In-situ generation of iron-dopamine nanoparticles with hybridization and cross-linking dual-functions in poly (vinyl alcohol) membranes for ethanol dehydration via pervaporation

Abstract In this study, poly (vinyl alcohol) (PVA) hybrid membranes with iron-dopamine (Fe-DA) nanoparticles were fabricated by the in-situ complex cross-linking method between Fe-DA nanoparticles and the PVA matrix. Based on the molecular structure feature of DA and the chelation interaction between Fe 3+ and PVA chains, the Fe-DA/PVA hybrid membranes demonstrated superior hydrophilicity, higher mechanical strength, swelling resistance, and high separation performance for ethanol dehydration via pervaporation (PV) technology. Fe-DA/PVA hybrid membranes were characterized by a scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, an X-ray diffractometer (XRD), thermo gravimetric analysis (TGA), a mechanical test, and water contact angle measurement. The effects of Fe-DA nanoparticle size, loading level, operation temperature, and the feed compositions of PVA hybrid membranes on PV performance were explored. Accordingly, the hybrid membranes exhibited excellent water permeability and selectivity for water/ethanol mixture separation. Especially, the permeability flux of the Fe-DA 30 /PVA hybrid membranes could reach 995 g/(m 2  h), and the separation factor was as high as 2980 under 90 wt% ethanol at 30 °C. The Fe-DA 30 /PVA hybrid membranes exhibited excellent potential in the PV application of ethanol dehydration.