Facile Fabrication of High Performance Nanofiltration Membranes by Using Molecular Coordination Complexes as Pore-Forming Agents

Abstract

Nanofiltration (NF) is widely used in water treatment; however, the fabrication of NF membranes with high permeability and selectivity still remain a challenge. Here, we propose a facile and feasible approach to design and prepare nanoporous polymeric membranes (NPMs) by using soluble molecular coordination complexes as pore-forming agents for the removal of dyes from water. Enhanced porosity and tuned pore sizes of the membranes were achieved by using several selected coordination complexes with different compositions and structures. The resulting membranes display high permeance without compromising rejection compared with corresponding pristine membranes. Particularly, one of membranes, with tBu-MOP acting as the pore-forming agent, shows an optimal separation performance of the water permeance over 209 L/(m2·h·MPa) and a rejection about 98% toward both methyl blue (MB) and eriochrome black T (EBT). This permeance is 4.5-fold higher than that in the pristine membrane fabricated without using any pore-forming agent. This method is expected to extend to the fabrication of other polymeric membranes with required pore properties by selecting suitable coordination complexes as pore-forming agents for different separation applications.

Ultrastable Nanofiltration Membranes Engineered by Polydopamine-Assisted Polyelectrolyte Layer-by-Layer Assembly for Water Reclamation

“…Besides desalination of brackish water and seawater, water reclamation has been considered as a significant indispensable solution to sustainably augment water supply. , Membrane technologies, with the merits of easy operation, small footprint, and high-quality effluent, have played a key role in water reclamation. In particular, nanofiltration (NF), with separation characteristics between ultrafiltration (UF) and reverse osmosis (RO), shows a great promise in wastewater recycling owing to its ability of effective removal of divalent/multivalent ions, pathogens, and small organics molecules along with high permeation flux under low operation pressure. − An ideal NF membrane for water reclamation should have the following features: (i) high water permeability, thus reducing the requirement of membrane area; (ii) high removal efficiency of divalent/multivalent ions and most organic compounds; (iii) low rejection to monovalent ions, thus reducing the operation pressure and energy consumption; and (iv) robust chemical stability and antifouling property, enabling stable performance in a long-term operation. , However, current NF membranes for water reclamation are suffering from high operation pressure and severe membrane fouling problems. Thus, significant efforts have been devoted to develop and engineer novel NF membranes with enhanced performance. − …”

Cu-MOF-Polydopamine-Incorporated Functionalized Nanofiltration Membranes for Water Treatment: Effect of Surficial Adhesive Modification Techniques

“…Both fil-MOF-coated and dip-MOF-coated membranes exhibited enhanced (89% and 93%) FRR% compared to a blank membrane (75%) and fil-coated and dip-coated membranes. This antifouling enhancement is attributed to the hydration layer formed on the membrane surface due to MOF hydrophilicity, which significantly weakened the interaction between the dyes and the membrane surface . This trend demonstrated that the antifouling performance of the more negatively charged membranes [dip-MOF-coated (−43 ± 3 mV) and fil-MOF-coated (−36 ± 3 mV)] was improved compared to those of the less negatively charged membranes [dip-coated (−27 ± 3 mV), fil-coated (−27 ± 2 mV), and TFC blank (−23 ± 3 mV)] (Figure ).…”

Water Absorption Behavior of Dual-Sponge Structure Sealing Elastomers Assisted by Machine Learning

“…However, when a pore making agent mixture of acetone and sodium bicarbonate is added at a ratio of 1.5:1.0, the SAP exhibits an absorption rate of approximately 160% compared to the initial rate without a pore making agent. 25 S1. F L (failure load) represents the initial tensile strength of the banana sample in the tensile test, measured as 0.27 dNM, while Fmax indicates the maximum tensile force achieved during the test at 10.77 dNM.…”