A facile and versatile strategy for fabricating thin-film nanocomposite membranes with polydopamine-piperazine nanoparticles generated in situ

We propose in this study a facile and versatile strategy for fabricating thin-film nanocomposite (TFN) membranes, wherein polydopamine-piperazine (PDP) nanoparticles were formed in situ from the oxidative polymerization reaction of dopamine and its subsequent reaction with piperazine. Accordingly, PDP nanoparticles were then directly used as nanofillers for TFN membranes fabricated through interfacial polymerization. The characteristics of PDP nanoparticles and the performance of TFN membranes were easily tailored by varying the water-ethanol ratio in the PIP solution, solution pH, dopamine concentration, and reaction time. The TFN-PDP membranes exhibited an optimum separation performance (high water permeability and high salt selectivity): J(H2O) = 59.1 +/- 3.3 L m(-2)h(-1); R-Na2SO4 = 98.0%; R-Nacl = 44.1% (6 bar, 25 degrees C). Moreover, the TFN-PDP mem- branes demonstrated high water flux recovery and enhanced antifouling property during cycles of filtration tests, with bovine serum albumin protein used as model foulant.