Synthesis and testing of double-target molecularly imprinted composite polymer (MIP) membranes for selective adsorption of 17β-estradiol and testosterone

Abstract

This study focused on the development and assessment of composite microfiltration (MF) membranes for the selective adsorption-based removal of endocrine-disrupting compounds (EDCs), specifically 17β-estradiol (E2) and testosterone (TST), as emerging hazardous micropollutants in drinking water and natural water sources. The preparation of the composite membranes combined polyethersulfone (PES) with molecularly imprinted polymer (MIP) particles, synthesized through precipitation polymerization. Molecular imprinting was performed by utilizing E2 and TST as templates to create specific recognition sites, while non-imprinted polymers (NIPs) served as references. With the deposition of a MIP/NIP particle layer between two PES layers, sandwich-type composite membranes were prepared and further characterized using scanning electron microscopy (SEM), water permeance, and EDC adsorption tests, which were central to evaluating the effectiveness of molecular imprinting in the MIP-based composite membranes. By comparing EDC adsorption loadings between reference PES and composite membranes through dynamic adsorption experiments, the study assessed the adsorption capacity, selectivity and reusability of the membranes after regeneration cycles. The main objective was to determine whether double-target MIP particles for E2 and TST could be synthesized and incorporated into composite membranes with dual selectivity. Following successful membrane integration, imprinting, and synthesis, the double-target MIP membranes efficiently adsorbed TST (0.48 µg mg⁻¹) and E2 (0.51 µg mg⁻¹). Membrane reusability was tested, revealing that composite membranes do not lose adsorption capacity over at least three cycles. Double-target MIP membranes show promise in effective, low-pressure, low-energy removal of EDCs in water treatment applications.