Water vapor dehumidification using thin-film nanocomposite membranes by the in situ formation of ultrasmall size iron-chelated nanoparticles

초록

A facile in situ method by which to incorporate iron oxide nanoparticles (IONPs) entrapped by iron-chelated hyperbranched polyethyleneimine (HPEI) within a polyamide (PA) matrix was successfully applied to form thin film nanocomposite (TFN) membranes. The mechanism of the formation of Fe-HPEI-IONPs and their incorporation into the PA matrix are proposed. The performance of the membranes coated with Fe-HPEI-IONP-TMC combination underwent a mixed water vapor test with N-2 gas with different operating parameters. Additionally, the effect of operating time on relative humity and the antibacterial properties were studied. The TFN membranes showed a significant improvement in the membranes Fe-HPEI-IONP content, hydrophilicity, and roughness, providing evidence of their outstanding performance as compared to pristine and thin film composite (TFC) membranes. The best performance of membranes achieved by water vapor/N-2 permeation was a water vapor permeance value of 2093 GPU and a water vapor/N-2 selectivity value of 1050 at a feed flow rate of 1 L/min and relative humidity of 70% for the M(40) TFN membrane with an iron chloride concentration of 40% with respect to HPEI. Moreover, the M(40) TFN membrane showed excellent anti-biofouling performance as compared to pristine PSf and TFC membranes, likely due to the biocidal effect of IONPs and Fe(III) ions toward E coli.

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