High performance loose nanofiltration membranes obtained by a catechol-based route for efficient dye/salt separation

Publication date: 1 November 2019Source: Chemical Engineering Journal, Volume 375Author(s): Jing Wang, Rongrong He, Xinwei Han, Dechao Jiao, Junyong Zhu, Feili Lai, Xiangting Liu, Jindun Liu, Yatao Zhang, Bart Van der BruggenAbstractLoose nanofiltration membranes with excellent dye rejection and high inorganic salt transmission are promising for dye/salt separation. Herein, a mussel-inspired organic solvent-free method was chosen to prepare loose nanofiltration membranes with tunable surface structures and properties. A low-cost material, 1,2-dihydroxybenzene (catechol), was used to replace dopamine for the mussel-inspired surface coating strategy. With the assistance of CuSO4/H2O2, a catechol/PEI coating layer was formed on the polyethersulfone (PES) substrate in only 10 min. Through constructing the coating layer based on polyethylenimine (PEI) with different molecular weights, catechol/PEI ratios and solution deposition times, different membranes were obtained. The separation performance of the membrane is tested by a lab-scale crossflow setup under the pressure of 4 bar. Especially, LNM-3 have an ultrahigh water permeability (24.5 LMH bar−1) and an extremely low rejection for both NaCl and Na2SO4 in the concentrations between 1.0 and 50.0 g L−1. Meanwhile, LNM-3 shows superior rejection for different types of dyes, demonstrating their great potential in practical applications. Overall, such an approach enabled by an organic solvent-free process and low-cost chem...
Source: Chemical Engineering Journal - Category: Chemistry Source Type: research