Resveratrol-interlayered nanofiltration membranes with enhanced permeability and antifouling property via interfacial polymerization

Construction of hydrogel interlayer and nanovoid to develop NF membranes with good antifouling property and permeability

Design an in-situ anti-bacterial structure of nanofiltration membrane with a novel bisimidazoline aqueous monomer

Improved separation and antifouling properties of thin-film composite nanofiltration membrane by the incorporation of cGO

Fabrication of electro-neutral nanofiltration membranes at neutral pH with antifouling surface via interfacial polymerization from a novel zwitterionic amine monomer

Zwitterionic forward osmosis membrane modified by fast second interfacial polymerization with enhanced antifouling and antimicrobial properties for produced water pretreatment

A comprehensive review of recent advances in nanofiltration membranes for heavy metal removal from wastewater

In this work, a dendrimer trimesoyl amide amine (TMAAM) monomer was proposed to be used as a key functional monomer to modify the conventional aromatic polyamide thin-film composite (TFC) nanofiltration (NF) membrane, and a new kind of TMAAM-based semi-aromatic polyamide composite NF membrane was thus prepared by interfacial polymerization. The effects of the PIP/TMAAM ratio (PIP = piperazine) on the membrane chemical structure, surface properties and separation performances were investigated systematically. With the increase in TMAAM content loaded in the membrane, the water flux strongly increased but the salt rejection decreased only slightly. When the PIP/TMAAM ratio was 1, the membrane NF-2 exhibited a smoother and more hydrophilic surface, as a result of which it displayed an optimum separation performance for different valent salts. In addition, the TMAAM modified TFC membrane presented an extremely high rejection to negatively charged dye molecules and high permeation for monovalent salts, leading to good prospects for dye/salt separation application. Moreover, both the water flux and salt rejection of the TMAAM-based membrane were stable in a long-term running process, and the membrane showed a favourable anti-fouling property and efficient cleaning recovery. Therefore, this work provides a new type of semi-aromatic polyamide composite NF membrane fabricated by a facile and straightforward method via interfacial polymerization with high hydrophilicity, good stability and strong anti-fouling property.

It is known that the polyamide (PA) barrier layer's inherent microstructure and surface physicochemical properties of thin film composite nanofiltration membrane are crucial for its separation performance. Herein, we designed and synthesized a new zwitterionic aromatic diamine monomer 3-(4-(2-((4-aminophenyl)amino)ethyl)morpholino-4-ium)propane-1-sulfonate (PPD-MEPS) through a three steps reaction, and this hydrophilic molecule was incorporated into the active layer to tailor the poly(piperazine-amide)-based nanofiltration membranes with significantly improved water permeability and antifouling properties. As a p-phenylenediamine (PPD) derivative, PPD-MEPS possesses two active amine units, which can react with trimesoyl chloride in the organic phase during the interfacial polymerization reaction process. Thus, the super-hydrophilic zwitterions were not only on the membrane surface but also across the whole PA layer to facilitate water molecule transportation. The successful augmentation of zwitterions into the PA layer was well illustrated by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) results and X-ray photoelectron spectroscopy analysis. With increasing loading content of PPD-MEPS in PIP aqueous solution, the as-fabricated nanofiltration membranes (NFMs) exhibited higher hydrophilicity, increased active layer thickness, and molecular weight cut off. When the zwitterionic monomer reached 60% to PIP for NFM-4, the water permeability went up to 9.82 L m-2 h-1 bar-1, increasing by 45%; meanwhile, the Na2SO4/NaCl selectivity increased from 2.54 to 4.03. In addition, the fouling experiments illustrated that the fouling resistance of the zwitterion-modified NFMs to bovine serum albumin was significantly improved.

BACKGROUNDTailored design of high‐performance nanofiltration membranes is desirable. The physicochemical properties of the organic phaseare essential for the preparation of nanofiltration membranes. Therefore, byfine‐tuning the organic phase, it is possible to achieve nanofiltrationmembranes with enhanced performance.RESULTSIn this work, oleic acid, a naturally extracted fatty acid, wasintroduced into three different organic solvents (n‐heptane, n‐octane andisopar G) to construct special oil phases for interfacial polymerization. Testingresults showed that proper dosage of oleic acid addition can effectivelydecrease the nanofiltration membrane pore size and enhance the salt rejectionregardless of the solvent type. Taking n‐octane as example, 5% oleic acidaddition in it can decrease the mean pore size from 0.500 nm to 0.341 nm and improve the MgSO4 rejection from 52.4% to 95.5%. Further characterizationindicated that the introduction of oleic acid into organic solvent cansignificantly reduce the interfacial tension and promote the diffusion of piperazinefrom aqueous phase to the oil phase. In addition, oleic acid could react with piperazineand produce some white particles that could be embed into the polyamide layer, thus altering the surface morphology.CONCLUSIONIn this work, a novel modified thin film composite nanofiltration membrane was prepared by a simple and controllable oleic acid assisted interfacial polymerization strategy, which exhibits good water permeability, solute selectivity and antifouling property. Without changing the existing process, our strategy opens up a simple, environmentally friendly and operable route for the synthesis of thin film composite nanofiltration membranes. © 2024 Society of Chemical Industry (SCI).

Study on a novel nanofiltration membrane prepared by interfacial polymerization with zwitterionic amine monomers

Zwitterionic nanofiltration membrane with enhanced perm-selectivity and antifouling property via introducing acyl chloride monomer with rigid pyrrolidinyl group

Ti2AlN MAX phase as a modifier of cellulose acetate membrane for improving antifouling and permeability properties

Interfacial polymerization plus: A new strategy for membrane selective layer construction

Preparation of graphene oxide modified polyamide thin film composite membranes with improved hydrophilicity for natural organic matter removal

Polypropylene (PP) porous flat membrane is ultrathin and has high porosity, which is suitable for the support of forward osmosis (FO) membrane. However, its high hydrophobicity is its Achilles heel. In this study, dopamine and UiO‐66‐NH2 were co‐deposited onto the surface of PP support, and then interfacial polymerization was performed to fabricate a thin‐film nanocomposite (TFN) FO membrane. The reaction‐generated polydopamine improved the hydrophilicity of PP membrane, and at the same time enhanced the adhering of UiO‐66‐NH2 to the support. The experimental results indicated that the UiO‐66‐NH2 nanoparticles were anchored evenly on the surface of the support, which improved the water flux of FO membrane from 11.1 LMH (TFC, TFN‐0 without UiO‐66‐NH2) to 20.7 LMH (TFN‐0.1, with 0.1 wt% UiO‐66‐NH2) using 1 mol/L NaCl as the draw solution in FO mode. Compared with TFC membrane, TFN‐0.1 membrane also exhibited relative lower specific salt flux (~0.252) and structural parameter (~379 μm). When separating sodium alginate foulant, the normalized water flux recovery ratio of TFN‐0.1 was remained 0.89, and most of the fouling was reversible, as for TFC membrane the data decreased to 0.76 after 2 cycles of operation. These results suggested that UiO‐66‐NH2 modified FO membrane exhibited good permeation and antifouling property.