Enhanced antifouling and separation capabilities of polydopamine@Ce-MOF functionalized PES ultrafiltration membrane

Abstract

The need for antifouling membranes is substantial due to fouling’s negative impact on the effectiveness and durability of ultrafiltration membranes. In recent times, Metal-Organic Frameworks (MOFs) have emerged as effective additives for crafting ultrafiltration (UF) membranes. However, to harness their benefits and mitigate their drawbacks, a well-considered approach is imperative. In this work, polyethersulfone (PES) UF membranes were tailored with polydopamine (PDA)-modified cerium (Ce)-MOF (PDA@Ce-MOF) to achieve satisfactory antifouling properties and to remove biological macromolecules such as bovine serum albumin (BSA) and humic acid (HA) from wastewater. The non-solvent induced phase separation (NIPS) method was used to simultaneously fabricate the membrane and modify it with different PDA@Ce-MOF concentrations ranging from 0.05 to 0.50 wt.%. Results showed significant improvements on the membrane’s morphology, hydrophilicity, porosity and pore size at 0.10 wt.% loading of PDA@Ce-MOF. The synergistic effect of the PDA and Ce-MOF on the membrane improved the pure water flux (337 L m−2 h−1) and filtration performance in the filtration of Bovine serum albumin (BSA) and humic acid (HA) reporting 145 L m−2 h−1 and 98% rejection, and 164 L m−2 h−1 and 88% rejection; respectively. Further, water-attracting functional moieties of PDA@Ce-MOF hindered the deposition of BSA protein on the membrane surface, resulting in an excellent flux recovery ratio (FRR) of ~87%, alongside mitigated irreversible fouling.