Novel Poly(ester amide) Membranes with Tunable Crosslinked Structures for Nanofiltration

Area of Science:

• Materials Science
• Chemical Engineering
• Membrane Technology

Background:

• Nanofiltration (NF) membranes require tunable crosslinking density for diverse applications.
• Traditional polyamide and polyester membranes have limited tunability in crosslinking.
• Developing novel monomers is crucial for advanced membrane properties.

Purpose of the Study:

• To introduce tris(hydroxymethyl)aminomethane (THAM) as a novel monomer for poly(ester amide) (PEA) membrane preparation.
• To demonstrate the tunable crosslinking density of PEA membranes via interfacial polymerization.
• To evaluate the performance of PEA membranes for both desalination and dye/salt separation.

Main Methods:

• Interfacial polymerization using THAM and other monomers to create thin-film composite membranes.
• Varying THAM concentration to control membrane crosslinking density.
• Characterizing membrane properties including pore size, porosity, water permeance, and salt/dye rejection.

Main Results:

• PEA membranes exhibited a wide range of tunable crosslinking densities, from loose to dense structures.
• Dense PEA membranes achieved high desalination performance (97.1% Na2SO4 rejection, 11.1 L m-2 h-1 bar-1 permeance).
• Loose PEA membranes showed excellent dye/salt separation (>95% dye removal, <7.5% NaCl rejection, >45 L m-2 h-1 bar-1 permeance).

Conclusions:

• THAM enables unprecedented control over PEA membrane crosslinking density.
• Tunable PEA membranes offer versatile solutions for specific separation tasks.
• This work opens new avenues for designing task-specific separation membranes.