Nanofiltration membranes engineered via bidirectional regulation for enhanced antibiotic desalination

Nanofiltration provides an energy-efficient approach for nano-scale contaminant removals, such as antibiotics and desalination. The trade-off between membrane permeance and selectivity remains a great challenge. Herein, we propose a bidirectional control strategy to manipulate the chaotic ternary reaction for the construction of ultrapermeable, highly selective, and antifouling membranes. Through the introduction of glycerol, the ternary reactions among phenolic compounds, polyethyleneimine, and metal ions are bidirectionally regulated. Mechanistic investigation reveals that glycerol facilitates the coordination reactions but restricts the covalent reaction. Thus, a thinner and more hydrophilic selective layer with a more negatively charged surface is constructed. The membrane achieves an ultrahigh permeance of up to 100 L m⁻²h⁻¹bar⁻¹, and selectivity of over 100 toward salts and antibiotics, surpassing the state-of-the-art nanofiltration membranes. Furthermore, the universality of our bidirectional control strategy is demonstrated in a variety of important systems, paving a novel way for synthesizing the next-generation nanofiltration membranes for diverse applications.