Preparation of poly (m-phenylene isophthalamide)-ZIF-8 nanofiltration membranes with enhanced filter performance

Poly (m-phenylene isophthalamide) (PMIA) membranes are prepared via evaporating part solvent of the casting solution before its nonsolvent-induced phase separation. Zeolite imidazolate framework-8 (ZIF-8) is added into the PMIA solution as an inorganic filler to improve the filtration capability of the PMIA membrane. The structure of composite membranes is characterized by scanning electron microscopy (SEM), Zeta-potential analyzer (ζ-potential) and X-ray diffractometer (XRD). The filtering capabilities of the membranes for dyes and inorganic salts were deeply evaluated, in order to study the membrane separation performance. The PMIA-ZIF-8 membranes have excellent filtration properties for Congo red dye with a rejection rate of above 99.3%. The PMIA-ZIF-8 composite membranes have excellent properties that point to the possibility of using nanofiltration in commercial applications.