Alginate Hydrogel Assisted Controllable Interfacial Polymerization for High-Performance Nanofiltration Membranes

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Freshwater scarcity drives demand for advanced desalination technologies.
• Nanofiltration membranes face a trade-off between water permeance and salt rejection.
• Developing efficient and scalable desalination methods is crucial.

Purpose of the Study:

• To propose a facile and scalable method for enhancing nanofiltration membrane performance.
• To overcome the trade-off limitation between water permeance and salt rejection.
• To investigate the role of alginate hydrogel in interfacial polymerization.

Main Methods:

• Constructing a calcium alginate hydrogel layer on porous substrates.
• Utilizing the hydrogel to tune interfacial polymerization for polyamide nanofilm formation.
• Characterizing the morphology, surface charge, and thickness of the resultant nanofilms.

Main Results:

• The alginate hydrogel layer facilitated the formation of smooth, thin, and negatively charged polyamide nanofilms.
• The composite membranes exhibited significantly improved water permeance (~30 Lm^-2h^-1bar^-1).
• The membranes maintained high sodium sulfate rejection efficiency (>97%).

Conclusions:

• Alginate hydrogel acts as a regulator for interfacial polymerization, enabling high-performance membrane fabrication.
• This method offers a feasible approach for manufacturing advanced nanofiltration membranes.
• The developed membranes show promise for practical desalination applications, addressing freshwater resource challenges.