聚酰胺功能层形貌调控及其纳滤膜性能研究

Study on Morphological Regulation of Polyamide Functional Layer and Its Nanofiltration Membrane Performance

通过调控基膜结构进而聚酰胺功能层微观形貌是改善复合纳滤膜性能的一种较为简单高效的策略之一。本文通过将杂环聚酰胺(HPA)与聚砜(PSf)共混的方式来调控基膜表面形貌,进而影响界面聚合制备出具有环形结构的聚酰胺复合纳滤膜,结果表明:共混HPA后能够明显提高基膜的孔隙率、亲水性以及纯水通量。而界面聚合后其聚酰胺功能层表面出现了环形山结构,且该环形山结构随着基膜中HPA的含量的增大而逐渐变小变密集。此外,随着基膜中HPA含量的由0%增加到8%,其纳滤膜的纯水通量由1.75 L/(m^(2)·h)增加到60.69 L/(m^(2)·h),对MgSO_(4)的截留率均在90%以上。

One of the relatively simple and efficient strategies to improve the performance of composite nanofiltration membranes is to regulate the microstructure of the polyamide functional layer by adjusting the substrate structure.Here,the regulation of the surface morphology of the substrate by blending heterocyclic polyamide(HPA)with polysulfone,thereby affecting the interfacial polymerization to prepare polyamide composite nanofiltration membranes with a ring-shaped structure.The results show that blending heterocyclic aramid can significantly improve the porosity,hydrophilicity,and pure water flux of the substrate After interfacial polymerization,a ring-shaped structure appeared on the surface of the polyamide functional layer,and this ring-shaped structure gradually became smaller and denser with the increase of the content of heterocyclic aramid fibers in the base film.In addition,as the content of heterocyclic polyamide in the base film increases from 0%to 8%,the pure water flux of the nanofiltration membrane increased from 1.75 L/(m2·h)to 60.69 L/(m^(2)·h),and the retention rates of MgSO_(4)were all above 90%.