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以聚偏氟乙烯(PVDF)为基体材料,N,N-二甲基乙酰胺(DMAc)为溶剂,加入二氧化硅(SiO_2),利用相转化法制得共混膜PVDF/SiO_2,利用扫描电子显微镜(SEM)观察共混膜的结构。另外,通过成膜动力学、水通量、截留率、接触角以及差示扫描量热法(TGA)等测试,对共混膜的性能进行表征,确定SiO_2的最佳用量。结果表明:与PVDF膜相比,添加微米SiO_2可使共混膜的综合性能显著提高,且随着SiO_2含量的增加,共混膜的热稳定性呈增强趋势。当PVDF与SiO_2质量比为90/10时,成膜性能较好,成膜后表面孔分散均匀且孔径较小,膜内部形成相互贯通的孔结构,水通量由12.8 L/(m~2·h)增大到62.72 L/(m~2·h),截留率提高了17.9%,接触角降低了8°,共混膜的综合性能最佳。
Polyvinylidene fluoride (PVDF) as matrix material and N, N-dimethylacetamide (DMAc) as solvent, silica (SiO 2) was added and the blend membrane PVDF / SiO 2 was prepared by phase inversion method. The structure of the blend membrane was observed under a microscope (SEM). In addition, the performance of the blend membranes was characterized by film formation kinetics, water flux, rejection, contact angle and differential scanning calorimetry (TGA), and the optimum amount of SiO 2 was determined. The results show that compared with PVDF membrane, the addition of micro-SiO 2 can significantly improve the overall performance of the blend membrane, and with the increase of SiO 2 content, the thermal stability of the blend membrane tends to increase. When the mass ratio of PVDF to SiO 2 is 90/10, the film forming properties are better. The surface pores are evenly distributed and the pore size is small after film formation. The interpenetrating pore structure is formed inside the film. The water flux increases from 12.8 L / (m 2 · H) increased to 62.72 L / (m ~ 2 · h), the rejection increased by 17.9% and the contact angle decreased by 8 °. The blend membrane exhibited the best overall performance.