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Conventional interfacial polymerization (IP) requires excessive amounts of reactive monomers and solvents due to the dip-coating method. Herein, we report a rod-coating assisted IP process to prepare nanofiltration (NF) membranes. The results demonstrate that a perfect PA layer can be fabricated by using low monomer dosages of PIP (0.08 g/m2) and TMC (0.016 g/m2). This can significantly reduce the consumption of monomers and organic solvents, and effectively avoid the waste of hazardous and expensive chemicals. Thanks to the fewer monomer dosages, the prepared NF membranes were much thinner and looser, which significantly improved the membrane permeability. The highest permeance of the rod-coated membranes reached 204.0 L/(m2 h MPa), which was increased by ∼251% compared to the dip-coated NF membrane. More importantly, the rod-coated membranes possessed excellent Na 2 SO 4 rejections (>99.0%) and ultralow NaCl rejections (<14.4%). And the maximum NaCl/Na 2 SO 4 selective efficiency reached 125.7, which was about 7 folds to that of the dip-coated NF membrane. This study suggests that the rod-coating method is highly feasible for the preparation of polyamide NF membranes with high performance. It is reasonable to expect that this rod-coating assisted IP process offers a new approach to fabricating NF membranes. [Display omitted] • High performance PA-NF membranes fabricated by rod-coated assisted IP process. • The rod-coating method significantly reduce the consumption of the monomers. • The rod-coated membrane possesses an excellent permeate flux of 204.0 L/(m2 h MPa). [ABSTRACT FROM AUTHOR]

The textile industry consumes large quantities of freshwater and discharges large quantities of dye/salt wastewater, causing serious environmental problems. Nanofiltration (NF) has proven to be able to achieve efficient dye/salt separation. However, conventional polyamide (PA) NF membranes are often constrained by the trade-off between selectivity and permeability. Herein, we developed a highly dye/NaCl selective nanofiltration membrane with a rod-coated PVA interlayer. The rod-coating approach allows better control of PVA dosage to create a perfect PVA interlayer. The formation and effect of rod-coated PVA interlayer significantly improved the permeability. With an optimal PVA dosage of approximately 0.32 g/m2, the permeance of the iTFC membrane (>30.0 L/(m2 h bar)) was almost 3 times that of the control membrane. Moreover, the iTFC-PVA membrane had an outstanding Rhodamine B rejection (99.8 %), low sodium chloride (NaCl) rejection, and maximum NaCl/dye selectivity ratio as high as 428. It is anticipated that the iTFC membrane has great potential in the field of dyehouse wastewater treatment. Furthermore, our study proves that the Mayer rod-coating approach is suited to fabricating high-performance PA-NF membranes with PVA interlayers. It is anticipated that organic-containing wastewater can better be treated by the developed membrane to achieve a better water environment and resource recovery. [Display omitted] • Rod-coating approach works well to produce and regulate PVA interlayer. • Optimal PVA dosage for a perfect interlayer is about 0.32 g/m2. • iTFC-PVA membrane possesses an excellent NaCl/dye selectivity ratio of 428. [ABSTRACT FROM AUTHOR]