微米SiO_2对PVDF膜性能的影响

Effects of Micron SiO_2 on PVDF Membrance Performance

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。

Poly （vinylidene fluoride） （PVDF） as the base material and N, N-dimethylacetamide as the solvent, silica （SiO2） was added to improve the performance of PVDF membrance, which was prepared by phase inversion process. SEM micrographs was used to observe the structures of composite membrance. In addition, the tests of filming kinetics, the water flux,interception capacity,contact angle and TGA were taken as indexs to analyze the optimum mass ratios of the SiO2 in the composite membrance. The results showed that the properties of PVDF membrane were improved due to the addition of SiO2 , and with the SiO2 content increased the thermal stability of composite membrance showed an upward tend. When the mass ratios of PVDF and SiO2 was 90/10, membrance forming performance was better, the surface porous was small and well dispersed,the water flux increased from 12. 8 L/（m^2· h） to 62.72 L/（m^2 · h）, interception capacity was improved by 17.90% ,the contact angle reduce by 8° ,combination property of the composite membrance was the best.