Publication
Biomass-derived hydrogel membranes that derived from natural polymers exhibit excellent anti-fouling properties, environmental sustainability, and molecular/ionic separation performance. However, their applications are significantly hindered by poor mechanical strength, excessive swelling behavior, and low permeation flux. In this study, we report the polymer structures featuring topological defects through the in-situ synthesis of copper oxychloride particles (CP, Cu2(OH)3Cl) within the hydrogel membranes. The functional hydrogel membrane, designated CP-CuCaAlg, was prepared using a strategy that modulates topological defects through secondary cross-linking. Not only does this approach enhances the mechanical and anti-swelling properties of the resulting membrane, it also increases the internal network spacing, thereby effectively overcoming the trade-off between the selective separation and permeation. The CP-CuCaAlg membrane exhibits exceptional dye/salt separation performance, achieving a dye rejection rate of approximately 99.0 % towards Coomassie Brilliant Blue (CBB) and Direct Red 23 (DR). Furthermore, the salt rejection rate for sodium chloride (NaCl) remains below 10.0 %, while the permeate flux achieves an impressive value of 57.63 L m-2h−1 bar−1. We anticipate that our hydrogel membranes featuring the topological defect structures and high separation efficiency will provide a promising option for the effective treatment of dye wastewater.