Low-cost amino acid derivative-modified PA TFC membranes featuring enhanced permeability and antifouling characteristics

Polyamide thin-film composite (PA TFC) membranes are generally leverage in water purification, but the large-scale commercialization is hindered by high modifier synthesis costs and complex preparation processes. A hydrophilic amino acid derivative 2-amino-3-hydroxy-3-phenylpropanoic acid (AHPA) using natural amino acid as the precursor, which boasted the advantages of abundant sources, low cost, and renewability, was designed and synthesized via a one-step method and incorporated into PA TFC membranes through a two-step interfacial polymerization process. Comprehensive characterizations confirmed successful AHPA incorporation, enabled by reactive functional groups of the low-cost precursor, which regulated surface charge, enhanced membrane hydrophilicity, and diminished roughness. The AHPA-modified membranes revealed enhanced water permeability with MgSO₄ rejection of 98.97%, achieving a balance between functionality and cost-effectiveness. Molecular dynamics (MD) simulations revealed that enhanced antifouling performance stemmed from synergistic hydration layers and electrostatic interactions. Long-term stability tests demonstrated consistent water flux and salt rejection, with superior organic pollutant removal for textile wastewater. This economical, scalable strategy based on low-cost precursors bridges lab-scale modification and industrial application, providing a feasible route for mass-producing high-performance water treatment membranes.