mg(OH)_2对PVDF膜结构和性能的影响。以牛血清蛋白(BSA)为模拟污染物进行超滤试验,测试膜的纯水通量和截留率;测定膜表面和水之间的接触角,进而定量分析比较膜表面的亲水性;利用微机电子控制万能试验机测试膜的机械性能;通过扫描电镜(SEM)、原子力显微镜(AFM)、X射线衍射仪(XRD)等方法表征膜表面特征。结果表明,添加纳米Mg(OH)_2的改性膜保持了原有膜的晶型结构,证明纳米Mg(OH)_2与PVDF材料有很好的相容效果。当纳米Mg(OH)_2添加量为0.8%(质量分数)时,改性效果达到最优。此时,接触角从73.1°降至59.6°,纯水通量为333.37 L/(m~2·h),较未改性前提高了126.3%,膜的拉伸最大力为6.8 N,断裂伸长率为16.2%,较未改性膜的机械性能有明显提高,膜的抗污染性也显著提高。
The nano-PVDF / Mg (OH) 2 blend ultrafiltration membrane was prepared by phase inversion method. The effect of Mg (OH) 2 loading on the structure and properties of PVDF membrane was investigated. The bovine serum albumin (BSA) was used as the simulated pollutant to carry out the ultrafiltration test to test the pure water flux and rejection rate of the membrane. The contact angle between the membrane surface and the water was measured, and then the hydrophilicity of the membrane surface was quantitatively analyzed. The mechanical properties of the film were tested by microcomputer controlled electronic universal testing machine. The surface characteristics of the film were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). The results show that the modified Mg (OH) 2 modified membrane retains the crystal structure of the original membrane, and the nanocomposite Mg (OH) _2 has good compatibility with PVDF. When the amount of nano-Mg (OH) 2 is 0.8% (mass fraction), the modification effect is optimized. At this time, the contact angle decreased from 73.1 ° to 59.6 °, and the pure water flux was 333.37 L / (m ~ 2 · h), which was 126.3% higher than that before unmodified. The maximum tensile force of the film was 6.8 N, Elongation of 16.2%, compared with unmodified film has significantly improved the mechanical properties of the membrane anti-pollution was also significantly improved.