UiO-66-NH2-Architected PVDF Membranes for Efficient Wastewater Separation

MOFs (metal-organic frameworks) have been widely applied in membrane modifications. In this study, a polyvinylidene fluoride (PVDF) membrane substrate was initially functionalized with one typical MOF, UiO-66-NH 2 , through simple vacuum filtration, followed by the deposition of a trace amount of perfluorohexane (PFHx) sulfonate potassium, successfully preparing a novel composite membrane named UxP1. Incorporating UiO-66-NH 2 onto the hydrophobic PVDF significantly enhances both hydrophilicity and porosity. The trace deposition of PFHx introduced F groups, enhancing the oil-repellent properties of the membrane. The WCA of the U5P1 membrane (5 mg of UiO-66-NH 2 and 1 mg of PFHx) decreased from 68.4° to 25.4°, while the underwater oil contact angle (UWOCA) increased from 139.5° to 150.5°, resulting in a superhydrophilic and oleophobic surface. In oil–water emulsion separation experiments, U5P1 achieved an oil removal rate > 99% at an operating pressure of 0.085 MPa. In filtering wastewater containing Congo Red (CR) dye, the membrane exhibited a rejection > 99% and an impressive permeation flux of 1520 L m −2 h −1 , highlighting its outstanding separation efficiency. Moreover, during cyclic filtration experiments, U5P1 consistently maintained > 95% rejection at 0.085 MPa, and the FRR remained > 81%, demonstrating exceptional fouling resistance and rejection capabilities. This work provides a good basis for the advanced development of MOFs-modified membranes into efficient practical water treatment.