海藻酸钠/聚乙烯醇/尼龙复合膜在油水分离中的应用研究

Application of sodium alginate nylon composite membrane in oil-water separation

通过自组装法制备了一系列具有水下超疏油性质的海藻酸钠/聚乙烯醇/尼龙(SA/PVA/尼龙)复合膜。通过改变交联剂钙离子含量,可以调控复合膜的孔径和表面润湿性。采用傅里叶变换红外光谱仪、扫描电子显微镜、接触角测量仪对复合膜的化学结构、表面形貌和润湿性进行表征,并测量复合膜对油水混合物的分离效率及分离通量。结果表明,随着钙离子含量的增加,交联程度提高使得复合膜材料表面粗糙度提高,同时在空气中亲水性增强,其中钙离子质量分数为5%时,复合膜水下超疏油性能达到最佳。稳定性实验表明,用质量分数5%钙离子交联的复合膜在强酸、强碱和饱和盐溶液中处理10d后,复合膜的润湿性没有明显变化,具有较好的化学稳定性。

A series of sodium alginate/polyvinyl alcohol/nylon(SA/PVA/nylon) composite membranes were prepared by self-assembly method.The pore size and surface wettability of the composite membrane can be controlled by changing the concentration of Ca^(2+).The chemical structure,surface morphology and wettability of the membrane were characterized by FT-IR,SEM and contact angle.The separation efficiency and flux of the membrane were measured.The results shown that with the increase of mass fraction of Ca^(2+),the surface roughness of the membrane increased,and enhanced the hydrophilicity in air.When the mass fraction of Ca^(2+) was 5%,the performance of underwater superoleophobicity of the membrane was the best.The stability experiment showed that the membrane crosslinked by mass fraction of 5% Ca^(2+) had good chemical stability,and had no obvious change in wettability after being treated in strong acid,or alkali,saturated salt solutions for 10 days.