High-performance dye/salt separation via glycine and chitosan intercalated two-dimensional talc nanofiltration membranes with enhanced anti-fouling property

To address the need for efficient separation of dyes and salts in textile wastewater, this study developed a novel two-dimensional talc nanofiltration membrane with high selectivity and fouling resistance. The membrane was constructed via vacuum-assisted self-assembly of exfoliated natural talc nanosheets with glycine (Gly) and chitosan (CS). The intercalation of Gly and CS achieved a synergistic functional coupling of “interlayer sieving” and “surface anti-fouling”: the former precisely tuned the spacing of the two-dimensional channels (∼9.20 Å), while the latter effectively smoothed the membrane surface. During dye/salt separation, the membrane exhibited outstanding performance, demonstrating a high rejection rate for Brilliant Blue (BB) dye (99.74%), a high permeation rate for sodium chloride (94.47%), and a water permeability of 60.95 L m −2 h −1 bar −1 . Furthermore, the introduction of trace amounts of CS significantly enhanced the anti-fouling properties of membranes. After ten fouling-cleaning cycles, the flux recovery rate (FRR) reached 80.06%, representing a 10.91% improvement over the unmodified membrane, while structural integrity and separation performance were well-maintained during long-term operation. This study provides a new strategy for designing high-performance dye separation membranes and broadens the application potential of natural clay minerals in wastewater treatment and resource recovery.