Insight of multifunctional Cu-alginate hydrogel membrane for precise molecule/ion separation applications

Membrane technology has garnered significant attention for its role in addressing the challenges of molecule/ion separation processes, yet it remains hindered by issues such as membrane fouling, including organic and biofouling. While calcium alginate (CaAlg) membranes have demonstrated remarkable antifouling and molecule/ion separation properties, they suffer from high swell ability and poor mechanical performance. This study introduces a one-step ion-crosslinking method to fabricate a series of copper alginate (CuAlg) hydrogel membranes. These membranes are then assembled into a dual-layer structure with a modified hydrophilic and mechanically robust microfiltration fiber support layer (MHSL). Notably, the CuAlg/MHSL membrane exhibits excellent separation performance, characterized by high selectivity and flux recovery rate. This membrane significantly enhances the long-term molecule/ion separation performance through improved mechanical strength, anti-swelling properties, and antimicrobial capabilities. In addition, the decreased thickness of the CuAlg/MHSL membrane enables higher flux rates, proving beneficial in cases of CaAlg membranes' inability to perform well under high-salt conditions. To further investigate the pore structure and anti-swelling mechanism of the CuAlg membrane, molecular dynamics (MD) simulations are conducted. Additionally, a life cycle analysis comparing the CuAlg hydrogel with various traditional polymers assesses their respective environmental impacts, highlighting the eco-friendliness of the hydrogel as a membrane substrate. These findings provide valuable insights for developing sustainable hydrogel membranes with stable performance and high separation efficiency in molecular/ion separation applications.

Automated summary

Membrane technology plays an important role in molecular/ion separation processes, but faces challenges such as membrane fouling. This study introduces a new ion-crosslinking method to fabricate copper alginate hydrogel membranes with improved mechanical strength and antimicrobial capabilities. The membranes exhibit excellent separation performance and enhanced long-term molecule/ion separation through improved anti-swelling properties. Molecular dynamics simulations and life cycle analysis highlight the pore structure and environmental friendliness of the hydrogel membranes. These findings provide valuable insights for developing sustainable hydrogel membranes with stable performance and high separation efficiency.